E349: No identifier Under Cursor

Question: Every time I switch back to vim window, it shows the list, if current cursor on an empty line, it shows error: E349: No identifier Under Cursor.
Comment: when switch back to vim, the current file's content open in the below buffer window, and acted like command 'less', can use hjkl move the cursor.
Comment: I get this issue too. It's maddening. I commented out the entire .vimrc, but it still happens.
Answer: The only workaround for this problem that I've discovered so far was to run tmux and then run vim inside one of tmux's panes.
Answer: According to https://unix.stackexchange.com/a/480138 ,
it is the FocusIn/FocusOut mode that can be disabled with:
echo -ne '\e[?1004l'

I encountered this problem when I would lose an ssh connection, so tmux on the remote server that enabled FocusIn/FocusOut mode would not be able to disable it. If I opened a vim on my local machine, vim would receive those events. If the FocusIn/FocusOut mode is not the default for your terminal, you can also disable it with:
reset

Comment: Met the similar problems on OSX and this solves it! Thanks! Not sure which program changes the terminal model.
Answer:
That list looks a lot like the output of :ilist! Plugin or [I with the cursor on Plugin or ]I with the cursor on the first Plugin. See if you don't have that somewhere in your vimrc (that you should append to your question, by the way).
The error message is likely caused by :help gd or :help gD.
Comment: thanks for your answer and the jpg, but I think it's not caused by gd, no matter where, which file my cursor at, when re-focused, vim shows file content in this way:(, maybe I should comment the plugin one by one, and see if I'm lucky!
Answer: It caused by the wincent/terminus plugin.
Fixed
Append let g:TerminusFocusReporting=0 to .vimrc
Comment: No, this solution doesn't work. You are right, it is absolutely outrageous and it only started happening today, but looking at the /var/log/apt/history* I can see that vim-common was upgraded ages ago (on 26th April 2018), so some other package is causing this.
Answer: Alt-tabbing into Terminal sends a ^] command to VIM. To ignore that command, put
nnoremap ^] <Nop>

in your .vimrc file
Comment: This solution doesn't work either, unfortunately. I.e. when I switch to the terminal tab where vim is running I get the list of strange items (like "map = ...") and when I move the focus away from that tab (or the whole terminal) then the list disappears. And it re-appears when I bring the focus back. I need to find out what is causing it asap because otherwise it is absolutely impossible to do any work...
Answer: I had to fix by removing the line set ttymouse= from my .vimrc.
You may need to set ttymouse to an appropriate value, see :h ttymouse.
Answer: I appeared in the 3.12 version of iterm2, and now it disappears after upgrading to 3.15

E349: No identifier Under Cursor


qfield will not highlight selected feature

Question: When selecting a feature in qfield it will not highlight the way it did in past versions. I do not know why this is happening. Was this taken out from the past update?
Answer: According to Denis Rouzaud, this will be fixed in the next update. You can check it out in this APK.
"""
This has been fixed and will be available in upcoming 1.0.4 (still this week).
If you have the chance to test the APK it would be very helpful, see the link here (usually you need armv7 builds)
https://github.com/opengisch/QField/commit/0d19e80fd1d85764480329b6334fbb05bc662fe3#commitcomment-33180529
Cheers,
Denis
"""


Can I be charge with burglary of habitation for giving someone a ride?

Question: I recently gave smy friend a ride to his uncles house and he ended up stealing. They trying to charge me for it because my friend is saying I helped him but I only gave him a ride.I live in Texas.
Comment: You need an actual lawyer.  This site does not provide personalized legal advice, and it would be unwise to rely on random internet advice when actual criminal charges are at stake.
Comment: No one "tries to charge you" for something.  They either do or do not.
Comment: @TigerGuy I suppose an exceptionally incompetent cop could try and fail to charge a suspect by misfiling the relevant paperwork, but the bar to charges is sufficiently low so that we can assume that the police tried to press charges against OP and were successful.  OP is charged with a serious crime.
Comment: Is this a real question or satire on the recent Texas abortion law?
Answer: It all depends on whether you knew (or should have known) beforehand that your friend was going to commit a crime.
But more importantly, if you think you are likely to be charged with a crime (rightly or wrongly), you really should get legal advice, not opinions from the Internet.
Answer: You "can" be charged as an accessory before the fact, if the evidence shows that you know of the intention to break into the house. This is covered in Texas Penal Code Ch. 7. Driving the getaway car is also a crime, so it really depends on what you knew. See especially §7.02:
(a)  A person is criminally responsible for an offense committed by the conduct of another if:

(1)  acting with the kind of culpability required for the offense, he
causes or aids an innocent or nonresponsible person to engage in
conduct prohibited by the definition of the offense;
(2)  acting with intent to promote or assist the commission of the
offense, he solicits, encourages, directs, aids, or attempts to aid
the other person to commit the offense;  or
(3)  having a legal duty to prevent commission of the offense and
acting with intent to promote or assist its commission, he fails to
make a reasonable effort to prevent commission of the offense.
(b)  If, in the attempt to carry out a conspiracy to commit one
felony, another felony is committed by one of the conspirators, all
conspirators are guilty of the felony actually committed, though
having no intent to commit it, if the offense was committed in
furtherance of the unlawful purpose and was one that should have been
anticipated as a result of the carrying out of the conspiracy.


Using an Apartment's Recycling Bin

Question: An individual drives into an apartment complex, of which they do not reside, and adds an item to the recycling bin. This occurance is hypothetically during COVID-19, during Washington's "Stay Home, Stay Healthy, Stay Safe". Are there legal grounds to punish?
Comment: Are you only interested in violations specific to covid-19 orders? Because a lot of places have laws where using someone else's trash/recycling bins without permission is itself a crime (illegal dumping), independent of pandemics.
Comment: I am interested in the proposed violation as a whole. COVID-19 orders makes it more interesting.
Comment: What would be your evidence of harm?  Is there "No Trespassing" notice on the property?  Are you aware that their activities are not on the list of allowed activities?
Comment: For this question, say there are no noticies of "No Trespassing". I don't think those are common in these type of properties.

What do you mean by "their activities"?
Answer: Punishment is probably not possible, though there are so many recycling schemes in the state and the law changes in three waves this summer: it depends on where this recycling comes from. As described, it does not constitute "dumping". The lockdown does not contribute anything (it is not a punishable offense to be outside or to put stuff in a recycling bin). State trespass law does not clearly apply, since it requires knowingly entering upon premises (still, a prosecutor might creatively argue that it is). There might be local ordinance.
The owner of the complex could sue the errant recycler for damages, depending on what harm was done. In a worst-case scenario, the substance could be something illegal to recycle and the owner could be fined, so the owner could sue to recover for his loss. Since most recycling schemes don't restrict you to just what fits in the bin, the "used up our space" argument doesn't work, but there is a small chance that addition of legally-recyclable material could make other material not recyclable on this run. (Civil liability is about compensating a person for the damage that you did, whereas punishment is about the government meting out a statutorily specified consequence for committing a crime; being required to pay damages is not a punishment).

Using an Apartment's Recycling Bin


Why do people say a larger object exerts a larger gravitational pull?

Question: By Newton's third law of motion there will be equal and opposite forces of gravity exerted on two objects despite their masses. Hence why does a larger objects exert a larger gravitational pull? In other words why does force of gravity increase with mass?
Comment: "Why do people say a larger object exerts a larger gravitational pull?" I guess by "larger" they mean "more massive." Anyways, in that case they say it because it is true. Consider a test mass of mass $m$ placed one meter away from a **big** mass $M$ versus the same test mass of mass $m$ placed one meter away from a **small** mass $\mu$. In the former case the force felt by the test mass is **big**: $G M m$. In the latter case the force felt by the test mass is **small**: $G \mu m$.
Comment: @Kuhlambo if I were to hear someone say "the gravitational pull of Jupiter is much larger than that of Earth", I'd assume that to mean that the gravitational force due to Jupiter on some *third* object is higher than that due to Earth, *not* that the force of gravity exerted on Earth by Jupiter is larger than that exerted on Jupiter by Earth.
Comment: If by "larger" they mean massive, then you are right by Netwon's third law the force is the same. However, what is meant by "pull" here might not be the force but how they perceive the resulting acceleration, the acceleration would be greater on a smaller mass than on a larger mass.
Comment: How is it that this question needs to be "more focused", please? I see many reasons for at least re-wording, if not discarding it but how does "focus" come into it, anyone?
Comment: Also consider the accelerations. https://physics.stackexchange.com/q/454332/123208 & https://physics.stackexchange.com/q/3534/123208
Comment: @Kuhlambo We often talk about forces by considering a fixed test mass or a fixed test charge. For a fixed test mass, that mass feels a larger force due to a more massive second body. For a fixed test charge, that charge feels a larger force due to a more highly charged second body. What is so hard to understand about that?
Comment: Yes the force is proportional to the product of masses. Yes, Newton's third law still holds. So what? I'm talking about the fixed test mass that is put into a variety of situations and the force that that fixed test mass feels.
Comment: @Kuhlambo no problem
Answer: It is just a small semantic confusion.
Newton's third law tells that the two forces below are equal regardless the masses:

Notice that the two forces are acting on different bodies.
When we say "larger objects exert a larger gravitational pull" we compare them acting on an identical third object.

(opposing forces still there, but not shown)
Answer: The gravitational pull is proportional to both masses: $$F =\frac{G m_1 m_2}{ r^2}$$ So if you increase either $m_1$ or $m_2$ while keeping the other constant then the force will increase.

there will be equal and opposite forces of gravity exerted on two objects

That would correspond to swapping $m_1$ and $m_2$. That would effectively increase the mass of one and decrease the other. So you cannot consider a swap to be just an increase in mass.
Answer: There are two different ways of describing gravitation involved here.   One is the two-body problem,
where there is a force being determined.
The other, is a 'gravitational field' picture, which identifies a single body's gravity contribution in the surrounding space, independent of the presence
of other masses.
The gravity field around a large body (Earth)
is greater in magnitude (because it is proportional to the mass of Earth) than the
gravity field around a cat (which is proportional to the lesser mass of the cat).
For practical purposes, like standing upright, we need to accomodate the Earth's gravity but not the cat's.   So, we
identify the Earth's gravity as the larger
influence.
As is the way with felines, the cat will also ignore the gravity due to humans.
Comment: +1 for cats ignoring people.
Answer:
By Newton's third law of motion there will be equal and opposite forces of gravity exerted on two objects despite their masses. Hence why does a more massive object exert a larger gravitational pull?

