Uninstall Ubuntu Dual boot

Question: After installing Windows 10 on a partition, I want to remove Ubuntu 18.04 completely and use the entire hdd for Windows.  Can I delete the partition with Windows still working? I'm not sure if grub will affect the boot.
Comment: Depends on whether UEFI or BIOS. Duplicate if UEFI: http://askubuntu.com/questions/63610/how-do-i-remove-ubuntu-in-the-bios-boot-menu-uefi
http://askubuntu.com/questions/429610/uninstall-grub-and-use-windows-bootloader/497720?noredirect=1#comment1369050_497720
Answer: Follow the below steps properly:
STEP - I: Deleting Ubuntu Partitions

Boot into Windows OS
Press Windows + r keys together and type diskmgmt.msc to enter into your disk management utility
You can easily recognize the Ubuntu partition by their size. Another hint to recognize the partitions is to look at the partitions which don't have a file system and drive number. Windows partition is labeled with a drive number such as C, D, E etc and are usually in NTFS or FAT file system
Manually select all your Ubuntu partitions one by one and right click on each and select the option - Delete Volume
All the deleted space will show as Unallocated on your Windows partition table. Now, either extend any of your existing partitions or simply create a new partition (using the entire Unallocated space you got)

STEP II: Fixing the Boot loader

Use your Windows OS disk and restart your computer. Press F10 or F12 at the boot time to go into BIOS/UEFI and choose to boot from removable disk
Select 'Repair your computer' option
Go for the 'Troubleshoot' option here and then select 'Advanced options'
Look for the 'command prompt' option and select it
Once you enter into the command-line interface, type the following command:
bootrec.exe /fixmbr
Once it's done, restart your computer and this time boot normally from the hard disk. You should be able to boot into Windows.

In case you encounter Grub rescue error, try the steps below:

If the command bootrec.exe /fixmbr did not work, try the 'Automatic Repair' option in advanced troubleshoot option
It will find the issue and take some time to repair it

Once done, reboot your system and you should be able to boot into Windows OS directly (with no GRUB options).
Comment: Fix Boot loader first and confirm it directly boots Windows before deleting any partitions. The grub boot loader has parts of it in the Ubuntu folder and you may not be able to boot if you delete partitions and then reboot before installing Windows boot loader.
Comment: for step one i see that the ubuntu partition if left to my windows drive and is not allowing me to extend backwards
Answer: If you dont have your windows boot disk or pendrive you can download the exact same version of windows (for eg. If you are using win8.1 there are different version like single language and win8.1core etc. ) select it and download that (preferably from microsoft's own website"It's free") and take any pendrive and make it bootable using the downloaded iso file image.Then use it as mentioned above!!Worked for me!! (I didnt have my windows installation disk!!) Hope it helps!!
Answer: Run cmd as administrator
Diskpart
List disk
Sel disk 0 (if boot partition on the disk 0. On my system only one disk so disk 0)
List vol
Sel vol 2(if the EFI boot partition on volume 2 which can be guessed boot partition is a FAT 32. On my system, it is volume 2)
Assign letter=Z: (safest side)
Exit
Z:
Dir
Cd EFI
Rmdir /S Ubuntu grub

Uninstall Ubuntu Dual boot


How to restrict entity reference displaying values?

Question: I have a requirement which I feel quiet complex. I am using Entity reference in X content type to reference a content type(assume Y). This works fine by displaying all the values of Y in X.
  Y content type is having one field that is true or false type. So I want to display values in select list of X content type only which is having true value in the Y content type.So how can I achieve that, any suggestions will be appreciated.
Comment: answer this two questions :

1 .where do you want  achieve this ? in node full view mode? in views ? where?

2.   you want if boolean field of content type Y is true  show  entity_referece field ( I mean a field that is in X content type) ?
Comment: @zhilevan , 1. I want to achieve this in admin panel only may be that is only called as node full view mode. 2) Actually that is a text field only,but while adding content we will write true or false
Answer: You'll have to dynamically create that select list based on the field's values which are TRUE from the CT Y. I suppose that this select list belongs to a from, and what a convenient hook hook_form_alter is!
/**
 * Implements hook_form_alter.
 */
function module_name_form_alter(&$form, &$form_state, $form_id) {
  if ($form_id == 'node_xyz_form_id') {
    // Find all referenced items
    $target_ids = $form['field_reference_to_ct_y'][LANGUAGE_NONE][0]['#options'];
    // Load all referenced items
    $nodes = node_load_multiple(array_keys($target_ids));
    foreach ($nodes as $node) {
      if ($node->field_to_check_if_true[LANGUAGE_NODE][0]['value']) {
         // Alter the select list options
         $form[field_select_list][LANGUAGE_NONE]['#options'][$node->nid] = $node->title;
       }
    }
  }
}


VMWare Workstation MSI Failed Install Windows 7

Question: When attempting to install VMWare Workstation 6 (as well as when I attempted to install an evaluation version of 9), the installer fails with an error simplay stating that '~\vmware workstation.msi failed'. This is in 64-bit Windows 7.
Comment: I suggest to move this question to superuser site as it is an installation problem of a software.
Answer: I found that stopping after the temp directory gets created and running 'vmware workstation.msi' directly instead of using the already-running installer allowed me to finish the installation.
Answer: Do you have Avast! antivirus installed?
That was the cause of my failed installation message. I tried deactivating it for some time and it didn't work. I had to totally uninstall it, install vmware and then reinstall the antivirus.
It won't work if you use the disable feature of the antivirus, you must completely uninstall it.


How do I use a multimeter to check for power?

Question: I need to check that power going from my light switch, to a light fixture on the same wall, as well as a light fixture on the opposite wall. How do I use a multimeter to do that?
Comment: Could you edit the question to be a bit clearer as to what is happening? What happens when you flip each switch? When did this start?
Answer:
WARNING
If you're not comfortable working on live wiring, please contact a local licensed electrician. Working on live wiring can be dangerous, and could lead to property damage/loss, personal injury, and/or death.

To test voltage, you'll want to set the meter to the "Volts AC" setting. On the meter it will likely look like a capital "V" followed by a "~".

Typically there will be more than one setting within the range, so you'll want to choose the setting that is higher than what you expect to get. For example. In the US a lighting circuit is typically 120 volts, so you would choose the "200" setting typically found on most meters.
Check the documentation for the meter you're using, to determine where each probe should be plugged in. Typically the black probe goes in "COM", while the red goes in "VΩmA", "VΩ", or "V".
Carefully touch one probe to a known good ground, and the other to the "hot" conductor. (When I say "ground", I don't mean dirt. I'm talking about electrical ground). Next with the one probe still touching ground, touch the other probe to the "neutral" conductor.  (When I say touch the conductor, I mean touch an exposed part of the conductor with the tip of the probe. Touching the probe to the insulation on the wire, isn't going to do anything). Finally, touch one probe to the "hot" conductor, and the other to the "neutral".
When you measure between ground or "neutral" and "hot", you should measure line voltage (about 120 volts). When you measure between ground and "neutral", you should measure 0 volts.
Answer:
How do I use a multimeter to do that?

First
Check your multimeter

Marked as Cat II rated, credibly so?
Probes and leads marked for an AC voltage greater than your supply?
Good-sized finger-stops on the probes
Probe-tip shrouds to prevent shorts (or fingers reaching metal)
HRC fused?

Then
See other answers
But
Test your tester

Measure a genuine 120VAC (or 230VAC) source and check the meter
shows the correct reading for a live and dangerous condition.
Turn off the supply to the circuit you are working on and check for 0V.
Before touching anything, go and check a live circuit elsewhere
to be sure your meter didn't coincidentally die between the previous steps.

The last step is a bit overkill, but better safe than sorry.
Answer: I generally don't recommend using multi-meters to the uninitiated, 120V is pretty painful and you need a healthy concern for your own safety when working around exposed wiring. Most people I find aren't scared enough until they get shocked and that could be too late.
In all honesty, You really don't need a multi-meter, a non-contact voltage detector is easier to use, and hands down safer since you don't have to have exposed wiring. they cost between $10 and $20 and should be in your pocket when doing electrical work.
The use is simple. First make sure it works right. Find a live working outlet, place the probe end near the smaller opening for the plug, that's the hot side. the probe should light up and make a noise. You don't need to touch anything, just get with in an inch or so.
Now that you know it works, turn your switch on, use the probe to check for power at it, then go to each light and test for power. Get as close to the bulb base as you can, with in 1 inch usually is close enough.
Comment: 1" is rarely close enough for the one I use, you need to be on the correct side of the romex cable, or with the plastic tip inside the hot side of the outlet.
Answer: When using a meter on a live circuit you would use the volts AC and select a range that is higher than what you expect 120V standard outlet herein the U.S. 220v across the Pond. If auto range select the correct function and make sure leads are in the correct locations on the meter.
If you have the power off and want to verify continuity you would use the ohms setting at the lowest value. (using a ohmmeter on a live circuit will let the magic smoke out).
Answer: if you don't know how to use a multimeter, you don't understand even rudimentary circuits.
you should not be messing with anything electrical.  call an electrician.
not trying to be rude, but the magic wall pixies in electrical doodads can in fact kill you.  nobody wants that.
Comment: I disagree. I had a firm grasp on electrical wiring, circuits, and micro controllers before I knew how to "properly" use a multimeter.
Comment: i am not sure if "properly" is even a concern here.  if you can't figure out voltage across line and neutral or line and ground in an ac installation, you shouldn't be touching them.


What is the adjectival form of "turmoil"?

Question: What is the adjectival form of "turmoil"?
Might it be "turbulent"? I have a feeling that that isn't it, though.
Answer: As simchona said, there is no adjective derived from turmoil, nor any adjective with a related etymology. So in the strict sense, there is no adjective form of the word turmoil.
For a word with the appropriate meaning, I would suggest tumultuous:

(adj) disruptive, riotous, troubled, tumultuous, turbulent (characterized by unrest or disorder or insubordination) "effects of the struggle will be violent and disruptive"; "riotous times"; "these troubled areas"; "the tumultuous years of his administration"; "a turbulent and unruly childhood"

Source
Answer: Having checked the Oxford English Dictionary for turmoil, it turns out that it is derived from the Old French tremouille or mill-hopper. However, while there are both noun and verb forms of turmoil, there is no adjective which shares that etymology. So, I suggest turbid:

not clear or transparent because of stirred-up sediment or the like; clouded; opaque; obscured: the turbid waters near the waterfall.

thick or dense, as smoke or clouds.

confused; muddled; disturbed.
Comment: makes sense now!
Answer: tumultuous can be considered the adjective form of both turmoil and tumult.
another alternative would be turbid which literally means "in turmoil or confusion"


Result starts with someone who is not a friend in Facebook search

Question: I've noticed that recently when I enter a letter into the search bar, the first person that comes up isn't a friend of mine, but the rest are. Does anyone know why this person comes up first?
Answer: Normally it will list your friends. If not it will list the recommended friends like friends of friends
Answer: The search is performed across all Facebook, not just across your group of friends and the results returned take into account several parameters, not just your friends: it might be that you searched for that person in the past, or that you visited his/her profile, or that is friend of friends. Or is somewhat famous, thus having a higher "search rank."


