Should this solution edited into question be rolled back?

I just noticed  in the related question sidebar while browsing today.  I know updating the question to reflect the solution is discouraged.  Questions should remain a question, and solutions (even from the OP) belong in the answers, but given how much changed in the final revision and given the age of the question and popularity of the question, is rolling back, editing, and entering the solution (as CW) in the answers appropriate in this case, or is this a historical issue that should be left alone?


What are the rules on when to use commas, colons, semicolons and dashes?


Delineate polygonal catchment areas from a raster using open-source GIS

I'm 90% sure this basic question has been asked before but looking through the other posts I simply do not see a useful answer.  I need to calculate polygonal(vector) catchment areas from a raster based on minimum driving distance/cost from a set of points. I've already got the raster, and for that matter, the nodes(intersections with cost attribute) used to interpolate it. What I need now are polygons for each point describing the area nearer it than any other point. This is basically like a voronoi diagram but based on network distance rather than euclidean space.   How exactly can I do this using only open-source tools? I'm comfortable with the command line if I just know what I'm looking for. I feel like GDAL is going to be the answer, but if so, what exactly is the command I'm looking for?  Thanks!


Primary filegroup is full SQL Server 2008

I have a large table (~50 million rows) I'm trying to bulk insert into SQL Server and I get the error:      Could not allocate space for object 'myDB' in database 'I 3 Stroke' because the 'PRIMARY' filegroup is full. Create disk space by deleting unneeded files, dropping objects in the filegroup, adding additional files to the filegroup, or setting autogrowth on for existing files in the filegroup.   There is another table in the database with around 25 million rows.  This database will only be used on a single machine, and it will be designed to mine data that already exists and it under no circumstances will ever grow beyond its current size.    For a situation such as this, what's the best way to tackle this so SQL Server doesn't complain?  Will the solution matter that this DB won't be exposed to multiple users?


Oracle: Delete Duplicate Rows, Comparison Excluding ID Column

I have an Oracle table as Follows:  ID       A      B      C 1       aaa    bbb    ccc 2       aaa    bbb    ccc 3       ddd    eee    fff 4       ddd    eee    fff 5       aha    bqb    ccd 6       aaa    bbb    ccc   I am looking to delete every duplicate row, even if they different IDs.  The intended result is the following:  ID       A      B      C 4       ddd    eee    fff 5       aha    bqb    ccd 6       aaa    bbb    ccc   I am indifferent about keeping the smallest or largest ID.  In other words, i would not mind the following:  ID       A      B      C 1       aaa    bbb    ccc 3       ddd    eee    fff 5       aha    bqb    ccd   Your help is greatly appreciated.


Identify a 1950's era story about a man left on empty planet who slowly becomes native

This is one of the two stories I read as a kid in the 1950's, early 60's which forever locked me into sci-fi.   Spoiler alert! I want to identify a short story about a spaceman who ended up marooned alone on an empty planet of ruins. I recall the planet as desert like, all sand and wasteland and no water, with all the inhabitants long gone.   He finds the ruins of a town and the ruins of a house that still has power and begins to respond to him with water, food, a bed. Slowly he begins to train the house to supply his needs,though it nearly kills and poisons him at first. He is elated to realize he will survive until the rescue ship arrives, never realizing that it is actually he who is changing.   When the ship arrives it ends with him raising his snout to the air and hooting a greeting... something like that.


Find all polynomials $P(x)$ with odd degree such that $P(x^2 - 2) = P^2(x)-2$

The problem says :     Find all polynomials $P(x)$ with odd degree such that   $$P(x^2 - 2) = P^2(x)-2$$   I tried a lot if ways (using high school mathematics) but the only solution I have so far is $P(x) = x$. Can anyone solve this problem using only high school mathematics ?  PS: I have reduced the solution set to  the subset of all polynomials with leading coefficient 1.


How to show modal box whenever choose the select option using jQuery?

I am using bootstrap to show modal box. When the user chooses the select option value I just call the jQuery to show the specific modal box.   Like below:  $(document).on('change','#apply',function () {    if($(this).val() == 1 ) {       $('#update').modal("show");    } else if ( $(this).val() == 2 ) {       $('#delete_ticket_booking').modal("show");    } });   The HTML code of select looks like this:  <select name="apply" class="form-control full-width" id="apply"> <option value="">--Action--</option> <option value="1">Confirm</option> <option value="2">Delete</option> </select>   Now, for example: when the user chooses the confirm option it's showing the confirm modal box.   Again If the user chooses the confirm option then it's showing nothing.   I need to show that modal box again when user click on the confirm option!  How can I do this?


If there is some continuous function in $\mathbb{R}$ that satisfies $f(x)\notin \mathbb{Q}$ for every x. Is f then a constant function? How would I show this?


How can the root of an irreducible polynomial exist?

Let $K$ be a field, $P(X)$ an irreducible polynomial in $K[X]$, and let $\alpha$ be a root. This is a very common statement I've seen in lecture notes. The question is: how does $\alpha$ even exist? If $P(X)$ is an irreducible polynomial, then by definition, shouldn't it have no roots? What exactly is the above statement supposed to mean?


Which is correct — "a year" or "an year"?

The word year when pronounced starts with a phonetic sound of e which is a vowel sound making it eligible for being preceded by an. Yet, we tend to write a year. Why?