First the first part, you are correct $ {\vec {F}}_{{A\to B}}=-{\vec {F}}_{{B\to A}}$ should always hold, or we a are in trouble.
Let's say you just let an apple ($m$) fall and look at the forces between apple and earth ($M$).
Let's say, away from earth ("up") is the positive direction, so force on earth by the apple is:
$$F_{{a\to e}}=\frac{G m M}{ r^2}$$
And force on the apple by earth is
$$F_ {{e\to a}} =-\frac{G m M}{ r^2}$$
right?
So, you are right opposite and equal forces apply.
So the other part of the question is also answered, a more massive object like earth doesn't pull more on the apple, than the apple does on the earth, it's actually equal and opposite.
But why doesn't earth rush towards the apple, like the apple does towards it, you ask?
Well, you know Newton's laws so apply the 2nd one here. Calculate the acceleration for each individually and see why one would be much much bigger.
(hint: it's really easy to see, you don't need a calculator, just use the fact that the earth is about $10^{25} $ times heavier... but you can of course ask for help...)
And a bonus question: What would happen if the earth was actually pulling the apple more than the other way around?
Comment: +1 for mentioning equal forces but non equal accelerations, which is what I think OP was the root of the confusion.
Answer: Presumably because of approximation, a body with much larger mass may not appear to move, for example in the case of your mass acting on Earth's.
Answer: Consider the force between two cannonballs.
Now add another cannonball beside the first one. That doubles the amount of force on the third cannonball, because both of the first two are acting on it.
Add a third cannonball beside the first one. Three sets of interactions each like what you got when there was only one.
When there's more mass there's more force. There's always that equal and opposite reaction, but it adds up to more.
Incidentally, imagine that gravity doesn't act instantly but only at lightspeed. Then by the time the force from right now arrives at the other weight, the other weight might have moved. The distance and direction could be different. So maybe it isn't an equal and opposite reaction after all?


Terraria: I lost my data / weapons and tools when I cloud saved

Question: When I was going to my cloud save world this message popped up if I wanted to change it to local save I picked cloud save and it deleted two traps a chest with 3 stacks of pumpkin moon medallions and a godly drax an artificial tree and a couple of banners. How can I get my data back?
thanks for your help
Answer: The latest patch notes for 184.108.40.206 recommend not saving the world to the cloud as there are currently issues with the cloud save functionality for worlds that may result in data loss.  It sounds like you hit one of these issues. The game creators mentioned that you most likely wont be able to restore any of the data and to switch to local world saves instead to prevent any further data loss/corruption along with making backup copies of your worlds while they look into the saving issues.


Popcorn with truffle oil/salt

Question: I bought (and ate) popcorn made with truffle oil and truffle salt.  I noticed one kernel had a small, moldy spot on it and I tossed it aside and continued eating because the rest of the popcorn looked fine.  As I was eating I did notice two other kernels with the same, small, dark green spots but finished the bag anyway! Now I'm worried that I ate something that is going to make me seriously ill - spores or...????  I don't know what I was thinking!!!!  Should I have thrown the bag out?  Really worried.
Answer: Most molds are harmless, especially if you heated it properly which you should have had done when you popped the kernels. Don't worry and relax first of all. If you do feel sick or if it would put you at ease then go see a medical professional and explain what happened. But overall you should be fine.
P.S. Oils like truffle oil lose their scent, aroma and overall taste when heated too high so most things like truffle popcorn go to waste; just get truffle oil and add it to popped popcorn. Be sure to see that the oil is mainly truffle. (most truffle oils have lots of additives.)
If you meant pre-popped...
Again, most molds are fine and it's good that you threw away any odd bits.

Popcorn with truffle oil/salt


How to use an Xbox one controller with an android device?

Question: While connecting an Xbox one controller to a Windows PC via USB works fine after downloading the respective driver, I was wondering how to use it on an android device via USB OTG, or to an OUYA.
Answer: With Android 4.0 or higher and a wired controller it's just a Plug&Play via the USB OTG.
However there are games/mobile phone which aren't compatible for USB OTG.

To find out whether your mobile phone is, just google your mobile phone and add OTG.
To find out whether a game is compatible there is an app from NVIDIA (should be installable for any android device 4.0+) which checks the compatibility.
Answer: It is possible to use the controller via USB OTG, but your device MUST be rooted and it may be difficult.
First of all check your X1 controller DeviceId, on Windows you can do it through Device Manager:
Device Manager -> Xbox Controller -> Properties -> Details -> Hardware Ids
VID should be 0x45e
PID will be either 0x2d1 or 0x2dd
Easy method for older controllers (0x2d1)

If you are running a ROM based on Linux kernel 3.18, then the controller will work out of the box! So you might want to flash a new ROM/Kernel if it's very important to you... This is probably the easiest solution.
Otherwise, You can probably make the controller work with the "USBBT Joystick Center GOLD" application which you can get here.
Just follow this Youtube video and it SHOULD work if you're lucky :)

Hard method for newer controllers (0x2dd)
If the above didn't work or you have the new controller, and you're not shy about recompiling the Android kernel, you can:
A. Download the Android kernel sources for you device (see instructions h-ttps://source.android.com/source/building-kernels.html)
B. In the kernel sources, replace the file xpad.c under /drivers/input/joystick/ with the newest sources from here: h-ttps://github.com/paroj/xpad
C. Rebuild the whole kernel and replace your boot image, or just build xpad as a kernel module and load it using insmod from the adb shell
GOOD LUCK!


Is it possible to spoof the mac address of a wireless adapter so that windows sees the spoofed mac as the physical?

Question: I know that its possible to spoof a mac address out to a network. But is it possible to spoof the address, so that the Windows operating system and applications running on Windows see a spoofed address as the physical address for the network card?
Answer: Partially, yes. Windows OS (eg. using ipconfig command) sees the spoofed MAC address as the permanent MAC address.
However you can NOT say all of the applications running on Windows will see the spoofed one as the permanent one. Applications might be using some ways to acquire the permanent (burned-in) MAC address of the adapter. (For instance they might be using DeviceIoControl with OID_802_3_PERMANENT_ADDRESS option.) So some applications are harder to be fooled.
Comment: Yes, but application can also check if it is running on VM or not and deny if it is a VM.
Comment: That is not the question that was asked and that's actually a whole different subject.
Comment: Actually, you could fully spoof the MAC address for all applications by running the system in a VM instead of running it on metal.
Comment: My only issue with fully spoofing the mac in a VM is that I need to spoof the mac for a physical and specific type of adapter. Not just a generic virtual adapter, and I don't know if that is possible.


How long should I wait before watering my beheaded echeveria stem?

Question: I recently (yesterday) beheaded an echeveria plant that had grown leggy. The leafy upper part is currently set aside, forming a callous and (hopefully) roots. I can find plenty of information about how to replant and when to start watering that part of the plant, but if I want to give the beheaded stem a chance to form new blooms, how should I care for it? Should it be on essentially the same watering schedule that the plant was on before beheading?
Answer: Getting growth from a stump is not assured, even if you do everything right (I assume the base has no leaves. If it does, just treat it normally and it'll be fine). I hope it was actively growing before you cut it
If it's outside, I'd put it in an area with less harsh, filtered light. If it's inside, I'd just do normal culture. As for water, just water it normally. The soil should dry out between waterings


In what direction does D.VA eject from her Mecha?

Question: I can't seem to ever predict where D.VA is going to go when she ejects from a dying Mechasuit. Is it player controlled, or is there a predetermined direction that she can go?
Answer: She ejects out the back of it, so she's left standing directly behind where the mech died.  The reason you can't predict where she's going to go is that as soon as she's ejected out the back, she has a moment of invulnerability where she is free to move and dodge attacks.  This is to prevent players from immediately one shotting her as soon as she pops out the back of the mech.
Comment: The eject itself is not player controlled, but because she can start moving almost immediately after the eject it might look player controlled
Comment: She does have control over where she goes.  Once she pops out the back, she has a moment of invulnerability and can start moving.  But if she didn't move, she would be directly behind the mech
Comment: Your question is "What direction does D.Va eject from" and I feel like I answered that.  If your real question is "Why can't I hit D.Va when she ejects" then you should edit the title
Comment: And she has no control over which direction she goes? I distinctly remember there are times when she is to the left or right of her dead Mecha.
Comment: Then the answer isn't exactly "standing directly behind where the mech died"...
Comment: If you read the entire question, I go on to ask "is it player controlled", which you hadn't answered before your edit. Thanks.
Answer: According to these two sites, Icy Veins and Furious Paul, players can control the direction of ejection by using the movement keys.  The default direction is backwards.
This matches with my own experiences.
Answer: From Furious Paul's D.Va Overwatch guide:

Steer D.va's Ejection
When your mech gets destroyed, you can hold down the direction you want D.va to eject out at and she will jump out that direction.  This means you can hold your strafe, forward, and backward keys down while getting ejected and she will pop out that direction.  By default, if you don't press any movement keys, D.va will eject backwards away from her mech.

I play a lot of D.Va and can confirm that I try to eject in the direction that will put the mech in between me and enemies and/or get me closest to cover.


Pomodoro Software for OSX?

Question: I have recently been using the Pomodoro Technique to help me accomplish tasks. I currently do it using timer on my phone. I was wondering if there is any software that runs on OSX Lion that can place a Pomodoro countdown clock in the task bar and possibly provide other features related to the Pomodoro technique.
Comment: http://osx.iusethis.com/search?q=pomodoro
Answer: I went with the highest rated option there which is called Pomodoro. It's open source, so I compiled from source. So far it seems to be what I wanted. It has nifty integration with lots of other software and I can see myself using that functionality in the future.
Answer: A simple pomodoro timer can be implemented with a few lines of code. The advantage is that you don't need to install any third-party software and you can customize it as you imagine.
Here is a simple script link.
Download the pomodoro.sh file from the above link and execute the following to run it:
$ bash pomodoro.sh
It will give you 25-minute sections for your tasks and 5-minutes of breaks in between. Though you can change the time as you like in the script.
I can help you customize if you want. Hope it help.

Pomodoro Software for OSX?