How does multi-rate processing work?

Question: In the case with a 1-D input like audio, how can a system with one input do many different kinds of processing at different sampling rates and still, at the end of the processing, produce one waveform? For example an ADC/DAC reading and writing at 48kHz, but has an FFT running at 8kHz or another set of processes running at 16 kHz? Is it a matter of decimating and interpolating? How would all of these processes line up?
Answer: You are on the right track.  You can use decimation and interpolation (or resampling, which is a combination of both decimation and interpolation) to change the sample rate.  For instance, if you start with 48 kHz samples you can decimate by 6 to get down to 8 kHz, do some processing, then interpolate by 2 to get to 16 kHz, do some processing, then interpolate by 3 to get back to 48 kHz.
"Lining up the processes" is not in and of itself difficult.  You can decimate and interpolate whenever you want.  Doing it in a way that makes sense and is useful, on the other hand, requires knowing more about what you start out with and what you want to accomplish.
Comment: @AnthonyParks: Think of it this way: your ADC is continually spewing out samples at 48 kHz. This might feed a decimator that reduces the input sample rate by 3 (to 16 kHz). The output of the decimator feeds your 16 kHz filter. That feeds a decimator that reduces the sample rate by 2, which then feeds your 8 kHz filter. Data continually streams through the system; for every 6 samples in from the ADC, 1 sample comes out at the end of the chain.
Comment: @AnthonyParks: In practice, it's likely that the decimators could actually be combined with the filters you mentioned (since decimation typically requires a lowpass antialiasing filter), but that's an implementation detail. There are entire books written on multirate signal processing; I would recommend the [classic text by fred harris](http://www.amazon.com/Multirate-Signal-Processing-Communication-Systems/dp/0137009054/ref=sr_1_1?ie=UTF8&qid=1432294055&sr=8-1&keywords=multirate+signal+processing).
Comment: Thanks. To illustrate my confusion, imagine I have audio at 48khz, but i want to apply one filter at 8kHz and another filter at 16kHz. Thats 6 sample periods for the first filter and 3 sample periods for the second. Every 1/48kHz, the DAC is reading out a sample, what does it read out in the interim? Am I thinking about this correctly?
Answer: If you are running a causal/real-time process, note that any upsampling/downsampling sub-process involves anti-alias filtering that will add a delay (a linear delay in the case of a symmetric FIR filter).
So, if you want to re-combine resampled and non-resampled processing chains, you might want to add delays to the non-resampled processing paths to match the anti-alias filter (and other) delays in the resampled processing paths to "line things up", depending on what you are doing, of course.

How does multi-rate processing work?


Shape in Illustrator so it can be editable in PowerPoint

Question: How to save a shape in Illustrator so it can be editable in PowerPoint 2016 (MAC OS). I should be able to recolour and it has to scalable on re-sizing.
Comment: On a Windows machine you can just copypaste and then ungroup and it will become native.
Comment: Can you help me out on MAC..??
Comment: Well, for starters, have you tried @joojaa's suggestion on your Mac?
Answer:
Save your shape from Illustrator as .EMF file.
Go to PowerPoint -> Insert a picture -> select your .emf file and
click open.
At this point it will act as a picture. You will have to
right click the shape -> Group -> Ungroup.
A prompt will appear asking you if you want to convert it. Click yes and after Ungroup it one more time.
You will see that the shape has a transparent
shape/background. Delete that and group the elements again (if there are more than one).

Done!
Comment: Just a tip, using `` tags makes posts like these a lot clearer :)
Answer: Try to export your Illustrator file as EMF or WMF (File > Export).
They should be compatible with Windows Office software.
Answer: You can copy/paste from Illustrator into MS Word, then copy/paste from MS Word into PowerPoint. Then you can right-click and "edit picture" to break it apart, recolor, etc. It will be fully scalable. Unfortunately, Powerpoint doesn't support copy/paste directly from Illustrator. (At least 2010 version doesn't.)
Edit: As joojaa has pointed out, you CAN paste directly from Illustartor into Powerpoint, but you have to right-click and paste as a picture. Thanks for the tip, joojaa!
Comment: It does not? Weird at least it works on my pc, you just have to specify your pasting a picture.
Comment: Copy/paste worked for me


How do you stop an algorithm at a specific run time?

Question: so I'm trying to write an algorithm in C to play the game of Reversi. I've already written in basic minimax algorithm yet I am not very satisfied with it. I want to implement alpha-beta pruning to my code to run at a higher depth. However, my code is only given 1 second to run and generate a move and I'm worrying that my ai would not be able to check all the relevant nodes in the designated time. My thought is that I could implement iterative deepening, but I have no idea how to do that (so I really need some inspiration). And also how could I stop my code at a specific time? I want to push my code to the maximum depth if possible.
Comment: https://en.wikipedia.org/wiki/Iterative_deepening_depth-first_search, https://www.chessprogramming.org/Iterative_Deepening
Comment: Thank you that is helpful, but how do I define time in a function/thread? Is there a way to  stop a function when a specific time runs up?
Answer: As far as I know, it is not possible to achieve that exactly unless you are running a hard-real-time operating system (which neither Windows nor Linux are).
Anyway, you can obtain close to this behavior by one of two methods:

internal timing: choose one or more check points in your algorithms, that are frequently passed through and where you read the wall-clock time*. When the desired delay is reached, or a little before, let the algorithm terminate. The difficulty is to find a point where the algorithms passes frequently enough. The maximum running time between two passings should not exceed the desired time accuracy. This may pose a challenge if the algorithm behaves irregularly or at a pace that depends on the input data.

external timing: you can launch the algorithm in an auxiliary thread and start a timer synchronously (waiting call). Upon timer expiry, kill the auxiliary thread. There are two technicalities involved:

you must make sure that the algorithm can be interrupted at any time; in case the algorithm updates a list of results, the update must be made atomically, i.e. cannot be interrupted in the middle of a sequence of modifications that temporarily breaks data coherence.

you must make sure to regain control when the auxiliary thread is effectively killed, so that it won't change the results after the fact.

With all solutions, the system load may cause extra latencies; they cannot be avoided.

*Alternatively you can start a timer asynchronously (non-waiting call) and periodically check whether it has elapsed or not.
Comment: check clock_gettime() which can return the time since your computer started, on an M1 Mac under MacOS with 1/24th of a microsecond resolution. That should work on Linux as well. Don't know about Windows. There is one clock that stops when the computer goes to sleep, and one that keeps running.
Comment: @gnasher729: under Windows (PC), see QueryPerformanceCounter.
Answer: When you implement alpha-beta pruning, it is important to try the best moves first. To do this, you evaluate one move and sort the moves from best to worst. Then you evaluate two moves, trying moves in the order you found by one move, and sort again. Then three moves and so on.
In C or C++ you can use the clock() function which returns the time spent in the current thread, in multiples of CLOCKS_PER_SEC. So after evaluating a move, you check the time and estimate how likely it is to finish in the time you have.
If you absolutely need to finish in the given time, you run the calculation in a separate thread which updates the best result so far, and set a timer to display the best result after one second.
Note that clock() stops counting when the thread is not running, so if your computer is very busy it might take longer until clock() increases by more than a second. clock_gettime() might help.
Answer:
check all the relevant nodes in the designated time.

You will never be able to check all the nodes. The whole point of iterative deepening is that you search just a part of the tree, and return the best answer you have so far once time runs out. There are therefore two different problems to consider:

Making sure the program runs within the given time.
Having the program return the best solution found so far.

To address 1, you need an if-statement at the start of your loop that simply measures the time that has elapsed so far and if the program has less than 0.001s remaining  to make a move, then it will return immediately. You can adjust the 0.001s threshold as needed.
To address 2, you use iterative deepening. In iterative deepening, you first search the game tree up to depth 1. The heuristic will be evaluated at depth 1 nodes. The best result for depth 1 is stored somewhere. Then you do the same thing for depth 2. Replace the depth 1 result with depth 2's result. And so on, you keep raising the depth by 1 and exploring the game tree only up to that depth and saving the best solution. If you are running out of time, you immediately return the best solution found so far.


Move data from field to another field as a batch

Question: I recently have taken over managing CiviCRM for an orchestra in Holland. Some fields have been used inconsistently, for example Nickname and First Name. I now need to copy all data in Nickname to First Name. That would be no problem running a SQL query, but I am afraid that would be too bold a step in CiviCRM. How do I go about? Is there an extension to do the job?
Comment: Why not just import the nickname field to first name field?
Comment: this is something we would likely do via an sql query - but you would also need to then update Display Name and Sort Name fields, so they showed the updated data, via another query
Answer: You could do it just with API Explorer 4 using chaining:

I've added a couple of 'where' clauses for minor sanity - you might want to adjust those.
This finds all the contacts satisfying the 'where' clauses and for each one, runs an update where $id and $nick_name in the chain clause refer to the values from the contact just looked up.
Take a backup & test carefully!
Comment: Thanks for the great write up on how to do this
Answer: I don't think there's an extension but there is an api (https://docs.civicrm.org/dev/en/latest/api/). If you do it in SQL it wouldn't autoupdate other items like the "display_name", so you could write a little php script using the api to do it, and then run it with cv php:script. Basically you would want Contact.get and then Contact.create, e.g. something like (untested! Make a backup!)
$contacts = civicrm_api3('contact', 'get', ['contact_type' => 'Individual']);
foreach ($contacts['values'] as $c) {
  civicrm_api3('contact', 'create', [
    'id' => $c['id'],
    'first_name' => $c['nick_name'],
  ]);
}

You may also want to e.g. check that nick_name isn't blank for that record. May need to experiment.
FYI contact.create means "update" when you give it an id.
Comment: another option might be an export/import but would need to check how to deal with a field, eg nickname, which might have data but which should be overwritten to be NULL or empty
Comment: Great, thanks, I am going to work on it!


