How to manipulate a CSV file with sed or awk?

How can I do the following to a CSV file using sed or awk?   Delete a column Duplicate a column Move a column   I have a big table with over 200 rows, and I'm not that familiar with sed.


What's the difference between 8 MB and 16 MB Cache on a hard drive?

I'm looking to replace a dead hard drive in an older notebook.  The current (bad) hard drive is a Toshiba 60 GB 5400 RPM HDD with 16 MB cache.  It's very difficult to find replacement ATA-100 notebook drives with 16 MB cache.  Do I even need this extra cache?  Is twice the cache noticeable?


Is it ethical to use a recommendation letter from a deceased professor?

She was a really nice professor and she wrote me a good recommendation letter that resulted in a lot of good results with applications. Recently, this professor died from brain cancer, which was a fast and shocking death for me.  Tomorrow is the deadline for a grant. What should I do? Is it professional to use letters from the deceased?


I've noticed a significant issue with the \input command, it seems.  For some reason, I can't seem to prevent it from adding a space after it reads its input.  Even if there is no newlines or spaces at the end of the file, LaTeX seems to be just driven to add a space.  Minimal working example is this:  \documentclass{article} \begin{document} A\input{TestInput.out}B \end{document}   Where TestInput.out contains only the text "SomeText" and no special characters  This provides the output:  ASomeText B   Does anybody know how to prevent this?  For a typesetting program, it's kind of weird to just arbitrarily add spaces IMO.  I'd like to think there's an easy fix, but I'll take any portable, robust fix if it works.


How do you update npm to the latest version?

I'm having issues with npm in a Vagrant box I'm setting up. I noticed that the npm version is somewhat old, so I wanted to check the problem with the latest release.  It is my understanding that you should be able to update npm using npm install -g npm, but the command has no effect on the npm being used:  vagrant@box:~$ npm -v 1.3.10 vagrant@box:~$ sudo npm install -g npm npm http GET https://registry.npmjs.org/npm npm http 200 https://registry.npmjs.org/npm npm http GET https://registry.npmjs.org/npm/-/npm-2.1.12.tgz npm http 200 https://registry.npmjs.org/npm/-/npm-2.1.12.tgz /usr/local/bin/npm -> /usr/local/lib/node_modules/npm/bin/npm-cli.js npm@2.1.12 /usr/local/lib/node_modules/npm vagrant@box:~$ npm -v 1.3.10   I also tried using n (as suggested in ) to update, but it affects neither npm nor node:  vagrant@box:~$ node -v v0.10.25 vagrant@box:~$ vagrant@box:~$ sudo npm install -g n /usr/bin/n -> /usr/lib/node_modules/n/bin/n n@1.2.9 /usr/lib/node_modules/n vagrant@box:~$ sudo n stable       install : v0.10.33        mkdir : /usr/local/n/versions/0.10.33        fetch : http://nodejs.org/dist/v0.10.33/node-v0.10.33-linux-x64.tar.gz    installed : v0.10.33  vagrant@box:~$ node -v v0.10.25 vagrant@box:~$ npm -v 1.3.10   What do I have to do to update npm to the latest version?


Is there the possibility to produce PSTricks graphics in LuaLaTeX?  I tried it, but i get       ! Undefined control sequence.     <recently read> \c@lor@to@ps       l.9 \psline(         -5,2)(5,4)   With auto-pst-pdf I get a warning to use pdflatex.  So how can i use pstricks in LuaLaTeX?  Edit:@Marco Daniel  I asked where to pack packages for specified for lualatex, "normal packages", and pstricks packages: Maybe something like this:      \RequirePackage{ifluatex}     \documentclass{scrartcl}     \usepackage{amsmath}      \ifluatex         \usepackage{fontspec}         \defaultfontfeatures{Ligatures=TeX}         \usepackage{lua-visual-debug}     \else          \usepackage{pstricks}          \usepackage{pst-plot}     \fi          \usepackage{auto-pst-pdf}     \begin{document}     Here text...     \end{document}   Niklas


I haven't talked to my wife for three years.   I haven't talked to my wife in three years.      Are in and for interchangeable in these sentences?


LIDAR files were released for major part of Slovenia few months back in zlas format. Decompressed LAS format is 1.4 version. I have tried many options how to generate DEMs and had some success in programs and tools but unfortunately they were all trial versions of license pay versions.  Problem is that I can't open and generate DEMs of LAS version 1.4 in many open and free tools (such as MCC-Lidar).   Can you help me converting LAS from 1.4 to 1.2 in some free tool? Or if it is any other way for LAS 1.4.


Generated code does not respect correct protocol (eg. HTTPS)

Browsing StackOverflow, I've found out, that not all resources are loaded over HTTPS (if using that protocol)  Looking into code, I've found out, it's related to Imgur addresses:     view-source:

0

votes

0

answers

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views

OnUpgrade Android SQLite Database from Assets Folder

        android database sqlite assets

             55m ago             LukeG224 10

   Also related links, are not using the same protocol:  eg. Hot Network Questions

                      Hot Network Questions

                     Is it better to have light come from the left side?
   or main noscript
Stack Overflow works best with JavaScript enabled


How to visualize $SO(4) \simeq SO(3)\bigotimes SO(3) / \mathbb{Z}_2 $

Is there a simple way to see that $SO(4) \simeq SO(3)\bigotimes SO(3) /\mathbb{Z}_2$ ?


How can I upscale a low-res image to make it appear higher-res?

I want to enlarge an image to a bigger size. This will cause pixelation.  So I want to apply some treatment to it in Photoshop that will suppress some of this pixelation. Of course I cannot generate new pixel information, only smoothen it etc. so that the pixelation is not so much apparent in full views and prints. Example, one effect popular with photographers is to copy the image into a second layer, set its blending mode to overlay or soft light etc., then apply a blur to it. This somewhat smoothens the image. But it also changes its appearance into a glowy kind of look (which is the aim, usually).   I want a treatment that will fake the appearance of a higher-res smooth image without too many side-effects.  Any tricks of this kind?


Interpolation of multibeam bathymetry using ArcGIS Desktop?

I'm trying to make a 3D map with multi-beam bathymetry (65536 features, xyz), but it seems that the interpolation methods are too rigid. I need to smooth the data so it looks more natural and realistic.   Which parameters do I have to vary so I can get this?


Proof by contradiction : $n^3 −n−6 = 0$ means $m^3 − m − 6 ≠ 0$ when $m≠n$

I have to prove by contradiction that if $n$ is a positive integer such as $n^3-n-6 = 0$, so for any positive integer $m$ such as $m ≠ n$, we have $m^3-m-6 ≠ 0$ I am new to proofs, but I tried and here is what I did. I first assume the opposite of the conclusion, so $m^3-m-6 = 0$ $(m-2)(m^2+2m+3) = 0$ m=2 If I do the same thing for the n function and find the solution for $n^3-n-6 = 0, n=2$. This is a contradiction since $m=n$, but we said $m ≠ n$. I feel like im doing something wrong here and I would like someone to tell me what it is ! (Again, I am a beginner)


The inequality:  $$\sqrt{a^2+c^2}+\sqrt{b^2+d^2}\ge \:\sqrt{\left(a+b\right)^2+\left(c+d\right)^2}$$  But can someone help me with a nice elegant solution. This is an olympiad question I was trying to solve, but couldn't manage an elegant solution.


Moving Ubuntu 18.04.1 OS from HDD to new SSD for faster boot

I want to move Ubuntu from my 2TB hard drive to a 512GB solid state drive to improve my boot speed. Ubuntu is the only OS I use.   How can I achieve this?


How could Molly Weasley not know the platform number for Hogwarts Express?

Heart hammering, Harry pushed his trolley after them. They stopped and so did he, just near enough to hear what they were saying.   'Now, what's the platform number?' said the boys' mother.   'Nine and three-quarters!' piped a small girl, also red-headed, who was holding her hand.   'Mum, can't I go...'   'You're not old enough, Ginny, now be quiet. All right, Percy, you go first.'   (Harry Potter and the Philosopher's Stone, Chapter Six, "The Journey from Platform Nine and Three-Quarters")   Now, as far as I'm aware, Hogwarts Express always departs from Platform Nine and Three-Quarters.  And Molly have been there innumerable times, both as a student, and many many years prior to Book 1 with older Weasley kids going to school.  Hell, she even knows easily how to get onto a platform:     'Not to worry,' she said. 'All you have to do is walk straight at the barrier between platforms nine and ten. Don't stop and don't be scared you'll crash into it, that's very important. Best do it at a bit of a run if you're nervous. Go on, go now before Ron.'   So why did she not know/remember the platform #?


Unity2D - Horizontal Scaling to Support Various Aspect Ratios?

I am trying to work out how to support various resolutions for my Android game. I have come up with a solution, but do not know how to implement it.  Automatically, I am told that Unity vertically scales the screen to match the screen, leaving more room at the sides. How can I change this behaviour? I am hoping to shrunk the game down till it fits horizontally, and filling it the background above and below with more decorative features. How can I achieve this?  I'm sorry if there is an obvious answer, I'm quite new working with the Unity UI system.  If it makes it any easier, my game is heavily based on UI, and is locked in landscape.  BIG EDIT: I completely rephrased this question because it was so broad and messy.


Buying expired domains - what to look for?

I want to purchase a few expired domains, who have some backlinks, but some of those sites have PR of -1 with backlinks which are pretty bad.  But what exactly do I need to look for when looking for an expired domain (and I don't want to pay up the nose for a PR3+ domain).


Changes to capitalization in .bib file not reflected in output

In reviewing my document I found errors in capitalization of some acronyms in titles of references (dc or Dc instead of DC, etc). When I corrected the .bib file, changes were not reflected in the output. If I make more substantive changes (adding/removing words) they are reflected.  I am using BibTeX, MikTeX, and TeXstudio with:  \documentclass[conference]{IEEEtran}   to set up the document class.  And this call for building the bibliography:  \bibliographystyle{IEEEtran} \bibliography{ref}   Here's an example reference entry in ref.bib:  @article{patterson2012:green_building,   title={DC, come home: DC microgrids and the birth of the `enernet'},   author={Patterson, Brian T},   journal={IEEE Power and Energy Magazine},   volume={10},   number={6},   pages={60--69},   year={2012},   publisher={IEEE} }   And the output:    As others with similar problems attempted, I deleted all temp files (aux, bbl, blg, log, and gz) then compiled twice - but this didn't work.


I noticed people aren't voting that much. At least not as much as me, I vote for more than 70% of the questions I see, and more than 50% of each answer.  In fact, I haven't found a single question or answer with more than 2 days that had a max(total_question_votes; answer_1_total_votes; ...; answer_n_total_votes)/views ratio superior to 10%. If these were elections of a law in a parliament, it would be seriously weird to have more than 90% abstention.  What do you think of this? How do you vote yourself?