Where to find pre-trained models for transfer learning

Question: I am new to the machine learning field, but I wanted to try and implement a simple classification algorithm with Keras. Unfortunately, I have a very small set of data, so I thought to try to apply transfer learning to the problem; however, I couldn't find anything on this online, so I wanted to understand which are the best places to look for a pre-trained neural network. Do you have any suggestion in this regard? Which website is best for getting an idea on how to start a machine learning project?
Answer: Keras itself provides some of the successful image processing neural networks pretrained on the ImageNet: https://keras.io/applications/
Other deep learning libraries also offer some pretrained models, notably:

TensorFlow: https://github.com/tensorflow/models
caffe: https://github.com/BVLC/caffe/wiki/Model-Zoo
caffe2: https://github.com/caffe2/caffe2/wiki/Model-Zoo
pytorch: https://github.com/Cadene/pretrained-models.pytorch
Lasagne: https://github.com/Lasagne/Recipes

Many pretrained models for various platforms can also be found at https://www.gradientzoo.com.
Moreover, if you are interested in some particular network architecture, authors sometimes provide pretrained models themselves, e.g. ResNeXt.
Answer: Since the question title is generic (and not specific to computer vision), I will give the NLP-related answer as well, in case it helps someone who stumbles upon looking for pretrained vector embeddings:
The two most popular pre-trained vector embeddings can be found on these links:

GloVe- https://nlp.stanford.edu/projects/glove/
Tensorflow Embeddings - https://code.google.com/archive/p/word2vec/

There are also a couple of less popular and/or more recent ones:

LexVec - https://github.com/alexandres/lexvec
FastText - https://github.com/icoxfog417/fastTextJapaneseTutorial
Meta-Embeddings - http://cistern.cis.lmu.de/meta-emb/
Comment: Do you think I should edit the title? Also, I am actually looking for a pre-trained texture classification model, but reckoning such a question to be too specific, I thought a general idea on where people look for pre-trained models would have been a good starting point
Comment: As it stands, it is a general question, so assuming there aren't others like this on the website, this may be a useful source for everyone. However, I don't think someone with the answer to the specific question you have in mind will be drawn to this just from the title.


Non-Thesis Masters

Question: I am completing my masters in chemical engineering. I have completed my first two semesters but was unable to find a research thesis topic to work upon. Will it be bad to complete my masters degree without a thesis, if I don't get a better option?
Comment: Related: http://academia.stackexchange.com/questions/1165/planning-to-do-phd-masters-thesis-important-usa, http://academia.stackexchange.com/questions/8288/how-do-i-plan-for-my-phd-now-that-i-have-graduated-with-a-masters-degree-without
Answer: Whether it will be 'bad' or not depends on whether you intend to pursue further studies (PhD), also, it depends on what the university policy is regarding the completion of your Masters.
I would suggest that you discuss your concerns with your supervisors/advisors (if you have not done so already).
Another possibility is to write and submit papers for publication.
Comment: "depends on what the university policy is regarding the completion of your Masters": specifically here (Germany, natural sciences), the thesis is a *required* part of the master's. But then, we have lists of projects to choose from, so "unable to find a topic" doesn't happen. However, most students will do projects that are extensions of mandatory research practica - which again come in form of project lists from which students choose. Students have a right to get a project and a right to get a thesis topic (though I don't think there is a "hard" right to a topic in your favourite institute).
Comment: Thank you Damien, Well the only concern is will I be able to get a job after I complete my masters without thesis. I would love to go both ways; Job = money, Phd = Passion. I discussed the matter with my Advisor, she advised me to do thesis, but as of now I am unable to find a good option (There are couple of options available from Environment engineering department that I am trying to grasp, but still unable to finally sign up for any project/thesis).
Answer: If you're mainly interested in getting a job in the industry after you graduate, it probably doesn't matter too much.  Sure, a really good thesis could be a bonus, but you'll probably have have to get pretty far in the recruiting process before anyone's even going to look at your thesis, and if and when someone does, they probably won't look much beyond the abstract.
The one exception might be if you already have a fairly specific idea of what you want to do in your job, and can arrange a thesis topic that lets you demonstrate the same skills you expect to be using.  But it doesn't really sound like you have that specific a vision for your future yet.
If you plan to pursue a PhD degree, though, things are completely different.  What people looking for prospective PhD students are most interested in is the ability to carry out academic research and describe its results, which is exactly what a thesis demonstrates.  Without a thesis, you're going to have to find some other way to demonstrate your research and writing skills.  It's not completely impossible — for example, you could try writing an independent research paper and getting it published in an academic journal, as suggested in this answer to a related question — but it does have the potential to put you at a significant disadvantage.

(Background disclosure: I'm a PhD student in mathematics with several years of past experience working in the IT industry.  I've also had some experience in helping to evaluate candidates for both academic and non-academic positions, although I cannot really claim extensive first-hand knowledge of that side of the process.)
Comment: By the way, this is actually the first time I've even heard of such a thing as a coursework-only master's degree. Around here in Finland, pretty much _all_ degrees, even at bachelor's level, require _some_ kind of written dissertation. No thesis = no degree. Of course, the amount and level of research required depends on the degree, but the only places I've heard of that don't require any thesis at all are vocational schools, and even those typically require a final project that sort of carries the same role.
Comment: Thank you IImari, the course work involves unit(small) projects but these are not publishable and/or are not supposed to contribute towards a new invention or addition. The thesis I was asking about is equivalent to min 9 credit hours out of my 30 credit hours (30% of masters degree). Though I got the answer and it was helpful for me to decide what way should I go.

Non-Thesis Masters


Editors for different parts of Wordpress

Question: I'm preparing my page (not published yet) and need Your help. I didn't find any answer in forums about roles and capabilities. Have you heard about plugin or an other solution, that allows editor to publish only in his category/page.
I have 10 departments, in each of them 1 author and 1 editor. I need to ensure that editor from department 1 can not publish for department 2.
Thanks a lot.
Answer: My recommendation would be to install WordPress as a multi-site network and give each department their own site.  You can do this based on sudomains (department-1.mysite.com, department-2.mysite.com, etc.) or as subfolders (mysite.com/department-1, mysite-.com/department-2, etc.).
Users can have different roles across each site in the network.  You, as the super administrator, would have full access to everything.  If you have an author who's only supposed to be an author on one department's site, you can limit them that way.  You can also grant a user permission to be an author on one site, an editor on another, and merely a subscriber on another.  It's a very flexible system.
This is the easiest way to separate authors into specific "departments" within WordPress ... and the biggest advantage is that you don't need a plug-in to make it work!


Migrate pictures and data from a Document Library to a Picture Library?

Question: I have a SharePoint Document Library containing about 1500 pictures and about 15 columns of metadata created years ago, and I have a new requirement that requires the functionality of a Picture Library.  Is there a way to migrate the 1500 pictures and their metadata to a Picture Library?  Is manual data entry the only way to accomplish this?  I hope not.
Thanks in advance for your help!
Comment: Do you have those 15 meta data columns available in the Pic Library. And does it the meta data fields have the same name?
Comment: Using content and structure to copy the files to the new library should create and copy all the same metadata fields over. If this works to your liking, then you can use content and structure to move the files.
Comment: Revised again as I seem to be narrowing down the problem.  It is occurring when trying to copy anything from one library to another, even if they are identical structurally.  When using the "Content and Structure" page to move my files from one library to another,  I'm getting the following error:  "Microsoft.SharePoint.SPException: List does not exist. The page you selected contains a list that does not exist. It may have been deleted by another user."  I'm now researching based on this latest finding..
Answer: It turns out that the answer to my question was answered by Eric. Data can be moved from one library to another simply by using Content and Structure in Site Settings.
NOTE:  The error I mentioned in my comments is still occurring, but only on my Office 365 site.  I will research that as a separate issue.
NOTE:  The "SharePoint Server Publishing" feature needs to be turned on before the Content and Structure settings are available.


Detect activity on RJ45

Question: I would like to make a circuit that allows to detect activity on a RJ45 cable (on which Ethernet would be used).
When the cable is only connected to a single computer, link test pusles are emitted. These signals are about 1 us long and between 0,5 mV and 3 V.
Otherwise, data is Manchester-encoded, with a frequency of 100 MHz. I do not know the amplitude.
I would like to detect, with a diode, activity on the RJ45 cable. As the signal is not continuous, a simple LED would not work. I also would like not to damage the signal.
Do you have an idea on how it would be possible to do it?
Comment: Well, I guess it's possible but it won't be easy. The cable pairs are electrically isolated from the equipment by transformers at both ends, so you'd need to make sure you don't break that. You'll also have to make sure you don't put any significant load on the pairs or you'll disrupt its proper functionality.
Comment: Isn't that what the LED on the back of your computer is for...
Comment: Are you trying to detect efforts to establish an actual Ethernet connection or just some other custom protocol being used on an Ethernet-style cable?
Comment: maybe a good hall-effect sensor can detect the differentials.
Comment: Tom Carpentier :
Yes, but I would like to do it remotely.
Comment: Finbarr :
I am interresting in all solutions : detecting efforts to establish a connection, a real connection or both
Comment: Was sort of imagining putting a coil around it and looking for induced voltage... Don't know if that's a daft idea, whether it'd wreck the LAN signalling?
Comment: Finbarr: what do you mean by "break that" ? (sorry, I am not an eletronics expert)
Comment: All : Thank you for your suggestions, they are all considered and appreciated
Comment: I mean by connecting anything to the pairs that results in them becoming connecting them to ground through a DC path. The pairs are twisted so they don't generate a great deal of magnetic field to detect, either.
Comment: TonyM, a coil around wouldn't hurt the signalling, but all it would detect is common-mode current (noise), which is dependent on the devices involved and can vary greatly. (Or, if it's PoE and the device is sourcing/sinking transients along an alternative return path, the common-mode current will be all over the place.) It might be possible to detect Ethernet harmonics with a sensitive probe, but it's not easy.
Answer: As suggested by Tom Carpenter, the cheapest and easiest solution in Ghetto Engineering Mode will be to insert an Ethernet switch and monitor the LED.
Answer: In the answer for this question one methodology to observe an activity (in the form of EM emission) on the cable is referenced and its results are depicted. From there:

Evaluated by measuring CM current on cable
RF current probe place on ... cable

You do not need a spectrum analyzer but an appropriate filter/amplifier+integrator. Cannot provide you with schematics but think the method may be useful for you.

Detect activity on RJ45


How to rollback a deleted table data?