Brittle resin prints

Question: I do not have a clear understanding of what causes resin prints to become brittle. Firstly, it appears excessive cold (in the 40s or even 30s, I am in New England) may be a factor. What else can cause brittleness in resin prints? Is there a difference between resin types?
Comment: I consider 30 or 40 unlivable Cold. Some gasses are fluid at that temperatue. But then again, Water freezes at 273.15 and boils at 373.15 Kelvin. **Please** use SI units!
Answer: Many printing resins are inherently brittle.
Brittle is a property of the material - so of the used printing resin.
Look at the first seconds of this video - Punished Props Academy drops an SLA/DLP printed dagger on the ground from about 1 meter and it shatters, despite having been carefully post cured and washed and everything. To mitigate that trouble they did a cast of the item with a different resin.
However, the exact brittle behavior of the print is inherently linked to the exact formulation and thus the exact brand and type of resin used.
Some are less brittle than others - and outright flexible.
You might need to test around, but there are flexible resins. This german essay contains pictures and even a video of a super flexible printing resin. Just an example: One such rubbery resin is Formlabs Flexible 80A, and Matterhackers has a range of different flexible resins. Google does show other brands too by googling "SLA Resin Flexible"

I am not affiliated with Formlabs, Matterhackers, or Techstage.de
Answer: disclaimer: I own a company manufacturing 3D printing resins, and all links lead to my products :)
Key reason - resin formula
First of all, it really depends on the composition of your resin. Some of them are more brittle than others. Usually cheaper resins are more brittle.
What causes properties to change?
That being said, some tougher resins even with some flexibility once printed can still become brittle over time. That could happen due to:

Continued exposure to UV light. It continues to cure your model and it loses its flexibility. The same goes to over-curing of your prints. If you print with longer exposure time settings than needed it will produce stiffer prints with less flexibility.
Arid environment. If the air in your environment is dry, some resins can become more brittle.
Cold environment. Heat makes plastics more flexible.

What can you do?
Best way to protect your models from getting brittle - covering them with paint or other UV resistant coating.
You can also choose resins that don't become brittle over time and is less sensitive to above mentioned causes. For example our TGM-7 resin:
Comment: Thanks for the disclosure of your affiliation - and hi and welcome to SE.3DP.

Brittle resin prints


Grub on start up changed color from purple to black?

Question: A while ago, i reinstalled 12.04 on my computer and a few day later when My system restarts after updating itself, the grub is no longer purple. It is  just black and I didn't change anything that could do that. my system works fine and there is no problems with anything. I just don't like looking at a black grub while waiting in the booting process. Can you change the grub back to being purple or choose a different color?
Answer: In terminal type
sudo gedit /lib/plymouth/themes/default.grub

for Saucy:
sudo gedit /lib/plymouth/themes/ubuntu-logo/ubuntu-logo.grub

for Bionic (18.04)
sudo gedit /usr/share/plymouth/themes/ubuntu-gnome-logo/ubuntu-gnome-logo.grub

And you can change the grub background colour by changing the values of the 3 in numbers in the text document.
Black is this
if background_color 0,0,0 ; then
   clear
fi

and purple is this
if background_color 44,0,30 ; then
    clear
fi

Once you have finished editing that file save it and run
sudo update-grub

Refrences here and here.
Answer: Spent an hour trying to figure this out on Ubuntu 16...no posted solutions worked but good news I figured out how to do this, it easy!
in terminal;
sudo gedit /boot/grub/grub.cfg

search for "background" and change

### BEGIN /etc/grub.d/05_debian_theme ###
      set menu_color_normal=white/black
      set menu_color_highlight=black/light-gray
      if background_color 45,51,53; then
        clear
      fi
      ### END /etc/grub.d/05_debian_theme ###

to

### BEGIN /etc/grub.d/05_debian_theme ###
      set menu_color_normal=white/black
      set menu_color_highlight=black/light-gray
      #if background_color 45,51,53; then
      #  clear
      fi
      ### END /etc/grub.d/05_debian_theme ###

*you need to comment out if background... and clear.
save. reboot!
This makes grub look far nicer when used to dual boot a Windows 10.
Comment: comment "fi" line at bottom.


Does Making And Or Selling Fishing Lures Haram?

Question: Assalaamu'alaikum,
I've read about imitating the creation of Allaah is haram. Does making lures like these is considered as imitating the creation of Allaah and is haram?
Comment: As Salaamu 3laykum, please see my answer below regardless of the votes.
Answer: Bismillah Hir Rahmaan Nir Raheem
As Salaamu 3laykum,
I hope you are doing well. By default everything for us is halal unless stated otherwise. When we look at all the ahadith (Prophetic sayings) we first see that images are haram to make (please read entire answer to get the full answer because there are exceptions).

The Messenger of ALLAAH [SAW] said: 'Among the people who will be most severely punished on the Day of Resurrection will be the image-makers.' (Nasai in the chapter of adornments)

The Messenger of ALLAAH [SAW] said: 'Whoever makes an image will be commanded on the Day of Resurrection to breathe the soul into it but he will not be able to do so.' (Nasai in the chapter of adornment)

However, when we dig deeper we find out that there are two types of images that can be made. One of animate beings and the other of inanimate beings. The former being haram to create.

"I heard the Messenger of ALLAAH [SAW] say: 'The angels do not enter a house in which there is a dog or an image of an animate being.'(Nasai in the book of adornment)

the Messenger of ALLAAH (ﷺ) said: "Jibra'il came to me and said: "Indeed I had come to you last night, and nothing prevented me from entering upon you at the house you were in, except that there were images of men at the door of the house, and there was a curtain screen with imagines on it, and there was a dog in the house. So go and sever the head of the image that is at the door so that it will become like a tree stump, and go and cut the screen and make two throw-cushions to be sat upon, and go and expel the dog." So the Messenger of Allah (ﷺ) did so, and the dog was a puppy belonging to Al-Husain or Al-Hasan which was under his belongings, so he ordered him to expel it. (Tirmidhi in the chapter of manners)

Please Note We do see that it can become permissible if an animate being is changed to something that could not be living. Such as changing a living being image to that of a non living image by severing the head.

We also see during the time of the Prophet Muhammad (Peace Be Upon Him) that images were in the Kaaba and ordered them to be destroyed.

The Prophet (ﷺ) entered the Ka`ba and found in it the pictures of (Prophet) Abraham and Mary. On that he said' "What is the matter with them ( i.e. Quraish)? They have already heard that angels do not enter a house in which there are pictures; yet this is the picture of Abraham. And why is he depicted as practicing divination by arrows?" (Bukhari in the chapter of Prophets)

The Prophet (ﷺ) ordered Umar ibn al-Khattab who was in al-Batha' at the time of the conquest (of Makkah) to visit the Ka'bah and obliterate all images in it. The Prophet (ﷺ) did not enter it until all the images were obliterated. (Abu Dawud in the chapter of clothing)

Furthermore, during His (Peace Be Upon Him) life images were being created and being hung in his house in which he commanded to be destroyed.

ALLAAH Messenger (ﷺ) visited me (33isha). and I had a shelf with a thin cloth curtain hangin. over it and on which there were portraits. No sooner did he see it than he tore it and the colour of his face underwent a change and he said: A'isha, the most grievous torment from the Hand of Allah on the Day of Resurrection would be for those who imitate (ALLAAH) in the act of His creation. A'isha said: We tore it into pieces and made a cushion or two cushions out of that. (Sahih Muslim in the chapter of clothes and adornment)

The Messenger of ALLAAH [SAW] went out, then he came in, and I had hung up a curtain on which there were (images of) horses with wings. When he saw it, he said: 'Get rid of it.' (Nasai in the chapter of adornment)

I will say at the end that for young children dolls/toys seem to be allowed as in the following hadith.

When the Messenger of ALLAH (ﷺ) arrived after the expedition to Tabuk or Khaybar (the narrator is doubtful), the draught raised an end of a curtain which was hung in front of her store-room, revealing some dolls which belonged to her.
He asked: What is this? She replied: My dolls. Among them he saw a horse with wings made of rags, and asked: What is this I see among them? She replied: A horse. He asked: What is this that it has on it? She replied: Two wings. He asked: A horse with two wings? She replied: Have you not heard that Solomon had horses with wings? She said: Thereupon the Messenger of ALLAH (ﷺ) laughed so heartily that I could see his molar teeth. (Abu Dawud in chapter of general behavior)

Conclusion
From the aforementioned ahadith we come to the conclusion that fishing lures in your picture example are not permissible. They are imitating the creation of ALLAH (Glory Be To Him). If they were to be cut in half to resemble a creation that could not live such as the tree stump hadith then the ruling would change to being permissible.

Have a nice day!


Lost my data because of uninstalling the game

Question: I uninstalled my Clash of Clans and now my data is being lost.  I have tried everything to recover it.  How can I recover my save data?
Comment: What platform are you on?
Comment: That's odd, according [to this question](http://gaming.stackexchange.com/q/164343/1721) uninstalling the game does not delete your game data. Did you do anything in addition to uninstalling the game?
Answer: If it wasn't saved in the first place, most likely you will not be able to get it back. You can try contacting Supercell, but they make no guarantees that you will get your game data back. Next time, make sure to either back up your game to Game Center or any other backups you may have.
Comment: Supercell support is atrocious you will be lucky to even get a reply asking for more information.


Changing color image in Adobe Illustrator

Question: I wanna change the color of an image in Illustrator. I've downloaded one flat icon from google in png format I just wanna change the color of that particular icon. Kindly help me with the same.
Answer: PNG is a raster format.
Illustrator is a vector editor, that wouldn't be possible, here are some possible workarounds:
If it's a single color icon you can easily change the color using Photoshop.
If it's simple enough, you can trace it in Illustrator and turn it into vector paths which would be usable in Ai.
I would recommend trying to get a vector format of the icon.
Some common vector formats are .ai, .eps, .svg
Answer: To be clear, Welz is totally correct that altering a placed raster image in illustrator isn't the best or most effective workflow at all, and should in most cases be avoided.

That said, it depends on the image / logo you have whether you can 'alter the colour' in Illustrator... but there is a 'trick' you can play which will allow easy shifting of the overall hue of a placed image, which functions like colourising the whole image; it's not subtle, it's a blunt-instrument approach, but it can work well for some specific use-cases.
It will do nothing if the primary colour in the placed image is black.

Add a rectangle above your placed image, fill the rectangle with colour, and set its opacity / blend mode to colour, then alter its colour as desired to get the effect you wish.
Base colour of placed image:

Rectangle above with hue shifting to yellow-orange:

Rectangle above shifted to green:

If either your placed icon is black, or you wish more control, then everything Welz has said is spot-on: use a raster image editor for raster image work, vector for vector - far more effective and efficient, and better match of tools for needs.
Hope this helps.