I am working to build an deep reinforcement learning agent which can place orders (i.e. limit buy and limit sell orders). The actions are {"Buy": 0 , "Do Nothing": 1, "Sell": 2}.     Suppose that all the features are well suited for this task. I wanted to use just the standard "Profit & Loss" as a reward, but I hardly thought to get something similar to the above image. The standard P&L will simply place the pair (limit buy order, limit sell order) on every up movement. I don't want that because very often it won't cover the commission and it is not a good indicator to trade manually. I would be interested that the agent can maximize the profit and give me a minimum profit of $100 on every pair (limit buy order, limit sell order). On the picture, I would be interested in something similar to the above picture.  Is there a reward function that could allow me to get such a result? If so, what is it?  UPDATE  Is the following utility function can work with the purpose of that question?  $$ U(x) = \max(\$100, x) $$  That seems correct, but I don't know how the agent will be penalized if it covers a wrong transaction, i.e. the pair (limit buy order, limit sell order) creates a loss of money.


What is meant by the spin of a particle?

I have been studying that electrons have quantum number called spin quantum number(s), this number can have either +1/2 or -1/2 value. If s=+1/2, the spin is clockwise and if s=-1/2, the spin is anti clockwise about it's imaginary axis. But, I am facing some problems now with this concept, the problems are, photon have 1-spin, another recently discovered sub-atomic particle having spin 3 (), how physicists explain these spin?


How can I auto-sync my files from Google Drive and make them in a Google-Drive folder whenever a new file added/removed it would update the changes rather than downloading the whole Google Drive from scratch whenever I try to access it.  I have used the native Google Drive app on my Windows and MacOS devices and they worked perfectly.


I tried to use  sudo service networking restart   and  sudo /etc/init.d/network restart   but they both crash the window manager and I can no longer use my keyboard for input into X.  when I use the /etc/init.d/ method it complains saying that I should use the service utility  e.g. service networking restart   but it crashes just the same.  Is there a GUI method of restarting networking?


Why shouldn't I revert an upvote on comment after 60 seconds

I found that I cannot revert an upvote after 60 seconds of upvoting it.  And I also found  which confirms that behavior. But why is it so?  . At first thought, it looks like a very valid comment, but soon you will realize that there are many edge cases where that would fail, so I wanted to revert my upvote.  And when I tried to revert I got the dialog asking me to confirm, but before I could read through the dialog and confirm it 60 seconds had passed and I was not able to revert my upvote.  But why go through the pain of implementing such a behavior? This seems to limit people even in genuine scenarios.


“A similar hat to Jane” vs “A hat similar to Jane’s”

Of late I have noticed British people using the following sort of construct:     John and Jane make such a cute couple because John always wears a similar hat to Jane.   To my ear, that is ungrammatical, or at least nonsensical, because John seems to have mistaken his wife for a hat!  John’s hat cannot be similar to Jane;  it can only be similar to Jane’s hat.   For me, that sentence must therefore be recast as this:     John and Jane make such a cute couple because John always wears a hat similar to Jane’s.   That way the hat is no longer similar to her, merely to hers.  Is the former formulation actually grammatical, or is it a common mistake or simple carelessness?  Doesn’t it confuse people? Is it fit for formal writing?  How long has this been going on?   To the American ear, it sounds really messed up, like it is making a wrong comparison.  It’s like they have forgotten about the possessive case, which is the only one that makes sense here.    Edit  Here are actual “similar X to Y”  instances by British authors, where one would expect to find “Y’s” or “that/those of Y” instead:   In consultation, our members observed that other people with a similar disability to Mr Malcolm — perhaps with varying degrees of severity — would have been able to understand the sub-letting regulations.   Dave had a similar accent to dumper truck man, so that’s who I thought it was.   Believe it or not she was also Afrikaans with a similar accent to Anna, and, like Anna, she was not exactly a beauty.  Auroville’s two or three thousand inhabitants, most of whom live in similar style to André, come from all over the world, as a brief glance at its telephone book made clear . . .    But I still don’t understand it, nor do I know its history. When did the possessive go away, and why?  Shouldn’t those all have a possessive there?


How do I find out what directory my console app is running in?

How do I find out what directory my console app is running in with C#?


Should I accept a ship surrendering or should I finish it off?

Sometimes after taking heavy damage an enemy will offer to pay you off if you accept their surrender.   It's possible to deny this and go for the kill, which will also give you a reward. Which option gives you the most benefits?


How do indestructible creatures actually work?

If a First Striker does lethal damage to an indestructible creature, does this remove the creature from combat so it can not deal any damage?  Another scenario: An indestructible creature is dealt lethal damage, has destroy cast on it, or is hit during combat by a creature with deathtouch. Would casting  in the second main phase cause it to be exiled?


What is the best or most concise method for returning a string repeated an arbitrary amount of times?  The following is my best shot so far:  function repeat(s, n){     var a = [];     while(a.length < n){         a.push(s);     }     return a.join(''); }


Does the sorcerer's Extended Spell metamagic option extend the duration of a spell exponentially or linearly?

When it mentions that you can spend 1 sorcery point to double its duration, up to a maximum of 24 hours, does it mean that every time you spend a sorcery point you add the original duration again? Or does it exponentially double the duration?  For example, if I spend 4 sorcery points on a 1 minute spell, does it become 5 minutes (1 minute duration added four times) or 16 minutes long (1 minute doubled four times)?  What I meant by this question is just using Extended Spell on a spell once, but using more than 1 sorcery point on it as per the metamagic's description.  I know you can't re-extend a spell if it's already active, but I'm talking about the initial casting, where you can spend multiple sorcery points to double the spell's duration.


Computational complexity of Fibonacci Sequence

I understand Big-O notation, but I don't know how to calculate it for many functions. In particular, I've been trying to figure out the computational complexity of the naive version of the Fibonacci sequence:  int Fibonacci(int n) {     if (n <= 1)         return n;     else         return Fibonacci(n - 1) + Fibonacci(n - 2); }   What is the computational complexity of the Fibonacci sequence and how is it calculated?


