Tempdb log growth 3x as slow on new server, SP does not perform

Question: We are running into the issue that our stored procedure on our new SQL Server performs a lot slower than on the old server. We looked into the problem and noticed the following on our temp db. The incremental growth takes 3 times as long on the new server. The same happens for the log file of our database. What is causing this?
Comment: Could be a number of things, we'd need to know details of the IO subsystems and layouts on both machines (drive types, local or network, where are the data and log files stored, ...) to make educated guesses. Also is Instant File Initialization enabled on both instances? Same CPUs and amount of RAM? As an aside I'd be inclined to increase the growth increment to have fewer larger growths, but that is the same on both so won't be the reason for a difference.
Answer: While determining why the growth is taking longer on the new server is a task that can depend a lot o your environment, as noted by David Spillett's comment, it's likely that you might have sized the tempdb in a way that is not optimal for your server, causing auto growth to be triggered frequently.
As Brent Ozar says on his Cheat Sheet: How to Configure TempDB for Microsoft SQL Server:

configure one volume/drive for TempDB. Divide the total space by 9,
and that's your size number. Create 8 equally sized data files and one
log file, each that size. Presto, the drive is full and your TempDB is
configured for easy performance.

Sizing tempdb properly is also listed on the Optimizing tempdb performance in SQL Server doc as a good practice:

Preallocate space for all tempdb files by setting the file size to a
value large enough to accommodate the typical workload in the
environment. Preallocation prevents tempdb from expanding too often,
which affects performance. The tempdb database should be set to
autogrow to increase disk space for unplanned exceptions.

Finally, if your new server has more than 64 CPUs, the doc on Best Practices for running SQL Server on computers that have more than 64 CPUs says:

Do not rely on autogrow to increase the size of the transaction log
file. Increasing the transaction log must be a serial process.
Extending the log can prevent transaction write operations from
proceeding until the log extension is finished. Instead, preallocate
space for the log files by setting the file size to a value large
enough to support the typical workload in the environment.

Considering mainly the point about preventing transaction write operations, if the SP that is not performing does any write operation, it would be affected by the autogrow.
So, even though this advice does not answer your question about the reason the growth is taking longer to be performed, I thought it was worth mentioning it.
Answer:
We are running into the issue that our stored procedure on our new SQL Server performs a lot slower than on the old server.

Use the Session Wait Stats and the Query Store to figure out if there are more waits (like IO) on the new server or if the query plan is worse.

The incremental growth takes 3 times as long on the new server.

Use DISKSPD to benchmark the IO performance on both servers.  Log file growth always requires zero'ing the allocated space.  Also pre-size the log files and increase the auto-growth increment.


Increased speed limit and decreased speed limit signs located ~1/3 mile apart on opposite side of road. When is it legal to increase speed?

Question: Sorry for the confusing title, this is kind of hard to describe. I just moved to western MA. In my new town, there is this road where on one side, the speed limit goes from 40 to 30, but on the other side, rather than having the sign saying the speed limit goes up to 40 directly across the road, it is located another 1/3 to 1/2 of a mile further, meaning that oncoming cars will be legally travelling at 40 MPH in the opposite direction, but just going by signs it appears to the cars travelling in my direction that the speed limit is still 30 (I have drawn a sketch of what I am talking about below since it's difficult to describe). I always wait until I pass my 40 MPH sign before I speed up, but everyone behind me gets annoyed and starts tailgating me if I don't speed up. Also, when I'm driving behind someone, they always speed up to 40 after passing the 30 MPH sign on the opposite side of the road, even if they were driving 30 before. My question is whether it is legal to speed up to 40 once I get past the point where oncoming traffic needs to slow to 30, since from my understanding speed limits always work in "zones" where the limit is the same on both sides of the road. Or do I technically need to wait until I pass the 40 MPH sign even though it's quite far away?
Sorry for my bad drawing skills
Comment: Is the 30 MPH sign facing you or the opposing lane?
Answer: The national standard, found in the Manual on Uniform Traffic Control Devices (MUTCD), indicates, in Section 2B.13 Speed Limit Sign:

03 Speed Limit signs, indicating speed limits for which posting is required by law, shall be located at the points of change from one speed limit to another.

It would not be legal to accelerate to the new speed before reaching the sign.
All states were required to adopt the MUTCD no later than 2012. This standard is followed by all states.
Comment: Not just "accelerate to the new limit", but also "accelerate beyond the old limit". In this situation, accelerating to 31 is only legal at the 40 sign. On the other hand, you must have slowed down to 30 when you reach a 30 sign.
Answer: This question is really 2 different questions in one.  It can be broken down as following:

what is the legal speed limit in the area in question?
what is the best explanation for why many drivers are tailgating me when I follow the posted speed limit?

In case you just moved to MA from a different state, I'll answer the 2nd question (because it was clearly implied in the OP).
In some places it is an accepted convention to disobey speed limit signs. The convention is adhered to by most drivers and cars are only stopped by police if they travel at speeds far exceeding the convention. For example, in the NY-NJ tunnels the posted speed limit is (I believe) 25 mph. The convention is to travel at 40-50 mph. Similarly, it is a convention to travel 10 mph above all posted speed limit signs in NY/NJ. The drivers may be tailgating because you don't follow the accepted convention rather than the law.
Answer: It depends.
Massachusetts law says that a special speed regulation isn't valid unless certain hoops are jumped through by the government. They can't just put a sign wherever they like and legally enforce it.
It seems likely that the speed limits are not actually different for traffic going in opposite directions. One of the signs is likely misplaced, or perhaps a sign got knocked down and was never replaced. It's impossible for us to tell which sign it is; maybe it's supposed to be a 40 zone on both sides in that area, but it could just as well be that it's supposed to be 30 on both sides (although the lack of a sign would preclude prosecution for traffic in the other direction if it's supposed to be 30.) But you may be able to track down your local regulation establishing a speed limit on that particular road, and see where the speed zone is actually supposed to start.


Is reusing a variable in VB6 a good idea?

Question: Essentially I want to know if in VB.NET 2005 if using a sqlcommand and then reusing it by using the NEW is wrong.  Will it cause a memory leak.
EG:
try

dim mySQL as new sqlcommand(sSQL, cnInput)

// do a sql execute and read the data

mySQL = new sqlcommand(sSQLdifferent, cnInput)

// do sql execute and read the data
catch ...

finally

if mysql isnot nothing then
   mysql.dispose
   mysql = nothing
end if

EDIT: put try catch in to avoid the comments about not using them
Answer: Just to extend what Longhorn213 said, here's the code for it:
Using mysql as SqlCommand = new SqlCommand(sSql, cnInput)
  ' do stuff'
End Using

Using mysql as SqlCommand = new SqlCommand(otherSql, cnInput)
  ' do other stuff'
End Using

(edit) Just as an FYI, using automatically wraps the block of code around a try/finally that calls the Dispose method on the variable it is created with. Thus, it's an easy way to ensure your resource is released. http://msdn.microsoft.com/en-us/library/htd05whh(VS.80).aspx
Answer: Garbage collection will gather up the first new when it is run.
Only the second one you purposely dispose in the Finally block.  The first one will be disposed of the next time the garbage collection is run.
I do not think this is a good idea.  If the first command is not closed correctly it is possible you would have an open connection to the database and it will not be disposed.
A better way would be to dispose the first command after you are done using it, and then to reuse it.
Answer: Uh, to all those people saying "it's OK, don't worry about it, the GC will handle it..." the whole point of the Dispose pattern is to handle those resources the GC can't dispose of. So if an object has a Dispose method, you'd better call it when you're done with it!
In summary, Longhorn213 is correct, listen to him.
Answer: One thing I never worked out - If I have a class implementing IDisposable, but I never actually dispose it myself, I just leave it hanging around for the GC, will the GC actually call Dispose for me?
Answer: No, the garbage collector will find the old version of mySql and deallocate it in due course.
The garbage collector should pick up anything that's been dereferenced as long as it hasn't been moved into the Large Object Heap.
Answer: Whilst garbage collection will clean up after you eventually the dispose pattern is there to help the system release any resources associated with the object sooner,  So you should call dispose once you are done with the object before re-assigning to it.
Answer: Be careful.  If you have to do a lot of these in a loop it can be slow.  It's much better to just update the .CommandText property of the same command, like this (also, you can clean up the syntax a little):
Using mysql as New SqlCommand(sSql, cnInput)
  ' do stuff'

    mySql.CommandText = otherSql

   'do other stuff'
End Using

Of course, that only works if the first command is no longer active.  If you're still in the middle of going through a datareader then you better create a new command.


How to find out which port is located on a switch physically

Question: I'm trying to physically located a port on a switch. I know which port the mac address is connected to. The port is Gi2/0/14. But this is part of a stack. How do I know which switch this port belongs to in the network closet
Comment: Switch type/model?
Comment: Thanks fellas I was able to figure out what switch it was and which port it was on. Tracing it to the patch panel was another thing.
Comment: Did any answer help you? If so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you can provide and accept your own answer.
Answer: If the switches are indeed stacked, the hardware itself will very probably offer a way to show/display the stack member number of each given switch. You'll have to look it up in the given hardware documentation. Some vendors even have a 7-segment display showing the stack member number.
Taking "Gi2/0/14" to be a hint that it's a stack of Cisco switches, chances are good that the given specimen has a "mode" button on the left side of the front plate (port side).
Repeatedly shortly pressing the mode button cylces the port LEDs through different modes of information display, such as status (Link up/down/blocked/disable), speed (1G or 100/10), Duplex, PoE, Stack Member, Stack Master or CPU load. The available modes depend on the features of the given product family.
Answer: It is on switch 2 of the stack, but you cannot tell by looking at the stack which one is switch 2 unless you labeled it. You need to connect to the stack and try to figure out which switch is switch 2.
Answer: cisco stackable switches has led that showing the status of switch
one of this led is show stacking status that

if led 'master' is on then this switch is master and ports of this switch started by '1/0/1'
if led 'master' is off then this switch is slave and ports of this switch started from 'x/0/1' that 'x' can be '2=<'


strncpy_s does not work if the second parameter set to be 1

Question: I am so curious why for strncpy_s, when I set the second parameter numberOfElements to 1, it does not copy the first character to the destination. And when I set it to 2, it copy the first one to destination.
For example:
int main()
{
    char a[16];
    strncpy_s(a, 1, "1+1=2", _TRUNCATE);
    return 0;
}

Then in debugger, I found a[0] = 0'\0'. Why it is not a[0] = '1'?
Answer: Because the string "1" takes up two bytes and there's only room for one.
A C-style string has to have a terminating zero byte, otherwise there is no way to know its length. With just space for one character, the only possible legal string is just a terminator.