Remedy: create incident from WS without using first name and last name

Question: I'm trying to create an incident in Remedy through the web service HPD_IncidentInterface_Create_WS. Everything is working fine however it would be better for me if I could use the submitter's mail address or login instead of his "first name" and "last name", which both are mandatory fields in the WSDL file. Is there a way to create the incident without using them?
Answer: You would need to create a custom filter similar to HPD:HII:CreateIncident_020_GetPPLInfo (you can just save that as a copy).  Change the first namd/last name parameters with the email.
You can also post questions on the BMCDN forums, more remedy specific folks look at this forum.
https://communities.bmc.com/communities/community/bmcdn/bmc_it_service_support?view=overview
Answer: I see your dilemma.  I believe you'd need to modify the out-of-box WSDL to make 'First Name' and 'Last Name' optional.  I think you can change the 'Nillable' property (see Figure 1) of each WSDL attribute to 'true' to accomplish your goal.  I haven't tested this method, but I think it will work.
You'll also need to add a filter that executes on submit of the form 'HPD:IncidentInterface_Create' to set both the 'First Name' and 'Last Name' fields using the email address as the lookup criteria.
It might be a good idea to create a copy of the out-of-box WSDL and modify the copy.  That way any hot-fixes provided by BMC will still operate correctly.  But, that's just my preference.
P.S. I tried to upload a screenshot of the 'Nillable' property, but evidently I don't have enough reputation points to do that (drat!)  :-)


How could I restrict view access to message templates

Question: Wordpress. I know I can restrict edit access but I would like to restrict "use". So I can allow some users to send an email but not select a template. (otherwise they can use for instance CEO signature)
Comment: Not an answer to your question but if your concerns are mainly regarding the signatures you could have a look at this extension: https://docs.civicrm.org/signatures/en/latest/
Answer: I think its down to adding some code via php or js to restrict use of message template on some screen based on permission.


Is it possible to work with Microsoft Sharepoint with Go?

Question: I want to know is any library to work with Microsoft Sharepoint ?
Can we program with go language for Microsoft Sharepoint?
Answer: Sharepoint is many things and it is unclear what you mean by "Can we program with Go for Sharepoint", but you may want to take a look at Sharepoint 2013 apps, which will support "Self-Hosted Apps", that could be written in any language. From the linked article:
<code>You could be a PHP developer with a Linux machine and still make SharePoint apps.
</code>
If you're more interested in interacting with Sharepoint's APIs, it looks like Sharepoint 2013 provides a RESTful API, so again, no problem for Go.
Answer: Q1: Unfortunately, googling for such library was not successful in my case.
Q2: If MS Sharepoint (whatever that is) has some known or documented API or it can be accessed by some known or documented protocol(s) then the answer is definitely yes.
Answer: My best guess is that this will not be possible. Sharepoint as far as I know is an ASP.NET application designed for the Microsoft IIS platform and depends on the closed-source .NET framework.
Working with Sharepoint over APIs though, should be possible but judging by your question I don't think that's what you want.


Can I extend my ESC to motor using some thick wire? is it possible to do in that way

Question: I'm doing a drone project for my academics. my arm of the drone is a little bit longer. How can extend my ESC? I watched extending a power-ESC cable will make problem, but increase ESC-Motor cable will not affect. If is it true, then which wire can I use to extend my ESC length? will it affect my motor performance?
Answer: Extend wires on motor side. That side is expected to deal with voltage spikes due to the high inductance of the motor windings so some extra wire inductance from longer wires isn't a big deal. Not so on the battery side.
DO NOT CUT THE MOTOR WIRES to add on connectors. Those wire strands are directly from the motor windings and are coated in enamel which is tough to remove. Cut the wires on the ESC instead.
Answer: DKNguyen is half correct. I will do my best to answer your question. But first, I want to address what DKNguyen said.

"... extra wire inductance from longer wires isn't a big deal. Not so on the battery side."

This is true, however, it's actually the reactance that is our issue. The non-linear current draw reacts to the inductance of the wire and produces a reactance which adds to the impedance of the wire. There is a great curve which explains the reactance of wire with a varying frequency.

Image source: Electronics Tutorials - Inductive Reactance
If you eliminate the need of high frequency current draw, this no longer matters. For example (one of a few methods), if you had a Low ESR Capacitor Up the backside of the ESC. This will reduce the current ripple on the ESC power leads. Inductance is only a issue if we are not pulling a constant current, ie. if we are pulling current in the form of a sine wave.

"DO NOT CUT THE MOTOR WIRES to add on connectors. Those wire strands are directly from the motor winding's and are coated in enamel which is tough to remove"

This is only true in some motors. In fact most quadcopter motors these days are single core copper windings, with enamel coating. They have silicon insulated multi-strand wire soldered to these with heat-shrink and all covered up.
You would ideally need to give some specs as to your setup to get a tailored response, but...
On smaller < 300mm quads, it doesn't matter at all. Extend the Power leads! Extend the motor wires!  If you are looking for LEDs as well, look at something like RaceWire. This not only allows you to extend the wires, but you can also get some cool LED lights.
Comment: _"This is only true in some motors."_ - but isn't true in _any_ ESC, so safer to extend the ESC wires. Also a lot of multirotor ESCs don't come with motor wires, so you have to add them anyway (which is easier than splicing into existing wires).
Comment: @BruceAbbott I was not stating which is safer and you have not given any basis as to why you think it is so. My statement was merely stating that I think advising someone to "DO NOT CUT THE MOTOR WIRES" with nearly no information is a ill-informed advice.
Comment: It's not ill-informed, it's being safe.You said yourself that **most**  quadcopter motors these days have multi-strand wires - which means some _don't_. I have seen enough motors destroyed by people cutting the wires to advise newbies not to do it ever (since they won't know what type of wire their motor has). And there are other reasons not to do it too, eg. it voids the warranty, makes the motor non-standard, possibility of bad solder joints etc. Controllers usually come without connectors or even without wires, so extending them is easier and accepted practice.


Can Le Creuset Dutch Oven be used in the microwave in convection mode?

Question: I am reading that cast iron may pop or crackle in a convection oven, and aluminum is best for it. Since Le Creuset Dutch Oven is just enameled cast iron, I couldn't help but have a safety concern over using it in the microwave's convection mode.
Comment: Where are you reading "pop and crackle" be what do you mean by it?
Comment: Pop or crackle? That's complete baloney. Microwaving cast iron is a bad idea, but a convection oven is fine.
Comment: @GdD I see two possibilities: the source was talking about microwaving and being confusing; or the plastic knobs on some models being affected by intense direct heat.  You wouldn't grill/broil with the lid on anyway, but the knob couldn't take it if you did ([max 250°C](https://www.lecreuset.co.uk/en_GB/p/signature-phenolic-knob/CI94032.html))
Comment: Ignore that Quora post. It makes a fundamental error in assuming that a convection oven is the same thing as a microwave.  Then it  assumes that the failure mode of putting a big metal thing in a microwave is an explosion (a few sparks are likely, maybe confusing the electronics, but not an explosion you'd need to stand back from). It's nonsense from beginning to end
Comment: I suspect it's about microwaving @ChrisH, the temperature in a convection oven doesn't get hotter than a conventional, non-fan oven so I can't see knobs being a problem. Le Creuset knobs are indestructible as far as I can tell.
Comment: @GdD the air temperature  doesn't get hotter, but a black piece of plastic subjected to the halogen element at close range would.  Infrared absorption can get things stupidly hot.  But I agree that the fear is probably based on microwaving, which would obviously have food safety implications too, as the microwaves won't penetrate inside the dish
Comment: @ChrisH I should have been more specific about where I read it from-it was from a forum where users can post and the post I read it in wasn't even upvoted much:

https://qr.ae/pGLl2C
Answer: Le Creuset and convection ovens work well together.
One issue may be that some microwave ovens turn on the microwave part even in convection mode. More honest ones call this combination mode, and have a separate convection mode (like mine).
There are a couple of potential issues even with decent convection microwaves. One is that it will take a long time to heat through in a fairly weak oven. Another is that it's likely to be quite tricky to get a full size one in.
If you're using it with the lid on (if it even fits), the lid will come very close to the element. That's where the biggest issue arises, because the (oven-proof plastic) knob on the lid can't take that much direct heat. In some models the (top) element is far enough back that it won't directly heat the knob. In others I wouldn't trust it not to damage the plastic.
Comment: I thought only the models with a metal knob were oven-proof (I mean the lid, the vessels obviously are)
Comment: @Luciano the plastic knobs are definitely oven proof up to a point.  Mine was fine for years but suffered cosmetically when I used it for baking bread at 240°C (twice a week for most of 2020) and I've seen similar effects when they're used in an Aga
Comment: @Luciano found it:  [max 250°C](https://www.lecreuset.co.uk/en_GB/p/signature-phenolic-knob/CI94032.html)
Comment: Then be sure to set the right mode and you should be good
Comment: So I checked the microwave I am going to use and it explicitly mentions Convection as one option and Micro-Convection as another option.

