Improving sampling frequency of Raspberry Pi Pico's ADC pin to sample at frequency of 48 KHz

Question: I am trying to use Raspberry Pi pico to sample signal of frequency of around 24 KHz and store the values in an array. From Nyquist criteria, the sampling frequency should be 48 KHz. But I can properly sample signals of frequency 2 KHz. We tried overclocking to 270 MHz, but it improved from 2 KHz to 5 KHz only. Any suggestions on how should I do it? According to internet resources How to use ADC in raspberry pi pico
, the sampling frequency is 500 KS/s. Hence, my requirement should easily be met.
Comment: `I can properly sample signals of frequency 2 KHz` ... how did you measure this?
Comment: I used a signal generator to give a sinusoidal wave as input and sampled and plotted it in real time in Thonny IDE. I could see a sinusoidal wave as output for lower frequencies.
Answer: Take a look at this link: https://iosoft.blog/2021/10/26/pico-adc-dma/
The author pulls date from the ADC using DMA and includes a method to change the sample rate. I have tested the code and can verify that it works.
Jerry Wasinger
Founder, Pi-Plates
Answer: If you want to do more than a one-off capture and process it then you are likely to need more than one array to hold the data to allow concurrent capture and processing. As per the other answer, DMA is the way to go if you want jitter-free continuous capture at predictable rates, 2-5ksps sounds like a for loop in an interpreted language, that's going to be a struggle to get low-jitter captures.
I like using MicroPython/CircuitPython but depending on what you want to do with the data it may be time to switch to C++ to give you more control over what the hardware is up to and better performance particularly around the absence of an FPU on the M0-based RP2040. Having said that ulab may be an option.
This is a classic ping-pong approach using two buffers and the RP2040's DMA chaining https://github.com/zapta/simple_stepper_motor_analyzer/blob/main/platformio/src/acquisition/adc_dma.cpp - this happens to alternately read from two ADCs, useful for stereo audio work but the two will not perfectly be in phase due to the in sequence reads.
This is a well written C++ example of having dma from ADC GPIO26 at audio rates into a ring buffer
https://github.com/iwatake2222/pico-work/blob/master/pj_adc_fft/AdcBuffer.cpp
BTW, I'm currently experimenting with this and there's a conflict with WiFi/Bluetooth that I don't so far understand. Bear that in mind if you're on a Pi Pico W.


Why does gravity act at the centre?

Question: Why does gravity act at the centre of earth and how does that happen?
Comment: Are you asking about the force of gravity at the centre of the earth ? Or are you asking why is the force of gravity at the surface of the earth directed towards its centre ?
Comment: @Gottfried Helm: OK, to a first approximation, and assuming a spherical Earth :-)  But I think you wouldn't feel any effect from the sun, precisely because you are in orbit around it.  Just as astronauts in orbit don't feel the effect of Earth's gravity.
Comment: At what level are you asking this question?  At the lowest level, it's something you'll probably solve in a 1st year college physics course.  The answer involves some integration, but the answer is that in a uniform sphere, the forces from either side cancel out.  (And interestingly, as you go towards the center, everything outside also cancels out, so at the center of the Earth you'd be weightless.)  At the highest level, it's because that's the way the universe works :-)
Comment: @jamesqf - in the center of the earth: don't you have some momentum resulting from the elliptic track which the earth undergoes around the sun?
Comment: @jamesqf - ah, that might be right, good example...
Answer: All parts of the Earth exert a pull on another body (such as an apple) and all parts of the Earth are pulled by external bodies (such as apples).
Let's consider the pull that the Earth exerts on the apple. Imagine the Earth divided up into kilogram portions by imaginary surfaces. The portion nearest the apple will exert the greatest pull, straight downwards on the apple. The (antipodean) portion furthest away will exert the least pull, though it will still be downwards, that is towards the centre of the Earth. Portions of the Earth to the North, South, East and West of the apple and at various depths inside the Earth will also pull the apple, but not straight downwards. The vector sum of these forces is the resultant pull.
Newton famously proposed the Law of Gravitation that every particle attracted every other particle with a force proportional to the mass of each particle and inversely proportional to the square of their separation. He also showed that if the Earth is a sphere, with its mass distributed with spherical symmetry about its centre, then, according to his Law, the resultant pull on the apple was the same as if all the Earth's mass were concentrated at its centre.
So gravity doesn't really "act at the centre of the Earth" but it behaves more of less as if it did. Only "more or less" because the Earth is not a perfect sphere and its mass is not distributed with perfect spherical symmetry.
Comment: And this "more or less" becomes important when you're trying to keep satellites precisely where you want them to be (or want to know precisely where they will be).
Answer: Because the Earth is spherical (to the same level of approximation, to which we consider that the force of gravity is directed towards its center). In fact, there is a gravity force exerted by every element of the Earth, but when all these forces are added up, the net force is directed towards the center of the Earth.
Answer: Given a spherically symmetric Earth and a point $P$, the gravitational field vector at $P$ can be determined in two steps:

Why does the field point toward the Earth's center $C$? Consider rotational invariance about the axis passing through $C$ and $P$. The mass distribution of the Earth is unchanged by this rotation, and so must be the field -- i.e., the field is directed along the axis.

Why is the field magnitude equivalent to concentrating the Earth's mass at $C$? This is a special property of the inverse-square law that is more easily understood via Gauss's law. Consider the spherical surface centered at $C$ and passing through $P$. The gravitational field on this surface is everywhere perpendicular to it, as argued above. Gauss's law says that the integral of the perpendicular field component (i.e., in this case, the field magnitude) over the surface is proportional to the mass $M$ enclosed by the surface. Thus, given spherical symmetry, the field magnitude depends only on $M$ and is the same as if it were a point mass at $C$. Note that if $P$ is at or above the Earth's surface, then $M$ is the Earth's total mass; if $P$ is below the Earth's surface, then $M$ is the amount of mass located deeper than $P$.
Answer: Every single particle in Earth exerts gravitational attraction to an object in your example, and, all these effects add up/cancel, and the net of these is pointing towards the center.
Actually, at the center, all these effects cancel out, and you feel weightless.

Correct. If you split the earth up into spherical shells, then the gravity from the shells "above" you cancels out, and you only feel the shells "below" you. When you are in the middle there is nothing "below" you.

Would you be weightless at the center of the Earth?
This can be shown at the level of the Christoffel symbols and the Radial four acceleration, where the vector would always point towards the center of Earth, and its magnitude would only be zero at the center of Earth exactly.

When $r = 0$ the Christoffel symbol $\Gamma_{tt}^r$ is zero and that means the radial four-acceleration is zero and that means you're weightless.

What is the general relativity explanation for why objects at the center of the Earth are weightless?
So the answer to your question is that for Earth, the constituents exert gravitational pull from all directions, and the net of these points towards the center.

Why does gravity act at the centre?


Is Codenames meant to played in American English, British English, Australian English, or any of them?

Question: I'm playing Codenames online in an iOS app called Codewords, but I do not know the demographics of the game in general. When someone gave me the clue "rob", I picked "nick" because in informal British, nick means "steal" or "prisoner", and it was wrong. I am not British; I'm American, but I assumed the game was meant to be played by all demographics. Unlike playing in real life where you should play it based on where you live like if you live in America, you should just stick to American definitions, this is online, so I was wondering if the game was intended for a certain type of English or it could be any.
Comment: As you noticed, there is really no *intention* for an online implementation (or, I should say, with strangers). The activity is largely about how to connect shared experiences with your teammates. If I *know* you're British, then that would open up a new set of clues.
Comment: Why would you assume it was from a British meaning?
Comment: @JoeW I assume that because I assumed the game is played by every English-speaking person, American, British, Australian, etc. so I figured they would also assume the same thing that their words are subject to any English interpretation (American, British, Australian). I didn't want to assume everyone who played the game was American.
Comment: But what gave you reason to think it meant that instead of an american meaning? Seems strange to jump to that conclusion just because it can be played world wide. What was the clue for?
Comment: @JoeW What do you mean by instead of an American meaning? I first look at the general definition that is accepted worldwide "a small cut or notch", and then I look for foreign definitions like American-only, British-only, Australian-only. Because it can be played worldwide, that is exactly why I take into account all possible foreign definitions, like completely the opposite of your logic. "rob 3" was for "thief", "shop", and a third one but the game hasn't finished.
Answer: Codenames was designed by Vlaada Chvatil, a Czech game designer, and in its original form was published by Czech games edition. So in that sense, the answer is none of the above.
More generally, the best clues in Codenames are the ones that will lead your team to guess the right words, which means you should assume that you are playing in whatever version makes sense for the players. This can include consideration of things like pop culture references (will your team understand that "Mine" is a clue for "Seagull" because if Finding Nemo?), but also deeper cultural associations.
If your team is all from the US, you should feel safe using American English as the baseline for your clues. If you don't know whether your fellow players speak American, Australian, British, Singaporean, Canadian, whatever English, then you have to use clues that are (to your knowledge) as common across them all and hope for the best.


How can I simulate a dataset with a missing not at Random situation in R?

Question: I have a dataset with two categorical variables that are missing at random, so I want to create a simulation study with missing not at random in R. I want to compare the results afterwards.
Comment: The first thought I had was to remove all values above some threshold.
Comment: Is it that there are some observations where both variables are missing, or are there observations where one is missing and the other isn't? Are there other observed variables, or are these the only variables?
Answer: There's of course many different missing not at random scenarios. Here are two that are easy to simulate and have some practical relevance:

A simple to simulate one is to set the outcome to missing depending on the outcome that becomes missing. I.e. the probability of missingness is determined by (and varies according to) the true outcome value. The probability could also vary based on other covariates. A variant is to have some unobserved latent variable that correlates with covariates, the outcome of interest and the missingness probability.
A common scenario in (randomised) clinical trials that compare a treatment with a placebo is that when patients stop taking their intervention a) will often (on the past this was even often an automatic rule) stop trial participation and b) different things happen to patients in each group thereafter. In the placebo group not much might change compared to patients that remain in the trial (although if patients quit due to poor intermediate outcomes, there might be some regression to the mean). In the treatment group, the treatment effect will usually disappear (for some drugs almost immediately and for some gradually), or there might even be a rebound effect. If you are interested in a treatment policy estimand, you want to impute those unobserved off-treatment values, which a standard imputation under MAR does not do.