How do I edit disclaimer/contact information?

Question: I inherited this wordpress website called RxStudyGuides to use as a study tool for pharmacy students. However, the owner and creator of the website still has there contact information on the website at the bottom of the page and I can't seem to find how to edit that information. It only seems that I can edit the actual content of the website. The creator made me an editor and maybe since I am not the owner of the site I cannot edit information other than content? If that is the case is there a way to transfer ownership of the site?
Answer: The contents that existing in the header and footer that is the content that visible in all pages will usually integrate using theme option. so  take the admin and  go to  appearance->Theme option Then check the contact details is there in that .
Comment: Hello, thank you for responding. There is not an option to modify the theme/appearance. I only have the options to manage: site pages, blog posts, media, comments, feedback, and sharing. Like I said I'm not sure I have full editing capabilities because I am not the creator of the site. i have admin access to another site and I can see the options to "personalize" and edit admin/editors, however these are lacking with my RxStudyGuides site. Is there a way to transfer admin access from the creator of the site to me?
Comment: Update: I copied the URL https://wordpress.com/customize/rxstudyguidesuic.wordpress.com to go to what would be the customize page and it says I don't have permission to customize the site.
Comment: in that case i think you don't have the access in database too. Don't you....    if you have the db access you can simply search the content in db and update your new content in the contact information area.
Comment: one more possibility  is there, that is  contact information is in the footer,sometimes he put the contact details as static in the code itself...


Interpreting Infrared Spectroscopy (IR) Spectra

Question: I have already attempted to interpret some of the peaks. Please tell me if they are correct/incorrect and anything that I have missed.
Comment: In your first spectrum, I would be skeptical about the alkynic $\ce{#C-H}$ bond you've identified at approx. $3400\mathrm{cm^{-1}}$, as there is no corresponding alkynic $\ce{C#C}$ signal (typically roughly in the $2100-2300\mathrm{cm^{-1}}$ region).
Comment: i think you have made those interpretations very cautiously and will full effort because the trend followed by them is clearly visible . i mean as the position increases the intensity decreases i.e. they are inversely proportional to each other i cant detect any wrong or miscalleneous point in your graph
Answer: In your first spectrum, the band at 3517 $\mathrm{cm^{-1}}$ indeed fits best to the $\ce{N-H}$ stretch of a primary amine (source). However, I would not assign the shoulder of this band to a $\ce{#C-H}$ stretch. Such a band would be sharper and perhaps more intense, and as Greg E. already pointed out in his comment to your question, there is also no corresponding $\ce{C#C}$ stretch band present (reference). The absence of bands in the range between 2500-2000 $\mathrm{cm^{-1}}$ allows you to rule out some other functional groups with double or triple bonds, like nitriles, thiocyanates, isocyanates, carbodiimides or azides. The band at 1715 $\mathrm{cm^{-1}}$ is a typical $\ce{C=O}$ stretch, and while it could be a ketone, the presence of the broad band at 2932 $\mathrm{cm^{-1}}$ (which could actually be a double band) makes it likely to be an aldehyde, since the double band can then be assigned to the $\ce{=C-H}$ stretch of the CHO group (it could also include other $\ce{C-H}$ stretches due to its width).
Your second spectrum appears a bit more complex. The broad, intense band at 3298 $\mathrm{cm^{-1}}$ in combination with the band at approximately 1680 $\mathrm{cm^{-1}}$ could be assigned to an amide, but I would expect a stronger carbonyl band in this case. Nevertheless, the intensity and width of the 3298 $\mathrm{cm^{-1}}$ band suggest the presence of a functional group capable of H-bonding. The bands between 2900-2800 $\mathrm{cm^{-1}}$ could be assigned to alkyl $\ce{C-H}$ stretches (source). For the compound to be aromatic, there should be aromatic $\ce{C-H}$ stretch bands present, slightly above 3000 $\mathrm{cm^{-1}}$ (source).
Answer: My interpretation of the first spectrum:

I would say that the 3517 band belongs to OH group. This is a typical shape OH group. Amines look more like two bands with a shoulder. However secondary amine is also a possibility. Other bands of OH should be the broad band between 1400 and 1300 from which the sharp bands arise. Than probably 1166, which seems to be tertiary OH group.
≡C−H stretch is not right. Is is an overtone of the 1715 vibration.
The four bands around 2932 are CH3 and CH2 stretches.
1461 is an antisymetric deformation of CH3, 1411 is scisorring of CH2 and 1359 is an umbrella of CH3.
The rest is a fingerprint region.
I assume this is an aliphatic ester molecule.

The second spectrum I am not sure, however:

An aromatic vibrations are unlikely, there should be vibrations just over 3000, which are missing and the 2000 region also looks different.
There are aliphatic vibration just like in the first spectrum.
3298 is not typical for amine. However I cannot rule it out. It might be an OH-group as well.


Poincare group and free theories

Question: How exactly is the Poincare group related to the free relativistic theories in quantum field theory? I know Poincare group is the Lorentz group along with translations but don't see any connected why the field will influence the Poincare group.
Answer:
This is a general phenomenon. Whenever a theory/system $S$ has a symmetry,
it in particular means that some group $G$ acts $G\times S \to S$ on the system $S$. The system $S$ then constitutes a (possibly non-linearly realized) representation of the group $G$. See also my Phys.SE answer here.
Concretely the isometry group of Minkowski space is the Poincare group. Concerning representations of the Poincare group in relativistic field theories, see e.g. this & this Phys.SE posts and links therein.
Comment: I mean rotations and translations make sense for scalar fields, as well as vector fields like Electromagnetic field.

Poincare group and free theories


How to use "glad" properly?

Question: I'm happy to learn from someone that they have the possibility to return home to their family they haven't seen for so long. Should I say "I'm glad (that) you return to your family!" or " I'm glad (that) you're returning home to your family!" Is "that" necessary? Is "return home to your family" said?
Comment: Does this answer your question? [Omission of "that" (in this text).](https://ell.stackexchange.com/questions/56579/omission-of-that-in-this-text) Where the answer specifically includes [*I'm glad (**that**) she made it*](https://ell.stackexchange.com/a/56590/126) as an example of ***optional** omission of "**that**" after adjectives.*
Answer: A dictionary will tell you that "glad" means "feeling pleasure or happiness". However, the way you use this (or any similar word) and the context in which you do so can have different inferences.
If you say to someone "I'm happy you are going" without any other context, that sounds quite rude - like you did not want them to be around and their departure is making you happy. However, if someone had just shared with you happy news that they were going somewhere they always wanted to go, the same words could sound perfectly sincere.
One way to express what you want to say sincerely and naturally would be:

I'm glad you have this opportunity to see your family!

This makes it very clear that your source of gladness is their opportunity to see their family and not the fact they are leaving.
Answer: I would use a phrase that refers to a future or ongoing action: will be going, are going to go, or are going. There are many ways to express this idea.
As a complete sentence: "I am glad that you are going home to see your family."
You don't absolutely need to include "that," but it doesn't hurt. A way to decide: could it be confusing or strange without it?
"I know Monday is a busy day for you."
That could sound strange because "know Monday" might sound like you know a person named "Monday."
"I know that Monday is a busy day for you." makes the meaning clearer.

How to use "glad" properly?


SockJs - error trying to create an unsecure websocket connection from secure page

Question: Trying to connect to SockJs server.  I am running the following code from a secure https page https://localhost/index.php
    var sockjs_url = 'http://localhost:9999/echo';
    var sockjs = new SockJS(sockjs_url);

    sockjs.onopen    = function()  {console.log('[*] open' + sockjs.protocol);};
    sockjs.onmessage = function(e) {console.log('[.] message' + e.data);};
    sockjs.onclose   = function()  {console.log('[*] close');};

I get SecurityError: The operation is insecure. and it falls back to openxhr-polling
If I run it from http http://localhost/index.php websocket connection is established.
Is it not possible to create an unsecure websocket from a secure page?
UPDATE This happens in Firefox but in Chrome I'm able to open websocket
UPDATE 2 Eventually I resolved it by using a https server. See here.
UPDATE 3 Related Firefox Websocket security issue
Answer: Some browsers forbid running an insecure WebSocket connection from a secure page, including FireFox.


how to pronounce the word 'elementary'?

Question: In LONGMAN dictionary, the pronunciation of the word elementary is /ˌeləˈmentəri/. However, I heard some people pronounced it like /ˌeləˈmentri/. How should I pronounce the word correctly?
Comment: It depends how carefully people are speaking. Almost everybody will give it five syllables when speaking slowly and carefully; but many people elide the fourth syllable in ordinary speech. This is the case for other words where _-ary_ follows a 't', eg _secretary_; and also words formed differently where an unstressed vowel follows a stop consonant, such as _category_ and _allegory_.
Comment: I would pronounce it as the following, eh · luh · men · tr · ee Here is the link to the video that I found it from: https://www.youtube.com/watch?v=RJ7ImmpVXWM
Comment: I'd say it's /ɛ/ and not /e/, though. (Also read [this answer](https://ell.stackexchange.com/a/254188/106592) to a similar question.)
Answer:
/ˌeləˈmen.təri/

/ˌeləˈmen.tri/

Both of them are correct.
The first one has 5 syllables while the second one has 4. It depends on the dialect of English. Some British and American dialects have lost the weak syllable (second last in 'elementary'—/tə/) so they pronounce it with 4 syllables, but both are equally correct and acceptable.
In English, when a stressed syllable is followed by two (or more) unstressed syllables, the vowel immediately following the stressed syllable is usually dropped in colloquial/fast speech (not every accent/dialect and not in every individual's speech). The pronunciation varies from individual to individual. The process is called syncope. Other examples include: comfortable, camera, family, average etc.
In most dialects, the emboldened vowels have been syncopated, however, some dialects have retained them and still pronounce them.
Comment: In upstate New York, many people will pronounce it with initial stress and secondary stress on the penult (EL-em-en-TA-ry). Apparently this is [even more common with *sedimentary*](https://repository.upenn.edu/cgi/viewcontent.cgi?article=1143&context=pwpl). In terms of speech, it is the only distinction I associate with that part of the country.
Comment: @choster I've never heard the version you are discussing here. But a similar version has been brought to my attention and nagging at the back of my mind. A short while ago, a friend noted how I pronounced "elementary" two different ways, one stressing the first syllable /Ele-men-tri/, the other being the more common (ele-mEn-tri). And in my experience, the initial stress version is in the minority in AmE. I wonder if it is really a regional thing. I pronounce it exactly the same as Monica Byrne [here](https://youtu.be/8HfoKd873HY?t=236) who seems to hail from Pennsylvania.

how to pronounce the word 'elementary'?