Regarding the knob on the top of the lid of my Le Creuset Dutch Oven, as far as I can see it's made of metal. This is the model I am using:

https://www.amazon.in/gp/product/B07QFJ6TBG

The only issue I see here is that the microwave might take too long to heat up, but time is not that big of a constraint here.
Answer: I don't have a pot of that specific brand, but I've several enamelled cast iron and steel pots and they work fine in my microwave combi oven when used in (convection) oven mode.
Of course you have to make sure that you have the correct mode selected before turning on the oven (do NOT use the combined oven/microwave mode for example), but you should do that regardless of what you put in it.
I've been doing this for over 15 years, never had a problem and the pots nor the oven are any the worse for wear as a result.
Main problem you may have is finding one that's small enough to fit in the oven, as they tend to be rather small compared to dedicated convection


Questions about noun compounds

Question:
What exactly are "noun compounds"?
Is it possible to use any words to construct a noun compound?
How we can distinguish between a noun compound and an adjective compound?
Comment: Your ***noun compound*** is one example of what's more often called a ***compound noun***. In the standard version, ***compound*** is "natural" adjective (as with *compound interest, compound fractures*) modifying the actual "head noun" ***noun***. But in your version, ***noun*** is used as a "noun adjunct" (noun used adverbially) modifying ***compound*** used as a noun (as in *Oxygen is an element, water is a compound*). A "compound noun" is any idiomatically-established combination of two or more words used collectively as a noun (possibly collapsed into a single word, or hyphenated).
Comment: ...a "compound adjective" is much the same thing, but you might find [this explanation](https://www.grammar-monster.com/glossary/compound_adjectives.htm) useful. The difference between a *compound **noun*** and a *compound **adjective*** is essentially the same as the difference between a noun and an adjective, except in both cases we're talking about an established combination of two or more words rather than a single word.
Comment: A compound word is **always** a single word, sometimes hyphenated, but **never** written as two separate words, the latter being a syntactic construction as opposed to a compound. If I have time later, I'll post a more detailed answer for you.
Answer: I think you mean compound nouns.
What are compound nouns?
A compound noun is a noun formed from two or more words. Sometimes they form a whole new word, for example, toothpaste (tooth+paste). Sometimes they are hyphenated, for example, dry-cleaning. Other compound nouns, such as Hot Dog are sometimes written as two separate words but are still a compound noun.
Is it possible to use any words to construct a noun compound?
Yes and no. Accepted, widely used compound words are usually in the dictionary in their own right. You can't just make new words and expect them to enter the dictionary. However, new compound words are formed all the time. For example, in 2019 the word "peoplekind" was added to some dictionaries. Also, it is quite common for English speakers to form a compound noun which is easily understood, yet does not need to make its way into the dictionary. For example, if you described someone as a "garage-dweller", it would convey the idea that the person spends a lot of their time in a garage.
How we can distinguish between a noun compound and an adjective compound?
It would be no different from distinguishing between any regular noun and adjective. The noun in a sentence is normally the subject or the object. Use a dictionary to look up words you don't know, and it will tell you if they are a noun or an adjective.
Answer: Compound noun
According to EnglishClub.com, a noun compound, better known as a compound noun is a noun made of two words:

noun + noun (football)
adjective + noun (blackboard)
verb + noun (playground)
preposition + noun (underground)
noun + adjective (mouthful)
noun + verb (sunset)
verb + preposition (sign-in)

There are three forms for compound nouns:

open or spaced - space between words (tennis shoe)
hyphenated - hyphen between words (six-pack)
closed or solid - no space or hyphen between words (bedroom)

Compound adjective
According to Grammar Monster, a compound adjective is a single adjective made up of more than one word. The words in a compound adjective are usually grouped together using hyphens to show it is a single adjective.
Example of a compound adjective: cross-country competition. In this case, "cross-country" is a compound adjective that modifies the noun "competition." A compound adjective can be made of different words, which may or may not be adjectives themselves, for example in a 12-page document, "12-page" is a compound adjective, but neither "12" nor "page" alone are adjectives.
How can you distinguish between compound nouns and compound adjectives?
You can judge this from the context of the sentence in which they appear. A compound noun is always a noun, which can act as an object or subject. A compound is an adjective only when it modifies a noun.

Questions about noun compounds


How to make an appimage appear on aplications?

Question: I use a program called Stremio and I managed to download it and make the stremio.appimage file executable BUT I can't figure out how to get this file into Aplications. At the moment if I want to use the program I have to open Files and go to the folder where it is and click on it. BUT I want to be able to add it to aplications and to the dock.
Thanks
Answer: Sounds like the AppImage isn't creating a .desktop file for itself, so Elementary doesn't know it's available.
Never mind, there's an app in the AppCenter called "AppEditor", you can use that to create a new entry for your AppImage.


Taranis x 7 will not turn on

Question: Hey guys I'm having a issues with my transmitter when i press the power there is a click from speaker and nothing happens after. I tried also press the bottom two left and power at the same time, same story. I reached out to frsky they said i have the incorrect fireware. So im trying to write a new firmware and this want pops up when procces with the writing. Please help any one.
Comment: I'm not entirely sure what you're asking about the firmware. Could you edit to clarify precisely what you need help with in writing new firmware?
Answer: If I remember correctly, that happened to my Taranis x9 Lite one time (just the sound click but then nothing turns on). I removed the batteries, and then opened the transmitter cover (or back cover) and removed and reinserted the cell coin battery, and it worked again.
Answer: Remove the cell coin battery, clean it with a cloth, and then put it in.
PS: I wanted to post this as a comment to the other answer, but for that I would have needed at least 50 reputation.

Taranis x 7 will not turn on


What are the differences that a beginner should be aware of between opening with 1.e4 or 1.d4?

Question: I am preparing for a tournament, so which opening should I use or prepare? How can I become strong in a specific opening line?
Comment: Neither is better than the other one, it's mostly a matter of taste. I would suggest you play through a few games which started with both and pick the one which tends to lead to the sort of position you like.
Comment: What's your rating around?
Comment: The whole point of playing chess is dealing with incomplete knowledge. Human players somehow compile experience into a set of preferences, some conscious and some sub-conscious. All of this necessarily becomes subjective; indeed the scope for expression of individual flair and artistry is one thing that makes chess great. Here is a beginner who simply asks for a guideline as to how to climb the learning mountains. I see no indication that he invites descent into an opinion battle. TheAutomaton has shown a serious answer to this serious question. Please take the question off hold.
Comment: @TheAutomaton right now i am not a rated player but i am preparing for fide rating
Answer: Tough to tell
Benefits of Both
d4 is very strong controlling two central squares (e5 and c5)
e4 controls 1 (d5 since f5 doesn't help develop pieces it's not the best)
e4 opens up the white bishop and queen diagonals (Though queen's is easily blocked), while d4 opens up the bishop, d4 is also benefit by being naturally guarded by the queen.
Analysis of Both
I personally find d4 to be better at gaining control of the center, especially with my favorite white opening, the queen's gambit. Since black can't attack the e pawn black is forced to develop slower since it can't openly attack the center. In this case, d4 is solid.
e4 on the other hand promotes more activity from other pieces by opening up the two diagonals (Though the queen's is almost never used). Yet, since this allows black to fight for the center I have found more exchanges, and I like using e4 for creative openings such as the Ruy Lopez, Rio Gambit, or learning the Sicilian lines seizing space as white while black has to open up space for his pieces to develop.This makes e4 a very good way to open the board, though this opens up many weakness for white often in exchange for black's lack of development.
My Opinion
At high level play, the Sicilian is threatening and at GM-level play e4 has a very low win rate compared to d4 (Refer to Stat's section). It lacks the solid control of the center and e4 promotes a large amount of counter-play, though in my opinion, it doesn't matter at the moment. It's nice to play both and find your own comfort and flexibility.
Recommended Openings
If you are looking for lines to learn my top 3 for white (in order favorite-least) are: Queen's Gambit, English Opening, and for Black: Sicilian, Nimzo-Indian, and Modern Defense. These are solid and work great at tournament level play.

Stats
Chess.com's Opening Explorer (https://www.chess.com/explorer) documents e4 as having (38% wins, 32% ties0, 30% losses) with 879,507 recorded games. d4 is recorded as having (39% wins,34% ties,27% losses) with 693,538 games archived. While this is a fairly close margin the major notable point is the 3% deviation of loss rates, but these ideas aren't imperative as they encompass all levels of play.
The World Championship test
Another method to compare these two moves, using actual facts and information instead of general ideas, is to observe the world championships. In a world championship, the players prefer the move they consider more beneficial; the move they believe will offer them more opportunities to achieve victory (especially when playing white). The contenders have, of course, practiced time and again and every defeat signifies a major weakness. What is more, world championships constitute a great study sample simply because there is no other tournament where players demonstrate such seriousness and concentration. Let us examine the results of the modern chess era, meaning the most recent world championships, starting from the year 2000 when Kramnik became world champion.
"In 89 games 1.e4 was used 25 times resulting in: only one win, three losses and 21 draws.
In 89 games 1.d4 was used 62 times resulting in: 18 wins, 6 losses and 38 draws.
1.e4    wins: 4%    losses: 12% draws: 84%
1.d4    wins: 29%   losses: 9%  draws: 61%"
(https://en.chessbase.com/post/1-e4-or-1-d4-which-is-the-better-move)
At championship level play there is a drastic deviation between the openings, nearly 25%.
Comment: @TheAutomaton.The real statistical objection to basing an answer only on WCh games is not that you account for only a small number of games, but that you account only for a VERY small number of players.
Comment: "e4 has a very low win rate compared to d4" .. I don't know about that. The difference between the common first moves (e4, d4, c4, Nf3) is usually in a 1-5% range depending on the database you look into (and the order isn't always the same!), too minimal to matter significantly in non-GM play.
Comment: I changed the "high level play" to "GM-Level" as it was vague. I also added a section of stats that show database statistics of both, as well as how they also compare on the championship scene. I agree though, it was misphrased
Comment: That's true, but with a large sample of close to a million it's a prediction of the true mean ratio, since it abides by the 10% rule, or is close to it (http://www.statisticshowto.com/10-condition/). Either way I feel it represents a diverse community that may reflect the larger mass, and it's just an idea of how a certain population fairs with this opening.


Minhag of Kos Pagum

Question: Another Minhag that came from nowhere is the custom of filling a wine cup to overflowing. Some do it because of Kos Pagum, however it seems that Kos Pagum applies to a cup which is not filled near enough to the top to be considered full. Overflowing the cup is ba'al tashchis as well as davar m'geunah. Getting wine all over your hands and the tablecloth is not good table manners especially if you are a guest in someone else's home. The only time there appears to be a reason to do so is havdalah when it is considered a berachah. Is there a source for this?
Comment: http://judaism.stackexchange.com/questions/16428/drinking-the-wine-that-spills-over-the-cup-during-kiddush
Comment: "Another Minhag that came from nowhere" Please do not be disrespectful. Also, note, *bal* is Aramaic and is not *ba'al* which is Hebrew and means something different.
Comment: @YEZ, it is a common Chassidic Minhag in several groups. Some groups specifically use brimless cups so that it overflows a bit more.
Comment: This question needs a lot of work. The question appears to be part of some kind of ongoing discussion, without any clarity as to where it is coming from. Also, the author seems to be basing his question on sources and personal research that he has not cited.
Comment: See Rama (OC 296:1) and *Mishna B'rura* ([296:5](http://books.google.com/books?id=1kF9RT8oVg0C&pg=PA133#v=onepage&q&f=false)).
Answer: "Some do it because of Kos Pagum"
The common reason is that an overflowing cup is a b'rocho, as you mention below, and has nothing to do with kos pagum.
"Overflowing the cup is ba'al tashchis"
Because it is done for a reason, it is not "bal tashchis".
"as well as davar m'geunah."
No, it is not. It is a minhag and it is a beautiful one.
"Getting wine all over your hands and the tablecloth is not good table manners especially if you are a guest in someone else's home."