Maximum Safe Number of Threads To Run At Once

I have approximately ~60000 tests, each taking between 30 mins and 2 hours, to run. Sequentially that is insane, so I have decided to run the tests on separate threads.  I'm designing the solution now, and I feel it's important to know how many threads I should safely run at a time. I have a 12 core Linux server at my disposal. Is it possible to utilize as many cores as possible with a single Java application, and how would I find out a safe number of Threads to have alive at once without testing and possibly taking down the server?  Thanks.


Since installing Windows 10 Creators Update (version 1703), history dialog in Run command not storing previous searches

There is a similar post to this but does not work with my system. The previous suggestion was to turn on Start > Settings > Personalisation > Start > Show most used apps. Unfortunately, that option is set to Off and greyed out.  HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\RunMRU does not show the list either. it is empty.    I was running Windows 10 version 1703, and recently updated to the Redstone 3 Preview build 16170.  Any other suggestions?


I have a 300000 lines in a text file. And I have a file with list of line numbers that I need to extract from text file. Numbers are ordered. They are not ranges and there are about 4000 of them. So I need 4000 lines from source text file with specified ids.   Are there any efficient way to copy lines specified in a such file to a new file with unix console tools? Or any lightweight script?


Say $f:[a,b]\rightarrow \mathbb{R}$ is continous, $f(x) \geq 0$ for all $x$, and there is a $c \in [a,b]$ such that $f(c) > 0$. Prove $\int_a^b fdx > 0$.


To derive quantity $k=\frac{2-p^2}{p+2}$ for positive rational $p$ such that $p^2>2$ and $(p+k)^2>2$

I am reading Baby Rudin and stuck at one small point. $A$ is set of all positive rationals $p$ such that $p^2<2$ and $B$ is set of all positive rationals $p$ such that $p^2>2$. We wanted to show $A$ contains no largest element and $B$ contains no smallest element. So for any such $p$ in either set, author associated number $q$ as, $q=p-\frac{p^2-2}{p+2}$, which works fine. I was trying to figure out how to obtain the quantity $\frac{p^2-2}{p+2}$. I did it for set $A$ as follows. So, we have positive rational $p$ such that $p^2<2$. We want some $k>0$ such that $(p+k)^2 <2$ i.e. $p^2+2pk+k^2<2$ As all three quantities are positive, we can say $p^2+2pk<2$, which gives $k<\frac{2-p^2}{2p}$. But as $p^2<2$, we have $p<2 \Rightarrow p+p=2p<p+2$ Therefore, we can choose $k=\frac{2-p^2}{p+2}$. But I am stuck while deriving it for set $B$. I did following. So, we have positive rational $p$ such that $p^2>2$. We want some $k<0$ such that $(p+k)^2 >2$ i.e. $p^2+2pk+k^2>2$. From this point, I can say $p^2+k^2>2$, but not sure how this will take me to the desired result. Any hint or help. Thank you.


Proving inequation with maximum and 2nd derivative

Let $f(x)$ be twice-differentiable and $f(a)=f(b)=0$ with $a<b$  How to prove that  $$\max|f(x)| \le \frac 18(b-a)^2 \max|f''(x)|$$  (With $\max|f(x)|$ beeing maximum (or minimum) between a and b.)  How would I use Taylor-Expansion and Mean Value Theorem here?


Book about elementary geometry , triangles, circles ...

Currently, I'm studying a little about geometry and I was trying to find out some good book about it on internet, however I didn't find anything that I thought nice to me or what I really expected to which would be nice. What I'm looking for is a book with good proofs, in which show strategies to you reach the solution. and interesting exercises.  For instance :    , ,  ...  Something about mostly elementary geometry, proprieties of triangles, parallels lines, circles, triangle inscribed in a circle, so on.


The Problem     On an infinite plane there are two points, $A$ and $B$, a unit distance apart.  There is a $50\%$ probability that there is an invisible wall somewhere between the two points.  The wall extends $1/3$ unit in each direction perpendicular to the line between $A$ and $B$, and its position is uniformly distributed between the two points.  You don't know if the wall is present or where it is until you run into it.      What strategy minimizes the expected distance to travel to point $B$ from point $A$?   (This problem  but was closed for being "too mathy.")  My Solution  I use an $x$/$y$ coordinate system on the plane with the origin at $A$, and $B$ on the positive $x$-axis.  Once the position of the wall is known (i.e. when you run into the wall) the best strategy is to walk straight along the wall to the nearest end, then travel straight to $B$.  The best strategy should therefore be to follow a fixed path from $A$ to $B$ until you reach $B$ or hit the wall; if you hit the wall, follow the previously stated path around the wall.  I break up the fixed part of the path into a number of small segments.  A given segment covers a horizontal distance $\delta x$ and vertical distance $\delta y$.  The length of each segment is weighted by the probability it gets traveled, which is $\frac{1}{2} + \frac{1}{2}\left(1-x\right)$.  We also consider the probability that you have to walk around the wall, which for a given segment is $\frac{1}{2}\delta x$.  The distance it takes to get around the wall is just $(H-y) + \sqrt{H^2 + (1-x)^2}$, where $H=\frac{1}{3}$, the half-length of the wall.  Therefore the expected distance $E$ should be equal to:  $$ E = \sum_{i=1}^N\frac{2-x}{2}\sqrt{\delta x_i^2 + \delta y_i^2} + \frac{\delta x_i}{2}\left((H-y_i) + \sqrt{H^2 + (1 - x_i)^2}\right) $$  If we treat $y$ as a function of $x$ (assuming that the optimal path doesn't travel backward) we can factor out $\delta x$, since $\delta y = y'(x)\delta x$; then taking the limit as $\delta x\to 0$ we obtain an integral:  $$ E = \frac{1}{2}\int_{0}^{1}(2 - x)\sqrt{1 + y'(x)^2} + H - y(x) + \sqrt{H^2 + (1-x)^2}~\mathrm{d}x $$  Now I try to use the  to find the path $y(x)$ that minimizes $E$:  $$ E = \int \mathcal{L}(x, y(x), y'(x))~\mathrm{d}x \\ \mathcal{L}(x, y(x), y'(x)) = \frac{1}{2}\left((2 - x)\sqrt{1 + y'(x)^2} + H - y(x) + \sqrt{H^2 + (1-x)^2}\right) \\ \frac{\partial \mathcal{L}}{\partial y(x)} - \frac{\mathrm{d}}{\mathrm{d}x}\frac{\partial \mathcal{L}}{\partial y'(x)} = 0 \\ \left[-\frac{1}{2}\right]-\frac{\mathrm{d}}{\mathrm{d}x}\left[\frac{(2-x)y'(x)}{2\sqrt{1+y'(x)^2}}\right]=0 \\ 1 = \frac{y'(x)(1 + y'(x)^2) - (2-x)y''(x)}{\left(1+y'(x)^2\right)^{3/2}} \\ y''(x) = \left(1+y'(x)^2\right)\frac{y'(x)-\sqrt{1+y'(x)^2}}{2-x} $$  A solution to this differential equation should be a minimum-distance path, as long as it satisfies $y(x) \le H$ for all $x\in[0,1]$.  The boundary conditions are $y(0)=y(1)=0$.  Mathematica finds an explicit solution, but it it is extremely complex.  The simplest form I can get it in is:  $$ y(x) = \frac{168 \left(9 \sqrt{6}+\sqrt{38}\right) \xi -\sqrt{131-9 \sqrt{57}} \xi^3 - 448 \sqrt{3710+378\sqrt{57}}}{2688 \left(27+\sqrt{57}\right)} \\ \xi = \sqrt{7 \left(43+\sqrt{57}\right)-8 \left(27+\sqrt{57}\right) x} \\ y(x) \approx 0.3929 x\sqrt{1.2802-x} +0.3454 \sqrt{1.2802-x}-0.3908 $$  The solution looks like this:    The Question  Is this approach valid, and are my calculations correct?