What courses should I count when calculating my GPA in major?

Question: When calculating my GPA in major, should/can I only count courses that are meeting the requirement for major or should I count any course on the same topic and from the same department as my major? For example, if my major is Physics, and I have completed my major with courses A through J, but have also taken the course K after completing all the requirements as an optional course (which does not even count for graduation; a completely optional course), should I count the grade for course K when calculating my major GPA for reporting it on my CV and in applications, or can I not count that one?
Answer: If no specific guidance is otherwise provided, I would include additional courses in the same department as the major. The reason for this is that anybody looking over your transcript will assume that, unless the course is clearly marked as a graduate course, it's probably a requirement for your major.
That said, we're also not likely to check your math unless there's a gross error, and we're not likely to sweat a few hundredths of a point difference.
Comment: The course is a graduate course, and if the person reviewing my transcript is familiar with the course numbering system, it is numbered as a graduate-level course. But I have quite a few graduate-level courses that are being counted towards my major requirements.
Comment: Also, the numerical difference would be clear because excluding this course, I have GPA 4.0 in major. But if there is any grade other than A or A+, my GPA could not be a 4.0, so it would be obvious without doing any math that I did not count this grade in my GPA calculation.
Comment: If an admissions committee is going to accept you with a 4.0, odds are excellent that they won't bat an eye over a 3.95 or so.
Answer: My university calculated my GPA for me.  I did not bother to double check their arithmetic.
If your university does not calculate your GPA for you, then just imagine the GPA that you want.  No one cares.
Comment: This is GPA in major, which the university does not calculate. The GPA for the whole degree is calculated by the university and reflected on my transcript.
Comment: "just imagine the GPA that you want" -- not sure exactly what you're suggesting here. Intentionally misreporting your GPA could constitute fraud and lead to being expelled from the program if it is later discovered. Further, GPA matters a great deal at many universities.
Comment: perhaps you mean "calculate it any way you want"? Sure, absent any specific instructions, calculating it in any defensible way may well be preferable to contacting them and asking for clarification.


Can I change the colour of the Submit button?

Question: Can I change the colour of the submit button?
Answer: I am a developer for Cognito Forms.
You can change the color of the submit button. On the Publish page you can click "Form Styles" on the left side of the page. You will then be shown different styling options, one of which is Button & Link color.

Another option would be to use CSS if your form is embedded on your website. This can be done by using the following basic CSS, the color will need to be changed to the color of your choice.
.cognito #c-forms-form button {background-color:#ffffff;}


Moderation effect of a variable

Question: Should we include some control variables in regressions when we test a moderation effect of a variable?
Comment: In general, control variables are a good idea. Please give an example of the specific regression you would like to know about.
Comment: Thanks a lot! when I added relevant control variables to my regressions, the moderator variable "become not significant" but the interaction term remain significant..Should we say that there is a moderation effect?..Without control variables, both were significant..
Answer: Without additional information, it is hard to answer your question but I would say that a moderation model is like any econometric model (and in fact, it is an econometric model).
Therefore, I would tend to agree with @Student, adding control variables is a good idea but it must represent your theoretical considerations (is there an omitted variable bias, a confounding variable, etc ?). So you should only add relevant variables to your model in order to increase its precision.
Just adding random/useless variables will unnecessarily increase the complexity of your model; and as my econometrics professor used to say: "why use a bazooka to kill a fly when you can use a fly swatter ?"
Edit: I (scholar) googled "moderation effect economics" and I randomly chose a paper published in a good journal, you can see that they also use relevant control variables (p. 512).
Comment: Thanks a lot! I added relevant control variables to my regressions. For some regressions, the moderator variable "is not significant" but the interaction term is significant..Should we say that there is a moderation effect?

Moderation effect of a variable


Is one required to be in a project management job to be eligible for PMP certification?

Question: I would like to know if a person has to be currently working as a project manager when applying for PMP certification.
Comment: Did you check the [PMI website](http://www.pmi.org/en/Certification/Project-Management-Professional-PMP.aspx), which contains the requirements to apply for PMP certification?
Answer: Obtaining or holding a current PMP certification from the PMI does not require that the person is currently employed. However, to obtain the certification the applicant must provide evidence of three years of work experience in the knowledge domains tested.
The full criteria for applying for the PMP can be found here on the PMI Website's Certification page.
The certificate holder must keep current in the field over three years by continuing professional development through events or formal education. Otherwise the certification become expired and a new application and testing process must be completed.
Answer: No you do not have to work as PM.
You may have never got the title as PM before applying but as Polymath answered you have to show proof that you have the necessary expertise in the knowledge domains.
You will fill out a form, while applying for exam, in which you will state how many hours you have worked on each knowledge field on each and every project you have worked on.
Answer: You need to have 4500 hours of PM experience in a leading & directing role to to do PMP. So, PM role is must before doing PMP. However, PM role is not equivalent to PM designation/title. PM role means that you should have managed full or part of a project. Your role in the project could be of vendor management, team management, client management etc. The projects could be related to any industry. They could be big or small, technical or non-technical etc.
Answer: For any kind of certifications, there are some limitations, but it's not compulsory that you have to be in working in the same field. But to write any certifications you need to have proper experience with the education.
Now when you have raised as you need to be PM job so its not that necessary. There are larger benefits to grow when you want to be in Project Management stream. PMP is one of the best professional credentials in the field of Project Management.
The benefits of PMP Certification are immense! Not only will you become a more complete person, you will become a better project manager. Some benefits, if I could tell you is: Growth in career prospects, enhancing your marketability, improving your project management skills, and last but not the least, increased earnings.
I am planning to take this is up as it is very important when we have plans for abroad opportunities!
Comment: I feel like you didn't really answer her question.  It's not compulsory that you work as a project manager, but "proper experience with education" is not how you prove your experience. To meet the experience quotient, you must have worked in one of the practice areas as the above answers stated.
Comment: Kindly go  through  my  comment  once  again so  that  you  will  know I covered  all the  query given.  Thanks  in  advance
Comment: Shannon is right, it's not really clear what you mean by proper experience with education. That's really the only part of what you wrote that's actually applicable to the question, and it's vague. Perhaps you can clarify?


Does Tunisia require a Visa if I don´t disembark while in port?

Question: I am visiting Norway on a 90 day Schengen Visa Single entry. I am booked to go on a cruise from Barcelona to Rome, but it stops in Tunisia for a day and night. If I do not go off the ship, do I need to have a Visa for Tunisia? I am Filipino.
Comment: Welcome to travel.SE.  Presumption of visa necessity notwithstanding what's your citizenship?
Comment: I am worried that we might get denied during check in if the visa is really necessary. Since I am on a single entry visa, we thought it's best to not get off the ship so as to not to get a stamp on my passport showing I left the Schengen area.
Answer: Typically, customs and immigration formalities are completed in the cruise terminal at the port of departure. For international cruises, it's very likely there would be a border control (and Schengen exit stamp) right at the ferry terminal in Barcelona.
Much like in airports, border guards wait for passengers in little booths and everybody must go through the checkpoint, they don't travel with the ship to stamp passports depending on who leaves the ship or not. So I think you need a two-entry visa in any case, even if you don't plan to disembark in Tunisia or can enter there without a visa.


I Can't change my password

Question: I can not change my password to slide or no password, it says it is due to administrator policies but i have disabled all apps from there, What do I do?
Answer: That is because of credential storage. Go to settings--> storage and clear the credential storage. Reboot your device and now you will be able to set lock screen to swipe or no password.

I Can't change my password


error sending message to whatsapp

Question: I am member of a whatsapp group. My name is present in the group member's list. Nobody has removed me. But when I send any message I get the error not a member of this group cannot send any message. Friends also confirm that message has not arrived. Strangely though I can read new posts in the group but cannot see the group icon. I have no clue about how this can happen.
Comment: Try clearing the data for the app (you'll lose your messages) and then log in again.
Comment: Thanks but do I have to clear the data for google drive backup too or just local data?
Comment: @rancho We usually don't provide bugfixes for apps. Only the app developers can do that!
Answer: Inform the admin of the group to remove you and add again.
This will works.
And then you will able to send and receive messages.

error sending message to whatsapp


Why are springs shaped the way they are?