Is there a way to do a textual search through all stored procedures for a table name?

I've just inherited a database with a number of tables and stored procedures.  I use Microsoft SQL Server Management Studio.  One, or possibly more, stored procedures update a specific table.  I'd like to do a textual search through all the stored procedures to look for the procedure that updates the table.  If the raw SQL was in our code, I'd just grep the code base, but with stored procedures I'm not sure how to search through all the stored procedures.  I'd also like to rename a few things and do a find/replace throughout the stored procedures.  Is it possible to search and replace in stored procedures using Microsoft SQL Server Management Studio?


Why do we use zero infinitives with make, let, have?

When we use causative verbs as in    I asked you to do something   we use 'to do'.   However, we don't say    *I made you to do something    but just    I made you do something.   Is there any particular reason that we use zero (bare) infinitives after make, have, let?


Question about conditional probability and Baye's formula

I have the following sentence:  If I toss a biased coin with 2/3 chance of landing on heads, given that there was at least one head in 3 flips, what is the probability that there is only 1 head?  If we let $X$ represent the number of heads, then I can use $Baye's$ formula to find out the probability.     Which of the following would be the formula?  $$P(X=1 | X \geq 1)$$ $$P(X \geq 1 | X=1)$$  I think its the first one, but my sheet is saying the second one. I think it might have made a mistake. Which is the right probability?


Get group number in views-view-grouping.html.twig

Is it possible to get the group number inside the views-view-grouping.html.twig? So the first group gets the number 1, the second number 2 etc. Something like: <div class='group-nr-{{ group_number }}'>     {{ title }}     {{ content }} </div>  I need this to make three columns out of my groups.


How to prove the following inequality with trigonometric function

For any non-zero real number $x_1$, $x_2$,$$\left|x_1\sin{\frac{1}{x_1}}-x_2\sin{\frac{1}{x_2}}\right|\leq2\sqrt{|x_1-x_2|}.$$ I tried the following, $$\begin{array}{rl}\left|x_2\sin\frac{1}{x_2}-x_1\sin\frac{1}{x_1}\right|&\leq  \left|x_2\sin\frac{1}{x_2}-x_1\sin\frac{1}{x_2}\right|+\left|x_1\sin\frac{1}{x_2}-x_1\sin\frac{1}{x_1}\right|\\  &\leq |x_2-x_1|+|x_1|\left|\frac{1}{x_2}-\frac{1}{x_1}\right|\\  &=\frac{1+|x_2|}{|x_2|}|x_2-x_1|\\  \end{array}$$ But I don't know how to go on...


How to center a div that is used as a submit button for a form

I have a div which I'm using as a submit button for my form, but I cannot figure out how to center it. When the margins are set to auto, it ends up being just slightly right off the center of the page and of other divs with the same css style.    #submit {  background-color: blue;  height: 80px;  width: 720px;  margin: 0 auto;  text-align: center; } <form name="algForm">

 </form>     Thanks.


I have been trying to make out how: $\binom{2n}{n} \sum_{k=0}^{n}\binom{n}{k} \binom{n}{n-k}=\binom{2n}{n}^{2}$ so in essence, showing that   $\sum_{k=0}^{n}\binom{n}{k} \binom{n}{n-k}=\binom{2n}{n}$  but I do not see this is the case, I mean in each summand, for a given $k$ I get,  $\frac{n!^{2}}{k!^{2}(n-k)!^{2}}$ I do not see how I can take out a common $\frac{2n!}{n!^{2}}$ out of each summand.   Any help is greatly appreciated.


Lie algebras isomorphism $gl(2,\mathbb{C}) \cong sl(2,\mathbb{C}) \oplus \mathbb{C}$

Having a struggle finding a lie algebra homomorphism between these two spaces. So i know that $\mathbb{C} \cong \lambda\left( \begin{array}{ccc} 1 & 0  \\ 0 & 1  \\ \end{array} \right) $, where $\lambda \in \mathbb{C}$. A basis for $sl(2,\mathbb{C})$ is $ \{\left( \begin{array}{ccc} 1 & 0  \\ 0 & -1  \\ \end{array} \right),  \left( \begin{array}{ccc} 0 & 1  \\ 0 & 0  \\ \end{array} \right),  \left( \begin{array}{ccc} 0 & 0  \\ 1 & 0  \\ \end{array} \right) \}$.  The dimension of $< \left( \begin{array}{ccc} 1 & 0  \\ 0 & 1  \\ \end{array} \right), \left( \begin{array}{ccc} 1 & 0  \\ 0 & -1  \\ \end{array} \right), \left( \begin{array}{ccc} 0 & 1  \\ 0 & 0  \\ \end{array} \right), \left( \begin{array}{ccc} 0 & 0  \\ 1 & 0  \\ \end{array} \right)>$ is 4, and so this space generates $gl(2,\mathbb{C})$. So these two spaces are isomorphic as vector spaces, but I can't seem to find a function that would induce a lie algebra isomorphic. I tried defining a homomorphism by   $\varphi : gl(2,\mathbb{C}) \rightarrow sl(2,\mathbb{C}) \oplus \mathbb{C}$  by,  $\varphi(A) = (\varphi_1(A),\varphi_2(A))$  where $\varphi_1(A) = \left( \begin{array}{ccc} a & b  \\ c & -a  \\ \end{array} \right)$  $\varphi_2(A)= tr(A)$  where $ A = \left( \begin{array}{ccc} a & b  \\ c & d  \\ \end{array} \right) $ but this did not preserve the lie bracket. Any insight as to what this homomorphism would be?


How big is the space faring population in Star Wars?

In Star Wars, like in star trek, planets tend to have only one climate zone and only one location, where you can find all people you are looking for, just by knowing they are on this planet. And all spacefaring people of the whole galaxy (at least all smugglers and other criminals) seem to know each other by name and by ship.  Some of this could be explained if indeed the spacefaring folk are low in numbers, and most planets actually have have only one location (at least only one space port, where space folk will meet) where most of all people are, and if most planets have only a low population. It would also explain why the space battles on screen have only a low number of ships involved (30 X-Wing in A New Hope).  But in other questions I read that the galaxy far far away consists of millions of inhabited planets with billions of people and the empire has millions of ships. This seems to contradict everything I saw in the movies.  So what in canon tells us how many planets, places and people are in the galaxy far far away and how are the "the galaxy is a small place" observations (I know it's a trope) explained in universe?  (And yes, I know this would not explain the "Go to Dabobah and meet Yoda". Where on Dagobah exactly? Oh, I crash landed on Dagobah in a random location. I will look for Yoda. Let us walk in this direction and see if we can find him.)  EDIT:  Ok. So let us try to approximate an answer by dividing into subquestions:   What in canon tells us that there are indeed more than a few 100 planets (preferable on screen) and a few hundred races? (The only thing I can come up with is C3PO knowing 6.000.000 languages, but I think this is more to make him look elaborate than to establish millions of planets and races). If there are millions of planets, races and billions or trillions of ships, how can the "small world" impressions be rectified? What in Canon tells us on the opposite that there are only a few hundred planets and races?   To 3. I have a few Points:  The smuggler, princess and farm boy seem to know most of the planets, races, technology, ship and vehicle types, weapons, etc. When a planet is mentioned, it is done in a way that the speaker assumes that the listeners know it. When Han talks about "Lando" Leia seems to ask in a surprised and wondering tone "Where is the Lando System?" so she seems surprised that there is a System she does not know. Han "wonders" that Owi Wan and Luke have never heard about the falcon. Of course it is exagerated a lot, but it implies, that it is possible that there is a ship the whole galaxy has heard about. Hints that there are not millions of different technologies, models and types are: Leia able to do repairs an the falcon, Leia and Luke able to ride the speeders on endor, Luke able to use the weapons of the falcon and many more (I think).


Prove the railway metric is a metric: trouble proving d(x, y) = d(y, x)

I'm struggling to prove symmetry for the railway metric.  Let $d:\mathbb{R}^{2}\times\mathbb{R}^{2}\rightarrow[0,\infty)$  $$d(x,y)=\begin{cases}\|x-y||&\text{ if }x,y,0\text{ are collinear}.\\\|x−0||+\|0-y||&\text{ otherwise}.\end{cases}$$  I have managed to show $d(x,y)=\|x-y\|=\|x-x\|=\|0\|=0.$


In Windows 10 file is saved without permission and is visible only to the program that saved it

In Windows 10 different software behaves differently when I am trying to save files to the C:\ root directory. Some simply fail/refuse, saying I have no permission (MS Word, console copy command etc.), others let me do that after I confirm my administrator permissions through UAC. Such behavior is not a problem I am trying to solve. There seems to be the third kind of software which behaves rather strange. So far I have only observed such behavior with , but I don't think it's IrfanView-specific. This is what IrfanView does when asked to save a file in C:. It doesn't ask for administrator permission, and neither it fails. It looks like it saves the file to C:\ silently and without a question. However, such files can only be seen in IrfanView: they are invisible for FileExplorer or for dir /a, but if I run IrfanView first and select its "Open" menu command, the files are there, can be opened, edited, saved again, moved, copied etc. So, what's happening? Is it some sort of a compatibility thing for software that is too dumb to ask for permissions? What does Windows 10 really do with those files?


How can I prevent Windows 10 from sharing wifi details with my contacts?

In recent release of Windows 10 we could see a new feature named wifi sense, which raised the following security threat as per this  :     This brilliant new feature, which Microsoft has dubbed Wi-Fi Sense,   doesn’t share your WiFi network password per se — it shares an   encrypted version of that password. But it does allow anyone in your   Skype or Outlook or Hotmail contacts lists to waltz onto your Wi-Fi   network — should they ever wander within range of it or visit your   home (or hop onto it secretly from hundreds of yards away with a good   ‘ole antenna!).   As per faq :     For networks you choose to share access to, the password is sent over   an encrypted connection and stored in an encrypted file on a Microsoft   server, and then sent over a secure connection to your contacts’ phone   if they use Wi-Fi Sense and they’re in range of the Wi-Fi network you   shared   From  :     First, a bit of anti-scaremongering. Despite what you may have read   elsewhere, you should not be mortally afraid of Wi-Fi Sense. By   default, it will not share Wi-Fi passwords with anyone else. For every   network you join, you’ll be asked if you want to share it with your   friends/social network   From the above excerpts it's unclear whether Windows 10 shares wifi details with  my contacts; So my questions were few :  Does it really shares WiFi details with my contacts since many articles states it's shared & it's not shared.  If it's shared how can I prevent it?


buster blader the dragon destroyer swoardsman effect not working

Why doesn't buster blader the dragon destroyer swordsman with DNA surgery on the field stop destiny hero plasma's effect that allows plasma to take my monster. Oh BTW this is in the duel links game


I'm using the Interpolation plug-in in QGIS 2.18 to perform IDW Interpolation. I was hoping to specify a power of 2 and use the 10 nearest points to calculate the output, but I don't necessarily see a way to do so.   Is there another tool that I can use to accomplish this?