I just want to know can i installed the ubuntu 20.04 LTS. please let us know


I was continuing further on the project while I assigned different materials to the face of the cube i was stuck on assigning the the texture to highlighted face how do i do it?


Is there a way to search against ONLY questions (e.g. no matches from answers)?  Is there a way to filter out results from closed questions (only get matches from open ones)?


Up to which precision has the coulomb law proven to be true? I.e.  if you have two electrons in a vacuum chamber, 5 meters appart, have the third order terms been ruled out? Are there any theoretical limits to measure the precision ( Planck's constant?). Obviously there are practical limitations ( imperfect vacuum, cosmic rays, vacuum fluctuation). Still, does anyone know what was the smallest amount ever correctly predicted by that law?    Edit : Summary  On the high end of the energy spectrum a precision of 10^-16 has been shown ( 42 years ago )  For electron point charges at large distances the law might brake down due to practical reasons.  For moving particles QED gives a correction to the law:


Find all $f:\mathbb{R}\rightarrow\mathbb{R}$ for which $f(x^3)+f(y^3)=(x+y)(f(x^2)+f(y^2)-f(xy))$

Problem  Find all $f:\mathbb{R}\rightarrow\mathbb{R}$ which satisfy  $$f(x^3)+f(y^3)=(x+y)(f(x^2)+f(y^2)-f(xy))$$ for all $x,y\in\mathbb{R}$.    This is a contest math problem, and I have very little experience with functional equations. Thus I sadly have no progress to show. Admittedly, I'm posting this just to get some input on good strategies and solutions.


How to center element using flexbox when the div has width?

I am trying to center a div using flexbox, but when I set the div's width it gets pushed all the way to the left. I have tried setting the parent div's width to 50% and creating a child div and applying the flexbox styling to it, but this doesn't work either.   .App {   width: 50%; }  .container {   display: flex;   align-items: center;   justify-content: center;   flex-direction: column; }

Test
     Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nulla eget ligula varius, malesuada sapien vel, suscipit diam. Proin eu porttitor mauris. Vivamus lacinia, turpis ut tincidunt luctus, neque justo tempus arcu, vel congue quam eros at ante. Aliquam lobortis mollis orci eget ultrices. Nunc vitae dolor at quam elementum dignissim.


Dystopian sci-fi film about population-controlled future society

I am trying to remember the title of a sci-fi film I watched a few years back taking place in a future society where people lived underground in a tightly monitored, population controlled city. The main character was an officer of some kind tasked with capturing people who attempt to flee when their names are called for the culling ritual. Ends with a bunch of people walking out on the surface of the earth and seeing the world outside their city for the first time. I believe it was made in the 1960s and the costumes and special effects were very "early Star Trek".  I have searched lists of old sci-fi movies with no success.


Prove that $\sqrt{x}$ is continuous on its domain $[0, \infty).$

Prove that the function $\sqrt{x}$ is continuous on its domain $[0,\infty)$.  Proof.  Since $\sqrt{0} = 0, $ we consider the function $\sqrt{x}$ on $[a,\infty)$ where $a$ is real number and $s \neq 0.$ Let $\delta=2\sqrt{a}\epsilon.$ Then, $\forall x \in dom,$ and $\left | x-x_0\right | < \delta \Rightarrow \left| \sqrt{x}-\sqrt{x_0}\right| = \left| \frac{x-x_0}{ \sqrt{x}+\sqrt{x_0}} \right| < \left|\frac{\delta}{2\sqrt{a}}\right|=\epsilon.$  Can I do this?


Why am I am getting the error ":main() must have int return type"?