Question: Why are springs coiled the way they are? Why not some other shape? Is the shape due to its elasticity or something?
Comment: There are also leaf springs.
Answer: The shape is due to the underlying principle of what a coil-spring actually does.
A spring is originally a long (often metal) wire.  When you coil it, you are changing the way the forces can be applied to the spring.
For coil springs, you are making two surfaces that are often flat or have connections, that can be coupled with other systems.
The interesting thing is what is actually happening to the wire when you stretch or compress a coil spring.  Because of the helical nature of the winding, when you push/pull on the spring, most of the effort is not going into bending or stretching the wire.  It is twisting it.
You can visualize this by thinking of a coil from the side.  The twisting forces all the coils closer together or further apart, leading to the motion desired.
You can consider it as a long bar experiencing torsion, allowing it to twist.  As long as the bar has a constant cross section this relationship will also be linear, which may also have something to do with the shape.
Essentially, my understanding is that the helical shape allows you to use vertical motions to create twisting in the horizontal planes.
Helical shapes seem to do similar things in other applications.  Perhaps someone with a better understanding of the math could give a clear description of why helix shapes can change the nature of motion in general.
(for example, torsional springs actually create a spring that resists twisting, but the spring itself is actually acting like a long bent bar; basically the opposite scenario of a linear helical spring)
Answer: Well, metals can bend easily. If a length of metal is in the shape of a coil, then this bending can occur over the entire spring at once. Perhaps minimal temporary deformation at each point prevents permanent deformation. In any case, it maximizes lengthening ability while minimizing "effort" by the spring. I don't know if there are other shapes that would work better, but a cylindrical coil is certainly a simple and effective solution.
Comment: One says "bend," the other says "twist," but there's a better word that encompasses both ideas:  "strain."
Comment: A coil spring doesn't really _bend_ as you move it, it _twists_.  I believe the helical shape is important in that conversion from linear movement to the angular change in the wire (and tried to detail that in my own answer).
Comment: @jameslarge But encompassing them both with "strain" is ambiguous. When talking about bending vs. twisting you're also comparing normal stress with shear stress.  It does make sense to recognize the distinction here IMO; which is why I wanted to point it out.
Comment: There are springs that work by bending (e.g., the spring that drives a wind-up clock, or leaf springs in the suspension of a road vehicle), and there are springs that work by twisting (e.g, a coil spring, or a torsion bar in a vehicle suspension).  What Ziggurat appears to be saying is that springs like the clock spring and the the coil spring distribute the strain over a relatively long piece of metal, thereby effecting relatively small _spring constants_ as compared to the leaf spring and the torsion bar.


In Acts 26:23 what does it mean that the Messiah will "proclaim light"?

Question:
[Act 26:23 ASV] (23) how that the Christ must suffer, and how that he first by the resurrection of the dead should proclaim light both to the people and to the Gentiles.
[Act 26:23 MGNT] (23) εἰ παθητὸς ὁ Χριστός εἰ πρῶτος ἐξ ἀναστάσεως νεκρῶν φῶς μέλλει καταγγέλλειν τῷ τε λαῷ καὶ τοῖς ἔθνεσιν
Comment: See Isaiah 42:6, 49:6, 60:3.
Comment: So "proclaim light" means "preach the truth"? Did he do any preaching after his resurrection?
Comment: When the word of God resurrected? That is the same as saying God preached after his silence.
Comment: John 3:14-18 "Just as Moses lifted up the snake in the wilderness, so the Son of Man must be lifted up, that everyone who believes may have eternal life in him." For God so loved the world that he gave his one and only Son, that whoever believes in him shall not perish but have eternal life. For God did not send his Son into the world to condemn the world, but to save the world through him. Whoever believes in him is not condemned, but whoever does not believe stands condemned already because they have not believed in the name of God's one and only Son".
Comment: Hebr 1:3 "The Son is the radiance of God's glory and the exact representation of his being, sustaining all things by his powerful word. After he had provided purification for sins, he sat down at the right hand of the Majesty in heaven".
Comment: I was hoping @Mac's Musings may have an answer to this question.
Comment: "The exact representation of his being" is presented by Jesus on the cross, where he performed the 'crucifixion of the snake in the desert'. It is belief in, and application of, the "crucifixion of the snake" that purifies us from sins, and makes us Holy. The missing piece in our holiness search is - chastity. It is the stone that the builders rejected. Salvation through chastity is the "Good News".
Comment: All good verses but Isaiah 60:3 is particularly very, very beautiful. Thanks Lucian.
Answer: I think we have to understand this by going back to John 1, which gives us the best exegesis for what "light" is. John 1 states that Yeshua himself is the light. This light is also said to be serving the purpose of illuminating Creation by obliterating "the darkness". I submit that we can't properly understand this language without going back to Ezekiel. In Ezekiel chapters 8-10, a scene occurs which ends with the glory of YHWH leaving the temple. The scene is one where the Israelites exchange the light of YHWH's glory for the light of the sun, and YHWH hands them over to their sins. This is the origin of the darkness-and-light symbolism in John, but also the NT as a whole.
There are some verses such as Hebrews which are more plain about it, but Yeshua is the glory of YHWH, who once left out the east gate and who (in John's prologue) is now returning. So the light that's being proclaimed is the glory of YHWH, Yeshua himself.
The claim, however, isn't just that Yeshua is the light, but that he is (paraphrase): "The true light that gives light to all men." And the question is, the true light as opposed to what exactly? I submit that the answer isn't given in John because he's referencing back to Ezekiel: Yeshua, who is the glory of YHWH, is the true light that illuminates reality and makes the Truth accessible, as opposed to the sun.
Answer: The Light Bringer
Lets look at the part of Greek in question φῶς μέλλει καταγγέλλειν.

φῶς (phōs) - light - This is the accusative noun, it receives the action of the verb.
μέλλει (mellei) - he is to be - Here is our verb,  present infinitive active 3ps.
καταγγέλλειν (katangellein kata and aggelló) -  calling down, preaching down, proclaiming in the down direction, aggelos usually translates as angel - also the verb

The Build
he is to be sending down light
The Metaphorical Usage
Light in the bible represents realization, the verse says in other words: Because he resurrected both the people and the Gentiles would realize.
Conclusion
God sent the light for the realization within John 3:16.
Answer: According to Jewish midrash light was a symbol for the Torah:

The wicked walk in darkness, but those who have the light of God, the Torah, as their guide are restricted from committing sin even when they have a passing desire to do so.--Mid. Psalms 119.

Accordingly, light would bring both revelation and life [ibid.]:

...Light is often used as the symbol of life and joy (Job xviii. 5-6, xxxiii. 28; Ps. xlix. 20 [A. V. 19], xcvii. 11; Esth. viii. 16). It is likened to the word of instruction (Ps. cxix. 105; Prov. vi. 23)...

I would qualify that further to say that "light" is predominantly about "spiritual life" and that the entrance of the "light" also brings "spiritual life" aka "eternal life". Acts 26:23 seems to have that focus on "light" as "eternal life":

[Act 26:23 ASV] (23) how that the Christ must suffer, and how that he first by the resurrection of the dead should proclaim light [IE: "eternal life"] both to the people and to the Gentiles.

These are all the verses in the ASV that feature both "light" and "life" along with my comments:

"light" is used in apposition to "life":

[Job 3:20 ASV] (20) Wherefore is light given to him that is in misery, And life unto the bitter in soul;

"behold the light" is used in apposition to being redeemed from the pit:

[Job 33:28 ASV] (28) He hath redeemed my soul from going into the pit, And my life shall behold the light.

"light and salvation" is used in apposition to "strength/stronghold of my life":

[Psa 27:1 ASV] (1) A Psalm of David. Jehovah is my light and my salvation; Whom shall I fear? Jehovah is the strength of my life; Of whom shall I be afraid?

"fountain of life" is used in apposition to "in thy light":

[Psa 36:9 ASV] (9) For with thee is the fountain of life: In thy light shall we see light.

"Torah is light" and "reproofs of instruction" are identified as "the path to life":

[Pro 6:23 ASV] (23) For the commandment is a lamp; and the law is light; And reproofs of instruction are the way of life:

being liked by the king keeps you alive:

[Pro 16:15 ASV] (15) In the light of the king's countenance is life; And his favor is as a cloud of the latter rain.

"life" and "life" are equated:

[Jhn 1:4 ASV] (4) In him was life; and the life was the light of men.

"light of life"

[Jhn 8:12 ASV] (12) Again therefore Jesus spake unto them, saying, I am the light of the world: he that followeth me shall not walk in the darkness, but shall have the light of life.

In the light of all these passages I think we can say that Jesus' empty tomb and empty cross/post is silent proclamation that life and immortality are available and imparted through the "eternal-life-giving light" of the announcement of the gospel.

[2Ti 1:10 ASV] (10) but hath now been manifested by the appearing of our Saviour Christ Jesus, who abolished death, and brought life and immortality to light through the gospel,

I also note that "darkness" is associated with ignorance and death:

[Job 3:5 ASV] (5) Let darkness and the shadow of death claim it for their own; Let a cloud dwell upon it; Let all that maketh black the day terrify it.
[Job 10:21 ASV] (21) Before I go whence I shall not return, Even to the land of darkness and of the shadow of death;
[Job 12:22 ASV] (22) He uncovereth deep things out of darkness, And bringeth out to light the shadow of death.
[Psa 107:10, 14 ASV] (10) Such as sat in darkness and in the shadow of death, Being bound in affliction and iron,  ... (14) He brought them out of darkness and the shadow of death, And brake their bonds in sunder.
[Isa 9:2 ASV] (2) The people that walked in darkness have seen a great light: they that dwelt in the land of the shadow of death, upon them hath the light shined.
[Jer 13:16 ASV] (16) Give glory to Jehovah your God, before he cause darkness, and before your feet stumble upon the dark mountains, and, while ye look for light, he turn it into the shadow of death, and make it gross darkness.
[Mat 4:16 ASV] (16) The people that sat in darkness Saw a great light, And to them that sat in the region and shadow of death, To them did light spring up.
[Luk 1:79 ASV] (79) To shine upon them that sit in darkness and the shadow of death; To guide our feet into the way of peace.

I particularly like this verse because like the verse we are discussing, it links Christ, the True Light, with resurrection life:

[Eph 5:14 ASV] (14) Wherefore he saith, Awake, thou that sleepest, and arise from the dead, and Christ shall shine upon thee.


How to combine DLLs with .exe inside of a wpf / winforms application (with pictures)

Question: How to combine multiple dlls into the main .exe file? (without using third-party programs)
Comment: done, Thanks for telling me
Comment: this should be re-phrased so that it is a question. This isn't a forum it is a Q&A site, so your should post a question and then answer it. [Can I answer my own question?](http://stackoverflow.com/help/self-answer)
Answer: Update 3
.Net has this built in
https://learn.microsoft.com/en-us/dotnet/core/deploying/single-file
Update 2
you don't even have to include the dlls as embedded resources at all, just use Fody.Costura and it will resolve the referenced assemblies and auto-include them
Also if you are using .net core 3+ you can use the Single file executable & Assembly linking features
Update
if you want an easy tool to merge the assemblies without worrying about doing ANY work at all then Fody.Costura is the best choice you have, as all you need to do is just include the dlls and change their Build Action to Embedded Resource and it will work right away.