Most people do not make their own havdalah at someone else's house.
The Havdalah cup is usually on a plate or in a bowl because the candle is put out in it.
People who do not have a plastic on the table cloth probably expect to wash it.

"The only time there appears to be a reason to do so is havdalah"
Some people do it by every kiddush.
Comment: Aw c'mon ... a negative total vote? For answering a question that people commented that the question itself is vague??? I think this answer addresses all the questions pretty well. And yes, my granpa, father and I overflow the kiddush cup. I was taught that it is a sign of thanks to hashem that he has given us brachot during the week so that we can "afford extra wine", i.e. - he blessed us with more than what we need.
Comment: Heh. The tone of my post is not that great, so i can't complain about a negative vote. I started in the comment field, but when i saw it too small, i moved it here. The tone of the original question bothered me. I think i'll move the complaints out. They do not belong there...done.

Minhag of Kos Pagum


Can your android device get malware?

Question: I admit, I watch porn now and then on my android phone. But I never, ever, download something or click any adds or links. But here's the weird thing, sometimes when I visit such a website, an automatic download starts. I thought I removed them but when I installed an antivirus it detected 5 threats, all from that site. And the weirdest is, when I installed an other antivirus, it detected 4 more threats! Are these the same threats or did the first antivirus fail on me?
And do android devices get severe viruses?
Comment: Did you see: http://android.stackexchange.com/q/341/23379 and http://android.stackexchange.com/q/4236/23379
Answer: No, Android doesn't "get severe viruses" or malware much; it's Linux based, and is generally quite secure from being exploited even if a user does manage to install a malicious app.  And while it is possible to get it from a website that uses an exploit on a mobile browser, it is extraordinarily improbable.  Most likely the AV is reporting non-malware like tracking cookies as "threats".
More details:
AV companies define "threats" extremely broadly, in order to keep users paranoid and buying their software.  One of the ways they do this is to include things like tracking cookies and the like, which aren't technically malware.  This is probably what your AV is "detecting", as website drive-by malware infection on Android is hugely unlikely.  AV for the average user is useless on Android (and worse, slows down your phone); AV providers prey on user ignorance and fear from the fact that Windows requires AV (which most users have had drilled into them by now) to sell their products for Android.
The most likely scenario for getting malware is installing an app from someplace other than Play (sideloading), followed by being incautious when installing a Play app and not bothering to check the permissions an app is asking for (even then, extremely unlikely that it could do much other than send some of your personal info to a server for marketers to buy, or use up your bandwidth to pop up ads).
Many malicious websites will start automatic downloads, in the hopes that you'll be foolish enough to run whatever is being downloaded.  So long as you don't install whatever it is, there isn't a problem.

Can your android device get malware?


Potentials of two near conductors

Question: When two conductors (let's say spherical) of charges $q_1$ and $q_2$ and radii $r_1,r_2$ respectively are brought and connected by a metal rod,we know that flow of charge occurs unless potentials are the same. And the conventional method of doing this is by equating the potentials of the two separate spheres where the formula $\frac{Kq_1}{r_1}=\frac{kq_2}{r_2}$ is used. But this formula is true considering when there is only charge $Q$. When another charge is brought close,wont the potential due to the other charge be considered as well? So,what I am asking is why is the potential of the sphere $q_1$ still $\frac{kq_1}{r_1}$ instead of $\frac{kq_1}{r_1}+\frac{kq_2}{d}$ where $d$ is the distance from the center of the $2nd$ sphere to the surface of the $1st$ sphere. The same applies for the potential of the $2nd$ sphere.
Comment: [Electrostatics of two charged conducting spheres](https://users.fmf.uni-lj.si/podgornik/download/Lekner-attraction.pdf)
Answer:
For a sphere charged with a total charge ( Q ), the potential at a point located at a distance ( r > R ) (where ( R ) is the sphere's radius) from the sphere's center is given by ( \frac{kQ}{r} ). This formula is valid only when the charge ( Q ) is uniformly distributed across the sphere's surface.

In a conductor, the distribution of charge is such that the potential remains constant at every point on the conductor, provided the conductor is in electrostatic equilibrium.

When multiple charge distributions are present, the potential at any given point is the sum of the potentials contributed by each individual charge distribution.

Consider a charged spherical conductor. If a point charge is introduced near this conductor, the charge distribution on the sphere will become non-uniform. This is because the point charge will not produce a uniform potential across the sphere's surface. Specifically, the point charge will attract opposite charges closer to itself and repel like charges further away.

Now, addressing the scenario with two spherical charged conductors:
When two charged spherical conductors are placed in proximity to each other, the charge distribution on each sphere becomes non-uniform. This non-uniformity arises because one sphere's potential does not contribute uniformly to the other sphere's surface. Calculating the potential considering this non-uniform distribution can be mathematically intricate. Therefore, in textbook problems, it's often assumed that the conductors are sufficiently distant from each other, allowing for the simplification that their charge distributions remain uniform. Under this assumption, the potential of one sphere can be calculated using the formula from the first point without needing to consider the combined effect of both spheres. This is because, at an infinite distance, the potential contribution from one sphere to the other is negligible.

Potentials of two near conductors


Tortoisesvn seems stuck in non-recursive mode

Question: Just set up a new machine, running windows 10, and installed TortoiseSVN 1.9.4, Build 27285 - 64 Bit
Did plenty of reboots, needed the first one for the icons to appear. However it seems to be stuck in non-recursive mode. The icons are all there, working correctly, but when I click on a parent folder, it says there's nothing to commit. If I drill down to the child-most folder, and try to commit, it seems to figure out what files to commit. It's just a pain in the butt to have to drill down to every folder just to get the committing working, seems broken to me, or is there some setting for this?
Answer: Found my problem. One of the subdirectories, had an old svn repo in it. Had to do a clean-up, but also had to select break locks. Seems to have fixed the problem.


One attribute includes another attribute

Question: I have a telecom dataset that has many attributes, among these attributes, there is "Voice mail plan" attribute that takes yes or no, and another attribute is "voice mail calls" which has many values, but always zero when "Voice mail plan" is no. When removing "Voice mail plan" from the dataset the accuracy of classifiers is lowered, so how can we inform the classifier that No is impeded in zero voice calls
Answer: The two features "voice mail calls" and "voice mail plan" are related but they are not linearly correlated. "Voice mail plan" still contains some information that is not available from other features. Why do you want to remove "Voice mail plan" in first place? If you need to decrease your number of features, you can try dimension reduction (linear or non-linear), this way you make sure most of the variance of your feature set is considered for building your model.
Comment: I already applied PCA but it didn't distinguish between both, also it gave plan high principal
Answer: On the surface, There are feature selection methods type like filter, wrapper etc. which uses techniques like chi-sqaure, ANOVA,information gain etc. There also exists feature importance method in sklearn ExtraTreesClassifier which gives you the importance of the feature.
here are some to give you a glimpse of-
https://machinelearningmastery.com/feature-selection-with-real-and-categorical-data/
https://machinelearningmastery.com/an-introduction-to-feature-selection/
You can try these can plot and see which feature is giving you more value and select that.
It also depends on what kind of classification problem you are dealing with. From the telecom domain perspective also "plan type" might be giving high value information to the kind of output you are determining.IT is a good idea to check the underlying relation between your output and the "plan value" etc.
I might not disconnect my internet connection in near future if I have been taking a high value plan from your company for quite some time.