I created a c++ code for binary to Decimal conversion #include <cmath> using namespace std;  int binaryToDecimal(long int n){ int decimal=0,i=0; while(n>0){ decimal+=(n%10)*pow(2,i); n/=10; i++; } return decimal; } void main(){     long int num;     cout<<"Enter a binary number:";     cin>>num;     int d= binaryToDecimal(num);     cout<<"\nDecimal number:"<<d; }  However I am getting the error :main() must have int return type Why should I have my main as int return type when it does'nt need to return anything? What's wrong with having a void return type?


Proving an encrypted message contains (but does not 100% consist of) a plain-text message?

I have keypair (u,r), and two pieces of data, X and Y.  I reveal X publicly but keep Y secret. Y has high entropy.  I then combine X and Y, into c(X,Y) = Z.  I encrypt Z, into "encrypt(Z,u) = Q".  r is needed to decrypt Q back into Z.  Can I prove (including interactive zero-knowledge proofs) that Q contains X, without revealing r or Y?  Please help! Thank you very much.


Linking polygon features in one layer to polygon features in another, using largest overlap in QGIS?

I have two polygon layers: the first one contains small land lots (green in the image), the second one contains large zones (the purple line in the image attached separates 2 such zones).  I want to link (the id's of) the large zones in layer 2 to the small parcels in layer one, using the largest overlap as criteria or measure: the small parcel gets the id of the large zone with which it has the largest overlap.  How can this be done in QGIS?


I recently upgraded from 18.04 to 18.10... Wanting to revert to LTS. Can I do this without re-installing Ubuntu?


Refusal of UK Standard Visitor Visa, reapply after previous refusal?

I'm living in Turkey and i planned a holiday with my wife.Our visa refused today.I went to London 2 years ago so i got visa before.I think its all about income and savings.What i must do before reapply?How can i show an evidence for my savings?Is that needed for savings?(I know that this is needed for income.)


What's the 'correct' way of registering/installing an Assembly to the GAC?

There seems to be lots of different ways to register assemblies with the GAC, as in, they 'work'.  However, what's the "proper" way of doing it?  In response to Lou Franco (and gacutil):  I'm using Gacutil for development, but it seems to me to be not the proper way to install it, since gacutil isn't included in the basic .NET utilities past .NET 1.1 - it's only a developer tool.  Additional: Gacutil (as seen in responses below) is not redistributable, and therefore should not be used in any app that you intend to give to people who are not developers.  AKA, customers.  See .  In response to using WIX:  WIX might be great and all, but how does it work under the hood?  What details makes the way WIX installs the assembly the right way to install it?  How does it look it up?  Is it a system/.NET call?  Is there some call in a dll buried somewhere in System32 that needs to be made?    (Edit: it looks like WIX uses MSI under the hood.  See my comments in the accepted answer.)  Final edit: It looks like the correct way to install an assembly to the GAC is using windows installer, and nothing else.  I'm going to give Wix a try.  Thanks all!


How to see source code of menu blender 2.8.1?

In previous versions of Blender, you could see source code of a menu by right clicking and select view sources from a dropdown menu. How can you do it with Blender 2.8.1?


System.FormatException While Convert to Byte

I Got an Error while compiling this code for my encrypting class, it say "Exception thrown: 'System.FormatException' in mscorlib.dll"  public static byte[] StringToByteArray(String hex) {     int NumberChars = hex.Length;     byte[] bytes = new byte[NumberChars / 2];     for (int i = 0; i < NumberChars; i += 2)         bytes[i / 2] = Convert.ToByte(hex.Substring(i, 2), 16);     return bytes; }   Can anyone help?


Is time dilation a mechanical slowdown only?

I've recently read about the time dilation occurs at very high speeds. But I'm really wondering if it is just a mechanical slowdown of the clock only? What if we use clocks that does not use moving crystals or reflecting light to measure time? Can anyone please make it clear to me?


Preventing upgrading mysql on ubuntu when apt-get upgrade is run

I want to make sure that sudo apt-get upgrade does not upgrade mysql 5.7.22 to the latest mysql GA 8.0.  Last time I ran this command mysql 5.7.20 was upgrading to mysql 5.7.22 automatically, which was ok but if it upgrades to mysql 8.x,  the production applications will stop working.    What command to execute to disable auto upgrade of mysql while keeping every other package on auto upgrade list.


How might we *naturally* lead newbs to the tag wiki?

We have a tag wiki, it's actually really good. Here's the one we have in .  The  wiki is beautiful for newbs, it really is. It covers off:   The basics What JS is How to ask a JS question How to learn more JS Awesome previous questions Useful links, tools, specs...   What more could they ask for, really? It's nearly the combination of things we endless tell newbs in the chat room or in the questions they ask -- like, endlessly, asking what jsFiddle is, how do you use it, what's JSON, why doesn't JSONwork... again, and again, and again.  Wait a minute--we have an awesome resource on it. Maybe we need to just edit it. Or tell more of them it's there.  Okay, so I told a bunch of newbs about it. Turns out the new newbs don't know about it because... they're new, and nobody told them about it, and they didn't see it. So why bother improving it, if the only people who really find it are the people who aren't new to the site?  Right now, to get there I have to do this:   Look at the page, nothing there, maybe I'll click on JavaScript. List of questions, eh? I know, I'll look at more questions Well, that didn't work. What's this tiny nonchalant "about" link next to the tag? Oh wow, a page full of information.   We're effectively demoting importance of the wiki to the people it will be the most useful to.  So, what can we do on SO such that newbs will find the wiki? Because I'm really tired of explaining what jsFiddle is.


Ubuntu 18.04 upgrade does not find internal wifi card

I just upgraded from 17.10 to 18.04. Once the installation was complete, follow with resetting the computer, I could not log to the wifi anymore, "No Wifi Adapter found".   Here is a wireless and network diagnose report of my computer   miker:~$ rfkill list all 0: hci0: Bluetooth     Soft blocked: no     Hard blocked: no  Thanks for any help!