Question: I have deleted one table accidentally how can I rollback that.
Please suggest that.
Comment: Sounds like OP may have learned a hard lesson...
Comment: Why would you want to rollback a table that was accidentally deleted? As you are suggesting, that it was in a transaction, a transaction with actions in between was successful gets committed... in short - get the backups... you did make backups right?
Comment: @JNK: yup yup! Consider this as rite of passage - good job it aint a 'rm -rf' on the root of unix system :P
Comment: We do have backup, im done with that already.Is there anyway can we work with database log to rollback recent deletion.
Comment: @Simhadri: As mentioned in [my answer](http://stackoverflow.com/questions/3790883/how-to-rollback-a-deleted-table-data/3790927#3790927), you need a 3rd party tool to work directly with the log.
Answer: Get it from backups!
Comment: Is there any query to rollback that.
Comment: Nope.  Without backups, you're toast.  If it was within a transaction and you haven't committed, you have hope.  Otherwise, a backup is your only option.
Answer: As Joe Stefanelli said, ApexSQL tools can help. There are actually two tools - if the whole table was dropped - ApexSQL Recover. If only the table records are deleted, both ApexSQL Log and ApexSQL Recover can help.
The limitation of both tools while in trial is that they recover only 1 out of 10 transactions. The good news is that ApexSQL Log shows all the records in the grid even in trial, so you can see the records that can be recovered. The limitation is that you cannot create the undo script for all of them until you license the tool
The tools can bring back the data even if you don't have a full or differential database backup as they read the data (MDF) file (ApexSQL Recover) and transaction log (LDF and trn - online, detached, backups - ApexSQL Log)
4 techniques for recovering lost tables due to DROP Table operation
Disclaimer: I work for ApexSQL as a Support Engineer
Answer: If you don't have a good backup, you could give a 3rd party tool like ApexSQL Log a try. I don't know what the limitations on the free trial version are, but it might be worth a shot.
Comment: +1 for third-party tool suggestion. I guess what it comes down to is, how important was this table?
Answer: If you have backups then you follow the procedure described in How to retrieve a specific table or rows from database backups or transaction log backups in SQL Server:

Back up the current transaction log
  Back up your current
  transaction log with the NO_TRUNCATE
  option.
Restore a partial or full database backup
  SQL Server 2000 or SQL Server 2005 If your backup strategy includes
  filegroup backups, you can perform a
  partial database restore to a
  different location and restore only
  the part of the database that contains
  the table that you want to retrieve.
  See the following references for more
  information about how to restore a
  database to a different name and
  location: How to restore files to a
  new location (Transact-SQL)
Restore transaction log backups by using the STOPAT option
  Restore  the transaction log backups to the
  partial or full database restore and
  stop before the point in time when the
  table or rows were deleted. Use the
  STOPAT option of RESTORE LOG command
  to stop the transaction log restore
  and to recover the database before the
  time when the table was deleted. See
  How to restore to a point in time
Retrieve data
  After you restore the database, you can copy the table
  or rows back to your original database
  by using either INSERT, Bcp (Bulk Copy
  Utility) or SELECT INTO. ...
DBCC CHECKTABLE
  Run the DBCC CHECKTABLE Transact-SQL reference on
  the new table to verify the integrity
  of the data.

I ommitted the details, you can follow the link to the KB article for a full coverage of the topic.
Answer: A few people have mentioned 3rd party tools.  The only one I have personally had any luck with for transaction log playback is Toad by Quest.  It's not very cheap but if it's important it's a life saver.  We had some poorly written web apps that were attacked by SQL injections and ruined some old DBs.  The attack wasnt really a problem but we wanted to see what code they were executing and so being able to read back the T-LOG was amazingly convenient.
Answer:
We do have backup, im done with that
  already.Is there anyway can we work
  with database log to rollback recent
  deletion. – Simhadri

You may need to explore transaction-log replaying strategies.
Answer: Another helpful method for recovering deleted tables data in SQL Server is to use fn_dblog() function.
<code>use mydatabase
go
SELECT
 [Current LSN],
 [Transaction ID],
     Operation,
     Context,
     AllocUnitName

FROM
    fn_dblog(NULL, NULL)
WHERE
    Operation = 'LOP_DELETE_ROWS'
</code>
however the method of recovering data by using fn_dblog() function is too long, but it can be helpful for viewing the deleted records of a table.

How to rollback a deleted table data?


Will casting an aura on a creature with heroic trigger the heroic ability?

Question: I'll admit we've had a lot of trouble with the Battlewise Hoplite the last few games and what affects it and what doesn't. If he has a Battlewise Hoplite
in play and I play a Crippling Blight does his Battlewise Hoplite get a +1/+1 counter?
Answer: Heroic only triggers when "you" (the controller of the creature with heroic) cast a spell. So no, your opponent's Battlewise Hoplite will not trigger if you cast Crippling Blight on it.
Aura spells do always target when cast, so it will trigger heroic if you cast an aura spell and target a creature that you control with heroic.

303.4a An Aura spell requires a target, which is defined by its enchant ability.
Comment: Er, I think OP's situation is if a player casts Crippling Blight on another player's Battlewise Hoplite.
Comment: @HaoYe I missed/forgot that Heroic only triggers when you cast a spell, not when any spell is cast. Will edit.


Windows 7 Backup Fails

Question: I am trying to backup a Windows 7 laptop to my file server.
The error code is 0x80070005.  The Event Viewer shows this:

The backup operation that started at
  '2011-06-06T19:56:48.283117300Z'
  has failed with following error code
  '2147942432' (The process cannot
  access the file because it is being
  used by another process.). Please
  review the event details for a
  solution, and then rerun the backup
  operation once the issue is resolved.

There were no applications running other than background services and the backup program itself.  How can I resolve this?
Comment: 0x80070005 is Access Denied.
Answer: Try disabling your anti-virus while running it. Also, are you running it with administrative privileges.
Answer: That error looks like an access denied error.  Make sure the user the job is running as has access to where the output file is being written.
Answer: You may want to check the system event logs for problems with Volume Shadow Copy Service. The backup should have access to all the files on the system if Volume Shadow initialized properly.
If you can open a window to your file server and copy a file to it, you are probably in good shape there.
Finally, run Chkdsk (Error Checking) on your C: drive (right-click on C:, select Properties, click Tools, click "Check Now"). If there is a problem accessing a bad file record, this should clean that up.
Answer: Deactivate your anti-virus and any other security program when doing the backup.  Run the backup as an Administrator.  Remove compressed files from the Backup selection.  Do not backup anything but your C:\ drive
Under your Administrator account, get full rights and take ownership of the entire C:\ drive using the following procedures.  If you can't do some folders, skip them an do as many of them as you can.
To see your permissions, right click the folder/file, click on properties, and check out the security tab.  Check to see what permissions you have by clicking on your username (or user group).  Here are the types of permissions you can have: http://windows.microsoft.com/en-US/windows-vista/What-are-permissions.
You need to be an administrator or the owner to change permissions (and sometimes being an administrator or even an owner isn't enough - there are ways to block even them from access (though a smart administrator knows these ways and can get around them - but usually shouldn't because they were denied access usually for a very good reason).
Here's how to change folder permissions in Vista: http://www.online-tech-tips.com/windows-vista/set-file-folder-permissions-vista/.  To add take and grant full right permissions and ownership to the right click menu (which will make it faster to get in once it is set up), check out the following article: http://www.mydigitallife.info/2009/05/21/take-and-grant-full-control-permissions-and-ownership-in-windows-7-or-vista-right-click-menu/.
To fix this problem with the folders, take ownership of the folders or the drive (as an administrator) and give yourself full rights.  Right click the folder/drive, click on properties, go to the security tab and click on Advanced and then click on the Owner tab.  Click edit and then click the name of the person you want to give ownership to (you may need to add it if it isn't there - or it may be yourself). If you want it to apply to sub-folders and files within that folder/drive, then check the box for replace owner on sub-containers and objects and click OK.  Back out and now there's a new owner for the folders/drive and files who can change permissions as needed.
Here's more information on taking ownership of a file or folder: http://www.vistax64.com/tutorials/67717-take-ownership-file.html.  To add take ownership to the right click menu (which will make it faster to get in once it is set up), check out the following article: http://www.howtogeek.com/howto/windows-vista/add-take-ownership-to-explorer-right-click-menu-in-vista/.
I hope this helps.
Good luck!

Windows 7 Backup Fails


Should proper nouns be transcribed with Esperanto letters or not?

Question: Should proper nouns be transcribed with Esperanto letters or not? For example "Gia" (Italian name): Do I write "Ĝia" or "Ĝiao" or "Giao" or "Gia"?
Answer: The tradition within UEA is to transscribe the names of towns where UKs are held. Also the names of famous esperantists are usually transcribed or they have taken an Esperanto name.
I would say that for others, it depends. The more pronunciation differs from the Esperanto pronunciation, the better is the idea to transcribe.
Take for instance the Italian esperantist Gian Carlo Fighiera. If he does not have an Esperanto name, you can write "Gian" and provide a pronunciation hint, e.g. "Gian [Ĝian]". Or you can fully go with the transcribed version using a stipulative introduction "Gian, poste en formo Ĝian laŭ elparolado". But it really depends on the situation.
Names written in non-Latin-based writing systems, for instance the former emperor 嘉靖, are always latinized into form that follows pronunciation, so Ĝiaĝing. Here you can use an introduction like "Ĝiaĝing (ĉine 嘉靖, piĝine: Jiājng)" like they have done in Wikipedia.
Comment: So, what do you suggest? "Ĝiao" or "Ĝia" ?
Comment: it seems there is not the same way. look these wikipedia pages.

https://eo.wikipedia.org/wiki/Gian_Carlo_Fighiera

https://eo.wikipedia.org/wiki/%C4%9Cia%C4%9Ding
Comment: I added those two examples.
Comment: In my opinion, if the only change needed to esperantize a name is adding a hat ^ (as in the example given), I think it's OK to add it without sweating over the details, so Ĝia. On the other hand, if you changed J to Ĝ (or kept the J but changed the pronunciation as it is done with some "classic" names, like John → Johano), then I'd write a longer note as suggested: "originala: John, prononco: Ĝon, ktp".
Comment: @marcus, except that pronunciation-wise "g" and "ĝ" stand quite apart – up to the point that you can say that they have nothing in common.
Comment: That's exactly why I said adding the hat is good: it's a tiny change in spelling to keep the original pronunciation.
Answer: Historically there was a tendency (idealism) to Esperantize names, and in case of say the bible it was apt and unavoidable.
Nowadays a more modest approach is to let the latin names as they are (and also not accusativized): Gia. Following the transcription of non-latin scripts I think non-misforming accents are possible: Ĝia. Especially where the pronunciation is probably unfamiliar to the reader. Ĝon for John forms a secret language. Or better (as possible for all names) make a footnote of the phonetic pronunciation. Anything else would have needed a footnote for the original name!
Only in settings without couleur locale, like in a school play, a short story in any city, one might consider invented, hence Esperanto names, where Johano might be more appealing than Johannes or better prononciable.
Geographic names are a bit more Esperantized, though not for village level names. This is not uncommon in other languages: Liège/Luik/Lüttich, Aachen/Aken, Nijmegen/Nimwegen.