Explanation for non-integer degrees of freedom in t test with unequal variances

Question: The SPSS t-Test procedure reports 2 analyses when comparing 2 independent means, one analysis with equal variances assumed and one with equal variances not assumed.  The degrees of freedom (df) when equal variances are assumed are always integer values (and equal n-2).  The df when equal variances are not assumed are non-integer (e.g., 11.467) and nowhere near n-2.  I am seeking an explanation of the logic and method used to calculate these non-integer df's.
Comment: A University of Florida PowerPoint presentation contains [a good account](http://www.stat.ufl.edu/~winner/cases/satter.ppt) of how this *approximation* to the sampling distribution of the Student t statistic is derived for the case of unequal variances.
Comment: Don't choose between them on the basis of the $p$ value. Unless you have good reason (before you even see the data) to assume equal variance, simply don't make that assumption.
Comment: That's a lot of questions. You may want to break them out into new threads, rather than have them packed into comments where they will be difficult for future searchers to find.
Comment: The questions all relate to when to use the Welch test.  This question has been posted at http://stats.stackexchange.com/questions/116610/welch-t-test-when-should-it-be-used
Comment: Is the Welch's t-test always more accurate? Is there a downside to using the Welch approach?
Comment: If the Welch and the original t-test yield dramatically different p's, which should I go with?  What if the p value for the differences in variances is only .06, but the differences in the p vales of the two t-tests are .000 and .121?  (This occurred when one group of 2 had no variance and the other group of 25 had a variance of 70,000.)
Comment: Because you are using a lower df, the Welch test will have lower power, but often not much lower.
Comment: Under what conditions would the Welch t-test have lower power?  Would it ever have higher power?  Should the Welch t-test be used whenever there is a statistically significant difference between the variances of the two groups, or only when the variances differ by a certain factor.  If so, what rule of thumb can reasonably be used for the size of that factor?
Answer: The Welch-Satterthwaite d.f. can be shown to be a scaled weighted harmonic mean of the two degrees of freedom, with weights in proportion to the corresponding standard deviations.
The original expression reads:
$$\nu_{_W} = \frac{\left(\frac{s_1^2}{n_1}+\frac{s_2^2}{n_2}\right)^2}{\frac{s_1^4}{n_1^2\nu_1}+\frac{s_2^4}{n_2^2\nu_2}}$$
Note that $r_i=s_i^2/n_i$ is the estimated variance of the $i^\text{th}$ sample mean or the square of the $i$-th standard error of the mean. Let $r=r_1/r_2$ (the ratio of the estimated variances of the sample means), so
\begin{align}
\nu_{_W} &= \frac{\left(r_1+r_2\right)^2}{\frac{r_1^2}{\nu_1}+\frac{r_2^2}{\nu_2}}  \newline
\newline
&=\frac{\left(r_1+r_2\right)^2}{r_1^2+r_2^2}\frac{r_1^2+r_2^2}{\frac{r_1^2}{\nu_1}+\frac{r_2^2}{\nu_2}}  \newline
\newline
&=\frac{\left(r+1\right)^2}{r^2+1}\frac{r_1^2+r_2^2}{\frac{r_1^2}{\nu_1}+\frac{r_2^2}{\nu_2}}
\end{align}
The first factor is $1+\text{sech}(\log(r))$, which increases from $1$ at $r=0$ to $2$ at $r=1$ and then decreases to $1$ at $r=\infty$; it's symmetric in $\log r$.
The second factor is a weighted harmonic mean:
$$H(\underline{x})=\frac{\sum_{i=1}^n w_i }{ \sum_{i=1}^n \frac{w_i}{x_i}}\,.$$
of the d.f., where $w_i=r_i^2$ are the relative weights to the two d.f.
Which is to say, when $r_1/r_2$ is very large, it converges to $\nu_1$. When $r_1/r_2$ is very close to $0$ it converges to $\nu_2$. When $r_1=r_2$ you get twice the harmonic mean of the d.f., and when $s_1^2=s_2^2$ you get the usual equal-variance t-test d.f., which is also the maximum possible value for $\nu_{_W}$ (given the sample sizes).
--
With an equal-variance t-test, if the assumptions hold, the square of the denominator is a constant times a chi-square random variate.
The square of the denominator of the Welch t-test isn't (a constant times) a chi-square; however, it's often not too bad an approximation. A relevant discussion can be found here.
A more textbook-style derivation can be found here.
Comment: Great insight about the harmonic mean, which is more appropriate than arithmetic mean for averaging ratios.
Answer: What you are referring to is the Welch-Satterthwaite correction to the degrees of freedom.  The $t$-test when the WS correction is applied is often called Welch's $t$-test.  (Incidentally, this has nothing to do with SPSS, all statistical software will be able to conduct Welch's $t$-test, they just don't usually report both side by side by default, so you wouldn't necessarily be prompted to think about the issue.)  The equation for the correction is very ugly, but can be seen on the Wikipedia page; unless you are very math savvy or a glutton for punishment, I don't recommend trying to work through it to understand the idea.  From a loose conceptual standpoint however, the idea is relatively straightforward:  the regular $t$-test assumes the variances are equal in the two groups.  If they're not, then the test should not benefit from that assumption.  Since the power of the $t$-test can be seen as a function of the residual degrees of freedom, one way to adjust for this is to 'shrink' the df somewhat.  The appropriate df must be somewhere between the full df and the df of the smaller group. (As @Glen_b notes below, it depends on the relative sizes of $s^2_1/n_1$ vs $s_2^2/n_2$; if the larger n is associated with a sufficiently smaller variance, the combined df can be lower than the larger of the two df.)  The WS correction finds the right proportion of way from the former to the latter to adjust the df.  Then the test statistic is assessed against a $t$-distribution with that df.
Comment: It depends on the relative sizes of $s_1^2/n_1$ vs $s_2^2/n_2$. If the larger $n$ is associated with a sufficiently larger variance, the combined d.f. can be lower than the larger of the two d.f. Note that the Welch t-test is only approximate, since the squared denominator is not actually a (scaled) chi-square random variate. However in practice it does quite well.
Comment: @Glen_b, I'm sure that will be of great value here.
Comment: For one t-test, SPSS reports the df as 26.608 but the n's for the two groups are 22 and 104.  Are you sure about " The appropriate df must be somewhere between the full df and the df of the larger group"?  (The standard deviations are 10.5 and 8.1 for the smaller and larger groups, respectively.)
Comment: I think I'll expand on the relationship between the relative sizes of the $(s_i^2/n_i)$ and the Welch d.f. in an answer (since it won't fit in a comment).


Company claims mistake, wants to change contract unilaterally

Question: I recently started with a large MNC. When I joined they sent me a contract which had been signed by their CEO, I signed it and returned it. A couple of weeks later my new colleagues were chatting over lunch and mentioned a particular condition which apparently applied to everyone, which I had not seen. I checked my contract and it was not there. So I queried with HR and they said they had sent me the wrong contract, they would have to send me another one to sign. Can they do this? What if I don't want the change? Is this a red flag, even if it's a relatively minor point?
Comment: Next time you find a mistake in your favour... keep quiet :-)
Comment: You can refuse to sign - the whole point of contracts is that they are entered into freely and can only be amended freely. Of course, within your probation, they can fire you for any reason. Whether they *would* very much depends on how important the term is for the company. Hiring is expensive, and firing is not done lightly.
Answer:
Can they do this?

Yes, of course. Why not ?

What if I don't want the change?

You can refuse to sign. Your employer can either accept your refusal, negotiate, or terminate you. If there is a real disadvantage in the change you can ask for reasonable compensation,  accommodation, or adjustment so that its equivalent to the original contract that you signed. In general this will not be good for your career, so you should only pick a fight if the change is important to you.

Is this a red flag, even if it's a relatively minor point?

No, at least not if it's a one-off. Paperwork mistakes are (unfortunately) fairly common. Often, the people who process the paperwork don't understand the document but are just handling the "administrative side" of it.
Comment: True; I guess the OP is in a bind if it's not significant enough to fight over *now* at risk of being fired,  but might have made different choices *at the time of first signing* (eg. when holding a rival job offer).
Comment: Termination for refusing to sign an unilateral change to a contract? That wouldn't be legal in some (civilized) parts of the world. Check whether this is true where you live.
Comment: @Jeffrey:  Unless they are extremely stupid they wouldn't phase it as "we'll fire you because you didn't sign the contract", although in the US that would actually be perfectly legal (for at-will employment). But there are always ways to manage an undesired employee out the door, unless the employee is in a strongly protected class
Comment: @Jeffrey, I had this about 20 years ago, when the European Working Time Directive was introduced here (in the UK). A senior manager went round with a waiver to be signed by everyone, and stood over them while they signed it. There were no employee copies and they refused to allow their copies out of the building (eg for review by legal advisor). 6 weeks later, anyone who didn't sign was gone - for a miscellany of unrelated reasons. There were other examples of similar unilateral changes (e.g. "we're cancelling all unused or accrued vacation, unless you respond within 7 days").
Answer: HR apparently keep a version of the contract without this clause. They wouldn't do that if it truly applied to everyone.
You know your situation better than us, but I would push back a little (at least until the first hint of resistance) to see what gives.


How to keep the internet speed on a busy network constant

Question: I am using college internet. It is shared to the whole college. My problem is that i can't even browse at sometimes because the network become too busy. But I noticed something that if I download something in IDM or axel in Ubuntu it works. When I download, I can browse also. It feels like when I start a download other applications can communicate through the busy network. Is there any way to keep the connection speed constant. without a download.
Answer: By the way that standard network communication works, without QOS or similar technologies, nothing is guaranteed and it is simply down to best effort.
As for why you are seeing what you are seeing, there is no single rule and it depends on the networking equipment you use, but basically, when under load, the majority of networking equipment simply only delivers a few percentage of the total amount of traffic it should do - whilst UDP connections (voice/skype/other) will suffer, through the magic of TCP, it will keep resending and you will get the data in the end - you just see a lot of lag.
By hammering the connection, your machine will be sending a lot more packets and will get a lot more back - e.g. 2% of 1,000,000 packets is a lot more than 2% of 500 packets... (just non technical/random example).... which is why a download manager such as IDM which specifically opens multiple connections can give you higher speeds.
In addition, as for why other stuff appears to be faster - all I can think of is that the equipment they are using prioritises traffic based on where the most connections already are.
Answer: I've seen this with wireless networks sometimes, where leaving ping or arping running can help keep the connection stable.  It can also be useful because you can switch to it and see if there's a problem - high latency or dropped packets.  That might be a less abusive way to get the same effect as a running download.
Are you connected by wireless or by wires?
If you haven't already, you could mention this to your technical support.  They won't necessarily know about everything that happens automatically.  Especially if it's only a problem at very busy times.
If you have an ssh service, it should affect that much worse than web browsing.  (Some universities offer ssh shell access as an optional service to all students).  That might be something useful to point out, or to use as a demonstration of the problem.
Answer: I suggest you to read Linux Advanced Routing and Traffic Control. It exactly solved your question.
The problem you saw is caused by some applications (particularly P2P software) uploads a lot. All Internet traffic, like HTTP, will send something outside your internal network. At least, ACK packets have to be sent to confirm your computer has already received the packets sent by remote server. And those applications will block your upload link and delay the packet you sent to external network.
Also, downloading software will generate a lot of ACK packets, this also block your upload link.
So there is two ways to solve your problem:

Ask others in your network to lower their applications upload speed
Use some firewall to resort the upload traffic in your network and put small packets first

LARTC has already publish some scripts to achieve this. You can try to install them on your gateway.
BTW: Maybe you need to buy a router which run a Linux operating system. If you can access some Chinese shopping websites, try to get a DB-120. Very cheap and efficient.


Word for recursion in footnotes?

Question: There is what I believe to be a literary device that describes recursion, particularly in footnotes. For example, a footnote of a footnote. You can also have a footnote, that is the footnote of a footnote, and it can go as deep as you want it to. This would be known as ____ in literature. Recursion is taking place, but it's not the word I'm looking for. I believe I discovered this effect when looking at a list of literary devices but my Chrome history just isn't helping me find it again!
Comment: It would be known as extremely poor taste and useless annoyance to the reader in the literature, I'd say.
Comment: What you describe is not recursion. It is simply nesting. It would be recursive if one of the footnotes referred to a footnote that in turn (directly or indirectly) referenced it. Recursion is essentially self-reference, one way or another.
Comment: For the use of recursive footnotes (I can't think of another word) in fiction, see David Foster Wallace's footnotes to _Infinite Jest_. They're endnotes, though, rather than footnotes.
Comment: More on the use of footnotes and endnotes (especially in literature): http://lithub.com/the-fine-art-of-the-footnote/
Comment: To extend Drew's point, there are two types of recursion: (1) A footnote that refers to itself (2) A footnote that refers to a second footnote that refers to the first footnote. If each footnote always refers to a **different** footnote (never the same), then it is not recursion.
Answer:
There is what I believe to be a literary device that describes recursion

Mise en abyme is originally a heraldic term for a coat of arms put in the centre (en abyme) of another coat of arms. In terms of literature it is used of a story or related incident that is relayed as part of another story, and reflects that larger story (the play Hamlet has produced in Hamlet is perhaps the most frequently cited case). Some examples go so far as to have a mise en abyme within a mise en abyme, possibly even truly recursive in that it goes back on itself (e.g Gaiman's comic-book story Worlds' End is a story about a group of travellers in an inn "at the end of the world" telling stories, which give insight into the wider series that Worlds' End was part of. One of those stories involves a night where a teacher is telling pupils stories, including one about travellers in an inn "at the end of the world" telling stories).
Mise en abyme is also used in terms of other artforms, and the visual arts more readily allow for the perception that there are indeed infinite recursive mise en abyme within the picture. Literature can hint at that (as per the Gaiman story I mentioned above) but not as easily. This is sometimes called the Droste effect after Droste cacao which came in a tin with a picture of someone holding a tin of Droste cacoa, with a picture of someone holding a tin of Droste cacoa, and so on.