GitHub: Changes requested label stay after I answered all the code review questions

Question: I'm a Pull Request owner (I have created this Pull Request / branch).
I asked my boss to review my code after I completed working on it and it passed the build tests.
The boss reviewed my code and requested several changes / asked several questions about my code changes.
I have changed the code and answered all the comments however "Changes requested" label still presented for this branch.
What did I miss?
(Sorry for such a simple question, I'm new with GitHub and I could not find answer for this problem in GitHub Helps.
Comment: if this public repo could you share a link?
Comment: Sorry, this is my company product repo. I can't.
Answer: The reviewer who requested changes has to either "dismiss" the review or "approve" the change. You might think you addressed everything, but the reviewer might disagree ;-)
It'd be nice if there was a way to differentiate between "<reviewer> requested changes" and "<reviewer> requested changes, and <submitter> updated the PR", but there currently isn't any.
Answer: Things have changed since the currently accepted answer.
Since February 2019 you can differentiate a little bit by "re-requesting" a review: https://github.blog/changelog/2019-02-21-re-request-review-on-a-pull-request/
This won't make the "changes requested" label go away, for reasons already explained by Mikeage. However, it will add a "pending reviewer" label making it clear what the current status of the PR is and notify the reviewer that it is their turn again in order to keep the process moving.
Answer: Beside re-requesting mentioned in this answer: https://stackoverflow.com/a/67110179/1266040
There some situation when you need merge without waiting for re-review (user what submitted request change is on leave, not responding, fix need to be merged)
So you can dismiss review to unblock pipeline:

Source: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/dismissing-a-pull-request-review
Comment: Thank you for this answer. As you may understand, this question is no more relevant for me, but maybe it will be helpful for others.
Comment: Exactly - it was viewed 11k times so people looking at it.


JUnit vs TestNG

Question: At work we are currently still using JUnit 3 to run our tests. We have been considering switching over to JUnit 4 for new tests being written but I have been keeping an eye on TestNG for a while now. What experiences have you all had with either JUnit 4 or TestNG, and which seems to work better for very large numbers of tests? Having flexibility in writing tests is also important to us since our functional tests cover a wide aspect and need to be written in a variety of ways to get results.
Old tests will not be re-written as they do their job just fine. What I would like to see in new tests though is flexibility in the way the test can be written, natural assertions, grouping, and easily distributed test executions.
Comment: Any changes from 08 to now????
Comment: Just use `TestNG`, it got everything that Junit has, and a lot more !
Answer: I've used both, but I have to agree with Justin Standard that you shouldn't really consider rewriting your existing tests to any new format.  Regardless of the decision, it is pretty trivial to run both.  TestNG strives to be much more configurable than JUnit, but in the end they both work equally well.
TestNG has a neat feature where you can mark tests as a particular group, and then easily run all tests of a specific group, or exclude tests of a particular group.  Thus you can mark tests that run slowly as in the "slow" group and then ignore them when you want quick results.  A suggestion from their documentation is to mark some subset as "checkin" tests which should be run whenever you check new files in.  I never saw such a feature in JUnit, but then again, if you don't have it, you don't REALLY miss it.
For all its claims of high configuration, I did run into a corner case the a couple weeks ago where I couldn't do what I wanted to do... I wish I could remember what it is, but I wanted to bring it up so you know that it's not perfect.
The biggest advantage TestNG has is annotations... which JUnit added in version 4 anyways.
Comment: JUnit can do the grouping thing you are talking about by defining a test suite and then adding the tests in the desired group to that suite.  You can then set up a target in your ant script that only runs that suite, and set up your source control to run that target upon checkin.
Comment: The biggest advantage TestNG has over JUnit is the ability to dynanmically generate test data for parameterized tests.  Each test data element is a different "test", so it makes it really easy to create data-driven tests http://testng.org/doc/documentation-main.html#parameters
Comment: TestNG groups can be done in JUnit 4.8 with Categories: http://kentbeck.github.com/junit/doc/ReleaseNotes4.8.html.
Comment: Parametrized tests are easy done with Theories, that are integrated in newer versions of Junit (but are experimental at the moment).
Comment: Some things not mentioned: I think TestNG's best advantage is being able to pass the same parameters that you passed into each test method, also into the before/after test configuration methods:  this is great help in setup and teardown, IMHO very powerful. If you dont understand that, you might think you dont need it.  Also, I like how you can define test suites in code.
Answer: First I would say, don't rewrite all your tests just to suit the latest fad.  Junit3 works perfectly well, and the introduction of annotations in 4 doesn't buy you very much (in my opinion).  It is much more important that you guys write tests, and it sounds like you do.
Use whatever seems most natural and helps you get your work done.
I can't comment on TestNG b/c I haven't used it.  But I would recommend unitils, a great wrapper for JUnit/TestNG/DBUnit/EasyMock, regardless of which route you take. (It supports all the flavors mentioned above)
Comment: Unitils doesn't look like it has been updated in a while; will it work with newer versions of JUnit/TestNG?
Comment: Just for anyone finding this answer in 2011, I checked, and the latest unitils version (3.2), has a release date of: 2011-09-29.  So it *is* being actively maintained.
Answer: About a year ago, we had the same problem. I spent sometime considering which move was better, and eventually we realized that TestNG has no 'killer features'. It's nice, and has some features JUnit 4 doesn't have, but we don't need them.
We didn't want people to feel uncomfortable writing tests while getting to know TestNG because we wanted them to keep writing a lot of tests.
Also, JUnit is pretty much the de-facto standard in the Java world. There's no decent tool that doesn't support it from the box, you can find a lot of help on the web and they added a lot of new features in the past year which shows it's alive.
We decided to stick with JUnit and never looked back.
Comment: IMHO, TestNG's killer feature is the ability to pass context args in via Before and After setup methods.  You can do a lot of neat magic tricks there that Junit cannot do.  95% of people don't bother to learn TestNG that well and are ignorant of it.   Also, TestNG has a neat way of threading via DataProvider, but only if you take advantage of it.  Also, testng.xml can contain Beanshell.
Answer: TestNG's biggest draw cards for me include its support test groups, and more importantly - test group dependencies (marking a test as being dependent of a group causes the tests to simply skip running when the dependent group fails).
TestNG's other big draw cards for me include test parameters, data providers, annotation transformers, and more than anything - the vibrant and responsive user community.
Whilst on the surface one might not think all of TestNGs features above might not be needed, once you start to understand the flexibility bring to your tests, you'll wonder how you coped with JUnit.
(disclaimer - I've not used JUnit 4.x at all, so am unable to really comment on advances or new features there).
Comment: I am using both JUnit4 and TestNG, TestNG has better support for spring spring-test integration. Makes testing spring based application a lot easier.
Answer: Cheers to all the above. Some other things I've personally found I like more in TestNG are:

The @BeforeClass for TestNG takes place after class creation, so you aren't constrained by only being able to call static methods of your class in it.
Parallel and parameterized tests, maybe I just don't have enough of a life... but I just get a kick writing one set of Selenium tests, accepting a driver name as a parameter. Then defining 3 parallel test groups, 1 each for the IE, FF and Chrome drivers, and watching the race! I originally did 4, but way too many of the pages I've worked on break the HtmlUnit driver for one reason or another.

Yeah, probably need to find that life. ;)
Comment: finally some meaty comment  after all the ummm they are both equal ..and  awwhing
Comment: Yeah, TestNG rules: I load driver instances via test args from the TestNG DataProvider as well.  here is how I did it:  https://github.com/djangofan/yet-another-selenium-framework/blob/master/src/main/java/qa/se/framework/ShootoutSuiteTestBase.java
Answer: I wanted to share the one I encountered today. I found built-in Parameterized runner is quite crude in Junit4 as compare to TestNG (I know each framework has its strengths but still). The Junit4 annotation @parameters is restricted to one set of parameters. I encountered this problem while testing the valid and invalid behavior for functionality in same test class. So the first public, static annotated method that it finds will be used, but it may find them in any order. This causes us to write different classes unnecessarily. However TestNG provides clean way to provide different kind of data providers for each and every method. So we can test the same unit of code with valid and invalid way in same test class putting the valid/invalid data separately. I will go with TestNG.
Answer: Also one more advantage of TestNG is supporting of parallel testing. In our era of multicores it's important, i think.
I also used both frameworks. But i using hamcrest for assertations. Hamcrest allows you easily write your own assert method. So instead of
assertEquals(operation.getStatus(), Operation.Status.Active);

You can write
assertThat(operation, isActive());

That gives you opportunity to use higher level of abstraction in your tests. And this makes your tests more robust.
Answer: JUnit 4 Vs TestNG – Comparison by mkyong.com ( updated on 2013).
Conclusion: I suggest to use TestNG as core unit test framework for Java project, because TestNG is more advance in parameterize testing, dependency testing and suite testing (Grouping concept).
TestNG is meant for functional, high-level testing and complex integration test. Its flexibility is especially useful with large test suites.
In addition, TestNG also cover the entire core JUnit4 functionality. It's just no reason for me to use JUnit anymore.

In simple terms, TestNG = JUnit + lot more. So, Why debate ? go and
  grab TestNG :-)

You can find more detailed comparison here.
Answer: Why we use TestNG instead of JUnit?

The declaration of @BeforeClass and @AfterClass method has to be static in JUnit whereas, there is more flexibility in TestNG in the method declaration, it does not have these constraints.
In TestNG, we can parametrize tests using 2 ways. @Parameter or @DataProvider annotation.
i) @Parameter for simple cases, where key value mapping is required.(data is provided through xml file)
ii) @DataProvider for complex cases. Using 2 dimensional array, It can provide data.
In TestNG, since @DataProvider method need not be static, we can use multiple data provider methods in the same test class.
Dependency Testing: In TestNG, if the initial test fails, then all subsequent dependent tests will be skipped, not marked as failed. But JUnit marked it failed.
Grouping: Single tests can belong to multiple groups and then run in different contexts (like slow or fast tests). A similar feature exists in JUnit Categories but lacks the @BeforeGroups / @AfterGroups TestNG annotations that allow initializing the test / tearing it down.
Parallelism: If you'd like to run the same test in parallel on multiple threads, TestNG has you covered with a simple to use annotation while JUnit doesn't offer a simple way to do so out of the box.
TestNG @DataProvider can also support XML for feeding in data, CSVs, or even plain text files.
TestNG allows you to declare dependencies between tests, and skip them if the dependency test didn't pass.