The following is an exercise in Hungerford (Ch. III, ex. 5.6).     Let $R$ be a commutative ring with identity. If $f=a_nx^n+\dots+a_0$ is a zero divisor   in $R[x]$, then there exists a nonzero $b$ in $R$ such that $ba_n=ba_{n-1}=\dots=ba_0=0$.   I can see for example that $\{g\in R[x]\mid fg=0\}$ is a nonzero ideal, so it contains a nonzero element of smallest degree.  But how to show that such an element is actually a constant?


My background is mathematics. I would like to study celestial (not classical) mechanics and looking for an appropriate book.  I found that somebody has already asked a similar question "", but let me ask more specific question: Is there any textbook on celestial mechanics which contains lots of figures and is of mathematical flavor?  I don't need too elementary book; the level should be graduate math level. At the same time, a textbook without figures often makes it difficult for me to continue reading it.  Any suggestions/recommendations are welcome :-)


How to decompose a unitary transform into two-level unitary matrices?

I'm struggling to understand the process of how to decompose a unitary transform into two-level unitary matrices. I've been trying to understand the process as detailed in , but I don't get where those 2x2 matrices in the individual two-level matrices are coming from, or what P actually is. If anyone could walk me through a numerical example of decomposing for example, a 4x4 matrix into two-level unitary matrices, that'd be greatly appreciated!


I have, unfortunately, been put in a question ban. The good part, is that I know exactly why, and that this ban has pretty much forced me to read through many wiki posts, rules, FAQ's, and  In the help center, I read:  How can I get out of a question ban? The ban will be lifted automatically by the system when it determines that your positive contributions outweigh those questions which were poorly received.  So, I tried to make more positive contributions to the community by actively looking for questions to answer for a week or two straight, and trying to answer the ones that I could. Unfortunately, answering questions was not enough to lift the ban, so I read on––more wikis, more posts, more FAQ's, etc. In my reading, I saw that a great way to get out of a ban, or to start the process of having it lifted, is to edit my questions that were received poorly/deleted. So, I went back to my old questions that I deleted and tried to find ways to improve them so that (a) they would be unique, well formed, and followed the rules and tips that I read, and (b) would be useful to future visitors. Sadly, I noticed that my questions are simply unredeemable: they were either too specific, or I had found the answer/solution since deletion. My question applies to all sites which is why I posted it on meta SA: What else can be done to get out of a question ban––to "outweigh those questions which were poorly received" through "positive contributions"? Does getting reputation simple counteract the ban or something else altogether? EDIT:  does not answer my question; this post says that I should edit my posts, as an important step, but as I said in my question, that is not really an option. I suppose that what I am really asking, is if a ban is lifted when the reputation from positive contributions is greater than the reputation lost from negative ones.


I'm trying to install the gnome desktop environment on my Ubuntu 14.04LTS using the command line:  $sudo apt-get install gnome-shell       but the terminal keeps saying:      "Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation: The following packages have unmet dependencies:  gnome-shell : Depends: gnome-settings-daemon (>= 3.4.0) but it is not going to be installed                Recommends: gnome-control-center but it is not going to be installed E: Unable to correct problems, you have held broken packages."     how do i fix this?


my Drupal 6 installation is on a MySql server, while my own custom database is on Oracle. I have made a custom module that can read and write data into my external database, but i would like to use Views module to handle the data to show. I know that I can programmatically build views, but i don't know if I can build one for Oracle DB while Drupal is on Mysql.


How can I separate a single object file into multiple objects based on closed geometry?

Let's say you have a single obj with a number of separate closed 3D geometries in it. For example's sake, imagine you have an obj called neighborhoodfirehydrants.obj that includes the model for all of the fire hydrants on a street, which themselves are closed, but as I said above, are all within the same obj file.  Now let's say you wanted to be able to process each of those fire hydrants one at a time, separately. To the user, it's very obvious to see visually that these faces can be subgrouped into separate "objects" but in the Blender world, it sees them all as one.  I'm looking for a way (script would be ideal) to iterate through a blender obj neighborhoodfirehydrants.obj and find each of the "objects" (fire hydrants) that make it up. I've been looking into using the looping tools, but that's not making sense in this context.


Preventing domain controller from adding A/AAAA for domain root

I have set up the domain contoso.com. The domain controllers in the domain are also the DNS servers within the network.  When users try to resolve contoso.com, they receive the A/AAAA records of the domain controllers. However, we want contoso.com to resolve to a different address (the web server of the company).  We added the A/AAAA records for the web server to the domain root, but noticed that there were additional A/AAAA records, pointing to the domain controllers. We removed those, but they are being re-created.  How do I prevent this from happening? I did not notice any degraded performance or other issues while the records were not present.


How do I port a .FON font to a Linux font?

I like the ProggyClean fonts a lot and would like to see them in my terminal. The "True Type Font" versions aren't great, but the bitmap (raster, *.fon) fonts are excellent. This should be a virtue since the Linux fonts are all raster as a matter of course.  I think the Linux font format is PSF2 (among others?) and is detailed here: .


Trying to use minted package and getting error "Package minted Error: You must invoke LaTeX with the -shell-escape flag."

I am using Windows 8.1, MiKTeX 2.9, TeXstudio. Everything including packages are fully updated.  I am trying to compile this:  \documentclass{article}  \usepackage{minted}  \begin{document}   \end{document}   And getting this error:      Question: What to do?


Finding equation of the parabola from tangent information

Two lines drawn through $T$ at $(-1,-2)$ are tangent to a parabola at $P$ $(2,3)$ and $Q$ $(3,-1)$, respectively.  Find the equation of the parabola.  I tried using similarity of triangles to find the focus, but to no avail.


What is the difference for fields vs properties which construct (immutable) value types in C#?

Example: public readonly struct Vector3 {     public readonly float x;     public readonly float y;     public readonly float z;      public Vector3(float x, float y, float z)     {         this.x = x;         this.y = y;         this.z = z;     }      public static readonly Vector3 oneField = new Vector3(1f, 1f, 1f);     public static Vector3 oneProperty => new Vector3(1f, 1f, 1f);      public static Vector3 operator +(Vector3 lhs, Vector3 rhs) =>             new Vector3(lhs.x + rhs.x, lhs.y + rhs.y, lhs.z + rhs.z); }  How exactly does the behaviour differ when doing: var v = Vector3.oneField + Vector3.oneField vs var v = Vector3.oneProperty + Vector3.oneProperty From my understanding the content of the field is loaded and stored in the Heap/RAM when the (relevant part of the) program is loaded, the value is then copied from there into the stack twice when the + operator is called. While the property will allocate the memory directly on the stack twice when the + operator is called. Is that correct? And which one would be 'technically' faster? (just curious about the details) EDIT I think technically its not a property but just an "expression-bodied member", however thats irrelevant for the question, but I will correct it for clarity if necessary.


I'm embarking on a new web map project that seeks to display simple geometries (lines, points, polygons) and rasters/basemaps. Ideally, the map will also allow authorized users to add/remove/edit geometries and their attributes.  What are the available options for the storage of data (e.g. SQL Server Spatial)?  What are the available options for the presentation of data (e.g. ArcGIS Server)?  I'm new to web mapping and am attempting to build a solid understanding of the available options and their pros/cons.


Font family used in creating inserted document

I'd be happy if someone could tell me the font family used in creating this document.    Thanks


My understanding of rolling motion:     When a body rolls, at every instant, there is just one point of contact between the body and the plane and this point has no motion relative to the plane.   Now if there is no motion relative to the plane, then how does the rolling friction came into being?      I researched a bit about the origin of rolling motion but could not understand what does the following paragraph means:     During rolling, the surfaces in contact get momentarily deformed a little (Why?), and this results in a finite area of the body being in contact with the surface.


Windows 10 - Stop Lock Screen from Sleeping

We'd like the Windows 10 lock screen to remain on all the time (or at least for a couple of hours) so that the picture remains visible. This is for aesthetic reasons.  When the PC is locked (i.e. user logged on, station locked), it seems to turn off the screen signal after a minute or so has elapsed. Moving the cursor wakes it.  Changing the corresponding setting in Power Options doesn't seem to impact how the lock screen behaves. Does anybody have any suggestions?   It seems to not sleep the screen if you have powered up the PC and not yet logged on.


Pulling an apk of paid app from the device

I was pulling the .apk files from the device using the following command:  ./adb pull /data/app/com.example.tracker-1.apk   When I tried using the same command for the encrypted app as below:  ./adb pull /mnt/asec/net.stfj.spelltower-1/pkg.apk    I get the following message  failed to copy '/mnt/asec/net.stfj.spelltower-1/pkg.apk' to './pkg.apk': Permission denied   The device is not rooted and the app is a paid app. The intention of pulling is not piracy but to understand the library and architecture of a set of apps. Is there a way I can retrieve that .apk file?


Is there a word or phrase for something that one might wish exists, but most certainly doesn't?

An example might be a car that is fast, luxurious, reliable, gets great gas mileage, and is very cheap. Clearly we'd all love to own such a car, but it doesn't exist, and probably never will. There's also some naiveté in assuming it would.  Is there a metaphor, idiom, or other phrase that connotes this?  "Gee, that sounds like a wonderful car, but unfortunately, it's a _____."    UPDATE:  With regard to the proposed dupe - that question has the same accepted answer, but it's not the same question. Two different questions can have the same answer. Please let me know if you disagree.


I'm going to drop a database. I want to monitor if any user is still using the database for a couple of months. Besides profiler, is there a better way to monitoring activities on a database?


“AMD-V is not available” even when Virtualization is enabled in the bios

I enabled virtualization in the bios yesterday and the virtual machine worked yesterday. Today, I double checked in the bios and virtualization is still enabled. But the virtual machine is giving me this error when I tried to start it up:  Failed to open a session for the virtual machine Ubuntu 15.04.  AMD-V is not available (VERR_SVM_NO_SVM).  Result Code: E_FAIL (0x80004005) Component: ConsoleWrap Interface: IConsole {872da645-4a9b-1727-bee2-5585105b9eed}   What's causing this, and what do I do?  My motherboard is a Gigabyte GA-78LMT-USB3  My CPU is an AMD FX-6300 3.5GHz 6-Core Processor Black Edition  Update: After installing a 32-bit version of Ubuntu on the virtual machine, it worked fine. However, that still doesn't explain why VirtualBox doesn't detect that I have AMD-V, I tried running ubuntu on vmware and that tells me that I have to turn Hyper-V off, so my virtualization is definitely on, it's just that virtualbox does not detect it.  Update 2: Ubuntu launches, but it keeps flickering non-stop; this means that VirtualBox is not detecting my Hyper-V.  Update 3: Hyper-V was installed on the system, Hyper-V apparently causes a conflict between other virtual machines, I'm turning this off now and letting windows restart.  Update 4: IT WORKS!