1 - make a folder that contains all of the Dlls or place them separately as you like

2 - Click on each DLL from the "Solution Explorer" and make sure they have these properties

Build Action = Embedded Resources

Copy To Output Directory = Do not copy

3 - Go to : Project > Properties > References , And make sure every Dll you add has the same name as the assembly like this :
In References :-

In Solution Explorer :-

Note :-

It's Better to Make copy local = True in references as it will give
you an updated DLL each time you publish the project

Now at this point you have your DLLs added to the EXE , all is remaining now is to tell the program how to read these DLLs from the EXE (that's why we made build action = Embedded resources)
4 - In Solution Explorer Open your (Application.xaml.vb) file ([App.xaml.cs] in c#)
OR
Go To : Project > Properties > Application > View Application Events

Now in this page we are going to handle the very first event of the application (Construction event) to tell the program how to handle the assemblies we add as DLLs before loading/reading them by using the AssemblyResolve Event

Check this MSDN page for more Info about the AssemblyResolve Event
https://msdn.microsoft.com/en-us/library/system.appdomain.assemblyresolve(v=vs.110).aspx

5 - Now to The code part :
first of all Import this namespace
vb.net
Imports System.Reflection

c#
using System.Reflection;

In the Constructor ([Sub New] in vb) add this code
Vb.net
 Public Sub New()
        AddHandler AppDomain.CurrentDomain.AssemblyResolve, AddressOf OnResolveAssembly
 End Sub

c#.net
public App()
{
    AppDomain.CurrentDomain.AssemblyResolve += OnResolveAssembly;
}

Then add the OnResolveAssembly Function
vb.net
'''
''' Tells the program that the Assembly it's Seeking is located in the Embedded resources By using the
''' <see cref="Assembly.GetManifestResourceNames"/> Function To get All the Resources
'''
''' <param name="sender"></param>
''' <param name="args"></param>
''' <returns></returns>
''' <remarks>Note that this event won't fire if the dll is in the same folder as the application (sometimes)</remarks>
Private Shared Function OnResolveAssembly(sender As Object, args As ResolveEventArgs) As Assembly
    Try
        'gets the main Assembly
        Dim parentAssembly = Assembly.GetExecutingAssembly()
        'args.Name will be something like this
        '[ MahApps.Metro, Version=188.8.131.52, Culture=en-US, PublicKeyToken=null ]
        'so we take the name of the Assembly (MahApps.Metro) then add (.dll) to it
        Dim finalname = args.Name.Substring(0, args.Name.IndexOf(","c)) & ".dll"
        'here we search the resources for our dll and get the first match
        Dim ResourcesList = parentAssembly.GetManifestResourceNames()
        Dim OurResourceName As String = Nothing
        '(you can replace this with a LINQ extension like [Find] or [First])
        For i As Integer = 0 To ResourcesList.Count - 1
            Dim name = ResourcesList(i)
            If name.EndsWith(finalname) Then
                'Get the name then close the loop to get the first occuring value
                OurResourceName = name
                Exit For
            End If
        Next

        If Not String.IsNullOrWhiteSpace(OurResourceName) Then
            'get a stream representing our resource then load it as bytes
            Using stream As Stream = parentAssembly.GetManifestResourceStream(OurResourceName)
                'in vb.net use [ New Byte(stream.Length - 1) ]
                'in c#.net use [ new byte[stream.Length]; ]
                Dim block As Byte() = New Byte(stream.Length - 1) {}
                stream.Read(block, 0, block.Length)
                Return Assembly.Load(block)
            End Using
        Else
            Return Nothing
        End If
    Catch ex As Exception
        Return Nothing
    End Try
End Function

c#.net
///
/// Tells the program that the Assembly its Seeking is located in the Embedded resources By using the
/// <see cref="Assembly.GetManifestResourceNames"/> Function To get All the Resources
///
/// <param name="sender"></param>
/// <param name="args"></param>
/// <returns></returns>
/// <remarks>Note that this event won't fire if the dll is in the same folder as the application (sometimes)</remarks>
private static Assembly OnResolveAssembly(object sender, ResolveEventArgs args)
{
    try {
        //gets the main Assembly
        var parentAssembly = Assembly.GetExecutingAssembly();
        //args.Name will be something like this
        //[ MahApps.Metro, Version=126.96.36.199, Culture=en-US, PublicKeyToken=null ]
        //so we take the name of the Assembly (MahApps.Metro) then add (.dll) to it
        var finalname = args.Name.Substring(0, args.Name.IndexOf(',')) + ".dll";
        //here we search the resources for our dll and get the first match
        var ResourcesList = parentAssembly.GetManifestResourceNames();
        string OurResourceName = null;
        //(you can replace this with a LINQ extension like [Find] or [First])
        for (int i = 0; i <= ResourcesList.Count - 1; i++) {
            var name = ResourcesList(i);
            if (name.EndsWith(finalname)) {
                //Get the name then close the loop to get the first occuring value
                OurResourceName = name;
                break;
            }
        }

        if (!string.IsNullOrWhiteSpace(OurResourceName)) {
            //get a stream representing our resource then load it as bytes
            using (Stream stream = parentAssembly.GetManifestResourceStream(OurResourceName)) {
                //in vb.net use [ New Byte(stream.Length - 1) ]
                //in c#.net use [ new byte[stream.Length]; ]
                byte[] block = new byte[stream.Length];
                stream.Read(block, 0, block.Length);
                return Assembly.Load(block);
            }
        } else {
            return null;
        }
    } catch (Exception ex) {
        return null;
    }
}

6 - now publish the application or build it and all your dlls will be embedded in a single EXE file (with some extra  milliseconds delay to load them)
To Update the DLLs
1 - Simply drag and drop your new dll to the Solution Explorer as the same folder as the old dll then accept the override (make sure to check that [Build Action = Embedded Resources] AND [Copy To Output Directory = Do not copy])

To Add New DLLs
just repeat step 1 => 3
Credits :
http://richarddingwall.name/2009/05/14/wpf-how-to-combine-mutliple-assemblies-into-a-single-exe/
*Feel free to ask if you had any problem
Comment: In step 3, I have no References tab in Project > Preferences of my C# project in Visual Studio 2017
Comment: @hughes it's in the solution explorer in a tab called References https://i.imgur.com/TrNq0ye.png , just click on the reference and in the property window edit the CopyLocal and make sure the name is the same as the dll reference
Comment: Thanks for the reply. If I have the .dll file in my dlls folder, but it doesn't show up in the References section of the Solution Explorer, does that mean I'm not referencing it properly somewhere?
Comment: Actually never mind, just realized that the Fody.Costura solution just works :)
Comment: happy to help ^^
Answer: Wasn't able to get bigworld12 answer to work for me, but I found this link and it worked perfectly for me.
Basically the gist of the page is to unload your project and add the following code to your csproj file
<Target Name="AfterResolveReferences">
    <ItemGroup>
        <EmbeddedResource Include="@(ReferenceCopyLocalPaths)" Condition="'%(ReferenceCopyLocalPaths.Extension)' == '.dll'">
            <LogicalName>%(ReferenceCopyLocalPaths.DestinationSubDirectory)%(ReferenceCopyLocalPaths.Filename)%(ReferenceCopyLocalPaths.Extension)
            </LogicalName>
        </EmbeddedResource>
   </ItemGroup>
</Target>

Underneath this line of code.
<Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
Once that is done, reload the project and add a new class to it, and add the following code to your new class.
[STAThread]
public static void Main()
{
AppDomain.CurrentDomain.AssemblyResolve += OnResolveAssembly;

App.Main(); // Run WPF startup code.
}

private static Assembly OnResolveAssembly(object sender, ResolveEventArgs e)
{
var thisAssembly = Assembly.GetExecutingAssembly();

// Get the Name of the AssemblyFile
var assemblyName = new AssemblyName(e.Name);
var dllName = assemblyName.Name + ".dll";

// Load from Embedded Resources - This function is not called if the Assembly is already
// in the same folder as the app.
var resources = thisAssembly.GetManifestResourceNames().Where(s => s.EndsWith(dllName));
if (resources.Any())
{

    // 99% of cases will only have one matching item, but if you don't,
    // you will have to change the logic to handle those cases.
    var resourceName = resources.First();
    using (var stream = thisAssembly.GetManifestResourceStream(resourceName))
    {
        if (stream == null) return null;
        var block = new byte[stream.Length];

        // Safely try to load the assembly.
        try
        {
            stream.Read(block, 0, block.Length);
            return Assembly.Load(block);
        }
        catch (IOException)
        {
            return null;
        }
        catch(BadImageFormatException)
        {
            return null;
        }
    }
}

// in the case the resource doesn't exist, return null.
return null;
}

Save your class, and open the properties menu of your project and select the startup object comboboxand select the name of the class you just created from the list.
All that's left is to build your project.
Comment: I got this to work easily.  The only step to remember is you want to include the .dlls you are using as an embedded resource and also add them to you project as a reference.
Answer: If you're using any recent version of .NET Core and Visual Studio, you can use the Publish... option to include all of your dependencies in the executable.
By default, this only includes DLLs from your solution and not native ones; to include all of the DLLs required to run the project, you have to add 1 line to your csproj file:
<PropertyGroup>

    <IncludeAllContentForSelfExtract>true</IncludeAllContentForSelfExtract>
</PropertyGroup>

If you don't already have a publish profile created for your project, R+Click on your project in the solution explorer and click Publish...:

(You can use the Folder option in the publishing window to publish without Azure)
Once you have a publish profile created, click Edit and make sure you set the deployment mode to Self-Contained and check the Produce Single File box:


Can you filter nodes in a view by the last date of one node referencing that node

Question: So I have two content types Tours and Concerts. Concerts has an entityreference field that references a tour. I want to filter a view of Tours and only show tours that still have upcoming concerts. Once all concert in a tour are over I no longer want to show the tour. Is there a way to do this? Could you use hook_field_extra_fields to calculate the date and then somehow filter by that value in views?
Answer: The following steps should set this up...

Create a view of tours
Add a relationship of type "Entity Reference: Referencing entity" to the concerts
Make sure "Require this relationship" is ticked
Add a filter for the date field on the concert type
Select "Text" under "Date selection form element"
Ensure the relationship you set up is selected in the "Use relationship" dropdown
In the filter settings, change Operator to "Is greater than"
Change "Select a date" to "Enter a relative date"
type "now" under "Relative date"
Comment: Yeah, I tried that. The problem is that there is one tour and many concerts, so as soon as you add the relationship to the concerts the tour shows up as many times as it has concerts.
Comment: Actually it looks like that will work if I set Distinct to true under Query settings. I just didn't think about because most the time checking distinct doesn't seem to help.