@Test(dependsOnMethods = { "dependOnSomething" })

This functionality doesn't exist in JUnit

Reporting:

TestNG reports are generated by default to a test-output folder that includes HTML reports with all of the test data, passed/failed/skipped, how long did they run, which input was used and the complete test logs. In addition, it also exports everything to an XML file which can be used to construct your own report template.
On the JUnit front, all of this data is also available via XML, but there's no out of the box report and you need to rely on plugins.
Resource Link:

A Quick JUnit vs TestNG Comparison
JUnit vs. TestNG: Which Testing Framework Should You Choose?

A good difference is given in this tutorial side by side: TestNG Vs JUnit: What's the Difference?
Comment: You didn't list TestNG's most distinct feature, IHMO:  the ability to pass context args into Before and After methods, which enables you do do some magic.  The DataProvider works this way, as an example.
Answer: A couple of additions to Mike Stone's reply:
1) The most frequent thing I use TestNG's groups for is when I want to run a single test method in a test suite.  I simply add this test to the group "phil" and then run this group.  When I was using JUnit 3, I would comment out the entries for all methods but the one I wanted to run in the "suite" method, but then would commonly forget to uncomment them before checkin.  With the groups, I no longer have this problem.
2) Depending on the complexity of the tests, migrating tests from JUnit3 to TestNG can be done somewhat automatically with sed and creating a base class to replace TestCase that static imports all of the TestNG assert methods.
I have info on my migration from JUnit to TestNG here and here.
Comment: the problem with checking in changes you did not intended is actualy because you have to review what you are checking in. And if you have a big check in , that is not an excuse, that is another problem: you should have many smaller checkins.
Answer: My opinion about what makes TestNG truly far more powerful:
1.  JUnit still requires the before/after class methods to be static, which limits
    what you can do prior to the running of tests, TestNG never has this issue.

2.  TestNG @Configuration methods can all take an optional argument to their
    annotated methods in the form of a ITestResult, XmlTest, Method, or
    ITestContext.  This allows you to pass things around that JUnit wouldn't
    provide you.  JUnit only does this in listeners and it is limited in use.

3.  TestNG comes with some pre-made report generation classes that you can copy
     and edit and make into your own beautiful test output with very little
     effort. Just copy the report class into your project and add a listener
     to run it.  Also, ReportNG is available.

4.  TestNG has a handful of nice listeners that you can hook onto so you can do
     additional AOP style magic at certain phases during testing.

Answer: Your question seems two folded to me. On one had you would like to compare two test frameworks, on the other hand you would like to implement tests easily, have natural assertions, etc...
Ok, firstly JUnit has been playing catchup with TestNG in terms of functionality, they have bridged the gap some what with v4, but not well enough in my opinion. Things like annotations and dataproviders are still much better in TestNG. Also they are more flexible in terms of test execution, since TestNG has test dependency, grouping and ordering.
JUnit still requires certain before/after methods to be static, which limits what you can do prior to the running of tests, TestNG never has this issue.
TBH, mostly the differences between the two frameworks don't mean much, unless your focusing on integration/automation testing. JUnit from my experience is built from the ground up for unit testing and is now being pushed towards higher levels of testing, which IMO makes it the wrong tool for the job. TestNG does well at unit testing and due to its robust dataproviding and great test execution abilities, works even better at integration/automation test level.
Now for what I believe is a separate issue, how to write well structured, readable and maintainable tests. Most of this I am sure you know, but things like Factory Pattern, Command Pattern and PageObjects (if your testing websites) are vital, it is very important to have a layer of abstraction between what your testing (SUT) and what the actual test is (assertions of business logic). In order to have much nicer assertions, you can use Hamcrest. Make use of javas inheritance/interfaces to reduce repetition and enforce commonality.
Almost forgot, also use the Test Data Builder Pattern, this coupled with TestNG's dataprovider annotation is very useful.

JUnit vs TestNG


Fluctuate vs. oscillate

Question: I understand that you say hesitate in the moral context. But what is the difference between oscillation and fluctuation?  Might be you could contrast these with swinging. Is there any difference when to use which?
Comment: As you could see by consulting a dictionary, *oscillate* differs from *fluctuate* usually in the sense that *oscillate* implies a regular, measured, reciprocal change (though some people use it less strictly than that); *fluctuate* just implies a more random kind of change. See also *vacillate*.
Comment: @Robusto The key difference lies in 'reciprocal.'
Answer: Something that oscillates repeats a pattern of motion in a regular rhythm, e.g. a pendulum swinging, a spring after it has been compressed or released.
Something that fluctuates is observed to change, but irregularly in magnitude or direction (and does not necessarily have both an observable magnitude and direction) e.g. demand, trade, mood
Comment: That much homework should have been done by the asker. Every question is expected to have supporting background effort. This question is thus GR.

Fluctuate vs. oscillate


What is the Max Alpha damage for a weapon in Diablo 3?

Question: By alpha damage I mean the max damage that a weapon can initially "do" without any gems placed into it, this means bonuses are okay.
I ask this because I saw someone who has a weapon that does about 8,000 damage without any gems placed in it.
Comment: I'm having trouble figuring out what good this information will do anyone.  Weapons don't function in a vacuum, and what weapon you use is going to be up to choice and availability.
Comment: Thank you all for your answers, I appreciate the given information, and am sorry for the odd phrasing; I was in a rush at the time. I'm just going to assume that the weapon was modded based off y'alls information, and the fact that I play on the console version of diablo.
Answer: Check out http://www.d3maxstats.com/
It displays the maximum damage of each weapon type at level 70.
It is worth noting that no weapon in the game will ever have 8000 tooltip damage.
-Edit-
As has been mentioned, weapon damage is a small part of sheet DPS, which is in turn a small part of actual DPS. In practice, you simply use the best weapon for your build which drops. However, for those who like theorycrafting, here is what I have been able to dig up from http://us.battle.net/d3/en/item/. It is consistent with the d3maxstats link above, but is from a primary source.
The way the question is worded is a bit odd, so I'm going to answer two questions:

What is the max damage that a weapon can display?
The maximum damage available on any normal level 70 legendary is 3700. This is found on two-handed maces. Ancient Legendaries should be able to roll 30% more damage, bringing this number up to ~4810. There is little concrete data available about ancient legendaries at this time, so it is possible this number is slightly off. The highest I was able to find with a google image search is 4529.
What is the maximum tooltip damage that can be displayed?
Tooltip damage is equal to the average damage on the weapon multiplied by the attackspeed of the weapon (while not wearing any other gear, or using passives/active abilities) multiplied by the %damage boost of the weapon. Assuming you roll max damage(1788/2324.4 on Ancient Legendaries), max attackspeed(7%), and max %damage(10%), the max damage of any weapon goes to Monk Diabos at 4105.317 DPS for a normal legendary or ~ 5336.912 DPS for an Ancient legendary.
Answer: The problem with what you are asking is you are singling out a single piece of gear on a pure stat based game completely Dependant on RNG to figure your stats.
Diablo 3 uses RNG is figure out how awesome your states are.  Currently there are no Weapons out there that do 8k Weapons damage(this is the Aplha stat you seek, but we all know it as just Weapons Damage).
Currently there is a thread on Battle.net that has people reporting no less than 5k Weapons Damage on Ancient Prefixed Items.  What I have been to verify is This weapon as currently highest I have seen.


1970s SF story of aliens on earth farming brains for use in war machines - anyone read it and remember what it was called?

Question: The aliens were often disguised as pretty women and the protagonist goes underground to battle them but is overpowered and ends up waking up as an alien tank on another world. He manages to telepathically wake up other brains in neighbouring tanks and they use their new fighting abilities to overpower the aliens and send word back to Earth warning them of the farming operations.
Comment: See apparent confirmation comment (presumably by OP from non-linked account user14901) on answer below.
Answer: It sounds very similar in plot to "A Plague Of Demons". URL: http://www.goodreads.com/book/show/1829054.Plague_of_Demons
The earliest I could find is "A Plague Of Demons" being published in 1985 and the aliens didn't use women as the recruitment method.
Edit: sjl found it was originally published in 1964 in serialized format, and first published as one complete work in May 1965 under the self titled "A Plague Of Demons".
Comment: _A Plague of Demons_ was first published in 1964 and was reprinted many times before 1985: http://www.isfdb.org/cgi-bin/title.cgi?1385.
Comment: Yes, that's it! Thanks. I read it in the early 1970s as a teenager and the story has stayed with me. Now I can read it again...
Comment: @sjl, thanks! I've updated the answer with the information you found.


XNA Silverlight 5 3D Model Position

Question: I am use to XNA and starting to learn XNA for Silverlight 5. My Question is that in XNA when you create a Model and load it using content.load you are able to access the models Position, scale etc.. In Silverlight XNA these options are not available. It would be possible  to change the Models position using World Translate, but I need the models position for collision detectection using boundingSphere Any Advice??
Answer: XNA should allow you to do something like this to create your BoundingSphere, so long as you get grab the vertex buffer for your model.
List<Vector3> vertices = GetModelVertices(scale);
BoundingSphere sphere = BoundingSphere.CreateFromPoints(vertices);

// Gets the vertices that make up a model
public List<Vector3> GetModelVertices(float Scale)
{
    List<Vector3> verts = new List<Vector3>();

    VertexPositionNormalTexture[] vertices = new VertexPositionNormalTexture[numVertices];
    vertexBuffer.GetData(vertices);
    foreach (VertexPositionNormalTexture vertex in vertices)
    {
        verts.Add(vertex.Position * Scale);
    }

    return verts;
}

Alternatively, you should be able to iterate through each ModelMesh part in your model, and each of those have a BoundingSphere that you can query. From that you can call BoundingSphere.CreateMerged(BoundingSphere, BoundingSphere), for each of the bounding spheres on the ModelMesh objects, and combine them to get your final bounding sphere.