Why TauDEM specialized tools (e.g. D-Infinity Distance Down) are only available with D-Infinity flow model?

Question: I would like to know why most TauDEM specialized tools have been developed just for the D-Infinity flow model.
Is it because the D8 would not make sense for these algorithms, or they just have not been implemented?
In the first case, what is the reason?
Answer: Mostly this is a matter of implementation.  They have not been implemented.  Typically, each tool was historically developed in for a specific project or purpose and this development process has not resulted in complete consistency in the functionality available.  I think all the algorithms would make sense with D8 too.  Two of the tools (DinfAvalanche, DinfDistUp) have a parameter that sets a threshold for flow proportions to use in the accumulation.  Setting this threshold to 0.5 (or 0.499 to numerically be >= 0.5) gives a result equivalent to D8. This could be added to each tool (given time and funding), and it would be good if there was a systematic process of upgrading each tool to include this threshold parameter so that equivalent D8 options are available to users.
If there is a developer who wants or needs this, these tools with an existing threshold could be used as a guide for implementation of others.  A fork and pull request in the github repository (https://github.com/dtarb/taudem) could be used to request inclusion of code changes in the official releases.
Comment: Thank you for your answer. I hope TauDEM will receive attention as it is an important tool for many applications.


Ubuntu 14.04 Brightness level problem

Question: I know we had a lots of questions about that problem but none worked for me. I have a dual boot with Windows 10 and Ubuntu 14.04 but cannot change the brightness level just when I use Linux. The only way I've found to change it is using Nvidia Xserver application but I had read that this is not the properly way to do that.
When I try to decrease the brightness level the bar on the top of the screen appears and tells me that it's decreasing but nothing happens.
Please, help me.
Answer: Same issue here. Used this link and it works perfectly now. Although updating to the latest version of Ubuntu fixes it as well.
http://itsfoss.com/fix-brightness-ubuntu-1310/
Comment: Don't just post a link. Summarise what the link tells you to do.  Links die and links change.
Comment: Thanks for answering.
Did you use this solution with Ubuntu 14.04 too ?

Ubuntu 14.04 Brightness level problem


Is there a kit that would allow me to replace a sealed beam headlamp with a halogen bulb?

Question: In the future, I could just replace the bulb as needed without replacing the whole lamp.
This is for a 1997 Toyota Tacoma 4x4.
Answer: I am showing that vehicle to already take these halogen bulbs. If you have sealed beams and you want to upgrade the lights you can try for example Hella Lights.


Which algorithm to use to classify plots based on graphical features?

Question: I have plots which I need to classify based on some features. For example, I need to differentiate between the following plots having smooth features or 'valleys' at certain x values. Which machine learning algorithm would be most appropriate to do so? I was thinking a combination of anomaly detection, clustering and classification. Any help is appreciated. Thank you!

Answer: Your question is unclear. Please provide more information about the dataset, the dataset size, the target, the motivation.
Until then I can only assume and try to help nontheless.
Assumptions
Since you speak of classification I assume that you have labels.
I further assume that you have access to the underlying data used to produce the plot.
In that exact case, the following will be useful:
Solution
Instead of classifying the plots, you could classify the underlying two-dimensional datasets treating them as time-series.
For your specific case, Dynamic Time Warping distance could be useful. You could therefore use this code:
<code>import numpy as np
from scipy.spatial import distance
from sklearn.model_selection import train_test_split
from sklearn.neighbors import KNeighborsClassifier
from sklearn.model_selection import GridSearchCV
from sklearn.metrics import classification_report

#toy dataset
X = np.random.random((100,10))
y = np.random.randint(0,2, (100))
X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.33, random_state=42)

#custom metric
def DTW(a, b):
    an = a.size
    bn = b.size
    pointwise_distance = distance.cdist(a.reshape(-1,1),b.reshape(-1,1))
    cumdist = np.matrix(np.ones((an+1,bn+1)) * np.inf)
    cumdist[0,0] = 0

    for ai in range(an):
        for bi in range(bn):
            minimum_cost = np.min([cumdist[ai, bi+1],
                                   cumdist[ai+1, bi],
                                   cumdist[ai, bi]])
            cumdist[ai+1, bi+1] = pointwise_distance[ai,bi] + minimum_cost

    return cumdist[an, bn]

#train
parameters = {'n_neighbors':[2, 4, 8]}
clf = GridSearchCV(KNeighborsClassifier(metric =DTW), parameters, cv=5)
clf.fit(X_train, y_train)

#evaluate
y_pred = clf.predict(X_test)
print(classification_report(y_test, y_pred))
</code>
Answer: For starters, the valleys or straight segments are not defined at any particular point, but at range of points - or line (curve) segments. Starting point could be separating N line segments with each being M km length, where N and M are depend on your choice. This will give you a representation of each graph as several smaller graphs.
Then it comes to the labelling those smaller graphs. For this purpose, clustering might work, but in addition to valleys and smooth section classes, we need to take into account other potential shapes, such as the uphill section in 23-35 km of the first graph. If the ending of all graphs are like given in the figures above - smoothing out at a higher value towards the end, this should cover all the classes. It is probably not the best approach but worth a try.


Automate daily collection of weather station data from NCDc

Question: Here is the link to where the data can be found. Scrolling down to Surface Data : Daily and selecting the Global and U. S. Web Page Icon. On the next page, Select the radio button Country and press continue. From the next page's drop down menu, select any state and then press the radio button for entire state (I need more than 100 stations per day).
The next page allows you to select the date range.
I am dumping these data files into excel and sorting (which is a pain, since it could obviously be
automated).
Is there a way I can access the most current data via a script (VBA or otherwise)?
My main problem is that I can't send the server a simple request to obtain the data. Also, there is an FTP site but only allows .gz files to be downloaded, each over a gig, so its not reasonable for my situation.
Any help would be appreciated!
Answer: There National Climatic Data Center has several data APIs available for this.


How can I count the number of different characters in a file?

Question: I would need a program, that outputs the number of the different characters in a file. Example:
> stats testfile
' ': 207
'e': 186
'n': 102

Exists any tool, that do this?
Answer: The following should work:
$ sed 's/\(.\)/\1\n/g' text.txt | sort | uniq -c

First, we insert a newline after every character, putting each character on its own line. Then we sort it.  Then we use the uniq command to remove the duplicates, prefixing each line with the number of occurrences of that character.
To sort the list by frequency, pipe this all into sort -nr.
Comment: On sed for Mac OS X it's `sed 's/\(.\)/\1\'$'\n/g' text.txt`
Comment: Very nice, but unfortunately it does not work correctly if the text contains Unicode (utf8) characters. There may be a way to make `sed` do this, but Jacob [Vlijm's Python solution](https://askubuntu.com/a/593503) worked well for me.
Answer: Steven's solution is a good, simple one. It's not so performant for very large files (files that don't fit comfortably in about half your RAM) because of the sorting step. Here's an awk version. It's also a little more complicated because it tries to do the right thing for a few special characters (newlines, ', \, :).
awk '
  {for (i=1; i<=length; i++) ++c[substr($0,i,1)]; ++c[RS]}
  function chr (x) {return x=="\n" ? "\\n" : x==":" ? "\\072" :
                           x=="\\" || x=="'\''" ? "\\" x : x}
  END {for (x in c) printf "'\''%s'\'': %d\n", chr(x), c[x]}
' | sort -t : -k 2 -r | sed 's/\\072/:/'

Here's a Perl solution on the same principle. Perl has the advantage of being able to sort internally. Also this will correctly not count an extra newline if the file does not end in a newline character.
perl -ne '
  ++$c{$_} foreach split //;
  END { printf "'\''%s'\'': %d\n", /[\\'\'']/ ? "\\$_" : /./ ? $_ : "\\n", $c{$_}
        foreach (sort {$c{$b} <=> $c{$a}} keys %c) }'

Comment: +1 for not doing that horrible sort
Answer: A slow but relatively memory-friendly version, using ruby. About a dozen MB of RAM, regardless of input size.
# count.rb
ARGF.
  each_char.
  each_with_object({}) {|e,a| a[e] ||= 0; a[e] += 1}.
  each {|i| puts i.join("\t")}

ruby count.rb < input.txt
t       20721
d       20628
S       20844
k       20930
h       20783
... etc

Answer: More obvious solution that I use to count occurrences of characters in a file:
cat filename | grep -o . | sort | uniq -c | sort -bnr

pipes output to grep, which then prints every char on one line | sort then reprints each char the amount of times it shows up in the file | uniq counts the amount of occurrences | sort -n sorts that input again, by number
With a file that contains the text "Peanut butter and jelly caused the elderly lady to think about her past."
Output:
     13
      9 e
      7 d
      5 s
      5 a
      4 o
      4 h

... and more

The first line would be the amount of space characters in the file, you can filter that out if you like using tr -d " "
Answer: Simple and relatively performant:
fold -c1 testfile.txt | sort | uniq -c

Just tell fold to wrap (i.e. insert newline) after every 1 character.

How tested:

a 128MB all-ASCII file

Created by find . -type f -name '*.[hc]' -exec cat {} >> /tmp/big.txt \; in a few codebases.

workstation-class machine (real iron, not VM)
environment variable LC_ALL=C

Runtimes in descending order:

Steven's sed|sort|uniq solution (https://unix.stackexchange.com/a/5011/427210): 102.5 sec
my fold|sort|uniq solution: 59.3 sec
my fold|sort|uniq solution, with --buffer-size=12G option given to sort: 38.9 sec
my fold|sort|uniq solution, with --buffer-size=12G and --stable options given to sort: 37.9 sec
Giles's perl solution (https://unix.stackexchange.com/a/5013/427210): 34.0 sec

Winner!  Like they say, the fastest sort is not having to sort.   :-)
Comment: `The GNU implementation of fold currently only works correctly with single-byte characters.`

See [Stéphane's comment](https://unix.stackexchange.com/a/486428/301396)
Comment: When speaking of multibyte encodings, helps to distinguish between fixed-width and variable-width encodings.  With fixed-width encodings, instead of the `-c`/`--characters` flag you could simply give `fold(1)` the `-b`/`--bytes` flag: `-b2` with UCS-2, `-b4` with UCS-4 _(also known as UTF-32)_.
Comment: In fact, `-c`/`--characters` appears to be a GNU extension; the POSIX spec of `fold(1)` (ref https://pubs.opengroup.org/onlinepubs/9699919799/utilities/fold.html) does not have it.