Which features of a data set can be used for market campaigning using propensity scores?

Question: A dataset contains so many fields in which there is both relevant and irrelevant field. If we want to do a market campaigning using propensity scoring, which fields of the data set are relevant?
How can we find which data field should be selected and can drive to the desired propensity score?
Comment: I think the term you are looking for is PCA...welcome to AI.SE.......anyways there are a lot of similar questions on DataSceince.SE...you can check the answers there also
Answer: The problem you are examining is called feature selection. There are many different techniques, but they fall broadly into three categories:

Filter approaches determine which features have high information content. A common approach is to score them based on their information gain.
Wrapper approaches score subsets of the features, using similar measurements. This is slower (since there are many subsets), but may yield better performance.
Embedded approaches use machine learning algorithms that can dynamically select features. For example, building a C4.5 decision tree learner on a dataset, and then selecting just the features that actually appear in the tree, yields a set of features similar to those found by information gain.


There doesn't seem to be any hostile mobs spawning in Minecraft: Pocket Edition

Question: I"m playing survival mode, but there seems to be no hostile mobs, such as creepers (which is kind of boring).
How can I make them appear?
Answer: Make sure you're not on peaceful mode - this can be selected in the options. Hostile mobs will not spawn in peaceful mode.
Mobs also won't spawn on half blocks/slabs or transparent blocks, so if you're surrounded by a huge area of glass there would be no valid spawn location.
If there is a large, dark area nearby, hostile mob spawning might all be concentrated in that area - search around for caves or overhangs and light them up to force spawns to happen away from the location. (This is often stated as the cause of not being able to find hostile mobs, e.g. on this Minecraft Forum post)
Conversely, if you've lit up the whole surrounding area to above light level 7, you might be stopping spawns - hostile mobs can only spawn in areas of light level 7 or less.
You can reset the spawns in your world by switching to peaceful mode to remove all mobs, and then switching back up to normal/hard to make them spawn again.
As for attracting a creeper once you've found one:
The Minecraft Pocket Edition Wiki page on Creepers states that Creepers will follow you from a range of sixteen blocks away.
Answer: You have to make sure It is not in peaceful mode or the mobs will not spawn! And you have to make sure that the torches amount is not above 8 even though you are in Normal/Hard mode, they will not spawn in that Area.
Comment: This doesn't add anything beyond shanodin's answer. As a consequence, your answer is superfluous. If you have any new information to add, please do, but duplicating the content of an existing answer is largely unproductive clutter.
Answer: Make sure your not on peaceful mode set this off by sliding up the diffulcuty bar as shown below
Answer: According to the Minecraft Bedrock Wiki's "Creepers" article:

If you go into range of the creepers, which is 16 blocks away, to be precise, they will start to follow you.

In order to get creepers to spawn you need to go to Options and turn your difficulty all the way up.
Comment: It doesn't have to be all the way up.


Trailhead 'Data Leak Prevention'

Question: I've got an access to Kingdom Management org (as described in trail) but when I try to act with tab CRUD & FLS Visualforce Demo (just try to choose the user) I get an error - Insufficient Privileges
What am I doing wrong?
Comment: Same here: to be more specific - within "Identify CRUD and FLS Violations in Visualforce and Apex" in the Data Leak Prevention module, a newly created dedicated developer org does not allow to literally follow the steps in this unit. The "CRUD Demo" should allow to view the results of running in user/system context in a custom Visualforce page. However, this fails with the aforementioned Insufficient Privileges error.
Answer: Enable the "Administrators Can Log in as Any User" setting in Setup > Login Access Policies. Afterwards the demo works without errors.

Trailhead 'Data Leak Prevention'


Raspberry Pi 3B SenseHat Not Detected

Question: Ordered a Raspberry Pi 3B and sensehat a couple of days ago, they've arrived and I have set it all up as per the instructions.
I've run sudo apt-get update,sudo apt-get upgrade -y and sudo reboot
but then upon trying to run the example code:
from sense_hat import SenseHat
sense = SenseHat()
sense.show_message("Hello world !!")

I get the following error:
Traceback (most recent call last):
  File "/home/pi/Desktop/testing sensehat.py", line 2, in <module>
    sense = SenseHat()
  File "/usr/lib/python2.7/dist-packages/sense_hat/sense_hat.py", line 39, in __init__
    raise OSError('Cannot detect %s device' % self.SENSE_HAT_FB_NAME)
OSError: Cannot detect RPi-Sense FB device

Furthermore, the SenseHat LED display continues to show the rainbow even after the login screen.
I've had a bit of a look around and done some diagnostics.
sudo dmesg returned:
[    4.764770] rpi-sense 1-0046: Read from reg 240 failed
[    4.764826] rpi-sense: probe of 1-0046 failed with error -22

which I figure is probably the reason I am having issues, but I don't know what that message means, nor how to go about rectifying the issue.
Any help would be greatly appreciated.
Thanks in advance!
Answer: I've just bought the same hardware and had the exact same issue.
After reading what felt like hours of webpages (not not understanding 99% of it), adding:
dtoverlay=rpi-sense

to the bottom of /boot/config.txt has resolved the issue.

Raspberry Pi 3B SenseHat Not Detected


Sox stopping after a specific amount of bytes

Question: My goal is to have a command line tool to record long multichannels wav files on a raspberry pi 3 (5 hours +, 18 channels). Audio interface is the Behringer XR18.
The way to do this is of course via arecord, which sadly produces buffer overruns on the pi. As arecord has a fixed max. buffer size of 500ms, that I can't/don't want to change, I pipe the output of arecord to sox, which in turn writes to a ntfs USB flash drive. As an added benefit sox converts the samples from 32 to 24 bit on the fly and does away with overruns (as far as I can see).
Here is the command I run:
arecord -M -D hw:CARD=X18XR18,DEV=0 -c18 -f S32_FE -r48000 | sox --input-buffer 51200 -t wav - -b24 -c18 -t wav <filename.wav>

The first part up to the pipe |works, no help needed there. The second part also works, the file gets created and grows, as the recording progresses. But for some reason at about 1,5GB the recording stops and sox exits.
Running arecord alone doesn't have this restriction, it runs for hours upon hours (with overruns of course).
I noticed that, shortly before reaching the final file size, the file stops growing continually but rather holds for quite some time and then grows in chunks of a few MB. That sounds terribly like a buffer overrun to me, but doubling the buffer size of sox to 100 MB has made no difference whatsoever.
The output of sox isn't very helpful either, even at verbose level 3 it only shows:
sox WARN sox: '<filename>' output clipped 13403 samples; decrease volume?
sox WARN sox: '-' balancing clipped 13403 samples; decrease volume?

What I've tried so far:

Changed the --input-buffer-size of sox - no difference
tried to start a new file just before 1,5GB - works, but as soon as the added filesize reaches 1,5GB it stops again
recorded straight to the SD card instead of flash drive - no difference (apart from introducing overruns)

I don't have a different linux machine to test it on atm, but the raspberry pi 3 should be absolutly capable of handling this task (cpu/ram-wise). Does anyone have a hint as to what might be causing this strange behavior?
Answer: This thread says to try using an xfs-formatted target disk/SD-card.


Create an SSL certificate for home network with XCA

Question: I have a web server in my home network. Since it is a home network, there is no domain. I use the computer's name as the web site's address. For example, suppose the server's name is vegetable, then I type https://vegetable to open the web site.
I have been using XCA as a GUI tool to create SSL certificates. I had created an SSL certificate with it and put vegetable in the common name field and signed  it with a self-generated CA certificate that is shared among computers in my network. It worked well, but recently, Chrome started to refuse the certificate.
According to my quick Google search, it seems that I am supposed to use "SAN" instead of "common name", but a newly created certificate with vegetable in the SAN field did not work. Is this because I did something wrong, or because it does not fit the domain name format (something like app.google.com)? As I have written, it is a home network, so I do not have a domain name.
In this case, is it possible for me to create a proper certificate with XCA? If so, how? The examples I have found using Google search all seemed to use the "common name".
Answer: You should fill "SAN" and "common name" with vegatable. In SAN you can add more aliases if needed.


How does large body gravity affect planet formation?

Question: If Jupiter's gravity is what kept the asteroid belt from forming a planet, then why didn't the sun's gravity keep the inner planets from forming?
Comment: This is a non sequitur.
Comment: @DavidHammen Flags are not for technical inaccuracies. If you believe the question is unclear, then suggest improvement to the question and/or flag as unclear. If you believe the question lacks sufficient prior research, then flag as "too broad" (I know it doesn't quite sound right, but too broad is meant to be inclusive of situations where the asker should have performed more research prior to formulating the question).
Comment: I'm voting to close this question as off-topic because this is a non sequitur.
Comment: @called2voyage -- This is more of a ding at stackexchange than at this question. This question poses an obvious non sequitur. Since the question is a non sequitur, there is no way to improve it. The closest I could find for a "reason to close" was "off-topic".
Comment: @DavidHammen I don't believe non sequitur questions are unanswerable. You can address in the answer that it is non sequitur and explain why. However, it may be that it is too trivial, and in that case you should close as too broad.
Answer:
why didn't the sun's gravity keep the inner planets from forming?