XNA Silverlight 5 3D Model Position


making executable file from a java project using NetBeans

Question: i have created a java project in NetBeans. now i want to make an executable file out of it.that can be executed (run) in other computers that have JDK or JRE installed but don't have NetBeans or any other Java IDE installed.how can i do such thing using NetBeans???
Comment: @this question can be reopened as through netbeans its possible to create native jar as well as described here https://netbeans.org/kb/docs/java/native_pkg.html what is marked as duplicate is how to create an executable JAR.
Answer: Do you mean compile it to JAR? Netbeans does that automatically, just do clean and build (hammer sybol) and look in the dist subdirectory of your project. There will be the JAR with lib folder containing the required libraries. These JAR + lib are enough to run the application.
Maby you unchecked an option:
Project Properties -> Build -> Packaging -> Build JAR after compiling
(but this is enabled by default)
Comment: i found the dist folder and in that folder there are just one jar file and one readme text but jar file doesn't work.and there is no lib folder.i am guessing that it is the problem. and also i opened the jar with winrar and there weren't anything in it but classess of the project and one "MANIFEST.MF" .what should i do?
Comment: thank u it was really helpful. but i double click on jar file as i said before and it doesn't work .why do you think it doesn't work?? i haven't used GUI do u think that is why.
Comment: thats all right, the jar file is the executeable file, you can either double click it, or use cmd **java -jar [JARFILENAME.JAR]**
Lib folder will only created when needed, if you dont uses external libs you wont need this folder. Found a short video which shows what excatly to and how it looks like: http://www.youtube.com/watch?v=LF5cLVivV_Y
Comment: And here with Pictures: http://www.javaquery.com/2011/12/how-to-create-jar-file-in-netbeans.html
Comment: Ah if you have no gui than you wont see the program running, but if there is no error message its running. You need to open cmd and switch to your dist directory using **java -jar YOURJARFILE** than you will see the output in cmd
Answer: You have to build your project. Just click on the hammer in the toolbar.
After that there should be a folder in your project called "dist".
In it is the *.jar File, which you can deploy to anybody who has Java installed.
Answer: you mean executable jar file. which can be executed using $java -jar myJar.jar . So you need to change manifest file inside jar. Second if you want a mouse double click execution then for Linux create .sh and for windows create .bat file containing the above specified $java -jar .
JVM installation is required to do so on whichever machine you want to execute.
Click Me :-)


Ideal, isotropic fluid and stress tensor

Question: An ideal fluid is the one which cannot support any shearing stress. It also doesn't have viscosity. My question is what does it mean by a fluid to be isotropic? Is an ideal fluid necessarily isotropic and homogeneous? What can we say about the stress tensor of an isotropic fluid?
Answer: Isotropy and homogeneity are different. The former is a consequence of invariance under rotations while the latter comes from invariance under translations. The stress tensor of an isotropic fluid then must be invariant under any orthogonal transformation, and this implies that it is a multiple of the "identity" tensor. More precisely, assume matrix notation for order 2 tensor and let $\sigma$ be the stress tensor of the fluid. If $O\in O(3)$ is any orthogonal transformation, then
$$O^T\sigma(x) O = \sigma(x),\qquad\forall x\in\mathbb R^3,$$
or, which is the same, $[\sigma(x), O] = 0$. This is possible only if $\sigma$ is a multiple, at every point, of the identity $3\times 3$ matrix $I$. Therefore there must exists a scalar function $p:\mathbb R^3\to\mathbb R$ such that
$$\sigma(x) = p(x) I.$$
In general $p$ need not satisfy any extra assumptions (physically it is just representing a pressure field, so perhaps you might want positivity as well) and if $t\in\mathbb R^3$ is any translation, then $p(x)\neq p(x+t)$ in general. But if the fluid is also homogeneous, then $\sigma(x)=\sigma(x+t)$ for any $t\in\mathbb R^3$, and therefore $p$ must be invariant under translations, so that you get a constant value $p_0$ for which
$$\sigma(x) = p_0I,\qquad\forall x\in\mathbb R^3.$$
So isotropy and homogeneity together imply that the stress tensor is just a pressure, which is constant everywhere in space.
Comment: with no viscosity there is not viscous stress tensor, hence no off-diagonal components, so you remain with something of the form $\sigma(x) = pI$, which is an isotropic tensor. For the homogeneity some extra  conditions are probably needed.
Comment: @ Phoenix87- Thanks for the illuminating reply. But my second question was that whether an ideal fluid is necessarily isotropic and homogeneous?
Comment: sorry to bother on an old question but, an ideal fluid has a stress tensor with no off diagonal components, though to me this alone doesn't mean that the tensor would be the identity matrix, we should still show that pressure is the same along any direction. Am I wrong?
Answer: The stress tensor in an ideal fluid is indeed isotropic, for it can be written as $\sigma_{ij} = -p\delta_{ij}$, $p$ being the hydrostatic pressure. In a real fluid in motion, however, the stress tensor has a "non-isotropic" part, which is also called the "deviatoric" part. It is proportional to the rate of strain tensor. In Newtonian fluids, the constant of proportionality is the coefficient of viscosity. Thus, the stress tensor in a Newtonian fluid is
\begin{equation}
\sigma_{ij} = -p\delta_{ij} + \mu\left(\frac{\partial v_j}{\partial x_i} + \frac{\partial v_i}{\partial x_j} \right)
\end{equation}
Note that, if $\vec{v} = 0$ then $\sigma_{ij} = -p\delta_{ij}$. A real fluid, which is isotropic at rest, ceases to be so in motion because of viscosity.
Isotropy, in this and other contexts, is being same in all directions. Homogeneity, on the other hand, is being same at all positions. An ideal fluid need not be homogeneous if it has a variable density. For example, when Lord Rayleigh analysed the instability of a heavy fluid resting on a lighter one, he assumed the fluids to be ideal (and hence isotropic) but they were not homogeneous.
Comment: What is $\mu$ in this expression? It looks like setting $\mu=0$ gives the expression for ideal fluid back. @AmeyJoshi
Comment: $\mu$ is the dynamic viscosity of the fluid.
Comment: So $\sigma_{ij}=-p\delta_{ij}$ is true for Newtonian inviscous fluid, not necessarily ideal fluid (which is also incompressible)?
Comment: There is no such thing as Newtonian inviscid fluid. Newtonian fluids have viscosity. They are called Newtonian because they obey Newton's law of viscosity. Ideal fluids are inviscid. They have $\mu = 0$.
Comment: Yes. My bad. So the off-diagonal parts of $\sigma_{ij}$ of a fluid are solely due to viscosity? @AmeyJoshi
Answer: As I understand it an isotropic fluid is a fluid whose properties are not dependent on the direction along which they are measured. In a (so-called) Newtonian medium that is isotropic the stress tenssor is related to the strain via
\begin{eqnarray}
\varepsilon_{v}(p, t) &=& \phi_{v}E_{v}(p, t) \\
\varepsilon_{s}(p, t) &=& \phi_{s}E_{v}(p, t)
\end{eqnarray}
where $E_{v}$ and $E_{s}$ are (respectively) the scalar isotropic and the zero-trace parts of the strain tensor and $\phi_{s}$ and $\phi_{v}$ are real constants.


GPU vs TPU for convolutional neural networks (NLP)

Question: I am testing ideas on IMDB sentiment analysis task by using word embeddings + CNN approach. What could explain a significant difference in computation time in favor of GPU (~9 seconds per epoch) versus TPU (~17 seconds/epoch), despite supposedly superior computational power of a TPU over GPU?
Answer: I don't think it makes a lot of sense to compare a generic TPU to a generic GPU. There is probably a factor of 10 or greater between a low-end GPU and the best GPUs on the market in terms of compute capability. Google has itself developed 3 generations of TPUs, each more powerful than the last.
I haven't kept up with the latest developments, but last I was aware, TPUs don't necessarily dominate over GPUs in all aspects. They may provide more compute per watt, but that's not the same as compute per unit or compute per dollar.
More specific to the architecture details, google has it's own documentation on exactly what sorts of computation TPUs are good at, versus what is more suitable for a GPU.


Is it possible to use car's battery instead electric motorcycle's battery?

Question: I want to buy an electric motorcycle but most of them are really slow. Is it possible to upgrade their battery or change their battery with car batteries after buying the motor?
Comment: Welcome to Motor Vehicle Maintenance & Repair!
Answer: You may be calling something by the name electric motorcycle that is not an electric motorcycle. Most production electric motorcycles are not considered really slow. A quality electric motorcycle will have substantial acceleration  from a standing start. Today's electric motorcycles use high-tech Lithium chemistry based batteries which provide substantial power.
On the other hand, there are low-end electric scooters which would use old-tech lead-acid battery chemistry, which are low power compared to Lithium based batteries. Those models will have limitations with respect to mounting space on the frame and will not easily adapt to having the pack or battery changed to another type or size of battery.
If you were to purchase a low-cost, low-tech electric scooter that uses lead-acid batteries, you could replace the batteries with Lithium based batteries, but you would not be able to use the charger. Lead acid batteries have a different charge profile which would damage lithium batteries, or worse, create a situation resulting in a fire.
Additionally, lithium batteries are fairly expensive and would increase the overall expense of the low-cost scooter if your intent was to have the same range as the original battery system. It would also be challenging to safely install lithium cells in locations once occupied by lead-acid batteries.
I have a riding lawn mower that operates on lead-acid batteries, sealed lead acid valve regulated batteries, often called gel-cells. The batteries (quantity 20) do not last more than three years and cost me about US$600 to replace a few years ago.
I was able to locate a used lithium chemistry battery that once powered a Nissan Leaf. One module from the pack also cost US$600 and was a good replacement, except that it's going to be extremely challenging to fit this rather bulky module into the location formerly occupied by twenty tiny (relatively speaking). Even if I have to bolt it onto the back deck, in the open, it will be an improvement over the lead acid pack.
I expect this battery to last me five to ten years based on my previous experience with this chemistry and it also provides about three to five times the range (mowing duration) compared to the lead acid pack.
It can be done, but it's expensive and you would be better off to purchase a quality transportation device rather than rebuild a poor model.