How can I set the processor affinity of a process on Linux?


$\int_0^\infty f(x) \; dx < \infty$ implies $\lim_{x \rightarrow \infty} x f(x) = 0$.

Let $f$ be non-negative, monotone decreasing such that $$\int_0^\infty f(x) \; dx < \infty$$ Show that $$\lim_{x \rightarrow \infty} x f(x) = 0.$$  I have the following solution, but wonder if there is a better way.  Let $\epsilon > 0$ be small. Suppose to the contrary that $\limsup x f(x) = c > 0$, then there is a sequence $x_n$ tending to infinity such that $x_n f(x_n) \geq c - \epsilon$. Moreover, $f(x) \geq (c-\epsilon)/x_n$ for $x \leq x_n$. Thus, the integral $\int_0^N f(x) \; dx$ is bounded from below by $$S_N = x_1 \frac{c-\epsilon}{x_1} + (x_2 - x_1) \frac{c-\epsilon}{x_2} + \cdots + (x_N - x_{N-1}) \frac{c-\epsilon}{x_N}$$ Since $x_n \rightarrow \infty$, we may suppose that the $x_n$ are spaced far enough apart so that $x_k/x_{k+1} < M < 1$. Then the partial sum $S_N$ will be bounded below by $$N(c-\epsilon) - (N-1)M(c-\epsilon)$$ which tends to infinity as $N \rightarrow \infty$.  Is there an easier solution?


when i sudo apt-get update run this problem face please help me

E: The repository 'http://ppa.launchpad.net/damien-moore/codeblocks-stable/ubuntu bionic Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. E: The repository 'http://ppa.launchpad.net/mc3man/trusty-media/ubuntu bionic Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. E: The repository 'http://ppa.launchpad.net/mc3man/xerus-media/ubuntu bionic Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.


How to check which package depends upon another installed package?

I just did apt-get upgrade on my Ubuntu 16 and noticed that mysql-client package was updated. I don't remember installing it though.  How to check which package I did install depends upon it?


How to tell Google Chrome to use my Keychain

Background:   Story: A colleague of mine told me about  and it seems good to me. I am always trying to use tools which Mac OS X itself gives me, so I've given the Keychain a try. It seems satisfying, but I don't know how to tell Google Chrome to use my specific keychain. I need it to separate saved stuff for work and for private (syncing private to work, but separated from work data).  Stuff:   Google Chrome 21.0.1180.57 (Fully updated) Mac OS X Lion (Fully updated) OS X Mountain Lion (Fully updated)   Question:  How do I tell to Chrome to use a specific keychain and to save data from/to this keychain?


Optimising $x_1x_2+x_2x_3+\cdots+x_nx_1$ given certain constraints

To seek the maximum value of $S=x_1x_2+x_2x_3+\cdots+x_nx_1$ on this domain:  $x_1+x_2+\cdots+x_n=0$ and  $x_1^2+x_2^2+\cdots+x_n^2=1$.  I have made some trivial observations:  1) $S\in[-1,1)$ by the rearrangement inequality.  2) We can make $S$ arbitrarily close to $1$ by increasing $n$.  3) An equivalent problem is to minimise $(x_1-x_2)^2+\cdots+(x_n-x_1)^2$.  But does the maximum have a meaningful closed form  for each $n$?


Test class for Http Request code coverage is 50 percent

I have a class  public class myclass {      @AuraEnabled      public static List <Json2Apex> customerData(String startDate, String enddate){           List <Json2Apex>  LSData = new List <Json2Apex>();          String queryString = endpoint;            Http http= new Http();         HttpRequest request= new HttpRequest();         request.setendpoint(serviceEndPoint + queryString);         request.setMethod('GET');         try {                     if (!Test.isRunningTest()) {                 HttpResponse response = http.send(request);                  if (response.getStatusCode() == 200) {                     String showval= response.getBody();                      JSONParser parser = JSON.createParser(showval);                     while (parser.nextToken() != null) {                         if ((parser.getCurrentToken() == JSONToken.START_ARRAY)) {                             while (parser.nextToken() != null) {                                 if (parser.getCurrentToken() == JSONToken.START_OBJECT) {                                     Json2Apex p = (Json2Apex)parser.readValueAs(Json2Apex.class);                                     LSData.add(p);                                     parser.skipChildren();                                 }                             }                                }                     }                 }             }          }catch (Exception ex) {             SystemLoggingService.log(ex);         }          return LSData;        }      }    My test class is  @isTest  public class Test_myclass {  @isTest static void testCallout() {          Test.setMock(HttpCalloutMock.class, new MockHttpLabGenerator());          Account account = CreateTestClassData.createCustomerAccount();          List<Json2Apex> res = myclass.customerData('2019-10-10','2020-01-01');            } }  Mock Test Class is       @isTest global class MockHttpLabGenerator implements HttpCalloutMock {      global HTTPResponse respond(HttpRequest request) {          HttpResponse res = new HttpResponse();         res.setHeader('Content-Type', 'application/json');         res.setBody('[{"Name":"Test",}]');         res.setStatusCode(200);         return res;      } }


Could humans in the LOTR Universe perform magic?

In the Hobbit: An Unexpected Journey, Gandalf attempts to convince Saruman that the "Necromancer" i.e. Sauron, has returned, but Saruman dismisses Gandalf saying:      Saruman: That's absurd. No such power exists in this world. This "Necromancer" is nothing more than a mortal man, a conjurer dabbling in black magic.   Would this mean that humans could learn and use magic? Or would Saruman be talking about what we would consider a magician in our world?


How come the Weasley twins didn't realize Wormtail was alive because of the Marauder's Map?

We are probably all familiar with this one: How come Fred and George don't realize the long-dead Peter Pettigrew is alive? They had the map for many years while Wormtail was at Hogwarts (he was Percy's rat first).


Proof of sum of cubes of odd numbers by induction

Prove by mathematical induction $$1^3 + 3^3 + \cdots + (2n - 1)^3 = n^2(2n^2-1),\forall n\geq1$$   Please help me solve this question using the mathematical induction method.


deformation retract and strong deformation retract

I am trying to gain some intuition about retracts, deformation retracts and strong deformation retracts (see  for definitions). We have that any strong deformation retract is a deformation retract and any deformation retract is a retract (of course, by definition). Also, it is easy to think in a retract which is not a deformation retract.  Which are some examples of deformation retracts which are not strong deformation retracts?


How to check if a process is running via a batch script

How can I check if an application is running from a batch (well cmd) file?  I need to not launch another instance if a program is already running. (I can't change the app to make it single instance only.)  Also the application could be running as any user.


How to do perspective projection “parallax” but without changing the scale or offset of objects?

Hello everyone I have this problem that I have tried everything I could think of. The problem: I am making a 2D game with parallax effect but I am using 3d space so am not simulating the parallax but letting the perspective projection take care of it for me. now the problem i have my own game editor where I design the levels, in this editor I use just images and I set a Z value for each layer. however I want the layers to show in the game engine exactly as I set them in the game editor, in short I want perspective projection to do parallax but without changing their scale or offset/position.  obvious solution is to scale them up and offset them but the problem how to calculate their offset? with scaling I tried object->Scale(object.Z/view.Z) and seems to return them to their real size but their positions are still wrong. I tried object->setPositionX(object->getPosition().x*(object.Z/view.Z)) and seems to be aligned except they all seems shifted.  I have tried unprojecting and tried to convert from world matrix to screen matrix and find some ratios and so on.  If anyone have any idea or anyway how this could be done in an elegant/mathematical way , I will be most grateful.  Thank you all in advance.


But for my father, I wouldn't have achieved anything. Is this correct?

I was wondering if anyone could confirm if this sentence is correct?  It somehow doesn't sound or feel correct but I saw it written today. Can anyone give me any insight if it is right or wrong?  'But for my father, I wouldn't have achieved anything.'


Python is soft link to python2.7, how to change link to python 3

on Ubuntu 14.04 has python-3, python-2.7 and python is linked to python-2.7 by default. I have to run python-3 code on ubuntu -14.04. Can I modify /usr/bin/python link to python3? Any idea?  Thanks


My desktop is nearly at the point where I'm happy with it. However I've noticed that half the ram (8GB) is in use even at idle. as one would expect this seems to have an effect on games and other programs.   I cannot justify a new CPU as yet, but would doubling the ram in the machine be give a worthwhile improvement in performance, or would it be better to wait a year or so and upgrade the CPU?  Full Specs:   AMD FX8350 4.0Ghz 8Gb 1600mhz DDR3 (2 4gb sticks running in dual channel) MSI 970A-G46 120GB SSD (For OS) 2TB HDD GTX 1060 6Gb GTX660 (I had spare power available and like having a PhysX slave)


It is possible to set multiple passwords to single login in ubuntu platform?

I tried with different ways, but not worked at all. Please any-one help me ?  I've looked at this question:      The referenced duplicate is not the same question. The referenced question is about how to use one password for normal usage and one for sudo.   This question question can imply that a person has 20 passwords (none of which needs to be sudo)


how to pass inputs to java using eclipse?

I am trying to get the user input using the following code but on running it gives the error that Arrayindexoutofbounds. Don't know what is the problem.  public static void main(String[] args) {     int T = Integer.parseInt(args[1]);     PercolationStats stats = new PercolationStats(             Integer.parseInt(args[0]), T);     double mean = stats.mean();     StdOut.println("mean = " + mean);     double stddev = stats.stddev();     StdOut.println("stddev = " + stddev);     double d = (1.96 * stddev) / Math.sqrt(T);     StdOut.println("95% confidence interval = " + (mean - d) + ", "             + (mean + d)); }


Can vinyl siding be painted or stained, and more importantly, does it last or will I be repainting every year like a wood sided house?


A comparison between Grade, Mark, Score and Point

Let's suppose a teacher wants to punish a student and wants to decrease his / her achieved points on a test paper; he would say something to the student; I would like to know which one of the following self-made examples may work here:        I have to take two marks of you.   I have to take two grades of you.   I have to take two scores of you.   I have to take two points of you.      For me all the first three mean the same and though the last one is not the same, but works here either. I need to get your feedback.


How to disable Ctrl+Alt+S in Ubuntu 18.04?

I couldn't find anything in Settings -> Keyboard -> Shortcuts, nothing that said Ctrl+Alt+S or Toggle shaded state as many other answers pointed out.  How do I disable the default action for Ctrl+Alt+S in Ubuntu 18.04?


iOS mobile app does not make sufficient closure checks

If the question is open on the iOS app and it is closed you can post an answer to it for a long time (over 30 minutes) after.