Example of a Borel set that is neither $F_\sigma$ nor $G_\delta$

Question: I'm looking for subset $A$ of $\mathbb R$ such that $A$ is a Borel set but $A$ is neither $F_\sigma$ nor $G_\delta$.
Comment: For references to the related problem of "explicit" examples of functions that properly belong to various lower Baire hierarchy ranks, see http://groups.google.com/group/sci.math/msg/addcfd658075c65f
Answer: There are many examples. Here's one:
Observe first that the rational numbers $\mathbb{Q}$ are an $F_{\sigma}$. This is because they are a countable union of points. The irrational numbers $\mathbb{R} \smallsetminus \mathbb{Q} = \bigcap_{q \in \mathbb{Q}} \mathbb{R} \smallsetminus \{q\}$ are thus a $G_{\delta}$. Since both $\mathbb{Q}$ and $\mathbb{R} \smallsetminus \mathbb{Q}$ are dense and disjoint it follows from the Baire category theorem that $\mathbb{Q}$ cannot be a $G_{\delta}$. [Edit: See also this thread here containing several proofs that $\mathbb{Q}$ can't be a $G_{\delta}$ in $\mathbb{R}$. These proofs explicitly avoid Baire].
The same reasoning shows that $F = \mathbb{Q}_{\geq 0}$ is an $F_{\sigma}$ in $[0,\infty)$, but isn't a $G_{\delta}$, and that $G= \mathbb{R}_{\leq 0} \smallsetminus \mathbb{Q}_{\leq 0}$ is a $G_{\delta}$ in $(-\infty,0]$, but isn't an $F_{\sigma}$. Their union $F \cup G$ is then an example of a Borel subset of $\mathbb{R}$ which is neither an $F_{\sigma}$ nor a $G_{\delta}$ because if it were an $F_{\sigma}$ then the same would hold for $G = (F \cup G) \cap (-\infty,0)$, for example. I leave it as an exercise to show that $F \cup G$ is both an $F_{\sigma\delta}$ and a $G_{\delta\sigma}$.
That's probably the easiest example. A few more (both more interesting but also more involved ones) can be found in this MO thread.

For a much more in-depth discussion of such ideas, I recommend looking into one of the following books:

A.S. Kechris, Classical Descriptive Set Theory, Springer GTM 156.
S.M. Srivastava, A course on Borel sets, Springer GTM 180.
J.C. Oxtoby, Measure and Category, Springer GTM 2.

Specifically, look up the sections on the Borel hierarchy.
Comment: Very nice example! I had in mind some countable union of copies of the irrationals or something like that.


Rear wheel arch rust on 2006 Ford focus 5Door Hatchback

Question: I have a 2006 Ford Focus 1.6 auto 5 door hatchback with bubbling paint and showing rust where the rear wheel arch meets the body sill. Can this be repaired or do I need a new wheel arch and respray, or a complete sill and wheel arch.
Comment: If there is a hole it needs more work or replace...
Comment: Welcome to Motor Vehicle Maintenance & Repair!
Comment: Without an image of the affected body panel(s) any answer will be pure speculation. Use the edit button to upload an image of the damage.
Comment: Unfortunately the only way to find out is to start removing paint and / or poking around with a tool such as a sturdy screwdriver.  With the panel still covered with paint you won't have any way of knowing how far the corrosion has progressed.
Answer: The rust you can see is usually dwarfed by the rust you can't see.  A lot of cars have rusty rockers and wheel arches because of the way manufacturers used to construct these parts, which was basically two pieces of sheet metal (inner quarter panel and outer quarter panel) folded together and spot welded.  Because it was spot welds, and not a continuous seam, it allowed water and dust to infiltrate into the space between the two pieces of sheet metal.  The water itself isn't as much the problem as the dust, which traps the water against the steel, promoting corrosion.
Unfortunately, the correct way to repair rusted body panels like this is to cut out the bad sheet metal and weld new sheet metal in its place.  Some cars that have commonly rusted areas have patch panels produced by the aftermarket for this specific purpose.


How to draw MS Paint like (aliased), 1px circle in GIMP

Question: I was trying to draw some pixel are amd first thing is to try a circle via stroke path with miter set to 0, anti-alias off, 1 px line.
Here is what I get in Gimp. Part of the circle are ok, others are not (red arrow points to them). Any suggestions? Thanks.
Answer: It seems you can get slightly better results by stroking the path with the pencil tool, using a single-pixel brush:

They're still not quite as nice and symmetrical as the pixel art circles produced by the Bresenham circle algorithm used in MS paint, but at least they're a little bit closer.
Comment: @Santropedro: I _don't_ know for sure, but it _looks_ like what Bresenham's algorithm would produce, and it's sort of the obvious choice anyway. Especially given how old MS Paint originally is. Back in the day, Bresenham's algorithm (specifically the integer-only form) would be what you'd use if you needed to draw a circle on a computer.
Comment: Hm, I guess I missed that option. Thanks. It seems I'm gonna turn to Paint.NET or other programs, made for pixel art (didn't succeed with photoshop either).
Comment: @Ilmari Karonen How do you know Bresenham circle algorithm is used in MS paint? I ask because I need to know which algorithm they use, and wanted to check that you are positive they use that.


Is it possible to read the contents of deleted folders in the RecyclingBin?

Question: I've been playing around with scripts that read deleted files from the recycling bin such as the one below but I can't figure out how to read the files within a deleted folder without restoring it first. I'm beginning to think it might not be possible. Perhaps running a SQL statement is the only way. Can someone confirm whether it is actually possible without resorting to SQL? As far as I can tell the recycling bin does not behave like a list.
<code>$rowlimit = 5000;
$site = new-object Microsoft.SharePoint.SPSite("http://sptest.com/ncart");
$query = new-object Microsoft.SharePoint.SPRecycleBinQuery;
$query.ItemState = "FirstStageRecycleBin";
$query.RowLimit = $rowlimit;
$itemcoll = $site.GetRecycleBinItems($query);
foreach ($item in $itemcoll) {
       write-host -nonewline "Found " $item.Title " ... ";
}
</code>
Answer: No - it is not possible to get content of a deleted folder.
Remains only two options (as You already mentioned):
1) restore items from recycle bin to the original location and examine;
2) get data from SQL directly, querying content DB tables [RecycleBin] and [AllDocs]


How do I download/install driver for HP Officejet 4655

Question: I have tried unsuccessfully to download a print driver for my HP OfficeJet 4655.  "I've tried using sudo apt-get hplip" in the terminal, and I've been to hp website and haven't had any luck.  Any ideas?
Answer: You can find a similar question here. Have a look at sugestion 4. In the approved answer.


Arduino Uno R3 HID with HC-06 BT module

Question: Im trying to make a macro pad using Arduino Uno r3 and 4x4 matrix (cherry blue clone) . I know using a pro micro is better than uno cause there isn't HID compatibility in uno but since i already have one , i want to work with this . I have already tested the macro pad after compiling and flashing a keyboard.hex file . But wondering if i buy a bt module like HC-06 (which is about 3.2$ here ) would that be able to send inputs even aftar flashing ? I have like basics coding knowledge so i have no clue what flashing actually would do to the module so . Anyone know would making that macro pad BT compatible    be possible or not ?
Answer: It is unclear to me, where you flashed what, so I will describe some basics.
The Uno cannot act as a keyboard/HID device, since the microcontroller on it (the Atmega328p) doesn't have native USB capability. For connecting to USB the Uno has a USB-to-Serial chip on it (actually another microcontroller, the Atmega32u4 I think). So with the Uno you only have a serial connection, unless you hack the Atmega32u4 and program it with your own firmware (firmware is a term for software, that runs very near to the hardware, in this case directly on the microcontroller, in contrast to normal software running on an operating system on a computer; so in the middle between hard- and software, thus firmware).
Flashing is the same as programming a microcontroller. It has this name, because the program is saved in flash memory on the microcontroller (that is a specific type of memory technology; the same technology, that USB sticks use for storing your data). Flashing the HC-06 means programming it with a different firmware.
All bluetooth devices use the same base technology (thought to be clear, BLE is a different technology). The role of the device depends on the characteristic/profile, that it exposes to the host. There are profiles for HID, Serial, Audio, ... .
The HC-06 is a bluetooth slave device, which acts as a bluetooth-serial-bridge (like the Atmega32u4 acts as a USB-serial-bridge). But this is a software limitation. The HC-06 has standard bluetooth hardware, but the firmware on it just gives you the Serial profile (in fact a HC-06 is mostly the same like the master device HC-05, just different firmware and corresponding breakout boards can break out other pins). So by flashing (programming) it with a different firmware, you can get different profiles. If you find a firmware, that gives you HID functionality, you can flash that to the HC-06 and use it. Though this is a bit hacky I think (haven't done it myself), so it might be a bit too much for a beginner.
Bluetooth Slave/Master: The bluetooth protocol uses fixed roles for the two connected devices. One is the master and one is the slave. The master controls, if the communication is really happening. For example a bluetooth headset is a slave device. You cannot connect the bluetooth headset to your bluetooth keyboard, because both are slave devices. You always need one master and one slave. The HC-05 is basically the same module as the HC-06, but it's firmware enables it do be master or slave (configurable by you). So some devices support both modes, but still in any specific connection they can only have one of the modes (need to either master OR slave at any time).

Anyone know would making that macro pad BT compatible be possible or not ?