Does only the current release of OpenWRT receive security updates or do all releases on the Table Of Hardware?

Does this mean that only the current release receives updates (including security updates) and fixes while older/all other versions do not?  Quoting from the openwrt website   " Historic Releases  The releases linked here are mostly for historic interest - they are long out of date and completely unmaintained. "  But on the , many older versions are recommended.  A related question is asked here () but it does not address this.


Story about main character with regeneration powers

I read a book 10+ years ago where the world was ruled by various factions, each one had a special ability of some sort. The main characters faction had regenerative ability. Another faction had the ability to speed up or slow down time. I am not sure of the plot, but I know at one point he is injured so badly he starts growing a clone which he attempts to kill, but comes back later in the story.    Any ideas?


How to merge pages of a pdf from the command line

From a pdf of n pages, how to reduce by half the number of pages by merging several pages on a single page? Each pair of pages from the old pdf should be found side by side on the new pdf.


Will the files inside my windows 7 get deleted when I install Ubuntu 20.04 version?


Why doesn't the boolean modifier work for me?

I want to use the top half of the circle to make a cut but whenever I apply the boolean modifier, the circle just stays there and becomes attached to my other object.  I've managed to make the cut in a standard cube but not sure why it's not working for this...?


Is the WoW experience fundamentally different if I've started playing in 2014?

I just bought the game yesterday and started playing for the first time. I have all the expansions up to Mists of Pandaria included by default. What I can't understand is whether things are different for me right from the get-go because of events in the expansion packs.  For example, a certain town called Auberdine was supposed to be a questing location for my night elf druid character, but for me that town is destroyed as a result of events from Cataclysm and I instead quest at a nearby town on the coast named Lor'danel.  I am playing basically the same quests, regardless of the superficial changes, right? Given that I have not "experienced" the plot of the expansions yet, it is confusing that I can see their effects already on the world, because I'm not there yet in the story.  Also, this also means that, in this case, there is literally no way now for me to ever experience the original Auberdine, the way it was before the expansions, right? I, and every other new person will always be sent to that other town instead.  How this works out in World of Warcraft is confusing to me and I was hoping someone can offer some perspective.


Is there a disk space impact when choosing NULL vs empty array {} for the default of an ARRAY[] column?

My intuition is NULL will take up less space than {} when used as the default value of an ARRAY[] column in PostgreSQL.  Am I correct?


How to determine neighbouring tile ids in QGIS?

I was asked in a recent training course if QGIS could automatically calculate the next/previous and above/below page numbers for a map book created using the atlas generator. I managed to work out a fairly reasonable label expression for a regular grid if you know the width and height of the grid.  But we then started to think of realistic examples where we don't want to draw pages that don't contain our district of interest, such as this one of my home county:    So this afternoon I had a play at a python script to work out the 4 neighbours I was interested in for each grid cell and added those values to my grid (this is heavily based on Ujaval Gandhi's ):  for f in feature_dict.values():     print 'Working on %s' % f[_NAME_FIELD]     geom = f.geometry()     # Find all features that intersect the bounding box of the current feature.     # We use spatial index to find the features intersecting the bounding box     # of the current feature. This will narrow down the features that we need     # to check neighboring features.     intersecting_ids = index.intersects(geom.boundingBox())     # Initalize neighbors list and sum     neighbors = []     neighbors_sum = 0     for intersecting_id in intersecting_ids:         # Look up the feature from the dictionary         intersecting_f = feature_dict[intersecting_id]         int_geom = intersecting_f.geometry()         centroid = geom.centroid()         height = geom.boundingBox().height()         width = geom.boundingBox().width()         # For our purpose we consider a feature as 'neighbor' if it touches or         # intersects a feature. We use the 'disjoint' predicate to satisfy         # these conditions. So if a feature is not disjoint, it is a neighbor.         if (f != intersecting_f and             not int_geom.disjoint(geom)):             above_point = QgsGeometry.fromPoint(QgsPoint(centroid.asPoint().x(),                centroid.asPoint().y()+height))             below_point = QgsGeometry.fromPoint(QgsPoint(centroid.asPoint().x(),                centroid.asPoint().y()-height))             left_point = QgsGeometry.fromPoint(QgsPoint(centroid.asPoint().x()-width,                centroid.asPoint().y()))             right_point = QgsGeometry.fromPoint(QgsPoint(centroid.asPoint().x()+width,                centroid.asPoint().y()))             above = int_geom.contains(above_point)                below = int_geom.contains(below_point)                left = int_geom.contains(left_point)             right = int_geom.contains(right_point)             if above:                 print "setting %d as above %d"%(intersecting_f['id'],f['id'])                 f['above']=intersecting_f['id']              if below:                 print "setting %d as below %d"%(intersecting_f['id'],f['id'])                 f['below']=intersecting_f['id']              if left:                 print "setting %d as left of %d"%(intersecting_f['id'],f['id'])                 f['left']=intersecting_f['id']              if right:                 print "setting %d as right of %d"%(intersecting_f['id'],f['id'])                 f['right']=intersecting_f['id']      # Update the layer with new attribute values.     layer.updateFeature(f)  layer.commitChanges()   This works just fine.     But to be honest the whole creating a test point to the North and then testing all the possible neighbours seems wrong. However after an afternoon of wracking my brain I can't think of a better way to determine what is a particular grid cell's northern neighbour?  Ideally I'd like something simple enough to put in a print composer text box, but I suspect that's too much to ask for.