What's the difference between “by night” and “at night”?

say by has the meaning of      6. indicating the period in which something happens: ‘this animal always hunts by night’   Then do we need to say, ‘Why does the sky glitter by night?’ And can’t we say, ‘Why does the sky glitter at night?’?   If we can use both, what’s the difference between the two?


Uncertainty Principle for a Particle on a Ring

In the case of a particle on a line, if I prepare an (although non-normalizable) eigenstate of the momentum so that the uncertainty in the measurement of the momentum vanishes, the uncertainty principle is (at least in a physicist's sense) still satisfied as the position measurement would yield a value from $-\infty$ to $\infty$ with an equal probability and the uncertainty in the outcome of the position measurement thus diverges.   But, in the case of a particle on a ring, if I prepare an eigenstate of the momentum (which will even be normalizable) so that the uncertainty in the measurement of the momentum vanishes, there seem to be some subtleties around how to think of the uncertainty principle. Naively, the eigenvalues of the position operator range only from $0$ to $2\pi$ and thus, although they are all equiprobable outcomes and the uncertainty in the outcome of the position measurement is maximal, this uncertainty (the variance) can only be finite as the range of the eigenvalues is of finite span. Thus, in this naive look, it seems that the product of the uncertainties in the measurements of the position and the momentum vanishes as the uncertainty in the measurement of the momentum vanishes and that in the measurement of the position is yet finite.   In the derivation of the uncertainty principle, we essentially only take into account the commutator of the operators which remains the same for the position and the momentum operators whether we consider a particle on a ring or a line. Moreover, we tacitly assume normalizable states which would suggest that the case of a particle on a line with a momentum eigenstate should be more subtle than the case of a perfectly normalizable momentum eigenstate of a particle on a ring. But, in fact, the roles seem reversed.   I can only think of one place from which the subtlety is arising. The uncertainty principle somehow takes all the identified positions such as $0,2\pi,4\pi,...$ as distinct and computes a divergent uncertainty as if it were simply a particle on a line. But, I don't know why it should be the case or how we could prevent it from doing it (via deriving the uncertainty relations more carefully) if it is indeed doing so.


Am pretty new to Linux.I could not set an root user account when I started my Dell laptop which came with Ubuntu. How do I reboot the same to set root. Kindly guide me. Thanks in advance.


Syntax highlighting thrown off by apostrophe in comment

I noticed a bug in the syntax highlighting for Objective-C code. See this post:   The apostrophe in a comment in the second code block seems to confuse the highlighter:    Oddly, when I paste the code here and manually tag it as Objective-C, it seems to work fine:  -(NSMutableDictionary *)getList:(NSString*)typeOfRequest{ //Declaration d'un objet SQLITE sqlite3 *database;  int i = 0; int j = 0; const char *sqlStatement = NULL; NSString *objectKey = nil;  //Declaration de notre String qui sera retourne NSMutableDictionary *aromaArray = [[NSMutableDictionary alloc] init]; // Ouverture de la base de donnees if(sqlite3_open([databasePath UTF8String], &database) == SQLITE_OK) {      //Chaine de caracteres de la requete     if ([typeOfRequest isEqualToString:@"aroma_huiles"]) {         sqlStatement = "SELECT name_fr FROM aroma_huiles";         objectKey = @"name_fr";     }     else if ([typeOfRequest isEqualToString:@"aroma_prop"]) {         sqlStatement = "SELECT * FROM aroma_prop";         objectKey = @"nom_propriete_fr";     }     else {         sqlStatement = "SELECT name_fr FROM aroma_huiles";         objectKey = @"name_fr";     }     //Creation de l'objet statement     sqlite3_stmt *compiledStatement;      //Compilation de la requete et verification du succes     if(sqlite3_prepare_v2(database, sqlStatement, -1, &compiledStatement, NULL) == SQLITE_OK) {          // Creation d'un dictionnaire des noms de colonnes         NSDictionary *dictionary = [self indexByColumnName:compiledStatement];         NSMutableArray *array = [[NSMutableArray alloc] init];         while(sqlite3_step(compiledStatement) == SQLITE_ROW) {              //Assigne la valeur dans la chaine de caracteres             char *tab;             tab = (char*)sqlite3_column_text(compiledStatement, [[dictionary objectForKey:objectKey] intValue]);             NSString *final = [NSString stringWithUTF8String:tab];             NSString *finalUpperCase = [final capitalizedString];             if (finalUpperCase != nil && finalUpperCase.length >0) {                 [array addObject:finalUpperCase];             }         }         NSMutableArray *table = [[NSMutableArray alloc] init];         while (i < [array count]) {             NSString *firstLetter = [array[i] substringToIndex:1];             table = [[NSMutableArray alloc] init];             while (j < [array count]) {                 NSString *secondLetter = [array[j] substringToIndex:1];                 if ([secondLetter isEqualToString:firstLetter]) {                     [table addObject:array[j]];                 }                 j++;             }             j = 0;             [aromaArray setObject:table forKey:firstLetter];             i++;         }     }     else {         //Envois une exception en cas de probleme de requete         NSAssert1(0, @"Erreur :. '%s'", sqlite3_errmsg(database));     }      // Finalisation de la requete pour liberer la memoire     sqlite3_finalize(compiledStatement);  } else {     //Envois une exception en cas de probleme d'ouverture     NSAssert(0, @"Erreur d'ouverture de la base de donnees"); } //Fermer la base de donnees sqlite3_close(database);  //Retourne la valeur return aromaArray;


how to add background image to lightning

I want to add background image, to part of my header i wrote code like this.  but its not working.   <div style="{!'background:' + v.backgroundColor + ' url(' + v.backgroundImageURL +') no-repeat;background-position: center;background-size: cover;'}">  </div>     doInit : function(component, event, helper) {          var url = $A.get('$Resource.RollingHillsGrey1');         component.set('v.backgroundImageURL', url);     }


If I were a dog, I’d bark all day. If I was a dog, I’d bark all day    Thanks in advance for your precious answers.


Are photons affected by Earth's gravity?

Just wondering if  the Earth's gravity affects the photons? We can obviously think about equivalent mass of photons by using de broglie relation and then use it to calculate force of gravitational interaction. But still this thought is very revolting. Help would be appreciated?


I am trying to use a for do command that I can run as a one liner in Solaris/Linux, and would like the do command to run asynchronously.  I have tried the following:  for i in `ls AMQ*.FMT`; do ./mqtrcfrmt.solaris $i $i.2 &; done   but I get an error like the following:  bash: syntax error near unexpected token `;'   Is there a way to get the do part of this for/do command to recognize the ampersand (&) and run this command asynchronously?


So this is about (preventing) an off-by-one error in the (interpretation of) English language. I have found some similar (not duplicate) questions but I don't feel entirely comfortable yet. For context, I'm an application developer, and I want my application to be crystal clear. To that end, I've found existing answers to be unsatisfactory. Let me give an example sentence that should explain it all.  The contract lasts from 1 January to 31 January.  The word to is ambiguous, although in this case is easily understood to be up to and including the 31st. However, it will not always be this easy! In Dutch, we have a simple solution to this ambiguity:  het contract duurt van 1 januari tot 1 februari (<) het contract duurt van 1 januari t/m 31 januari (<=)  I want to be able to use both forms in my application, but, again, it needs to be crystal clear to the user which of the 2 is meant. The English equivalent for t/m that first comes to mind is up to and including. However, that is just too long for my tastes compared to t/m. In Dutch, because it's so short, the ambiguity of tot is almost non-existent because laziness is not an excuse to write tot instead of t/m. I fear that some developers will write up to or until where they actually meant up to and including. I also considered the word through, so it would be this:  The contract lasts from 1 January to 1 February. (<) The contract lasts from 1 January through 31 January. (<=)  Is through really understood by everyone to be up to and including? Or is there an alternative, better word? Or perhaps I'm looking in the wrong direction for a solution and there's a word for to that explicitly excludes the boundary?  So again, to summarize, I'm looking for:  a word or phrase that unambiguously means less than a word or phrase that unambiguously means less than or equals


How to set an alias for a specific file or directory?

There are several files I work with often. For instance some configuration files or log files. Let's say the Apache log file. I often want to tail or grep it. Instead of writing:  tail -50 /var/log/apache2/error_log   I prefer to write  tail -50 apachelog  So that apachelog functions as an alias for this filename. But if I define an alias in my bashrc, it needs to be a whole command; it (apparently) can not be an alias for a filename so that you can reference it later. Is there a way to achieve this?   NOTE: I have a large variety of files and a large variety of different commands I want to run, so creating functions or aliasses for all of those different options will not be my preferred solution.


Is the structure $(\mathbb{R}, +, *)$ rigid?

Does the structure $(\mathbb{R}, + ,*)$ have only the trivial automorphism?


In publications the wording often resembles the following: "We found that our results followed what we found in our previous research."  I am now writing a publication alone, with no co-authors.  Is it bad form to use "my" in place of "our" in such cases?


after writing the app when i ran it iam getting following error  Unable to start activity ComponentInfo java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.v7.widget.RecyclerView.setAdapter(android.support.v7.widget.RecyclerView$Adapter)' on a null object reference   here is my mainactivity.java class  public class MainActivity extends AppCompatActivity {      ArrayList<Contact> contacts;      @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);          RecyclerView rvContacts = findViewById(R.id.rvContacts);          // Initialize contacts         contacts = Contact.createContactsList(20);         // Create adapter passing in the sample user data         ContactsAdapter adapter = new ContactsAdapter();         // Attach the adapter to the recyclerview to populate items         rvContacts.setAdapter(adapter);         // Set layout manager to position the items         rvContacts.setLayoutManager(new LinearLayoutManager(this));         // That's all!     } }


If $A$ is symmetric, then the matrix exponential $e^{A}$ is positive definite

This is a homework problem, but I feel like I'm struggling with not knowing facts from linear algebra.  Apparently this is supposed to be an easy question but I hit a brick wall at the following point.  Can anyone give me a tip or tell me if I'm going down the wrong road?  My approach:  Let $A$ be a symmetric $n\times n$ matrix, and then suppose $x$ is a real-valued column vector of dimension $n$ with not all entries equal to $0$.  I need to show that $x^Te^{A}x> 0$.  (based on looking up the definition of positive definite on wikipedia)  Then   $\begin{eqnarray*} x^{T}(e^{A})x &=& x^{T}(\sum_{n=0}^{\infty}\frac{A^{n}}{n!})x\\ &=& \sum_{n=0}^{\infty}\frac{x^{T}A^{n}x}{n!}\\ &=& \sum_{n=0}^{\infty}\frac{x^{T}A^{n}x}{n!})\\ \end{eqnarray*}$  As noted below, from here on is incorrect:  $\begin{eqnarray*} &=& \sum_{n=0}^{\infty}\frac{(x^{T}Ax)^{n}}{n!\|x\|^{2(n-1)}})\\ &=& \sum_{n=0}^{\infty}\frac{(x^{T}A^{T}x)^{n}}{n!\|x\|^{2(n-1)}}\\ &=& \sum_{n=0}^{\infty}\frac{((Ax)^{T}x)^{n}}{n!\|x\|^{2(n-1)}}\\ &=& \sum_{n=0}^{\infty}\frac{((Ax)^{T}(x^{T})^{T})^{n}}{n!\|x\|^{2(n-1)}}\\ &=& \sum_{n=0}^{\infty}\frac{((x^{T}Ax)^{T})^{n}}{n!\|x\|^{2(n-1)}}\\ \end{eqnarray*}$  As you can see this brings me no closer to getting $x^Tx$ somewhere, which I may assume is greater than $0$.  So my conclusion is that using only the fact that $A$ is symmetric is not enough.  Is there some result about symmetric matrices that I should use?