Possible, yes. But I suggest you invest in buying a ready to use bluetooth HID controller (immediately found this one from adafruit, though you might might cheaper versions). That will be way easier, than directly jumping into flashing a HC-06. Though that is still a possible path to go.
Another way to go would be to just use the serial functionality and write a small program for your PC, which reads from the Serial interface and issues key strokes according to the serial data. Then you don't need to reflash the HC-06.
Comment: Thank you chrisl for the valuable answer . I understand what you were saying .. somewhat . The thing is im from a third world country and there aren't any products from adafruit . Actually tinypico was a really good choice for my project but if i wanted to get one from AliExpress i would have to pay 20$+ on just shipping so the cost is too much .
Comment: You can search for other product than the one from Adafruit. That was just the first, that came up, when I quickly searched for it. If there are no better/cheaper modules available for you, you need to compromise. Either going the steep learning curve to learn reflashing the HC-06 or by writing the program for your PC, that handles serial input.
Comment: " I understand what you were saying .. somewhat" - Can you pinpoint, what you are not understanding completely? Then I can try to improve my answer in that direction.
Comment: I didn't understood master-slave relation in the BT module . Its because i haven't done any research in that matter . So instead of bothering you i just wanted to do some study on that matter :) again ,thank you very much for your answers , now i know what i need to look into
Comment: I added a short paragraph about this to the answer. For now I leave the rest for you to research :D If you think my answer is correct, then you can accept it. That marks the question as correctly answered.

Arduino Uno R3 HID with HC-06 BT module


Have Siri tell me when something is ready

Question: Is there a way to set a reminder or an event so when that event's time comes the iphone will say something like "your eventA is ready, keep in mind the traffic".  Where that phrase is something i can control?
Answer: As of right now SIRI can only be initiated by you. You can tell SIRI to remind you about something and you will get a notification about it but there is now way to have SIRI come on and say anything.
Answer: At the moment (up to and including iOS 12), you cannot have Siri speak to you based on an event (time/date, notification from app etc.). Only you can trigger Siri.
However, you could try a few things that may give you an approximation of what you want to do.

Shortcuts: you could write a Shortcut in the Shortcuts app that has a time delay and then speaks the text you want. You cannot have this shortcut automatically invoked - you will have to trigger it - via your voice or your fingers - yourself.
VoiceOver: you could enable VoiceOver to speak out your Reminders, Timers or Alarms.


Flutter - How to change color of marker based on magnitude of an int?

Question: I want to create markers at each GPS point with a color on a scale from white to red that corresponds to how slow or fast the GPS data indicates the speed is at that point. However, since Color.fromRGBO() requires const arguments, I'm having trouble getting the speed to change the color. How could I circumvent the Color class or find a better way to draw such a gradient than with Marker objects?
Answer: You can indeed use https://api.flutter.dev/flutter/dart-ui/Color/Color.fromARGB.html
const Color.fromARGB(
    int a,
    int r,
    int g,
    int b
)

with a=0, g=0 and b=0 and use your scale (you need to know the maximum value, lets call it r_max, to normalize the range). So whenever you have an intensity value, lets call it r_intensity, you'd simply compute
const r = 255 * (r_intensity / r_max)

to compute your color intensity. The result of r_intensity / r_max will always be in range [0, 1] multiplied by 255 to conform with

r is red, from 0 to 255.
from the docs.

Regarding the const issue: it sounds like you want to (heavily?) animate the color. Look at https://api.flutter.dev/flutter/animation/AnimationController-class.html and set the red color value to your Widgets state.
Other than that, it should work to either have

a method that returns the new red value (and does the aforementioned computation)
simply use var r = ... instead of const r = ... and pass it to Color

Looking at your image, the issue might stem from your int being null. Please make sure that your Color Widget is not wrapped into any Widget prefixed with const! This will likely be the case here and produces the result you are seeing. Tested it on my side to confirm.


the meaning of figure-work in the musical field perhaps with examples

Question: Reading the book The creative development or f Johann Sebastian Bach I happen to come across the term figure-work when the author analyzes pieces by the great musician.
Comment: More context as e.g. one simple complete sentence would be helpful.
Comment: Probably refers to his hand-written musical notation... But, yes, please clarify what you are asking.
Comment: I assume, that meaning 5 of *figure* is intended, as defind [here](https://www.lexico.com/en/definition/figure): *A short succession of notes producing a single impression; a brief melodic or rhythmic formula out of which longer passages are developed.*
Comment: Perhaps the intent was "figuration," as for example in a figuration prelude.
Comment: or as it is described here:
*We know that Handelian singers used to decorate his melodies with graces and melismatic figures, and cadenzas (often very considerable) which have disappeared for the greater part.* or later: *The vocal ornaments were not improvised and left to the fancy of the singer, as is often asserted, but they were marked with precise indications in the singer's parts, and also in the score of the accompanying clavecinist.* or as this wiki article shows:
https://en.wikipedia.org/wiki/Figure_(music)
Answer: Figure, figuration, figure-work, etc. In that sense figure basically means smallest musical unit. The meaning is similar to motif. Various authors define figure indifferent ways so there isn't one precise meaning.
From Grove's Online:

Figure (ii) A short melodic idea having a particular identity of rhythm and contour, often used repetitively or in conjunction with other such ideas to build a larger melodic idea or a theme. Thus it belongs to the category of musical ideas commonly called motifs ( see Motif ). Melodies that have florid motivic detail are sometimes said to be figurative, and the use of the term in this sense is related to the Italian canto figurato : see Analysis §II 2. . Certain musical figures in Renaissance and Baroque vocal music were seen as analogous

It seems to me a figure is usually about one beat in length, although the figure make overlap two beats as a kind of anacrusis.
Figuration is discussed in this dissertation: Callahan, Techniques of Keyboard Improvization... This illustration is a nice example of some common musical figures with their German names:

I see two important ideas related to figuration: embellishment and concatenation.
In the Callahan dissertation he talks about elaboratio (harmonic/voice leading framework) and decoratio embellishment of the framework with decorative figures. In that perspective the figures are applied to a given complete - but abstract - musical structure.
From the concatenation perspective, figures are connected sequentially like links of a chain to for a melody. Sometimes this is called "spinning out." The German term for it is fortspinnung. As I understand it, this is more about free flowing development with figures rather than conforming to a pre-set structure as in the embellishment model.
Comment: So this answer of you also confirms me in my assumption that *figured bass* is not just the "numbered" bass (*ciphered bass*) but a bass containing melodic figures like you are showing, Michael.
Answer: I've been struggling for weeks now about the English term "figur". It's everyday meaning seems to be the same as "number".
But in German figur is also meaning the shape and movement in the counterpoint or descant. Now the longer the more I get convinced that my understanding was correct: "Figured bass" stood originally for the embellished and decorated figures or melodic variations of a simple note against note counterpoint - so in opposite or contrast to this latter choral-like setting. But through the years it became the meaning of  "figured bass" that means thorough bass and the figured stands for the numbers.
I poste this here broadly hoping we'll  get other resources that might proof that I am wrong.
So to your question: What is meant by figured works?
Some will answer: Bach studied the thorough bass by analyzing and transcribing works of other composers.
But I would point out that this actually means:
Bach studied the embellished organ choral style  by writing figures in the descant and other voices (variations of motifs or musical "subjects") and in the bass line. ("flourished" counterpoint).
Edit:
A quite different interpretation of figure work could concern Bachs well known symbolism in motifs and number as it is described here:
Symbolism
A repertoire of melody types existed, for example, that was generated by an explicit "doctrine of figures" that created musical equivalents for the figures of speech in the art of rhetoric. Closely related to these "figures" are such examples of pictorial symbolism in which the composer writes, say, a rising scale to match words that speak of rising from the dead or a descending chromatic scale (depicting a howl of pain) to sorrowful words. Pictorial symbolism of this kind occurs only in connection with words—in vocal music and in chorale preludes, where the words of the chorale are in the listener's mind. There is no point in looking for resurrection motifs in The Well-Tempered Clavier. Pictorialism, even when not codified into a doctrine, seems to be a fundamental musical instinct and essentially an expressive device. It can, however, become more abstract, as in the case of number symbolism, a phenomenon observed too often in the works of Bach to be dismissed out of hand.
Number symbolism is sometimes pictorial; in the St. Matthew Passion it is reasonable that the question "Lord, is it I?" should be asked 11 times, once by each of the faithful disciples. But the deliberate search for such symbolism in Bach's music can be taken too far. Almost any number may be called "symbolic" (3, 6, 7, 10, 11, 12, 14, and 41 are only a few examples); any multiple of such a number is itself symbolic; and the number of sharps in a key signature, notes in a melody, measures in a piece, and so on may all be considered significant. As a result, it is easy to find symbolic numbers anywhere, but ridiculous to suppose that such discoveries invariably have a meaning.
So if this is not an answer to your unclear question I have found at least an answer to mine: a figure in English is more than just a number ..
Comment: Considering the definition I added as comment to the question, I don't believe this was asked for.
Comment: what do you believe then what was asked for?


Formal way to describe sexual acts

Question: I'm writing a statement of events that happened between me and my ex. It needs to be written formally but I don't how to write the following words in that way: "blowjob" and "eating her out." Thanks for any help you can offer!
Comment: The downvotes may reflect a disapproval of the tone of your request.  You do not just ask for alternative terms for slang, but purportedly refer to your ex's private activities. Not needed for the question, and bordering on offensive (not for the terms, but for the context).
Comment: Can someone explain the downvotes? This seems [on topic](http://english.stackexchange.com/help/on-topic), to me.
Comment: This should be closed as a general reference question.
Answer: It sounds as if the words you need are fellatio and cunnilingus.
Comment: I think *oral sex* is also a good umbrella term for this type of sex act, although that answer was deleted.
Answer: Performed oral sex on each other covers it as well. Although, as Barrie points out, fellatio (blow job) and cunnilingus (eating her out) are the technical terms for the exact acts, I would tend towards 'oral sex' as it is more generally understood and, well, sounds a bit more pleasant.

Formal way to describe sexual acts


inversion pairs in an array - application

Question: I came across an algorithmic problem to find out the number of inversion pairs in an array in O(nlogn) time. I got the solution to this. But, my question is that what is the real-life application of this problem? Like I want to know some applications where we need to know the inversion pairs.
Comment: Related: http://en.wikipedia.org/wiki/Parity_of_a_permutation
Answer: One example is the fifteen puzzle. If you want to randomly shuffle a grid of numbers, can you tell at a glance if
<code>1 14  5  _
7  3  2 12
6  9 13 15
4 10  8 11
</code>
can be solved by sliding moves or not? The parity of the permutation will tell you that it is not.
Answer: Here is the use of inversion count in real life..
suppose you want to know how similar two list are..based on ranking..
on any movie site..two wishlist of movies are compared and few of them who are similar , are shown to users who have same choice.
Same logic applies to shopping list on any shopping website.. for recommending shopping items based on his activity..