The short answer is, the asteroid belt orbits the sun, it doesn't orbit Jupiter, and you shouldn't expect the same effect with 2 different relations.
The sun is the gravitational object that the Asteroid belt orbits.  Jupiter is not and it has a stabilizing effect on the material that orbits around it.  Jupiter has a (mostly) destabilizing effect on nearby material that orbits around the sun, though there is some stability with orbital resonance and trojan points.   The reason why that is gets a little bit mathy, but I'll cover the basics.
When a solar system forms, probably out of a combination of strong solar wind from a supernova and a dense enough gas cloud, most of the solar-system material forms the young sun and maybe 2%-4% remains in orbit and over time, spirals and flattens out into a disk.  (see cool video)
The sun's gravity stabilizes that disk.  There's no reason for it to disburse it, though the young and usually strong solar wind can blast it and clear out the closer regions of smaller particles and any ices.
Jupiter is entirely different.  Jupiter and other planets which form inteh disk, tends to eat everything in their path.  That's one of the definitions of a planet.  It clears out it's orbital area.  These planets on their own would remain in orbit around the sun, but they can interact over time with each other.   Pretty much anything in Jupiter's path, once Jupiter gets large enough, either gets eaten or gets thrown into a very different orbit, either further our or closer in.
The asteroid belt is (as Suhrid Mulay points out) a relatively low density region of space that doesn't have enough mass to coalesce into it's own planet, but it might not have always been that low density and that's probably only part of the reason.  The other part of the reason is the proximity of Jupiter which tends to disrupt anything that orbits too close to it and Jupiter may have at one point, moved in quite a bit closer to Mars before moving back out.  Tossing much of the material in that region far away.
Planets don't do well forming too close to other planets because they will gravitationally disturb each other.  A planet the size of Jupiter had pretty significant reach when it comes to disturbing other planets and planet formation.
Answer: During the early days of the solar system there was a high abundance of matter in the early solar system. Easily enough to form the planets and a lot of matter to spare. Also during the initial stages of formation of the solar system matter was distributed very densely when compared to what the density is today. At that point there were lots of asteroids and other small bodies very close together therefore at that stage local gravitational fields played a major role in formation of the planets. rather than the sun
As for the asteroid belt. It cannot form into a planet because the matter density is very low and its proximity to the giant Jupiter makes it very vulnerable to its gravitational field. The gravitational fields between the asteroids are simply not enough to coalesce them together into a planet due to very large distances (between the asteroids) involved


Sim card for travelers in Turkey

Question: Is it possible to buy SIM card in Turkey for the time of travel? If so, how much does it cost and how much do calls, texts and - the most important - data transfer cost in average?
Comment: as a broad general point, Lebara is very good for "sim for travellers" in almost all of europe, hope it helps
Answer: This is a tricky one, but fortunately these days there's a wiki for this - PrepaidWithData.Wikia.
They point out that in theory, you can quite easily purchase a sim in a store in Turkey.  However, there are complications:

All mobiles phones purchased outside Turkey using a Turkish SIM card must be registered with the government. There is a grace period
  of 1-2 weeks (but apparently that can be as short as 2 days?), after
  which the phone will be blocked for the Turkish SIM.
Before any operator will register your phone, they require a special document from the local Tax Office that will set you back 115
  TL (around 40 EUR). So you have to go to the TAX Office first and pay
  115 TL to have your phone registered later to finally use a local SIM
  card.

There are some workarounds which might work, and locals on the ground may have other advice for you.  But I'd definitely suggest reading the wiki page about the rules regarding bringing your own phone into the country.
Comment: From my experience, it's 2 weeks before your phone is completely blocked. You can buy a dongle wifi at the airport which you can use it for data. The process of registering your phone is quite complicated if you don't speak Turkish as well.
Answer: Turkey is really a strange country when it comes to foreign mobile phones operating with a local SIM Card. Although the purpose was fighting against mobile phones' black market, if you don't register your phone's IMEI number, it might get blocked in 60 days according to new law.
If you are staying shorter than 2-3 weeks I would not suggest you to put an effort on registering your phone and buying a local sim card.
A turnaround might be renting a mobile wifi device, if your main concern is using data on your phone. Please take a look at mobile wifi rental offers in Turkey and compare other options.

Sim card for travelers in Turkey


How to deal with "no precooking required" lasagne sheets?

Question: I've always been a bit suspicious of "no-precooking-required" lasagne sheets.
What are the benefits and detriments of these sheets?
What would happen if you ignore the instruction and cook them a little in any case? I tend to do so - am I wasting my time?
Answer: They work fine. Here is an example of a vegetarian lasgana where I use them. The key is to make sure that there is plenty of well-seasoned liquid for them to absorb. You don't need to parboil them.
Comment: @Jefromi: So it was. Given that this is the second or third broken hyperlink I've seen in the past few days, I think it's sound advice to just use the Markdown instead, since it's much simpler.
Comment: You can play it safe and precook them anyway.
Comment: @Aaronut: The hyperlink in the original source was of the form `<href=...`, not `<a href=...`.
Comment: I agree with the liquid recommendation: my lasagne sauce recipe yields a very thick, meaty sauce, and I've found that even 'no precooking required' sheets need a good hour to soften sufficiently, especially where there are multiple sheets overlapping.
Comment: Also, never attempt to use any sauce using an absorptive-type and/or coarse thickener (eg breadcrumbs, nut pastes/flours) with them, for any layer... the noodles will pull all the moisture they can from it and leave you with only the solids. Such sauces are problematic with all baked pasta, but especially so with no-boil noodles ...
Answer: Lasagne typically need to cook in a hot oven for about 30 minutes. The main problem, as outlined by others in this thread, is the tendency of pasta sheets to dry up during this prolonged exposure to high temperatures.
To avoid this, I usually precook the sheets in slightly-salted boiling water for one minute (I just want to soften them, not cook them); a few oil drops in the boiling water should help preventing the sheets to stick to each other. Subsequently I drain the sheets and lay them on a clean cotton cloth to let the cooking water be absorbed while I attend the preparation of the sauces.
After lasagne are assembled in the pan, I cover it with aluminium foil and then put it in the oven to cook; after 20 minutes I remove the foil and let lasagne cook "naked" for the remaining 10 minutes.
Here are some pictures I took during the preparation of lasagne with crumbled sausages and mushrooms.
With this procedure, lasagne sheets retain most of the moisture, thus not needing an excessive amount of sauce to keep them hydrated.
I managed to obtain very good results even with Sainsbury's Value Lasagne Sheets (a brand of cheap "no precooking required" dry lasagne sheets commonly found in UK).
Comment: I don't think [adding oil to the water](http://cooking.stackexchange.com/questions/3994/does-oil-in-the-boiling-water-prevent-the-spaghetti-from-sticking-together-clos) will stop them from sticking
Comment: Generally speaking, me neither. Being Italian myself, I can confirm the uselessness of adding oil to prevent pasta from sticking. But in the case of lasagne sheets, it could be different given their much higher specific surface area compared to other pasta formats.
Comment: I don't have hard evidence supporting this theory and I'm a bit skeptikal myself (that's why I said "_should_ help") but at least it shouldn't do any harm either since oil would be drained with the water anyway, without adding much fat to the dish.
And besides, I've learned the hard way to always  **stick** to traditions and common knowledge when cooking :-)
Comment: For lasagne, it's probably irrelevant. For sauced pasta, adding oil is actually counterproductive, as it will prevent the sauce from clinging to the pasta.
Answer: Once again I will bring up America's Test Kitchen (AKA Cook's Illustrated). They like the no-boil sheets, but they have experienced some of the same problems already brought up here. To ameliorate those issues, they recommend soaking the sheets for 10 minutes in hot tap water before use. I've done it, it works great.
Comment: I do this too, based on CI's recommendation (they've never steered me wrong, and I'm a charter subscriber since the first issue in '83).
Answer: I prefer the flavor of fresh lasagna sheets over dried but between the different sorts of dried sheets I've not found there to be a big difference in "no-precooking-required" ones. I have however found that they vary a lot by brand.
The only thing I would say is that it can take a bit of trial and error to get a creamy texture with "no-precooking-required" ones as they soak up variable quantities of liquid depending on brand and how many layers you use so you can get a stodgy (but still delicious) finish. Dropping the layer count by one and adding extra sauce has worked for me.
Answer: I've been cooking lasagne for the past 15 years and never had a problem with instant sheets.
I use meat sauce, cheese sauce and the sheets, I cook for about 30-35 minutes in a moderate oven and stick a knife through the layers to check if it's done. Occasionally it will need an extra 5-10 minutes cooking time.
I love fresh pasta in every other instance but I find that dried sheets are a lot better for holding the shape of lasagne!
Answer: Do not boil the no-boil lasagna even for a minute. I did this and ruined every noodle. I can not unstuck them.
Comment: Sorry about your supper. Are you sure that "sticking" problem doesn't occur equally with both types (no-cook and cook) lasagne? that's my experience.
Comment: The no-boil noodles are par cooked by steaming; they will not tolerate boiling well.
Answer: I used dry sheets in cooking but found them hard in places where perhaps the sauce had not reached them so decided next time to boil first as per the packet instructions for 10 mins.  Most of them stuck together so ended up with about 50% not useable - a right pain.  Give up - I will use fresh next time.
Answer: It is all about the sauce and the time. If you are boiling your pasta sheets [or if you have fresh ones] the lasagna will be done within 30 min baking time. However without boiling your sheets it would need rather an hour.
I am using a bit more sauce - making a ragù and using it generously. I also use a bechamel-ricotta mixture [first make the bechamel sauce and when done stir in ricotta until smooth] - and use it also generously. Mixing ricotta cheese and sauce together makes it very smooth [no usual graininess] - and you have more sauce - which your pasta sheet can soak up.
Answer: I made mine without parboiling the pasta sheets and it was like concrete. I suggest you parboil them for 2-5 mins so it can be soft but not cooked. But I am no professional, it's just my opinion. Hope it was good use.
Answer: No cook lasagne noodles are better than those that require parboiling. They shouldn't need to be soaked or cooked or parboiled. They DO need to be completely covered in sauce.
To do this, I use fewer of the ricotta and Bechamel layers, and more of the tomato sauce layers. I used to drain my tinned chopped tomatoes but now I add all the juice to my sauce and all the juice from the ground beef which I used to drain off.
If you test the lasagna when cooking by inserting a fork in several places you'll figure out how long it takes to bake it until the noodles are soft and it's hot through.
The biggest issue I've had with the no cook noodles is that it's difficult to find disposable foil pans to fit the noodles without having to break them. I make loads at a time (10 litres of tomato sauce, 5 1lb. Tubs ricotta etc.)
There are apparently flat precooked lasagne noodles without the ruffled edge but I've never seen them. My family and friends love my lasagne.
As an added note, I don't bake the lasagne right away unless I'm serving it that night. I usually freeze them without baking. I put plastic film on top and then foil with a taped on note to be sure to remove the plastic then put the foil back on before putting it into the oven.
The frozen lasagne takes at least an hour to cook in a convection oven (9x11" pan). I'd never go back to sticky wet lasagne noodles.
Answer: I only ever use the packaged sheets. I cook them in a frying pan, not a saucepan. Start with hot tap water, no salt or oil added. About 3/4 heat. After 5 minutes, I use an egg lifter and slide between the sheets. Stops them sticking together. After 10 minutes, remove from stove and left one sheet out at a time and place on paper to towel to absorb excess water. Works well every time.