For example, a footnote of a footnote. You can also have a footnote, that is the footnote of a footnote, and it can go as deep as you want it to.

That's a nested footnote. To be recursive it would have to relate directly to itself1, or follow a circular path2, and that we would just call that recursive footnotes or circular footnotes. It's not a very common technique so not as widely used as mise en abyme though it can of course overlap with mise en abyme or for that matter so can just the use of footnotes at all; some of Pratchett's footnotes in his comic Discworld series can be considered as very brief mise en abyme in how they relate to the wider story.

See footnote 1.
This would require a lot of footnotes4
Footnotes being rare in literary use generally5, we might consider just about any use of footnotes in fiction to be "a lot".
Of course a lot is relative3.
Though some authors make heavy use such as David Foster Wallace using footnotes6 allowing for a straight read but also a reading approach that forces a lot of back-and-forth between different frames2, and Susanna Clarke using them to give an impression of the work being a non-fictional account.
Strictly speaking, Wallace used endnotes, not footnotes in his most famous work.
Comment: I could imagine Terry Pratchett doing something like this

Word for recursion in footnotes?


Permutation Question of Dihedral Group Order

Question: Let $n \ge 3$. Number the vertices of a regular n-gon by the numbers $1,2,...,n$. Each symmetry of the n-gon corresponds to a permutation of its vertices and hence to an element of $S_n$. The subgroup of $S_n$ of symmetries of the n-gon is the subgroup generated by the rotation $\sigma = (1,2,3...n)$ and the reflection $p= (1n)(2n-1)(3n-2)...$ is denoted by $D_n$. I need to show that $|D_n|=2n$ and list the elements. So i know that $n$ has rotational symmetries and $n$ reflection symmetries. So $<x,a | a^n = x^2 =1, xax^-1 = a^-1>$. I dont know where to go from here. I also need to show that $D_6$ is isomorphic to $<R^2, U^2>_G$.
Answer: We can show $D_{n}$ has $2n$ elements as follows.  You already know $D_n$ contains $n$ rotations (generated by $\sigma$) and $n$ reflections (including $p$) and hence at least $2n$ elements.  If an element of the symmetry group $D_n$ maps vertex 1 to vertex $i$, then it must map vertex 2 to a vertex adjacent to $i$, i.e. to either $i-1$ or $i+1$.  Once the map for vertex 2 is determined, the map for all the other remaining vertices is automatically determined, for eg, if 2 was mapped to $i-1$, then 3 must be mapped to $i-2$ (because 3 must be mapped to a vertex adjacent to $i-1$, i.e. to $i$ or $i-2$, but $i$ is already the image of vertex 1).  Thus, the total number of symmetries in $D_n$ is $n$ (the number of ways to map vertex 1) times 2 (the number of ways to map the vertex 2), i.e $2n$.
In general, one way to show there are no others symmetries is to use the Orbit-Stabilizer Lemma, which states that the size of a symmetry group $G \le S_n$ equals the number of elements in the stabilizer subgroup $G_x$ times the size of the orbit of $x$ under the action of $G$, in short $|G|=|G_x| ~|x^G|$. In the case above, the number of symmetries that fix the vertex 1 is 2, i.e. $|G_1|=2$, and $G$ takes 1 to every other vertex, whence the orbit of 1 is the set of all $n$ vertices, so $|1^G|=n$. Thus, $|G|=2n$ by the orbit-stabilizer lemma.
The elements of $D_n$ can be listed in the form $\{p^i \sigma^j: i=0,1, j=0,1,\ldots,n-1\}$.


Appium mobile tests - providing an apk in maven compiled project classes location

Question: I'm using appium/java/maven for some automated tests for an app. Currently I'm just grabbing the apk location via absolute path in my project:
cap.setCapability(MobileCapabilityType.APP, "D:\\abs\\path\\src\\main\\resources\\testapp.apk");

This works locally, but I need to be able to execute this a different machine (via mvn commands), so this won't work. I read online to grab the apk file from compiled class folder (target/classes/testapp.apk), which I did below:
ClassLoader classLoader = getClass().getClassLoader();
File apkFile = new File(classLoader.getResource("testapp.apk").getFile());

But when I run I get an error:
org.openqa.selenium.json.JsonException: Unable to determine type from: D. Last 41 characters read: {
  "desiredCapabilities": {
    "app": D

Error seems to me like it has part of the path (my local drive for this is D) but something is wrong with the full path.
Anyone have any ideas here? Am I mising something? Or is there a better approach for this?
Thanks!
Answer: you may consider using src/test/resources/ location, create a folder apps and save your apk there. it must work, also change location in capabilities.


Is there a jailbreak for iOS 4.2

Question: I want to jail break my 3Gs running 4.2.1.
Possible?
Answer: There is a howto in redmondpie.com for jailbreaking the iPhone 3GS with iOS 4.2.1, but it appears there is no unlock yet.
http://www.redmondpie.com/jailbreak-ios-4.2.1-iphone-4-3gs-3g-ipad-ipod-touch-with-redsn0w-0.9.6b4-guide/
Answer: YES! I have it currently on my iPhone 4. It's untethered for last-gen devices, but for the iPhone 4 it's a tethered jailbreak, which means that you'll have to connect it to your computer and use the program (redsn0w) to turn on the phone every time the phone gets turned off or looses power.
If you don't turn off your phone a lot, then it's not big issue, though. And because you have a 3GS, you'll be untethered anyway.
The jailbreak is at http://blog.iphone-dev.org which is the iPhone Dev Team, the MOST reputable source for iPhone jailbreaking. These are the actual people who do the work (or compile it from Geohot). DO NOT trust any info from places like BigBoss, RedmondPie, UltraPWN, or anyone else.
Comment: The link you provided is dead.  Do you have an updated one?
Comment: @AngryHacker Yeah sorry it was .org instead of .com. I already updated the post.
Comment: iphone dev team is the most reputable source for jailbreaking indeed. but it's also one of the most confusing ones for reading. and being on 3GS doesn't mean it will be untethered.
Comment: @Cawas The Redsn0w program uses Geohot's limera1n exploit to jailbreak it. On all last-gen hardware it should jailbreak it untethered, and it's only on the iPad, iPod Touch 4G, and iPhone 4 that will be tethered because of an upgraded BOOTROM. You are, though technically right, because a handfull of newer 3GS's are only capable of a tethered jailbreak.
Answer: It is possible and it includes unlock. All you need is a simple tutorial, Redsn0w and the correspondent firmware. Unless of course you prefer to go the "official" way. I did it with iPhone 3G and the first tutorial.
The 3Gs got is the only device that marks the bootrom change. Basically all "i devices" are only able to get a (bad) tethered jailbreak if they're launched after a given point. Here's a long guide with steps on how to check your bootrom to see if you're lucky or not. I'll summarize it for both mac and PC:

Put your iPhone in DFU mode (not recovery mode):

Connect your iPhone to your computer.
Turn iPhone off.
Start iTunes.
Hold Power and Home buttons together for 10 seconds or so.
Release Power button but keep holding the Home button until your computer recognizes a new USB device.
iTunes will now recognize your iPhone.

Note: Your iPhone screen at this time should be blank (black in color), if not, then you are most likely in Recovery Mode, not DFU mode.

Locate the value [iBoot-359.3] or something alike under System Profiler (mac) or Device Manager (win). Keywords are: USB and Apple Mobile Device (DFU Mode).
If the value after iBoot is 359.3 or lower, that's the old bootrom. Yippie!
If it's 359.3.2 or higher, tough luck you're stuck with new bootrom and lame tethered jailbreak.

Is there a jailbreak for iOS 4.2


Xcode 5 does not display assembly for arm64

Question: Xcode 5 does not appear to build assembly output for 64-bit arm iOS Device.
I have created a simple iOS Empty project.
Then, in the Build Settings, set the VALID_ARCH to arm64, and set ARCH to Standard architectures (including 64-bit).
Finally, displaying main.m in the editor window, then requested Assembly output with menu Product->Perform Action->Assemble "main.m".
Instead of an assembly for main.m, the window displays "Unable to figure out how to generate assembly for main.m".
I have tried this with both Xcode 5.0 and 5.0.1.  Assembly output does work when VALID_ARCH is armv7 armv7s (the 32-bit code is correctly displayed.) Also, I have been able to cut the working arm7 assembly command line from the Log Navigator, change the -arch armv7 to -arch arm64, and paste into Terminal, with the correct 64-bit assembly output file, main.s, produced.
BTW, the Log Navigator shows several lines for 32-bit arm (including Compile main.m with the -S option), but for arm64, the Log Navigator shows only "Build succeeded"; this makes me think the xcodebuild rule is missing, or Xcode is not producing the xcodebuild command line.
So, has anyone else tried to display assembly output for arm64, and if so, has anyone found a way to accomplish the output within Xcode IDE?  Or, is it time for a radar?  Thanks!
Answer: Have you tried using the Assistant Editor display and look at the "Disassembly" option. This gives me the output for ARMv8. There is an option to look at the Assembly as well.


Does anybody know what this mini vise-like tool is?

Question: Found this mini vise-like tool in the deep recesses of my toolbox. I'm sure my son picked it up from somewhere (he's always buying strange tools) but he can't remember what it's used it for.  It is about 2.5" x 3" and has "79168 K8" imprinted on it, but I couldn't find anything via google.
Comment: Looks like a bicycle chain pin remover/inserter.
Comment: the chain rivet (where it swivels) is placed under the tools pin (below the threaded handle). The chain is secured in tool by the stub-outs on either side of the pin so when pin is extended to push rivet out the chain link is supported and doesn't bend.
Answer: It's a Wrench Force Mini Chain Tool. You rivet and break bike chains with it.
Comment: I'm going to guess the PIN is missing from it, as the pushing shaft looks WAY bigger than any bicycle chain pin... There is likely a threaded hole in the end of the shaft?
Comment: @markf good point.  It might be a chainbreaker for a motorcycle, but given the amount of thread visible, there is not enough thread to push a pin out of a chain.
Comment: Visible thread isn't a good indicator. The tool can obviously be reversed to retract the pin through the entire jaw width.