Why do we calculate the curl of curl of the electric field and what does it mean physically?

I was trying to derive wave equation. We know that the curl of an electric field is the rate of change of magnetic flux then why we have to calculate the curl of the curl of the electric field after that. What is the reasoning behind this Faraday's law $$ \nabla\ \times E = \frac{\partial B}{\partial t} $$ Taking curl of the equation $$ \nabla \times \nabla\ \times E = \frac{\partial (\nabla \times B)}{\partial t} $$ I would like to know what is the physical significance of taking the curl of the curl of the electric field.


References for weighted linear regression with linear constraints on the coefficients?

I would like to estimate a multiple linear regression model $N$ observations (with $\beta$ of length $k$):  $$Y = X \beta + \epsilon$$  subject, however, to some linear constraints on the coefficients. I.e a constraint of the form  $$M \beta = 0$$  where (at least in my case) $M$ is of dimension $2 \times k$ but more generally can be expressed as  $$M \beta = c$$ where $M$ is of dimension $p \times k$ with $p < N$ and $c$ of dimension $p \times 1$.  I have not been able to find much about this online and would appreciate references to read up on this..  Thanks


I am using bash  I wanted to read the documentation of set  But when i typed man set,it is showing   No manual entry for set    But when i code  set hit="COVID19" echo $1   it prints as   hit=COVID19   How to find and add the man page of set inside the current man pages.


What is the recommended way to empty a SSD?

I've just received my new SSD since the old one died. This Intel 320 SSD supports TRIM. For testing purposes, my dealer put Windows on it, but I want to get rid of this and install Kubuntu on it.  It does not have to be a "secure wipe", I just need the empty the disk in the most healthy way. I believe that dd if=/dev/zero of=/dev/sda just fills the blocks with zeroes and thereby taking another write (correct me if I'm wrong).  I've seen the answer , but it looks like it's suited for clearing empty blocks, not wiping the disk.  hdparm seems to be the program to do it, but I'm not sure if it clears the disk OR cleans empty blocks. From its manual page:     --trim-sector-ranges           For  Solid State Drives (SSDs).  EXCEPTIONALLY DANGEROUS. DO NOT           USE THIS OPTION!!  Tells the drive firmware to discard  unneeded           data  sectors,  destroying  any  data that may have been present           within them.  This makes those sectors available  for  immediate           use  by  the firmware's garbage collection mechanism, to improve           scheduling for wear-leveling of the flash  media.   This  option           expects  one  or  more  sector range pairs immediately after the           option: an LBA starting address, a colon, and  a  sector  count,           with no intervening spaces.  EXCEPTIONALLY DANGEROUS. DO NOT USE           THIS OPTION!!              E.g.  hdparm --trim-sector-ranges 1000:4 7894:16 /dev/sdz   How can I make all blocks appear as empty using TRIM?


How to find an integer solution for general Diophantine equation $ax + by + cz + dt... = N$

I know how to solve $ax + by = c$ using Extended Algorithm. But with more than variables, I'm lost :(.   To verify if it has an integer solution is easy, since we only need to check for $\gcd(a,b,c)|d$. Other than that, how can we find an integer solution for this equation?    Thanks, Chan


Why another login is required for http://data.stackexchange.com/, when I've already logged into Stack Overflow with the same OpenID

I use the same OpenID to log onto SO sites. When I log in to , and then navigate to other site such as , it recognizes the same OpenID.  But when I open , it shows login link on the top bar, I'm required to enter the same login credentials aagain. Why is this behavior with ?


Why do Full Frame lenses and crop body lenses exhibit the same crop factor when used on a crop body camera?

I have a Canon 7D, which has a crop factor of 1.6x.  When using a Canon EF-S lens I get the focal length stated on the lens, when using a Canon EF lens I get the focal length times 1.6 when used on the APS-C body. At least that's what I thought.  I just compared two lenses:   Canon EF-S 15-85mm f3.5-5.6 Canon EF 70-200mm f4   .  The top photo is shot with the 15-85, the bottom photo with the 70-200 - both lenses are set to 70mm. Now why do they look the same?  I thought I would get 112-320mm (70mm*1.6 crop factor). What did I misunderstand about the crop factor calculation? Lightroom also displays the photos as having "70mm" and not 112mm.


Re-install Ubuntu without losing data in home folder

Recently I installed Ubuntu 12.10 x64 Server Edition on my PC. Unfortunately, I attempted to install a lightweight desktop but due to the fact that I have an old graphics card, the PC does not perform so well. I am thinking of re-installing an Ubuntu version but I do not want to lose the contents in my home folder. Is there any way to do that with a Live CD?


How does the Event Horizon Telescope capture the image of the black hole if no light can escape near the event horizon?

The  claimed they capture the first image of blackhole, at the center of galaxy M87. In the image we can see lightrays are bent near the blackhole, but how do we receive the light rays if the definition of the event horizon is the boundary where light cannot escape? Does the picture just show a place that is further outside of the blackhole? What's the significance of this?


Why can't we define fundamental unit of mass?

In my physics textbook of class $11^{th}$ The kilogram was defined as :-       mass of the platinum-iridium standard cylinder kept at Sevre's France     But this isn't a proper and scientific definition of an important fundamental unit. When we have advanced so much in atomic physics that we are creating matter, Then why are we unable to define unit of mass?


Short story: limited life spans, arm tattoos, gang of kids on minibikes

This is from an dystopian anthology I read in the early 1970's.  The world is run-down and brutal, reminiscent of Soylent Green / Make Room Make Room. Everyone has a tattoo on their arm indicating their birth date. You can earn a reward (I think: extending your own life) by killing someone and bringing their arm / tattoo to the authorities.  An old man meets a young boy who is in a theft-and-killing gang (they all ride minibikes) and tries to teach the boy about a better way to live. The old man has a different colored tattoo, much more valuable than the normal.  The story ends where the old man intentionally leaves a knife on a table (while cooking) and turns his back to the boy, leaving unresolved whether the boy believed and befriended the old man, or killed him for his tattoo / reward.


Would the clones be emotionally and mentally same as the original?

In the movie The Prestige, Angier with the help of Tesla introduces a machine that can clone whatever falls into it in his performance. However, we also know that the original Angier might have ended up either in the water tank or as The Prestige of the performance. We know the clones looked perfectly similar to the original, however, were the clones mentally and emotionally the exact same to the original? In the sense, would the clone know the original Angier's past and his entire story with Borden and Julia and the strain and enemity? The last confrontation scene between Borden and Angier at the old magic hall (where Angier stores his clones in water tanks), the Angier talking to Borden is a clone, but the confrontation happens like it's between Borden and the original Angier as if the clone knew everything that happened in the past, as if he had first-hand faced the betrayal and witnessed Julia's death. As if the clone knows the whole story and reason of ending up being shot by Borden.


How do I remove a Stack Exchange account from my profile?  Suppose I added an account that I now want to remove. How do I do that?


Proper way of including pictures into the Master's thesis

I'm doing mathematics and my thesis consists mainly of understanding and elaborating couple of articles, writing clearly everything down, and possibly including a little of my own original work at the end. Of course, I am citing everything, and also I am not copypasting, rather writing known stuff with my own words and trying to be more detailed. But I am not sure what to do with the pictures(there are about 20 of them which are relatively difficult to draw, next to the 30-35 pages of plain text). I have an access to the tex files of these articles and could easily copy paste the code for pictures. On the other hand, I could write down(rather draw) everything by myself, and anyway I would properly cite the source because many of these pictures represent ideas behind which are not mine. So what should I do? On the one hand, straight copypasting is not good. On the other hand, this is not a piece of text where I could write more details, although if I wouldn't have seen those pictures but I would been explained the ideas, then I would have drawn slightly differently. Should I draw everything by myself, while trying to be visually different then authors(while properly citing them of course).


I lost my textures when I exported my project to another computer

I'm not able to export textures of Blender on another computer. I've seen several tutorial videos and I did what they asked for and I still can't do it. I've already packaged the files and unpacked (I still haven't figured out which one I really have to do). On the export side in FBX I've already placed the copy option and clicked the button on the side. Do I just need to import the FBX file or is something else needed to come with the textures? Sorry for the blue text, my UI is in Portuguese


Python Script to Add Fields to Feature Classes

I have to try to add a field called 'Name' to a bunch of different feature classes using python, and then access the name of the feature class to fill in the field. I have no idea how to even start this! I know I need a loop but that's all I know.


Does editing a question move it to the front page?

Say, I ask a question. I add details a few days later. Will my question remain in the bottom pile of the feed or be brought to the top of the search list? Do people use this as a method to bump their answers when it receives very less attention? How are such activities caught? Does the community manually have to check or are software systems set in place to prevent such malpractices?


Why Do Jedi Use One Lightsaber in Combat?

While I've seen Ahsoko Tano, in The Clone Wars, fight with two lightsabers (one in each hand), this seems to be extremely rare for Jedi.  We've seen Sith do this frequently, like Asajj Ventress, with two lightsabers.  Darth Maul used a dual lightsaber against Qui-Gon Jinn and Obi-Wan Kenobi and then there's General Grievous, who uses multiple lightsabers with his multiple limbs.  But most Jedi use just one blade, and their lightsaber hilts tend to be simple, just a straight cylinder without much adornment, while Sith sometimes use curved grips or other more exotic stylings.  Is there a reason Jedi stick with the simplest lightsaber designs and why the vast majority (at least in the movies and in The Clone Wars series) use only a single lightsaber?


How to make a custom keyboard layout in OS X?

I recently moved to OS X and I find the system "Russian Phonetic" layout unsatisfying (it's not the one that I'm used to). How can I create a custom layout?  I've read about , but the layout I created and copied to Library/Keyboard Layouts doesn't show up in Keyboard Preferences.  I'm using OS X 10.9 Mavericks. I searched for solutions in internet, but most of them were outdated.