AABB of a sphere's screen space projection

Question: What is a nice, neat way to get the AABB of a sphere's projection onto the screen? This is to determine simplified geometry for lights in deferred shading.
Comment: Axis Alighned Bounding Box... So you want a box around the sphere??
Comment: I want to know what screen space rectangle to draw that will touch all of the pixels a specified sphere would touch.
Comment: Have you searched google for AABB of a sphere space projection?
Answer: Found the correct derivation of the extents on AltDevBlogADay.
Comment: Found a copy! http://www.gamasutra.com/view/news/164007/Indepth_Getting_the_projected_extent_of_a_sphere_to_the_near_plane.php @ZorbaTHut
Comment: Link's dead :/ Don't suppose there's a copy elsewhere?
Answer: Old question, but here's my version (GLSL):
<code>/// <summary>
/// returns the screen-space (normalized device coordinates) bounds of a projected sphere
/// </summary>
/// <param name="center">view-space center of the sphere</param>
/// <param name="radius">world or view space radius of the sphere</param>
/// <param name="boxMin">minimum (bottom left) projected bounds</param>
/// <param name="boxMax">maximum (top right) projected bounds</param>
bool GetProjectedBounds(vec3 center, float radius, inout vec3 boxMin, inout vec3 boxMax)
{

    /// frustum culling helper
    if (ShouldCull(center,radius))
        return false;

    float d2 = dot(center,center);

    float a = sqrt(d2 - radius * radius);

    /// view-aligned "right" vector (right angle to the view plane from the center of the sphere. Since  "up" is always (0,n,0), replaced cross product with vec3(-c.z, 0, c.x)
    vec3 right = (radius / a) * vec3(-center.z, 0, center.x);
    vec3 up = vec3(0,radius,0);

    vec4 projectedRight  = Projection * vec4(right,0);
    vec4 projectedUp     = Projection * vec4(up,0);

    vec4 projectedCenter = Projection * vec4(center,1);

    vec4 north  = projectedCenter + projectedUp;
    vec4 east   = projectedCenter + projectedRight;
    vec4 south  = projectedCenter - projectedUp;
    vec4 west   = projectedCenter - projectedRight;

    north /= north.w ;
    east  /= east.w  ;
    west  /= west.w  ;
    south /= south.w ;

    boxMin = min(min(min(east,west),north),south).xyz;
    boxMax = max(max(max(east,west),north),south).xyz;

    return true;
}
</code>
The version I'm using performs frustum culling at the beginning (view space).
And, here's the output (my visualizer adds some padding on the right and left):

The yellow represents the undistorted bounds of the sphere. Note that the left and right half-widths (relative to the real center of the sphere, at the center of the yellow circle) are different lengths.


Is there a way to use multi-finger gesture controls using a multi-touch touchpad?

Question: Is there a way to use multi-finger gesture controls using a multi-touch touchpad in Ubuntu 20.04? Windows has this feature built-in which is extremely convenient for laptop users. I have tried this tutorial and this extension but they didn't work!
Comment: The specific touchpad device that you have will determine the driver needed, and the manufacturer for your device may or may not provide a Linux driver.  As long as your device is supported, you should be able to adjust touchpad settings in system settings.  This is going to be different depending on what DE you use.  KDE/Kubuntu, for example, has a lot of options ranging from number of fingers, sensitivity, disable touchpad when typing, etc.  Please research the driver needed for your hardware device and perhaps try out another flavor "live" to find out what works best with your device.
Comment: @Nmath I am asking how can I enable this in Ubuntu? It is easy enough in windows. I can't find where I can enable this in settings.
Answer: synclient is a application for the command line to control synaptics touchpad driver There used to be a gui-program to called Synaptics or so, where you could control regions and sensitivity for the touchpad. In gnome settings  and in gnome tweaks there are some settings for the periferial...
You could open a terminal shell and type the command:
   'man 1 synclient'
and see what gives, or
   'synclient --help'


Why is equivalent resistance in parallel circuit always less than each individual resistor?

Question: There are $n$ resistors connected in a parallel combination given below.

$$\frac{1}{R_{ev}}=\frac{1}{R_{1}}+\frac{1}{R_{2}}+\frac{1}{R_{3}}+\frac{1}{R_{4}}+\frac{1}{R_{5}}.......\frac{1}{R_{n}}$$
Foundation Science - Physics (class 10) by H.C. Verma states (Pg. 68)

For two resistances $R_{1}$ and $R_{2}$ connected in parallel,
$$\frac{1}{R_{ev}}=\frac{1}{R_{1}}+\frac{1}{R_{2}}=\frac{R_{1}+R_{2}}{R_{1}R_{2}}$$ $$R_{ev}=\frac{R_{1}R_{2}}{R_{1}+R_{2}}$$
We see that the equivalent resistance in a parallel combination is less than each of the resistances.

I observe this every time I do an experiment on parallel resistors or solve a parallel combination problem.
How can we prove $R_{ev}<R_{1},R_{2},R_{3},...R_{n}$ or that $R_{ev}$ is less than the Resistor $R_{min}$, which has the least resistance of all the individual resistors?
Comment: Once you believe the 2 resistor answer, it extends to any finite number.  For each resistor, imagine combining all the rest into a single resistor by the law you cite.  Now the combination of the one resistor and the combination resistor is less than the one.  Do this once for each of the resistors, and you have that the total combination is less than any one.
Comment: With experience, you will find this fact obvious, and it is worth taking the time to ponder it until it becomes so.
Comment: I have to confess that when I saw that you had exhibited the harmonic sum form ($1/R_e = 1/R_1 + 1/R_2 + \dots$), I found the question confusing because I didn't understand what you didn't get. It's worth your time to think about this until it becomes *obvious*, not because this problem is so important but because it will start teaching you the habit of learning things from the functional form of the relationships that appear in your studies.
Comment: @dmckee I didn't quite get what you said. It'll probably help me if you'll elaborate.
Comment: I rolled back this question to the original version because you shouldn't put answers, or responses to answers, in the question itself. @imakesmalltalk Feel free to post an answer of your own if you would like to offer another method of answering the question.
Comment: @user49111 what dmckee means by " functional form of the relationships" is when a mathematical function shows up, you will recognize the pattern of it, and be able to understand all of the relationships that it entails simply based on the math. (e.g. equiavlent resistance of parallel resistors = 1/X + 1/Y = XY/X+Y ). You will see other questions that bear mathematical resemblance to other questions, and you can draw an understanding of it based mathematical relationships you've seen before with different variables
Answer: Think about current flow.
If we take each individual resistor and determine the current for the applied voltage, we get: $$I_T=\frac {V}{R_1} +\frac {V}{R_2} + ...$$
Dividing everything by the voltage give us:
$$\frac {I_T}{V}=\frac {1}{R_1} +\frac {1}{R_2} + ...$$
Which is the same as:
$$\frac {1}{R_{eq}}=\frac {1}{R_1} +\frac {1}{R_2} + ...$$
Since there is more current flowing in all the resistors than through just one resistor, then the equivalent resistance must be less than the individual resistors.
Answer: The individual resistances are all positive, so the sum
$$ \frac{1}{R_1} + \frac{1}{R_2} + \frac{1}{R_3} + \dots \,,$$
is larger than the inverse of any of the individual resistances, and that means that the inverse of the sum is necessarily smaller than any of the resistances.
No mucking around with the two-resistor form required.
Answer: We can prove it by induction. Let
$$
\frac{1}{R^{(n)}_{eq}} = \frac{1}{R_1} + \cdots+ \frac{1}{R_n}
$$
Now, when $n=2$, we find
$$
\frac{1}{R^{(2)}_{eq}} = \frac{1}{R_1} + \frac{1}{R_2} \implies R_{eq}^{(2)} = \frac{R_1 R_2}{R_1+R_2} = \frac{R_1}{1+\frac{R_1}{R_2}} = \frac{R_2}{1+\frac{R_2}{R_1}}
$$
Since $\frac{R_1}{R_2} > 0$, we see that $R^{(2)}_{eq} < R_1$ and $R^{(2)}_{eq} < R_2$ or equivalently $R^{(2)}_{eq} < \min(R_1, R_2)$.
Now, suppose it is true that $R^{(n)}_{eq} < \min (R_1, \cdots, R_n)$. Then, consider
$$
\frac{1}{R^{(n+1)}_{eq}} = \frac{1}{R_1} + \cdots+ \frac{1}{R_n} + \frac{1}{R_{n+1}} = \frac{1}{R^{(n)}_{eq}} + \frac{1}{R_{n+1}}
$$
Using the result from $n=2$, we find
$$
R^{(n+1)}_{eq} < \min ( R_{n+1} , R^{(n)}_{eq} ) < \min ( R_{n+1} , \min (R_1, \cdots, R_n))
$$
But
$$
\min ( R_{n+1} , \min (R_1, \cdots, R_n)) = \min ( R_{n+1} ,  R_1, \cdots, R_n)
$$
Therefore
$$
R^{(n+1)}_{eq} < \min ( R_1, \cdots, R_n , R_{n+1} )
$$
Thus, we have shown that the above relation holds for $n=2$, and further that whenever it holds for $n$, it also holds for $n+1$. Thus, by induction, it is true for all $n\geq2$.
Comment: $\frac {R_1}{R_2} > 0$ not 1
Comment: Your induction method is much more mathematical than the other answers....but is there any way to solve this using $AM-GM$ inequality?
Answer: It might be easier to think in terms of conductance which is the inverse of resistance.
The more paths there are between A and B which conduct electricity, the greater is the amount of current which can flow - ie the greater is the conductance of the network. The total conductance is greater than that of any individual path, because each additional path always increases the amount of electricity which can be conducted, it never reduces it. In particular, the total conductance is always greater than the largest individual conductance.
Translating this back in terms of resistance R (which is the inverse of conductance S - ie R = 1/S), the total resistance is smaller than the smallest individual resistance.