Examples of heterologous expression in human cell beside viral expression

Question: Usually, people are interested in expressing human proteins in fast-growing organisms like bacteria to yield a maximum of protein within a short time lapse. Codon usage harmonization/optimization have been used to increase the protein production. The role of codon usage have been studied in the context of viral protein expression, but outside this viral context, is there any example of using human cell lines for heterologous expression?
Comment: Are you asking for examples of human cell lines being used for preparaive protein production?
Comment: That should say "preparative".
Answer: Expressing GFP in human cell lines for research purposes is an extremely common example of heterologous protein expression.
For research purposes, it's usually unnecessary to optimize codons for increased expression, especially since using more efficient enhancers and promoters produces a far greater improvement in expression levels than codon optimization which is non-trivial and species-specific.
Answer: Besides research (as mentioned by mxwsn), there are a lot of actual protein based medicines and vaccines produced in human cell lines. One of the first mass cultures of a human cell line was in the monkey free production of a polio vaccine
   (source). Almost every researcher working in a molecular lab has grown HeLa cells at one point during their career!


How to push a local notification When a change happens in input data?

Question: I fetch some data from a url and display data on a tableview. I need to create a local notification and inform(allert) user about the change when a new data is added to data source. How can i create such a notification( it must work even in bacground too)? Any idea-tutorial recommendation will be appropriate. Thanks
Answer: You can create local notifications using UILocalNotification. You can either schedule it or present it. Look into Application.h for more info about it.
You can also plainly use notification center to handle such changes.
Some useful link:
<code>http://blog.corywiles.com/uilocalnotification-example-project-using-ios
</code>


Why isn't limited dissolve working?

Question: I was trying to google a way to merge overlapping meshes and everyone keeps saying Limited Dissolve, but it's not working for me for some reason :< ... I just want to make one n-gon without anything in the middle.
Comment: Why would they be dissolved? Only connected geometry located on the surface not exceeding specified angle will be dissolved. In your case circles don't seem to be connected. These are 3 intersecting but different meshes
Comment: You have been misinformed, limited dissolve is not the tool you are looking for
Comment: But I joined them >.> ... How do I merge them and get rid of the extra vertices then? <.<
Comment: Could you please suggest what might work?
Comment: https://blender.stackexchange.com/questions/7928/how-would-you-cut-a-shape-out-of-an-object-using-another-object or https://blender.stackexchange.com/questions/50538/how-to-cut-an-object-along-a-curve/
Answer: The maybe easiest way in this situation is manual stitching:
Just select a single vert from the inside of the circles.

Then hit GG. That way you enter vertex slide mode. Move the vert towards the outside and put it where both circles intersect. That way you keep angles roughly consistent. The more you zoom in, the more precise it gets.

The rest is stitching stuff together with ALTM. I usually prefer to use merge 'At Last'. Just put the rest of the verts on the newly placed verts.

You could extrude the circles into cylinders and use booleans but it's not worth the hassle, especially since they're already in a single mesh.
If you lose one of the faces, simply clear the selection, select all the verts that belong to it, for example with Circle Select C and then hit F to create the face.
If the holes are easy enough for Blender to understand, selecting everything and hitting F  will work, too.
https://docs.blender.org/manual/en/dev/modeling/meshes/editing/vertices.html
Comment: @Raksha Added a bit. If you use ALT M, they become connected. Before you merge, no circle cares for any other.
Comment: Thanks for the reply. I was trying to do it manually, but after removing the inner vertices and connecting everything back together, I just get the outline of edges and vertices, not a mesh sheet for some reason.
Edit: ok, dissolving them, rather than deleting, seems to have solved it, which is kinda strange since it didn't work on the WHOLE thing, just if i select the inside vertices.
Comment: Edit 2: nm, it looks like dissolve worked on just the vertices of one circle, like it's supposed to, but the circles don't appear to be connected since if i connect their respective vertices by "F", mesh disappears leaving just the outline...

Why isn't limited dissolve working?


Why does compton scattering provide evidence for the particle nature of light?

Question: I understand that compton scattering is modeled as a collision between a photon and an electron, but why does this conclusively prove that light can act as a particle? Why couldn't the same conservation of momentum and energy equations have been applied assuming that light is a wave?
Answer: The high energy photons are shown to have energy and momentum which is consistent with the Planck and de Broglie relations, which are quantum relationships that connect wave properties to particles.
The dynamics would be different if the interaction was wavelike: you see that in diffraction experiments, which follow the wave model of Bragg's law.
By the mid-1920s there was experimental evidence for particle behavior by photons, and of wave behavior by electrons.  This is the origin of the wave-particle duality description.


Use of verbatim quotes in reporting findings in qualitative research (semi-structured interviews)

Question: In qualitative research (semi- structured interviews) do we have to use verbatim quotes in reporting the findings?
Answer: There is no prescription.
However, it is always nice and useful to convey through your report the 'voices' of the interviewees through carefully selected quotes, i.e. the most significant, revealing or unique.
Hope that's useful.
Answer: I agree that there is no prescription to use quotes however more than being nice, using quotes provides verification.
In qualitative research we speak of verification instead of validity. So using a rigorous process and describing it for the readers helps verify the findings of your work. Using "rich" quotation to give context and voice to the participants is one method, among others such as triangulation, member checking, or collaboration.


Starting Ethereum Development

Question: Sorry for vague question but just looking to get some insight. I have just began developing a dapp for the ethereum network and I need some advice on what development frameworks/technologies to use.
I am fine with the Solidity smart contract development however I am struggling with the front-end UI and contract interaction.
Is drizzle a necessity when using truffle?
Is react recommended or can I just use a node-js front-end and interact with web3-js.
Any advice would be great.
Thanks
Comment: You can use a node-js front-end but drizzle simplifies greatly simplifies contract interactions.

I recommend exploring the existing truffle boxes boilerplates, but for simple applications there is no downside to using a front-end to interact with web3, I think it would make you a better Ethereum dev :).
Answer: you can use any front-end framework you want, but Dizzle provide a full integrated web3 layer that help for development process.
For example, I used web3.js with ember.js for some dApp test wich was working really well.

Starting Ethereum Development


How to plot Quantum Wave-Funktions like $e^{ix^2}$

Question: I would like to Plot a function like $e^{ix^2}$, similar to the one seen in this video at 1:26: https://www.youtube.com/watch?v=p7bzE1E5PMY&t=86s.
I think what I'm trying to do is to plot the imaginary part on one axis, and the real part on the other, both as a function of x.
Does anybody know how that works? I hope it isn't to complicated, since this isn't my task, just trying to boost my understanding of quantum mechanics.
Comment: The video and your description don't correspond. The video plots pos. vs. vel., not real and imaginary parts.  Which do you want? Possibly useful functions: `ReIm[]`, `ParametricPlot[]`, `ParametricPlot3D[]`.
Comment: @MichaelE2:  The OP unwittingly linked to a later time-stamp in the video than they intended to.  I've corrected the URL.
Comment: @MichaelSeifert Ah, thanks. I have little patience with video explanations as well. So already put out by a non-self-contained Q, I gave up.
Comment: Ah, I'm sorry for that, didn't realise there was a time stamp in the hyperlink @MichaelE2. Thanks for correcting it Michael Seifert.
Answer: As noted in the comments, the function you want is ParametricPlot3D.  You create the "graph" as a parametric curve with x as the parameter, and whose y and z coordinates are $\Re(\psi)$ and $\Im(\psi)$ respectively.
psi[x_] = Exp[I x^2];
ParametricPlot3D[{x, Re[psi[x]], Im[psi[x]]}, {x, -3, 3},
 AxesOrigin -> {0, 0, 0}, Ticks -> {Automatic, None, None}, Boxed -> False]

Comment: @chris:  probably `ColorFunctionScaling -> False,
 ColorFunction -> Function[{x, y, z}, Hue[Arg[psi[x]]/(2 \[Pi])]]]` would have more physical meaning, but let's walk before we run.  :-)
Comment: for fun you could add `ParametricPlot3D[{x, Re[psi[x]], Im[psi[x]]} // Evaluate, {x, -3, 3},
 AxesOrigin -> {0, 0, 0}, Ticks -> {Automatic, None, None},
 Boxed -> False, ColorFunction -> Function[{x, y, z}, Hue[z]]]'
Comment: Awesome, that was exactly what I was looking for. Thanks for taking your time!


Guitar : My sixth sting E cannot be tightened up

Question: My six string E cannot be tightened.
Mystring tightens to an extent which is very loose after reaching that extend, the peg keeps rotating but the string does not tighten.
I am talking about the the low string E, i opened up the string and wrapped it up again, but after 2 or 3 turns, the knob turns but the shafts doesn't
Comment: Can you tell us a bit more about your guitar? Pictures would be a great help. What model or price-range is it?
Comment: It's a Hertz HZA-4010
Answer: It sounds like the tuning machine has malfunctioned. It may be possible to disassemble and repair it, but probably easier to replace it. You will need a wrench or socket of the correct size and a small screwdriver.
Be sure to purchase a new tuning machine with the correct handedness. If this is the usual layout with 3 tuners on each side, then you want a "Left" one for the low E.
Edit: There was a suggested edit from an anonymous user that a "Right" tuner is needed. Bear in mind that "low E" means the E string with the lowest sounding pitch, not the one closest to the ground. Left refers to the left hand of the observer when looking at the headstock from top side of the guitar, not from an anthropomorphic perspective imagining the headstock to be a face with its own left- and right- sides. (I was a little unsure of this and checked a few online references and sales outlets. The confirmation is the fact that an inline headstock has 6 Left tuners, whereas a reverse inline headstock has 6 Right tuners.)
Comment: Any way to replace it instead of repairing it ?
Answer: Scant information means the question may well not get a helpful answer, but we need to know if the peg around which the string is wrapped is actually turning, and whether you do mean the low 6th E string, or are mixing it up with the high (thin) E.
To try to answer - the string may be slipping on the shaft. It may have far too many turns on it already. It may be that the knob itself isn't turning the gear, as it's slipping on its own shaft.
Far more information, please.
Comment: I am talking about the the low string E, i opened up the string and wrapped it up again, but after 2 or 3 turns, the knob turns but the shafts doesn't