Is the mole fraction equal to the weight fraction?

Question: Whenever there is a reaction is excess of air it is customary to assume mole ratio of $\ce{N2}$ to $\ce{O2}$ as $79/21$. However, in another reaction which states that it will contain $\pu{1 wt\%}$ of $\ce{C}$ in iron, I am absolutely confused whether weight ratio will suffice just like I did it for air. Is it absolutely necessary to convert mass to amount of substance and then take ratio or are they equal?
Comment: Yes $\vphantom{ghhh}$
Answer: Ratios can be quoted either as mass ratios or molar ratios
The trouble with the example you use is that, for air, the weight and mass ratios are close (oxygen and nitrogen molecule masses are only 14% different) so the ratio will similar either way. And you quote the ratio as a molar ratio but later describe it as a "weight ratio". The molar and mass ratios will not be remotely as close for carbon in iron. So you need to know which is which.
If you are trying to interpret a ratio don't overthink it, look at what the ratio claims to be. 1 wt% C in Fe claims to be a mass ratio (that's what wt% or weight percent means, if the ratio has been mol% it would have meant a molar ratio).
If you are given a wt% you don't need to work out the molar ratios, you can simply directly measure the relative weights of the components and be done. If you do convert to a molar ratio you will (usually) find that that is very different to the mass ratio.
Answer:
Is the mole fraction equal to the weight fraction?

If you had a mixture of two compounds then typically the mole fraction and weight fraction would be different quantities.
The odd exception would be mixtures of isomers. So a mixture of n-hexane and 2-methylpentane would have the same weight fraction and mole fraction since the two different molecules have the same molecular weight.

Is it absolutely necessary to convert mass to amount of substance and then take ratio...?

Typically a problem is posed so that you need to use either the weight fraction or the mole fraction. However some problems could require you to use both.


Are questions about Esperanto culture and community on topic?

Question: Am I right to assume that questions about Esperanto culture and community should be accepted as on topic here?
Answer: I want to point out that when Esperanto was initially proposed for StackExchange, it was originally only "Esperanto," because the idea was to also include questions about its culture and community. We changed the name, because all the other languages on StackExchanges were listed as "X Language" and it would be strange if Esperanto were the only language listed as just "Esperanto" and not "Esperanto Language." To be clear, I propose that questions about Esperanto community and culture should definitely be accepted here.
Comment: I believe Esperanto is so small already that there's no reason to splinter the community by having a separate StackExchange for "Esperanto culture" and one for "Esperanto community." To me, at least, it seems that if a question relates to Esperanto at all, it should be welcome here. I just added to my answer to make my proposal clearer.
Comment: It still does not answer the question... With given the information you wrote, will it be ok to ask about culture even though it's listed as "Esperanto Language"?
Comment: Thanks :-) (both for answering my comment and editing your answer)
Answer: Yes, certainly the cultural issues and challenges that come with the Esperanto movement should be a strong part of this site.
We went back and forth a few times on the name of the site itself, but ultimately we decided to use "Esperanto Language" to reaffirm its place among our successful language sites.
This shouldn't throw anyone off in actual practice. Our "Latin Language" site is chock full of questions about the history and contemporary issues of using the Latin language — it's one of the strongest and most interesting apects of that site — so no one seems to be confused by including "Language" in the title.
Answer: I would be in favour of allowing questions about Esperanto culture, especially because

Esperanto is not "owned" by any nation or ethnic culture, which makes it stand somewhat apart from other languages,
the creation of Esperanto has a specific historic background, which includes Zamenhof's goal to "foster harmony between people from different countries" (quoted from Wikipedia, and that goal has not lost its relevance.
Answer: It definitely should. The Esperanto language massively influences the Esperanto culture, and the Esperanto culture massively influences the Esperanto language. The scale is not comparable to the languages that have a country.
For example, we can think of the movement "La Bona Lingvo" who discourages the use of neologisms if it is possible to create a more easy word with the help of the word-construction rules of Esperanto. This mouvement originates from the Esperanto culture, from the will to have a language easy for people from all nations.
The values commonly shared in the Esperanto culture have active influence on the language. Also, Esperanto is a reflect of this culture since the ideas of creator of Esperanto is shared by many Esperantists.
I don't think we can really understand Esperanto without understanding its culture. This is why Esperanto culture should be accepted here, along with questions about the Esperanto mouvement.
Answer: In general, you can't disregard the cultural topics related to a target language.
It doesn't matter whether it is a planned or a natural language. On the Russian stackexchange site, there are many questions which one can't answer without explaining the culture. A language and its culture are strongly intermeshed with each other.
Answer: I am rather pessimistic as far as the potential of Esperanto SE to ever leave the beta stage is concerned. From what I have heard, SE sites that don't have enough activity will be deleted. (An archive is made available in that case.)
Currently even German language SE is struggling to get the expected 10 questions per day. Its average, after over 5 years of operation in beta, is about 5 questions per day. Given that German has almost 100 million native speakers and is among the handful of standard second languages taught in the Western world, that doesn't bode well for Esperanto SE - Esperanto having no native speakers worth mentioning in this context, an order of magnitude less non-native speakers (Wikipedia estimates), and much less grammatical problems to ask about.
Permitting questions about Esperanto culture is the absolute minimum for this site to have a chance of long-term survival. But that will hardly be enough. I believe the question that really needs asking is: What else can we declare to be on topic to ensure a steady stream of (non deletable) questions even after most reasonable Esperanto-related questions have been asked?
Comment: Yes!  Let's keep a flow of new questions and ideas flowing.  One of the things I intend to do is read through questions being asked in the Duolingo forum about Esperanto.  I'll suggest to the people posting them to either repost them here or let me do it on their behalf.  That should generate some new activity on this site as well.
Comment: [Leaving the Beta stage is not required](http://meta.stackexchange.com/q/257614/147191), though [it's not really Beta](http://meta.stackexchange.com/q/257652/147191).
Answer: I totally agree that questions of culture and community should be allowed.  Any language is a tool for communication, but Esperanto is historically linked to the idea of intercommunication between people with different native languages and cultures.  Zamenhof referred to it as "La interna ideo de Esperanto".


kill sessions for other machines

Question: I've an admin and client site. Multiple users will view at client site at the same time. It is possible that I can force the users logout of my client site from admin site? I'm now using classic ASP and the In Proc session is used. Is there a way where I can kill all the sessions of the users and force them to logout?
Answer: One way is to reset IIS server that the client site is hosted on, i believe you can do this by stopping & starting the site from IIS Manager.
Comment: for example, there are 2 users, named A and B..Both A and B sign in to the same website..and A restarted his own IIS..B will not be forced to logout

kill sessions for other machines


How can I use COM ATL project in Linux?

Question: I've got a small C++ library which is made as ATL Project in Visual Studio. I want to make it crossplatfrom. It will be used in Windows and Linux. It will be included in my project, which uses Qt 4.x. How can I easily convert the library?
Comment: I would not recommend to try something like this even if you would have nothing to do serving a long term in a prison.
Answer: Short answer: Not easily.
Long answer: The COM technology is an exclusively Windows technology and ATL is built on top of it. That means you can not compile/run it under linux, except if you use Wine or something similar.
Here's what you can do: You can switch to XPCOM - a cross platform implementation of COM technology, implemented by the Mozilla platform. COM and XPCOM are binary compatible under Windows (but only if used from XPCOM - MS Windows COM is agnostic of Mozilla's XPCOM).
I am unsure if you would be able to compile any ATL code using XPCOM instead of COM as a base though (but I doubt it), and if you go with XPCOM, you're better off using an XPCOM GUI (using the same code that Mozilla/Firefox does), instead of Qt.
This would mean implementing your GUI using Javascript and XUL.

How can I use COM ATL project in Linux?


What personal information is safe to share publicly?

Question: What personal information is safe to share publicly (online)? I have a CV online with my email address, mobile number, land line number, ID number and year of birth (not date of birth). I live in South Africa where there is a lot of physical crime, so I recently took off my street address to prevent potential burglars from finding out if my house is uninhabited or not (by calling the land line) before attempting a break-in. Am I giving away too much personal information?
Comment: Too late. Search for `google search cache` and you'll see several offers how to view previous versions of your CV.
Comment: Good point. The web is forever. OTOH assuming you control the site the CV is hosted on, you can request link removal by all the major search engines using their webmaster tools. I would remove that old link; as ott points out, your street address is likely out there now. Then upload the updated CV under a new URL.
Comment: I'm all for sharing as little as possible... but who seriously goes out looking for cached versions of resumes to conduct a single residence burglary? Wouldn't it just be easier to park out front and steal a wallet, watch, and get the keys on your way into that fancy house?
Answer: IMHO, the less the you share online the lower the risk of being targeted in some by spammers, hacker, identity thieves, phishing scams, ex-boy/girl friends,thieves etc.
Given the context (an online CV) lets look at each piece of data, and determine its risk/requirement for the context of an online CV.

email address

I would strongly suggest you do not provide your primary email address here, as you will certainly be targeted by email spammers, and your inbox will suddenly be filled with Viagra offers, lottery 'winning' notifications, urgent parcel delivery notices, PayPal refund notices, etc etc.  All spam or phishing attempts. You do want to be contacted by prospective employers, not by spammers. Lower the risk Use a Disposable email address service here, and you are safe.

mobile number, land line number

Again on an online CV, a phone number is nice, but not absolutely required if you have posted a disposable email address.  This again invites possible spam SMS messages, unwanted phone calls, and loss of privacy - assuming its your home phone, I would treat that like my home address: nobody gets that unless they are actual friends/colleagues/family.