Let $p(x)$ be a polynomial of degree $n$ satisfying $p(x)\geq 0$ for all $x$. That is, for all $x$, $p(x) = a_n x^n + a_{n-1} x^{n-1} + \cdots + a_1 x + a_0 \geq 0$, $a_n\neq 0$.  Show that $p(x)+p'(x)+p''(x)+\cdots+p^{(n)}(x)\geq 0$ for all $x$ where $p^{(i)}(x)$ is the $i^\text{th}$  derivative.  My interest: I know that, we can rewrite the LDE as follows  $$ p(x)+p'(x)+p''(x)+\cdots+p^{(n)}(x) = Lp(x) $$  where $L := I + D + D^2  + \cdots + D^{(n)}$. Can we say anything about a linear operator of this kind so that it does not change the sign of the input it takes? I can try to solve the question by writing for all the derivatives and factoring them using $p(x)$, but I think there should be a clever way of showing this by the properties of $L$. Can I figure out a solution by just looking at $L$ and the sign of $p(x)$ as in the question? Where should I look for that?


I'm trying to install GDAL and GDAL development libraries on Ubuntu 20.04 with the following commands (source: ): sudo add-apt-repository ppa:ubuntugis/ppa sudo apt-get update sudo apt-get install gdal-bin ogrinfo --version   GDAL installs successfully and it returns: GDAL 3.0.4, released 2020/01/28  After that, I tried installing GDAL development libraries: sudo apt-get install libgdal-dev  It returns the following error: Reading package lists... Done Building dependency tree        Reading state information... Done 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:  libgdal-dev : Depends: libpq-dev but it is not going to be installed E: Unable to correct problems, you have held broken packages.  What is the problem here? I read somewhere that "UbuntuGIS stable ppa (launchpad.net/~ubuntugis/+archive/ubuntu/ppa) does not have any 20.04 packages." Is there a workaround for this? Everything works if I try it on Ubuntu 18.04.


Evaluate: $$\int_{-\pi/4}^{\pi/4}(\cos(t)+\sqrt{1+t^2}\cos(t)^3\sin(t)^3)dt$$  I have tried substituting $t=\tan(\theta)$ and breaking up the $\cos(t)^3$ using $\cos(t)^2=1-\sin(t)^2$, but I can't figure it out.  This question is #21 from the Math subject GRE form GR1268.


Can you use a trailing comma in a JSON object?

When manually generating a JSON object or array, it's often easier to leave a trailing comma on the last item in the object or array.  For example, code to output from an array of strings might look like (in a C++ like pseudocode):  s.append("["); for (i = 0; i < 5; ++i) {     s.appendF("\"%d\",", i); } s.append("]");   giving you a string like  [0,1,2,3,4,5,]   Is this allowed?


Check which workstations a Windows domain user is logged into

I'm trying to find out on what workstation the user is loged in at the time. I haven't found a way yet. Is this even possible? I have a username and want to get his current workstation.  I have domainadmin permissions and the client is in a domain. Using Powershell v5.


Static Page > Post Page displays data from latest blog post instead of the page details

Background  I have created a Page called Blog. I have  selected "A Static Page" > Post Page > Blog In the "home.php" I am displaying all post with while(have_post()) This is working fine. It is displaying all post.  The issue I am having is when I return the page title with <?php the_title(); ?> is returns the most recent post's title which is "Post 6" instead of "Blog" the name of the page.  I am also displaying the content of the "blog" page as well but again it is displaying the content of the most recent post.  So how do I display the page content of the page blog?  <?php get_header(); ?>  <?php the_title(); ?>

 <?php if ( have_posts() )  { ?>
         <?php              while ( have_posts() ) {             the_post();         ?>
                  <a href="<?php the_permalink() ?>" rel="bookmark" title="<?php the_title(); ?>">                 <?php if ( has_post_thumbnail() ) { ?>                     <?php echo get_the_post_thumbnail(); ?>                 <?php } ?>
<?php the_title(); ?>
                 <?php the_excerpt(); ?>
          <?php } ?>
      <?php } else { ?>     No Post     <?php } ?>

     <?php get_sidebar(); ?>

   <?php get_footer(); ?>   ANSWER  This did the trick   $news_page = get_queried_object(); echo $news_page->post_title;


Where can I get the latest Ubuntu Alpha or Beta?

I'd love to test the latest Ubuntu alpha/beta (otherwise known as "Ubuntu+1"), but I can't find it.   Where can I find download for the pre-releases of Ubuntu?


I've recently come across a novel called , after which being curious I found a TV episode called .  Could someone shed some light on how to use "a most" and whether it has anything to do with "the most"?


I'm trying to update the "price" field in a product div.  I've managed to sort out the increments, so the price now changes.  However, It doesn't stay in it's format - it returns bad prices, such as: £1.5 as opposed to £1.50 £0.39999999999999996 as opposed to £0.40, etc - I just want it to add the price of a product (£0.50) to the total price at the push of a button.  Here is my JavaScript so far:  function incrementquan'.$row["pid"].'(){ var input = document.getElementById("quan'.$row["pid"].'"); input.value = parseInt(input.value) + 1; var element = document.getElementById("price'.$row['pid'].'"); element.innerHTML = ("&pound;" + (input.value * '.$row['pprice'].'));   }  Can anyone help me out with this?  Thanks a lot.


I want to install Ubuntu on a dual boot Windows XP machine which already has EXT2 space and Swap allocated for Slackware, I want to install Ubuntu in the area now used by Slackware. When I go into 'Something Else' and select Slackware section and Press 'Install Now' it comes back with 'No Root Filesystem defined'


What happens if your passport expires while you are visiting another country?

I was just reading this question   and began wondering what would happen if your passport expired while you were out of your home country?  I would assume that customs would realize that your passport would be expired within the time period of your stay (i.e., you want to stay for a month in X country, but your passport expires in 15 days), and refuse you entry to your destination, but what if customs didn't notice, and you were allowed entry?  I also saw this question   Where one of the answers mentioned that you would be sent back to your home country (if passport was lost away from home), or possibly be able to work with your country's embassy in order to work something out.  So I am curious what would happen if your passport does expire during a trip?  Is it similar to if you lost your passport, or is it something else entirely?  NOTE:  This question is purely out of curiosity.