If $D_1\subseteq D_2$ then the generated sigma-algebras are such that $\sigma(D_1)\subseteq \sigma(D_2)$

Let $A$ be a set of subsets of $\Omega$. Then, the $\sigma$-algebra generated by $A$ is defined as  $$\sigma(A):= \cap \{\mathcal{F}\; |\; \mathcal{F}\text{ is a }\sigma\text{-algebra and }A\subseteq \mathcal{F} \}$$  From the definition it is clear that $\sigma(A)$ is the smallest $\sigma$ algebra containing $A$.   Now, let $D_1$ and $D_2$ be two non-empty family of subsets of a nonempty set $\Omega$ such that $D_1\subseteq D_2$.  I want to prove that $\sigma(D_1)\subseteq \sigma(D_2)$.  I observed that   $A\in D_1$  $\implies A \in D_2$  $\implies A\in \sigma(D_2)$  $\implies D_1 \subseteq \sigma(D_2)$  From here, I don't know how to proceed. I am new to Probability Theory so please be gentle.


"Want to go look for something" - what is the verb?

1) I want to go look for my wedding dress today.   2) I want to go to look for my wedding dress today.   Are these both acceptable ways to say this?  Also, could someone point out the parts of speech? According to my thoughts, in first sentence:     I ⇒ Subject   want to go ⇒ compound verb (intransitive)   look for my wedding dress today ⇒ adverb


Add a number to each element with the same class

In order to count all elements with the same class I can write the following:   var count = document.querySelectorAll('#teamMember .r-team-member').length;  console.log(count);   How can I add a number to each of those elements as a class? For example, the HTML is:

Read Bio

   I have also written the following javascript:  function showBio() {     document.getElementById('bio').style.display = "block";     document.getElementById('readBio').style.display = "none"; }   Which is working, but if I click on the 'Read Bio' div, then it opens all of the Bios.  What javascript can I write than make it something along the lines of:

   etc?


I need a regular expression to accept a max value of 99999.99  I have tried this:  currencyPattern: /^(\d{0,5})(?:.\d{2})$/  but it accepts 123456 and 1234567 also.


Can you change the combined center of gravity (COG) of the rider and bike if you move?

In a closed system, I know the rider wouldn't be able to change the combined center of gravity of the system by moving his weight around. If he pushes the bike to lean to the right, he would go to the left by the amount that would keep the combined cog the same.  But a bike with tires and a road under it is not a closed system, the tires wouldn't let the lower part of the bike left or right when tryingo to initiate lean. Does this mean it is possible to push with your bodies inertia to the bike, and the combined cog will be changed? I thing if you do so above the cog of the bike, you could, but I am not sure.  Edit: My question is not about if you can move the center of gravity of the bike at all. My question is about if can you change the combine cog of the system by moving around on the bike?  English is not my mother tongue, sorry for the confusion


Whenever you die in Minecraft Java Edition, you get the option to respawn or quit to the title screen. You also are shown your score. What factors lead up to that score? Im thinking that stuff, like picked up XP or mobs defeated, would count towards the score, but what is the exact number of score you get for one thing that you accomplish?


I'm having some trouble while map matching these points for some streets. Could you lend me a hand?


How can I use `find` and sort the results by mtime?

I want to use find but sort the results reverse chronologically as with ls -ltr. Is this possible through any combo of flags or pipelines?


Prove the Leibniz formula for Determinants

I am trying to prove that if $A \in M_{n\times n}(F)$, then $$\det(A)=\sum_{\sigma\in S_n}\operatorname{sgn}(\sigma) \prod_{i=1}^n a_{i \sigma(i)}\tag 1$$ The question asks me to use the following theorem:  If $\delta: M_{n×n}(F) → F$ is an alternating $n-$linear function such that $\delta(I) = 1$, then $\delta(A) = \det(A)$ for every $A ∈ M_{n×n}(F)$.  The way I am interpreting the question is that I need to show that it satisfies the multilinear (n-linear), alternating, and normalized properties (the formula maps the identity matrix to 1) of the determinant. Then the second part of the question asks to show that if a single column of A is completely comprised of $0$'s, then $\det(A)=0$. I feel that the solution to second part of the question should be clearer after solving for the first part. How do I go about doing this?


What exactly does "Illegal instruction (core dumped)" mean?

I see a lot of solutions to resolving the problem exemplified by      Illegal instruction (core dumped)   But, I'm wondering what exactly that means? What generates that error, and what's the root cause of it? Is that the CPU getting someone it believes is an instruction but can't decode? What happens under the hood to generate that error?  From dmesg, I see  [429572.598803] traps: test[4054] trap invalid opcode ip:400066 sp:ffac8cc0 error:0 in test[400000+1000] [429758.598292] traps: test[4401] trap invalid opcode ip:400066 sp:ffa3f990 error:0 in test[400000+1000] [430066.170626] traps: test[4854] trap invalid opcode ip:400066 sp:ff8ab000 error:0 in test[400000+1000] [430439.855002] traps: test[5212] trap invalid opcode ip:8048071 sp:ffce2fa0 error:0 in test[8048000+1000]


I need to output the below text but since \ is a special character, I cannot:  [RegularExpression(@"\d+")]   Also sometimes I need use dollar sign $ as well but it seems to be a special char, too.  What is the way to escape those in LaTeX?  UPDATE:  I used \verb as suggested but I am unable to run commands inside it. Also, in the output the font and the opacity of the text is different than the default one:  \verb|[RegularExpression(\newline @"\d+")]|


Inverse of a bijection f is equal to its derivative

Does there exist a differentiable bijection $f: \mathbb{R} \rightarrow \mathbb{R}$ such that $f'(x) = f^{-1}(x)$ ?


Convert Number to Corresponding Excel Column

I need some help in doing a logic that would convert a numeric value to corresponding MS Excel header value.  For example:  1 = "A" 2 = "B" 3 = "C" 4 = "D" 5 = "E" ......... 25 = "Y" 26 = "Z" 27 = "AA" 28 = "AB" 29 = "AC" 30 = "AD" .........  Would appreciate some .NET codes (C# or VB) for this. Thanks.


Can I connect a generic bluetooth headphone to Xbox One?

I have Bluetooth Auvio headphones, which I bought on radioshack and I would like to know if there is any way to connect them to my Xbox One, so I can hear sound and use the mic.


I have a math problem: 2 ^ 56.198.375. When I do Math.Pow(2, 56198375), 0 comes out. Is there a class or trick, how to calculate higher numbers?


Can anybody explain why my score at , at the time of this writing, is 113 when it should be 112?


Questions on the legal protection of games and their parts (assets, sounds, title)

we started new pirate game, and I just want to ask some questions about rights. So I am new in game dev, I guess there are a lot of answers, but I guess professionals can advise something for first steps.  So we started some things like:   concept arts sounds we are working on the name of the game (just use temp one for now) we develop some models of ships and characters   I have question what's my step to protect everything I listed above. Do I need to protect everything separately? Do I need to register a game somewhere? Can I use my already made domain and subdomain for the game? Or do I need to register unique one domaine.


struct node{       struct node next;       int id;   }   gives "field next has incomplete type error ".    what is wrong with this struct ?


Why can't I see a folder in "/storage/emulated/0" on PC through MTP?

I use a banking app in my Android 8.1.0. All receipts are saved in /storage/emulated/0/APPNAME.  I can see the APPNAME folder and the receipts on Android if I use an explorer app like Google Files. But if I connect my Android on PC, the folder doesn't show up. I can see the other folders with no problem. Only that specific folder is missing.  What's going on?  (I suspect the devs marked the folder as not accessible through PC)


about "[to be] so unlikely to become common as to be innocuous"

The following sentence is from Bertrand Russell. I would like to know if in the emboldened part the  not so ... as is used or it's another structure with a different meaning.     ... they will conclude that a new belief is probably either an advance, or so unlikely to become common as to be innocuous.


How to check the real analyticity of a function?

I recently learnt Taylor series in my class. I would like to know how is to possible to distinguish whether a function is real-analytic or not. First thing to check is if it is smooth. But how can I know whether the taylor series converges to the function?   For example: $f(x)=\frac{1}{1-x}, x\in(0,1)$ has $n^{th}$ degree taylor polynomial $\sum_{k=0}^n x^k$. In this case, I understand that $f$ is analytic in its domain since the geometric series $\sum_{k=0}^\infty x^k$ for $x\in(0,1)$ converges to $\frac{1}{1-x}$.   In general, what is the trick? For example, how to know if $\sin(x),\cos(x)$ are analytic?


Programmatically find the number of cores on a machine

Is there a way to determine how many cores a machine has from C/C++ in a platform-independent way? If no such thing exists, what about determining it per-platform (Windows/*nix/Mac)?


Are there any tools to automatically search and download literature in a given .bib file?

I'd like to download automatically tons of papers listed on .bib file so I'm trying to find a way to facilitate the process by, e.g. I import or input to a tool a certain .bib file which contains a list of literature, the output is the literature's .pdf file. Any idea to do so?


How to create toggle button use python in blender

I want to make a toggle button for my custom operator. It works similar to checkbox: once the button is clicked, the operator keeps running until the button gets another click, so will the button itself greyed out. I tried to achieve the grey-out effect by implementing poll() function like this:  @classmethod def poll(cls, context):           return context.area.type == 'VIEW_3D' and context.region.type == 'WINDOW' and plane_toggle_flag   Every time the button is clicked I want the toggle state to change, so in the operator's init(), I write:  def __init__(self):        plane_toggle_flag=not plane_toggle_flag   However, it seems as long as poll() returns false, the init() function never get the chance to be called. Any idea how to solve this? Thank you in advance.


Gnome 3.14: Changing window icons to the left

How may I move window icons to the left in Gnome 3.14 under Ubuntu 15.04? This question has been asked before, but considerably older versions of Ubuntu and Gnome.


Confusion about hiding communities in your profile and hiding sites from HNQ

I figured it might be possible to hide unwanted SE sites from Hot Network Questions, and after a few clicks through profile/settings I thought I had found out where to do it, but it turns out I'd misread and that feature did something else. Apparently there is  for this with staus-deferred, but I don't think previous requests have done an adequate job of presenting motivations for the feature.  The reason I was looking for this is that it occurred to me that certain sites frequently have question titles that might be serious microaggressions/triggers (especially Skeptics, which often cites claims made by hate movements, and to a much lesser extent also Workplace and Academia), and many users might want to avoid that kind of content while using Stack Exchange sites.  Could the description of the "Hide Communities" profile tab be clarified to state explicitly that it doesn't hide things from Hot Network Questions? Could the deferred feature request for the ability to hide unwanted sites from HNQ be re-opened and completed, ideally with notification that you can do so and a link to do it right under the HNQ heading?


Why do I receive downvotes when I am genuinely trying to learn?