ID number

Careful with this one. In the US anyway, our ID numbers are Social Security numbers, and are really not shared.  SSNs any are primary identifies associated with tax returns, bank accounts, credit reports. etc. Even when communicating with trusted providers that have my account information, they will only ask for the last 4 digits for identification purposes.

year of birth

This data is fine I suppose, but again, why provide it in this context? One can simply guess your age based on your educational and work history, usually. I like to keep them guessing a bit on my age anyway.
In summary, name and a disposable email is all I would share.  If you used LinkedIn, that type of data is always good to see on a CV.
Perhaps I am paranoid, but I would only offer Name and Email as data.  If they like your CV, all they need to do is send an email! You provide more details as needed.
Comment: It's good advice, but if you're really paranoid get a disposable phone and list that number. Don't miss a job offer protecting information that major corporations and governments give away for free.
Answer: It really depends person to person what's considered safe. I happily provide the world with my address, phone, email, and other bits of personal information. I also have firearms and live in a good neighborhood where just about everyone is armed. If I was in a crime riddled area I may not be so open.
Answer: All of these are said to be PII (Personal Identifiable Information). If you trust the source you are putting your information into - i.e. if the the box of this information holder is secure, you'd be automatically secure. Otherwise, you are already in danger to data-theft given that the site has data leakages though any or all of the following:

DataBase Injection of any kind (MySQL, MS-SQL, etc.)
Physical Data Migration Weaknessess
SSI, LFI, RFI - you name it is leveraged to host compromises and then server side data-thefts.

Aforementioned are the cases wherein your data might or might not be compromised or even if the holder of this PII has taken care of it's information warehouses via a safe security audit and good well-formed best security practices - it's risk are only lowered but never gone.
Hence the question which is at stake might need a re-consideration since security isn't measured in terms of - this should had happened or not or am I at total risk or not (it's always safe to assume you are at risk to be cautious and prevent risks), the more appropriate question might be the holder I am trusting my data with has gone through proper security audits to minimize my data theft risk or not?.
Now that's upto you how you trust this information holder and leave the rest if you have had to upload your CV anyway.


Staying in pattern at a class C airport

Question: Before departing VFR from a class C airport, I contact Clearance Delivery and tell them what I want to do. If I am just looking to stay in the pattern, though, what do I need to tell them?
Comment: Welcome to aviation.SE! Which country or regulations are you asking about?
Answer: I would tend to agree with Michael Hall that you probably don't need to contact Clearance Delivery if you are planning on remaining in the pattern. In general you should contact Clearance Delivery (if a frequency is published) if you want to be assigned a discrete squawk code. So:

At a Class D, you do not need to contact CD unless you are requesting an IFR clearance or VFR flight following.
At a Class C, you do not need to contact CD if you are requesting to remain in the pattern. All other departures, even if you do not want flight following, should contact CD to receive a "local" code out of the Charlie.
At a Class B, all departures should contact CD to receive a squawk code, even if you'll just be staying in the pattern. This is because ATC provides radar separation to all aircraft operating in Bravo airspace. (I don't know if you'll get many Bravo towers to approve pattern work though.)

If you just want to remain in the pattern, it would probably be acceptable to contact Ground directly and use the following phraseology:

Ground, N12345 is at the FBO, request taxi to runway 27 for pattern work, we have information Alpha.

But it might be worth a call to your tower to see how they want you to do it. Their procedure might be for the CD controller to prepare all departure strips and hand them to Ground, so they want you to call CD anyway. Or they may have no problem with you calling Ground first. Where I work, we're slow enough that Ground and Clearance are almost always combined anyway so it doesn't matter which one you call.
Answer: There would be no need to contact either clearance delivery or departure control if you intend to remain in the pattern.  This presumes that the control tower is operational, because they of course control the Class D airspace that holds the pattern.
I am not aware of any Class C airspace where the primary airport would not have a tower, or that the tower might close while Approach/Departure control remains active.  However, if this was the case, or if you were staying in the pattern at a secondary airport underneath or adjacent to the Class C, it certainly wouldn't hurt to give them a quick call and let them know what you are doing.
Answer: Just tell the ground controller that you want to remain in the pattern.  If they have any local procedures that would require you to get a transponder code or any other requirements it will be on the ATIS or the ground controller will tell you.

Staying in pattern at a class C airport


How to access Unity assets natively on Android or iPhone?

Question: I need to access a file natively (from C++ or Java code) on Android and iPhone in a Unity plugin project. Does Unity provide any method to access files in the project Assets?
Answer:
My workaround was to copy the files from the Application.streamingAssetsPath (which is inside a jar and can`t be accessed by most native libraries) to the Application.persistentDataPath (which is totally fine)and then to pass that path to the native code.
The source files in the project should be under Assets\StreamingAssets

Small sample code in c# to copy files async:
Add this method to a script which inherits MonoBehaviour
IEnumerator CopyFileAsyncOnAndroid()
{
    string fromPath = Application.streamingAssetsPath +"/";
    //In Android = "jar:file://" + Application.dataPath + "!/assets/"
    string toPath =   Application.persistentDataPath +"/";

    string[] filesNamesToCopy = new string[] { "a.txt" ,"b.txt"};
    foreach (string fileName in filesNamesToCopy)
    {
        Debug.Log("copying from "+ fromPath + fileName +" to "+ toPath);
        WWW www1 = new WWW( fromPath +fileName);
        yield return www1;
        Debug.Log("yield done");
        File.WriteAllBytes(toPath+ fileName, www1.bytes);
        Debug.Log("file copy done");
    }
    //ADD YOUR CALL TO NATIVE CODE HERE
    //Note: 4 small files can take a second to finish copy. so do it once and
    //set a persistent flag to know you don`t need to call it again
}

Comment: It's 2016... is there easier solution for accessing files from StreamingAssets in Android plugins?
Comment: it's 2018... after hours of search, I am still using this method. it works well...
Answer: Access to files at runtime is limited to directory Assets/Resources. Everything placed in there can be accessed by Resources.Load method (doc) but there is no chance to get something from outside the folder.
Within Assets/Resources folder you can set up an arbitrary folder structure. I used it in an iPhone project for level building from predefined text files and it worked like a charm.
Comment: Resources.Load is not a native method though. Does anyone else care to offer some guidance on loading from Assets/Resources in native code (e.g. Objective C on iOS, C++ on Android (NDK))?
Comment: Assaf just provided another method to access data outside Assets/Resources folder [Unity Manual](http://docs.unity3d.com/Manual/StreamingAssets.html)


How is this question not "off topic"?

Question: https://stackoverflow.com/questions/30076342/what-features-are-not-available-in-intellij-idea-community-edition-vs-webstorm-f
I just failed a close vote audit for voting to close it.   It's almost nothing to do with programming, and almost entirely opinion based.   If we look at the answers we see "In my eyes, the main difference is...".   What's that if it's not opinion based?
Comment: I'm not sure why you failed the audit, so I'll decline to answer, but I do think that question is off-topic. It's asking for a list of missing features, so it should be closed as "too broad."
Comment: You won't fail the same audit again...
Comment: Funny - I see @Will was referring to the fact that I would vote the same way again, and this time pass, since the question is closed/deleted now.   Well, I learned something about how the audits work!
Comment: I failed the audit because (I was told) voting to close this question was the wrong thing to do.   Ostensibly, this is an example of a question that is perfectly fine.   That's what I came here to check up on: really??
Comment: I'm not sure what everyone can see, but here is the link I can obtain from @kasperd 's link https://stackoverflow.com/review/close/8044215
Comment: @GreenAsJade With that link I can see that you failed the audit by voting to close, and that the question is deleted. Users with enough reputation will also be able to see what the question was. But you won't fail the same audit again, because when a deleted question shows up in an audit in the close queue, you are supposed to vote to close it. So if the same question does show up in an audit again, then you will pass if you vote to close. Sometimes the audits are just wrong, and it seems people just learn to live with that.
Comment: I'd have voted to close from the title alone. Having read everything here, I still would (except it's not possible to vote to close when you can only see the title).
Comment: This metaquestion is lacking a link to the review. You can find a link to the review on https://stackoverflow.com/review/close/history
Comment: The element of the original question that made it appear to me to be too broad and opinion-based is "what are the biggest distinctions between WebStorm && IntelliJ IDEA Community Edition for the Dart workflow?".   This is a broad qualitative question.
Comment: @Will ... actually, I would.   Based on the feedback here, and the resulting action, I have not recalibrated my judgement, but rather had it reinforced as "in line with stackoverflow policy".
Comment: Hah - I thought we were talking about "the same _kind_ of question", not the exact same question :D :D
Comment: @GreenAsJade I think I have seen one question show up in an audit more than once. And I certainly have seen questions on which I voted previously show up in audits. (And trying to close as duplicate when I recognize that the "new" question showing up in the audit is identical to one I saw last week is not going to work.)
Comment: @GreenAsJade Exactly!  I'm with you, btw.  How audits are chosen is deeply flawed imho. Audits should be OBVIOUS.  Not borderline cases.
Answer:
What's that if it's not opinion based?

I don't know... "A question about a programming tool" maybe?
I gotta confess, I don't use Dart. And I'm not a big fan of IntelliJ. But I'm pretty sure that the features available in an IDE do not depend heavily on the subjective opinions of the user. Maybe things are different in the Microsoft world, but Visual Studio 2008 never managed to cough up a good SQL editor, no matter how often I closed my eyes and believed...
So it's a boring question about editor features, scoped to a specific pair of editors and a specific language. Unless you happen to notice everyone eschewing feature comparisons in favor of posting opinionated rants in the answers, I don't see how you can claim this is "opinion-based" much less primarily so.
That said... That doesn't necessarily make it a good question. Feature-comparison questions often suffer from other problems:

Duplicating information already available elsewhere in a more comprehensive format.
Becoming woefully out of date.
Being entirely too broad for anyone to answer completely.