Why do I get downvoted when I try to learn something about programming on Stack Overflow? Out of all the Stack Exchange sites, this one is the most unwelcoming to people trying to learn.  There was a post where a guy asked an innocent question and one of the comments was let the voting war start.  He just wanted to learn and people were downvoting his questions but others would upvote for being genuine. The downvotes make it feel like the community may not welcome beginner and novice programmers(?). Here are a few examples from me:   I did my research, provided the code, and made the plot.  I simply want to know why it isn't turning out correct.  Downvote. Edit: tom 10 responded and said it will be helpful to show the actual equation than just the code.  If that was the reason for the downvote, why not just say "Hey, from the code we aren't sure what the true equation is"?  Again I provided code and explained that the issue was due to  (e) not having enough in the array, but I wanted to figure out how to plot still.  Downvote.  I wanted to learn what the best method and format to save images is for publication quality. Downvote.  The environment feels so unwelcoming. I am sorry to state that again.


What do you call these?  Please provide a reliable source with your answer.


Due to a , I want to introduce a conditional definition that depends on whether or not \pgfversion >= 3. How can I do this?


Currently I'm self studying functional analysis, namely compact operators. In the text, the author gives the following example:  Example 1: Let $C_1$ and $C_2$ be positive constants and let $$ M:=\left\{x(t)\in C[a,b]:|x(t)|<C_1\text{ and }|x'(t)|<C_2\right\}.\tag{1} $$ Then $M$ is relatively compact.  I completely understand Example 1, it makes use of Arzela's theorem. Then the author gives the following example:  Example 2: The operator $$ Ax:=\int_0^tx(\tau)d\tau.\tag{2} $$ on $C[0,1]$ is a compact operator (use the previous example).  My question is fairly straightforward: using Example 1, how is this operator compact on $C[0,1]$? As of now I have the following two definitions of compact operators:  Definition 1: A linear operator $A\colon X\to Y$ is called a compact operator if and only if for every bounded sequence $x_n\in X$ the sequence $Ax_n$ has a Cauchy subsequence.   Definition 2: An linear operator $A\colon X\to Y$ is compact if and only if the image of the unit ball of $X$ is a relatively compact set in $Y$.  Just going off terminology, I would guess that Definition 2 should be used to solve Exercise 2, but I'm not seeing it through all the way. Any help is appreciated!


Special tags should render faithfully when using [tag:XXX] syntax

You can use the syntax [tag:navigation] to typeset something that looks like a tag on a post, e.g. . However, certain tags render differently, e.g. the 'compulsory' tags discussion, feature-request, bug, etc., and the 'status' tags, e.g. status-completed. When using the [tag:XXX] syntax these display just the same as usual tags. Could we fix this?


If $A = u*u^T$ where $0 \neq u \in \mathbb{R}^n$ , then find the eigenvalues of $A$ and show that $A$ is diagonalizable.

If $A = u\cdot u^T$ where $0 \neq u \in \mathbb{R}^n$ , then    find the eigenvalues of $A$ and show that $A$ is diagonalizable.   I mean how to find eigenvalues of $A$?


Conditions sent over ssh are performed locally, not remotely

So I am trying to do something like this:   ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -i \   /home/backupboy/.ssh/id_rsa user@server.com \   "[[ $(ls -1 /mnt/dir | wc -l) -gt 4 ]] && rm /mnt/dir/*"   If I do this, condition is performed locally. Meaning that ssh looks at the number of files in /mnt/dir locally and not remotely. Is there any way to get around this? I need to do the condition remotely.


while loop output for multiple condition

main() {     int i=0,j=0;     while(i<5,j<10)     {         i++;         j++;     }     printf("%d,%d,",i,j); }   output: 10,10  int main(){     int x=2,y=2;     while(x<=5,y<=3)          printf("%d %d ",++x, ++y);     return 0;         }   output: 3 3 4 4  In the first code how can output is coming as 10,10? can anyone explain,but the output for the second code is 3344, Are both running on different logic?


ifconfig shows a bunch of network interfaces

When I run ifconfigon my Macbook air 2018 with MacOS Mojave 10.14.6 I get this:  lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384     options=1203<RXCSUM,TXCSUM,TXSTATUS,SW_TIMESTAMP>     inet 127.0.0.1 netmask 0xff000000      inet6 ::1 prefixlen 128      inet6 fe80::1%lo0 prefixlen 64 scopeid 0x1      nd6 options=201<PERFORMNUD,DAD> gif0: flags=8010<POINTOPOINT,MULTICAST> mtu 1280 stf0: flags=0<> mtu 1280 XHC20: flags=0<> mtu 0 XHC0: flags=0<> mtu 0 VHC128: flags=0<> mtu 0 en3: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500     ether xx:xx:xx:xx:xx:xx      inet6 xxxx::xxxx:xxxx:xxxx:xxxx%en3 prefixlen 64 scopeid 0x7      nd6 options=201<PERFORMNUD,DAD>     media: autoselect (100baseTX <full-duplex>)     status: active ap1: flags=8802<BROADCAST,SIMPLEX,MULTICAST> mtu 1500     ether xx:xx:xx:xx:xx:xx      media: autoselect     status: inactive en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500     ether xx:xx:xx:xx:xx:xx      inet6 xxxx::xxxx:xxxx:xxxx:xxxx%en0 prefixlen 64 secured scopeid 0x9      inet xxx.xxx.x.x netmask 0xffffff00 broadcast 192.168.1.255     nd6 options=201<PERFORMNUD,DAD>     media: autoselect     status: active p2p0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 2304     ether xx:xx:xx:xx:xx:xx      media: autoselect     status: inactive awdl0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1484     ether xx:xx:xx:xx:xx:xx      inet6 xxxx::xxxx:xxxx:xxxx:xxxx%awdl0 prefixlen 64 scopeid 0xb      nd6 options=201<PERFORMNUD,DAD>     media: autoselect     status: active en1: flags=8963<UP,BROADCAST,SMART,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500     options=60<TSO4,TSO6>     ether xx:xx:xx:xx:xx:xx      media: autoselect <full-duplex>     status: inactive en2: flags=8963<UP,BROADCAST,SMART,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500     options=60<TSO4,TSO6>     ether xx:xx:xx:xx:xx:xx      media: autoselect <full-duplex>     status: inactive bridge0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500     options=63<RXCSUM,TXCSUM,TSO4,TSO6>     ether xx:xx:xx:xx:xx:xx      Configuration:         id 0:0:0:0:0:0 priority 0 hellotime 0 fwddelay 0         maxage 0 holdcnt 0 proto stp maxaddr 100 timeout 1200         root id 0:0:0:0:0:0 priority 0 ifcost 0 port 0         ipfilter disabled flags 0x2     member: en1 flags=3<LEARNING,DISCOVER>             ifmaxaddr 0 port 12 priority 0 path cost 0     member: en2 flags=3<LEARNING,DISCOVER>             ifmaxaddr 0 port 13 priority 0 path cost 0     nd6 options=201<PERFORMNUD,DAD>     media: <unknown type>     status: inactive utun0: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 2000     inet6 xxxx::xxxx:xxxx:xxxx:xxxx%utun0 prefixlen 64 scopeid 0xf      nd6 options=201<PERFORMNUD,DAD> ipsec0: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1400     inet xx.x.x.xxx --> xx.x.x.xxx netmask 0xff000000    I'm not very good at networking stuff but this seems strange to me due to the fact that I never saw this many network interfaces on my old macbook air.  Question: Is this normal or could this be something bad? What can I do about it if it is something bad?  Edit  All the "x"s were not there originally, I changed the addresses to them instead


Insecure Connection: issue on www redirect to non-www with https

I am not much familiar with server configurations, please help me on this issue:  I have a Debian8 server and a SSL certificate, the SSL certificate only for My non-www domain so I would like to redirect all of www request into non-www, by below htaccess code its working for some browsers but not working for some other  On Chrome: Successfully redirecting http://www.example.com or http://example.com request into https://example.com this is what I want for all browsers.  On Mozilla: Redirecting http://www.example.com request into https://www.example.com and stopped working with INSECURE CONNECTION error. I think from here browser checking first for SSL certificate of www and stop before non-www redirect.   Following is my .htaccess to redirect www to non www with https, is anything I missed on .htaccess? or any other solution through DNS or with help of apache default ssl.conf.  RewriteCond %{HTTP_HOST} ^www\.(.*)$ [NC] RewriteRule ^(.*)$ https://%1/$1 [R=301,L]  RewriteCond %{HTTPS} !on RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI} [R=301,L]   My SSL certificate is  and I followed this tutorial to install  you could see there is only one domain prompting that is non-www, no option for setting SSL certificate for www. If I could get a SSL certificate for www then also I can solve the issue.


Argument for template template parameter appears to be a non-template type

The following code produces an error, but I'm not sure why this is the case.  #include <utility> #include <type_traits> #include <tuple>  template <typename T, template <typename...> class F, typename = void> struct tuple_subtype_apply {     using type = typename tuple_subtype_apply<T, F,         std::make_index_sequence<std::tuple_size<T>::value>>::type; };  template <typename T, template <typename...> class F, std::size_t... Is> struct tuple_subtype_apply<T, F, std::index_sequence<Is...>> {     using type = F<typename std::tuple_element<Is, T>::type...>; };  template <typename... Args> using true_t = std::true_type;  template <template <typename...> class Fn, typename... Ts> struct prepend {     template <typename... Args>     using fn = Fn<Ts..., Args...>; };  template <typename T, typename Tup> using test = typename tuple_subtype_apply<Tup,     prepend<true_t, T>::fn>::type;   The error produced: (clang -std=c++1z)  <source>:29:24: error: type/value mismatch at argument 2 in template parameter list for 'template<class T, template<class ...> class F, class> struct tuple_subtype_apply'   prepend<true_t, T>::fn>::type;                     ^ <source>:29:24: note:   expected a class template, got 'prepend<true_t, T>::fn'   Manually substituting the template parameters for test compiles without errors (e.g. typename tuple_subtype_apply<std::tuple<int, int>, prepend<true_t, int>::fn>::type). Shouldn't prepend::fn be a templated type?


how to introduce multiplication in shell scripting

My command is:  tac some_directory/*.pre | grep -im1 "vdr" | cut -c129-140     Output is:    1.710577E-03     I want the output to be:    1.71   How can I achieve this in the shell command?


I have learned that fields are like global variables which can be accessed by the methods inside the same class. I have done it this way before and never had a problem. I have now a class where I have some fields but the methods cannot access them without having to make them static fields. I get the error "cannot make static reference to non-static..." I thought static was to access fields on other classes without having to create an object reference to the class. The only difference I have with this code is that I have a single class and my main() method within this class. Does having main() inside this class make a difference?


the microsoft.ace.oledb.12.0 provider is not registered windows 8.1 office 2016 vb .net

When I click on the button ADD, I got the following error: The 'Microsoft.ACE.OLEDB.12.0' provider is not registered on the local machine. I have no clue how to fix this. My operating system is Windows 8.1.