These have all been issues for, for instance, Visual Studio releases, which tend to be massive (covering multiple languages and a plethora of associated tooling), can change in key areas during and after the final release, and are usually documented more completely in official changelogs and release documentation anyway.
However, I'm not sure those concerns apply here either - again, we're talking about editors for Dart, not sprawling multilingual development systems.
Unless you observe these problems emerging, I wouldn't be overly concerned about this question at this point.
Comment: The problem is that this has a clickbait potential and an abuse potential since it's about two competing editors with money involved. It's also like "framework vs. framework" questions and is likely to go really outdated really fast.
Comment: I do think it would make a pretty solid blog post though, on the author's website. That would give it timely context.
Comment: While this matter seems largely resolved, I feel a bit compelled to point out that the quote that you re-quoted was from an answer, not the question.   It was demonstrating that the question was already drawing opinionated answers.   I think that this answer makes the point that one shouldn't be too concerned about whether this question stays or goes - it possibly didn't warrant a close vote in the first place.  While that's a fair point, it doesn't help in answering whether or not "Close" should have been a failing selection under audit, which is what this meta question is about.
Answer:
"This question has been removed for reasons of moderation ..."

If you like you can feel vindicated, however to be able to answer the question requires the knowledge that IntelliJ IDEA is the "all languages" flavour of JetBrains' IDE and WebStorm is their JavaScript IDE containing a subset of the IntelliJ IDEA features but optimised for JavaScript developers.
If you knew that then you probably shouldn't have closed the question. If you didn't know that then you probably should have skipped the question and if you suspected it was an audit question then you probably should have skipped it too because there is no way of guessing what the audit question was chosen to test for.
In my opinion you were correctly caught closing a question without applying an appropriate level of knowledge.
Comment: Did you get to see the body of the question before it was closed?   If so, in your opinion, did it seek opinions, or facts?    I thought it was an opinion based question about software tools (deserving closing) rather than a factual qustion about software tools (which is on topic).
Comment: I did see the question before it was closed. At the time I thought it was the latter but I can't go back to check the precise wording in its removed state. Either way, it was asking something of interest to a professional or enthusiast programmer working in that area. If in, your view, it did not meet the criteria for a "good question", in my view the appropriate action was either to improve it or leave it for someone else with the requisite knowledge of IntelliJ/WebStorm to answer or improve.
Comment: @GreenAsJade What made you think this particular question was "almost nothing to do with programming" and "almost entirely opinion based"?
Comment: That view is not consistent with the close vote reviewing process, in which voting to close questions that don't meet the guidelines is what we're asked to do.   The close vote queue presented the question to me as "This question is flagged for closure.  Does it meet the on-topic guidelines?"   I assessed it as being opinion based, so voted for closure.  Upon finding that I failed an audit for that decision, I came here to calibrate my understanding.    The sense I'm taking away is that my understanding of what to vote for closure is pretty reasonable :)
Comment: The element of the original question that made it appear to me to be too broad and opinion-based is "what are the biggest distinctions between WebStorm && IntelliJ IDEA Community Edition for the Dart workflow?".   This is a broad qualitative question.

How is this question not "off topic"?


How to calculate pre and post treatment Hedge's g effect size to use in meta-analysis of studies with no control group?

Question: How to calculate pre and post treatment Hedge's g effect size to use in a meta-analysis for studies with no control group? Can you do it with just pre and post treatment means and standard deviations and the sample size or do you need a correlation statistic?
Answer: You would need the correlation as well. If some studies report the correlation you could impute the correlation from them to the other studies. If there is no evidence about correlation available to you then trying the calculation for a range of plausible values would be possible. You would have to report the results from all of them obviously, picking the one which gave the result you liked best would not be a good idea.


What is the cheapest way to get from Zurich to Nice?

Question: I am travelling to Europe next month, and would like to know the cheapest means and/or modes from Zurich to Nice as I plan to depart from Nice.
Comment: Do you have any constraints? Departure time, travel time, etc?
Comment: no specific time
Answer: The cheapest way is probably ride sharing ("covoiturage") or hitchhiking. But these options require some luck and flexibility.
If you want something more predictable, take the plane or the train.
For the flights, use an engine like Kayak or Matrix Airfare Search to check the possibilities.  For the beginning of September I have found one-way flights for +- 110 EUR (Germanwings, Air Berlin, Iberia).
For the trains, you can use Voyages SNCF. I have e.g. found a ticket for 126 EUR by night train via Paris. This has the advantage that you save one accommodation. The price includes the ride plus the bed. On a daytime train you will have to foresee more or less the same budget.
You can also opt for multimodal transport. Easyjet flies from Nice into Basel and Geneva, from where you can easily proceed by train to Zürich. From Basel it is one hour and costs 32 CHF. From Geneva, it is a bit less than 3 hours and will cost 84 CHF. The price for the flight depends on the exact date of travel and the extras you want to take.
Comment: "From Basel it is one hour and costs 32 CHF. From Geneva, it is a bit less than 3 hours and will cost 84 CHF". If you buy a Sparbillet online in advance, you'll get half the Price (CHF 16.5 and CHF 42). And there are buses from Basel Airport to Zurich several times a day for €8-10
Answer: The cheapest way is probably a bus. Do compare prices with flights however, sometimes cheap flights are available if you book long enough in advance. Buses are also cheaper when you book in advance but they tend to cap much lower.
Rome2rio is convenient to get a review of the different possibilities. Make sure you check actual prices by starting the booking process, their price ranges are not always very reliable.
At least in summer 2016, Eurolines runs a daily bus from Zürich to Nice, leaving early morning and arriving mid-afternoon. There's also a connection via Turin, but that requires spending a night in Turin.
Zürich to Nice isn't particularly convenient. The straight route would go through the mountain and there aren't that many people doing that route. If you're touring the place, it would be a good time for a stop in Turin or Milan.


Are there infinitely many primes of the form $4n^{2}+3$?

Question: We, know that there are infinitely many primes of the form $4n-1,4n+1,5n-1,\cdots, \text{etc}$. I saw these things in Apostol's Introduction to Analytic Number theory textbook. I would like to have an argument working for $n^{2}$. The first expression which came to my mind was $4n^{2}+3$, which gives a prime for $n=1,2,3,4,5$. For $n=6$ it gives $147$ which is divisible by 3. For $n=7$ it gives $199$ which is again a prime. Then for $n=11$, it gives $487$ which is again a prime. I would like to know whether there are infinitely many primes of the form $4n^{2}+3$? If yes, then a proof!
Comment: See Schinzel's hypothesis H: http://en.wikipedia.org/wiki/Schinzel%27s_hypothesis_H. No result along these lines has ever been proved :-(
Comment: @Anonymous: You made a typo in your first five _n_. The polynomial $F(n)=4n^2+3$ is obviously not prime for $n=3m$.
Comment: @Robin: Ever or never!
Answer: Many people "would like to have an argument working for $n^2$", but what is available at the moment (and for the last two centuries) are conjectures.  For any list of integer polynomials there is a conjecture on how often all polynomials on the list are prime:
http://en.wikipedia.org/wiki/Bateman%E2%80%93Horn_conjecture
It is extremely hard to prove that any natural set of integers of density 0 contains infinitely many primes.  It is known for the set of values of $x^2 + y^4$ but not for the values of any single-variable polynomial of degree higher than one.
The asymptotic formula in the Bateman-Horn conjecture isn't necessarily the most general expression of what people in the field believe to be true (and it is probably a lot older than Bateman and Horn's article that formally codified it), but it does subsume many earlier conjectures on primes of the form $n^2+1$, prime twins and k-tuplets, Schinzel's Hypothesis and Buniakowsy's conjecture.  You can calculate from the formula the predicted frequency of $n$ such that $4n^2 + 3$ is prime.
Comment: The set should be defined without reference to primes or to an obvious disguise for primes.  Squares-plus-one is a natural set of integers for this purpose, but "integers with EulerPhi[n] divisible by (n-1)" is not natural because primality is expressible in terms of the Phi function.
Comment: Link to $x^2 + y^4$ theorem: http://en.wikipedia.org/wiki/Friedlander%E2%80%93Iwaniec_theorem
Comment: @T: I don't understand you. What do you mean by saying natural set of integers of density 0


Should data points of a data set be from the same distribution?

Question: My question is with respect to real-world custom data sets used for Machine Learning applications. The collected data set contains numerous audio signals (File1, File2, File3, etc) of a moving machine part captured over different points of time. Features are extracted using basic signal processing techniques such as FFT, signal envelope, etc. The machine is located in the real world and hence the audio signals have noise. Is it possible that the feature set for each data point in the audio signal has different distribution? If so, does this affect the ability of a Random Forest or Neural Network or any other ML model to generate a good fit? Also, is it possible that the audio signals themselves do not share a common distribution due to noise and other environmental factors?
Answer: Real world audio signals are a mixture of multiple signals. Some of these can be noise and some the sound of interest.
Which degree the noise affects the distribution of features really depends a lot on the feature extraction. It is of course desirable to have features which are as independent of noise as possible. If you hand engineer features, this is something you manually have to account for.
With deep learning it is possible to learn the feature extraction (representation learning). Techniques such as Data Augmentation with noisy signals can help the model learn noise-invariant features.
If no consideration is put into these things, the model is likely to perform badly on out of distribution data. If this can happen in a real world scenario, then it is important to evaluate the model on such cases. This is often referred to as mismatched conditions.


Why is it in the United State's national Interest to care what's happening between Israel and Palestine?

Question: Why is it in the United State's national Interest to care what's happening between Israel and Palestine?
Comment: I downvoted because its a poor question.  Though I did not vote to close because it is on topic and answerable.  Had you included some details of your understanding of the situation and what made you think it should not be in our interest then the question would be much better.
Comment: so far this question has been upvoted 5 times and downvoted 6 times.  People who downvote should say why.
Comment: Man, I could answer this question, but I only have very tenuous sources for my response, so I'll just say in a comment: There are domestic politics reasons, like an influential Jewish lobby and religious motivations by evangelical Christians, and Israel also represents foreign policy interests, as it fights terrorism and is the only liberal democracy in the middle east. It might be worth reading Michael Oren's book on this subject: http://www.amazon.com/Power-Faith-Fantasy-America-Present/dp/0393330303
Comment: LOL, "This question is opinion-based." on POLITICS. Let me know when POLITICS is not opinion-based.
Comment: Does the [wikipedia page](http://en.wikipedia.org/wiki/Israel%E2%80%93United_States_relations) answer the question?  Or are you looking for something more specific?
Comment: Because a nuclear war in the middle east will definitely affect the US and our allies.
Answer:
Geopolitics.

Israel is historically (after the switcheroo of 1960s alinements) America's beachhead in Middle East, in contrast to Soviet-client (these days Russia but no big difference) Arab states.
Why is America interested in Middle East? First, oil. Second, to prevent another hegemon (USSR/Russia; or regional like Turkey or Iran) from taking influence over the entire region and harnessing its resources.
If you're asking "What's the big deal", remember that Osama Bin Laden's main, and explicitly stated, beef with USA that led to 9/11 was basing US miliary in Saudi Arabia; and its relationship with Saudi rulers. As such, imagine if Israel isn't there. USA would have to have MUCH closer ties and explicit military relationships with other countries in Middle-East... so we get all sorts of local Osama's objecting to that to a higher degree than now.
Israel serves as a useful flashpoint for terrorism and Muslim anger. In case you forgot, USA's a "great Satan" and Israel is merely "little Satan". If Israel's gone, USA no longer has a flashpoint to deflect this, and becomes primary target.

Military industrial mutual symbiotism.

USA gets to have access to cutting edge Israeli military technology and research (see enhancements Israel demanded to Bradley for a very random example).
USA gets to field-test its military hardware in real combat situations
USA has a ready-made market for its military-industrial complex (a vast majority of money from USA's foreign aid, is gotten on a condition of spending that money right back in the States on military purchases).

As a side effect of that, USA gets to enforce on Israeli's military industrial complext the right to veto ANY arms sales; which happens either when USA doesn't want some advanced technology being given to potential opponent; OR when that sale would constitute a competitive challenge to USA's sales).

This one's more in Geopolitics column, but USA has stockpiles of reserve hardware in Israel. In case of rapid theatre deployment needs, they don't need to worry about transporting that hardware across the globe, merely flying in personnel.

Internal politics.

As I noted with references on another answer on this site; US Evangelicals (a super powerful demographics whose most recent leader was G.W. Bush) are strongly pro-Israel for theological reasons.
Another distinct pro-Israeli slice is moderate liberals who feel guilt over Holocaust.
Another somewhat distinct slice is non-Evangelical right-wing people who like Israel for being a democracy in an Middl-Eastern ocean of dictatorships or simply for being on - as they see it - Western Civilization's side in the conflict of civilizations (I'll leave aside whether that's a correct representation but the thinking definitely informs a sizable chunk of population).

In all fairness, this isn't "national interest" column, but it's a reality that a representative democracy like USA can not ignore no matter objective interests.
Comment: *If Israel's gone, USA no longer has a flashpoint to deflect this, and becomes primary target.* - That the key right there more than anything else I think.  The other points are icing on that cake.
Comment: @DVK I think this answer is largely correct but could really benefit from some sources. And I may be misinterpreting this, but "moderate liberals who feel guilt over the holocaust" implies that there aren't other liberal reasons to support Israel when it is pretty much impossible to be consistently liberal and not to: http://blog.writerofwrongs.net/2011/03/zionism-left-right-and-center.html (also, it could use support from poll data). Add some sources and I'll probably upvote.
Comment: @DVK I recognize there are people on the far left who are anti-Israel, but that doesn't itself imply any general statement, much less the one you were making.
Comment: the problem with the western is they are preventing any country in the middeleast to be strong , to have heavy industries or economic indepedent or even they are afraid such contries to control the oil. thats why they always creates war in middleast and africa so people stay weak and powerful countries such as france and usa suck people resources. why then made they made sykes-picot ? middel east are just colonies.
Comment: @dvk all right then I am new to the site here however bare with me , with my limited english and with my limited politics information, anyway I do agree usa is in the middeleast for oil and to prevent other countries to control the region and aslo isreal dream of its jews land (its in the history). USA support and created the 'anger musslims' they support kaaida and DAESH , because there goal is to make chaoes in the region like iraq and pakastan and theyv never supported palestinian.
Comment: @Avi - you haven't been to many Occupy Wall Street rallies/forums with all the kuffiahs (on white people) and "evil Zionists" propaganda, have you?
Comment: @user4012: Can you explain about "If Israel's gone, USA no longer has a flashpoint to deflect this, and becomes primary target"? Was USA in danger or a primary target before 1948?


Time capsule web site logging?

Question: If time capsule can not be set up to log the web sites that users access, is there third-party software that will accomplish this for time capsule?  Ideally something that would work through the time capsule and not have to be installed on each individual device, but would allow analysis by device.
Comment: Time Capsule DOES backup website history from Safari.
Answer: The router itself does have DNS caching, but that cannot be accessed without rooting the device (and probably changing a few settings that shouldn't be changed to do logging to disk). Furthermore, an automatic update may reset everything, so I wouldn't go down that path at all. Much better idea would be to set up a DNS on a small linux machine and then configure the Airport DHCP to use your small Linux computer's DNS server as the default. That will persist through updates, etc. All clients connecting will ask the linux machine for the IP address of the website they want to go to. Just log it.
Also, for what it's worth, even if this is your network and these sorts of invasions of privacy are easy to do, I really really REALLY recommend you make everyone (children, etc) aware that this logging is going on. For everyone's sake.

Time capsule web site logging?


Uniformly random planar map

Question: Is there a way to sample a planar map uniformly at random? I am aware of the Cori-Vauquelin-Schaeffer bijection that can be used to sample and study uniformly random quadrangulations. There are other results in the literature that allow for sampling other classes of planar maps, but I haven't seen any results for the entire class of planar maps.
Answer: Planar quadrangulation with $n$ faces are in bijection with planar maps with $n$ edges. The quadrangulation is bi-partite, so colour its vertices white/black. inside each face, add a diagonal edge between the two black vertices. Then delete all white vertices and incident edges. The result is a map with $n$ edges, and it is not hard to see that this is a bijection.
In fact, this is one of the reasons quadrangulations are a particularly interesting class of planar maps.
Comment: Are there methods for sampling fixing other statistics (e.g. number of vertices or number of faces)?
Answer: Something you may potentially be interested in :
http://www.lix.polytechnique.fr/~fusy/Articles/FusyAofa.pdf
Nathann

Uniformly random planar map


Stop notifications from chrome spam

Question: My new Android device is full of spams. I get chrome notifications continuously from a website I did not even visit once. looks like a gossip site. Are there any methods to stop these annoying notifications?
Answer: Try the following:

Open Chrome, then Settings,select Site Settings
Click on Notifications. Check if that website is listed among the Allowed sites.
If yes, Click on it. Remove or block the permissions given to it by clicking on the permissions
Comment: Thank you. the answer is really very helpful.it worked.
Comment: @KevinBarnes Please see the [Tour](https://android.stackexchange.com/tour) on how to the site works. If the answer helped you, then you can mark it as accepted.

Stop notifications from chrome spam


using lagrange multipliers to fit a curve through a point

Question: So this is part math/ part statistics. I have a set of data I'm fitting a 2nd order curve through using least squares method (matrix form). However, I've been given the requirement to pass the curve through a particular point. it's the y-intercept and starting point of the regression line in this case. I read you can use lagrange multipliers to do this. All the examples I read about these multipliers are related to min/max problems. I understand lagrange interpolation but it seems like this is another beast. Are these multipliers independant of the least squares or  can they be used independently? And/or does anybody know how to do this or know of an article explaining this? note there are 30+ points (not three). Also, if there are any other suggestions on how to do this I'm all ears. this is just what i had found so far. Thank you in advance!
Comment: What you need to do is minimize  the quadratic error subject to your constraints. (That's what least squares do without constraints)
Comment: I can't say I follow. what do you mean by constraints and how would you minimize said quadratic error?
Answer: For sure, there is another way if you look for a solution which does not use Lagrange multipliers (I should consider it simpler). You want to minimize $$\Phi= \sum_i (f(x_i)-y_i)^2$$ using $$f(x_i)=\beta_0+\beta_1 x_i +\beta_2 x_i^2$$ and you want to constraint the model such that $f(x_1)=y_1$. The constraint allows you to eliminate $\beta_0$ and let you with two parameters for a classical least-square fit.
Answer: The problem of least squares is:
$$\min_\beta \sum_i (f(x_i)-y_i)^2$$
Where $f(x_i)$ is your favorite form, in your case $f(x)=\beta_0+\beta_1 x +\beta_2 x^2$
Then what do you want is the next:
$$\min_\beta \sum_i (f(x_i)-y_i)^2$$
$$\text{s.t.} f(x_1)=y_1$$
What is equivalent to minimize the lagrangian:
$$L(\beta,\lambda)= \sum_i (f(x_i)-y_i)^2+\lambda(y_1-f(x_1))$$
Comment: It is the saddlepoint of the Lagrangian, not the min. There is no min anyways, since if you fix $\beta$, you can choose $\lambda$ to make the second term as negative as you want.


Do Google Chrome and Safari keep sending my IP address to websites while in the background on iOS

Question: When you are not actively using Safari or Chrome, but if they are in the background still with open tabs of websites that were visited while in the foreground, do they keep refreshing and sending my IP address etc. to the websites?
(iOS)
Answer: Unless you have Background refresh turned on for Safari or Chrome, they don't.
Note that when you minimise a app, the app just stays in Stand-by mode. When you again use it, it refreshes the data by sending your information again.


Accessing Google Group archive without receiving group emails in Gmail

Question: I have had a Gmail account, but don't want to receive emails there any longer. I signed up for a Google Group with a non-Gmail address. This prevents me from accessing the group archives. How do I use my Gmail address to access the group archive, without receiving group emails in my Gmail?
Comment: Thanks Ruben but that was not my problem. I am in a google group, but my google account shows I am in no groups. So I can't access the archives of the group I'm in. The moderator signed me up with a non-google email address. I have several gmail addresses. So I asked him to add one of my gmail address and will see if that works.
Answer: From Leave a group or unsubscribe from emails

Unsubscribe from a group
You can stop getting emails from a group by changing your settings or leaving the group.

Sign in to Google Groups.
Locate the group you want and then choose an option:

To stay in the group but stop getting emails, under Subscription, click the displayed option and then select No email.