How can I add a Stack Exchange login to my preexisting account?

When I created my account, I used Facebook Connect as my only login type and I can only log in to my account using it.  I wish to create a Stack Exchange login to be able to log in with instead of Facebook Connect, but I can't find how to do this. It seems that the option for creating a Stack Exchange login is only present when creating a new account?


How can I fix Malformed line (54) when gedit wont load?

Malformed line (54) error message gedit not running, cannot fix as line editor will not load.  I  cannot load any new software or programs.   gedit worked before when I was in dual boot but I wiped the detested windows 10, in doing so and moving partitions I had to reinstall ubuntu from thumb drive.    When I started to try to load previously running programs that is when the trouble started.   I dont know if my hand stuttered and placed an extra character somewhere?


What different approximations yield Gravitoelectromagnetism and Weak Field Einstein Equations?

This question is inspired by ,  which cites  (GEM) as a valid approximation to the Einstein Field Equations (EFE).  The wonted presentation of gravitational waves is either through Weak Field Einstein equations presented in, say, §8.3 of B. Schutz “A first course in General Relativity”, or through the exact wave solutions presented in, say §9.2 of B. Crowell “General Relativity” or §35.9 of Misner, Thorne and Wheeler.  In particular, the WFEE show their characteristic  which can be visualized as one way dilations in one transverse direction followed by one-way dilations in the orthogonal transverse direction. GEM on the other hand is wholly analogous to Maxwell’s equations, with the gravitational acceleration substituted for the $\mathbf{E}$ vector and with a $\mathbf{B}$ vector arising from propagation delays in the $\mathbf{E}$ field as the sources move.  My Questions:   The freespace “eigenmodes” of GEM, therefore, are circularly polarized plane waves of the gravitational $\mathbf{E}$ and $\mathbf{B}$. This does not seem to square exactly with the WFEE solution. So clearly GEM and WFEE are different approximations, probably holding in different approximation assumptions, although I can see that a spinning polarization vector could be interpreted as a time-varying eigenvector for a $2\times 2$ dilation matrix. What are the different assumptions that validate the use of the two theories, respectively? The Wikipedia page on GEM tells us that GEM is written in non-inertial frames, without saying more. How does one describe these non-inertial frames? Are they, for example, stationary with respect to the centre of mass in the problem, like for Newtonian gravity? There would seem to be very few GR-co-ordinate independent ways to describe, when thinking of GEM as an approximation to the full EFE, a departure from an inertial frame. It’s not like you can say “sit on the inertial frame, then blast off North from there at some acceleration”. Are there any experimental results that full GR explains that GEM as yet does not? I’m guessing that these will be in large scale movements of astronomical bodies. Here I apologise for being ignorant of physics history and also because I am at the moment just trying to rehabilitate my GR after twenty years, so this may be a naïve one: if GR can in certain cases be reduced to analogues of Maxwell’s equations, what about the other way around: are there any theories that try to reverse the approximation from GR to GEM, but beginning with Maxwell’s equations instead and coming up with a GR description for EM? I know that Hermann Weyl did something like this – I never understood exactly what he was doing but is this essentially what he did?   I am currently researching this topic, through  and , so it is likely that I shall be able to answer my own questions 1. and 2. in the not too distant future. In the meanwhile, I thought it might be interesting if anyone who already knows this stuff can answer – this will help my own research, speed my own understanding and will also share around knowledge of an interesting topic.


We have by  Heine–Cantor theorem that:     If $M$ and $N$ are metric spaces and $M$ is compact then every continuous function $f : M \to N$, is uniformly continuous.   Is the inverse of this theorem is satisfied?


Cannot upgrade from Ubuntu 14.04 to 16.04

I have the following Ubuntu version: 14.04.6 LTS and I'm trying to upgrade to 16.04 with  sudo do-release-upgrade   This command fails reporting:  An unresolvable problem occurred while calculating the upgrade: E:Unable to correct problems, you have held broken packages. This can be caused by:    * Upgrading to a pre-release version of Ubuntu    * Running the current pre-release version of Ubuntu    * Unofficial software packages not provided by Ubuntu   And /var/log/dist-upgrade/main.log says:  2019-09-06 17:15:26,873 ERROR Dist-upgrade failed: 'E:Error, pkgProblemResolver:::Resolve generated breaks, this may be caused by held packages   My question is: how to identify and delete these broken deps?  Thank you.


I have created a custom block of id downloadourapp and I would like to show/hide it base on certain statements.  I have create my custom module along with .module file where the code should be, however, I failed to find the right function to be used for that matter.  is hook_block_view_alter is the right function and how to hide or show this downloadourapp specific block.


I've got a variety of frozen fruits in a freezer that I've been neglecting...For 12 months or so, at this point. At this point I'm wondering whether I should bother with the fruit at all or if there's a receipe that works better with aged produce? Part of my stock is fruit that was already frozen and part were cranberries that started fresh and then got the freeze. Any tips?


How do I know if this is a positive or negative feedback to the op-amp?

I am trying to build a line-following robot with the schematics I found below. I have just started to understand the use of feedback in op-amp. Ie. The continuous balancing mechanism creates a very stable gain determined by resistors connected to the op-amp.  I have tried to trace the current path marked in green and orange lines for the respective op-amp. Both lead to the same inverting and non-inverting input terminal of different op-amp.  I am kind of puzzled by this.  1) What is the point to have feedback to the different input terminals?  2) Because of the different input terminals used, how do I know which is the negative feedback? And is there even a thing like "positive feedback" happening here?  3) Or could it be a schematic drawn wrongly because it is just not technically practical nor possible to have the feedback wired in this manner?  Many thanks in advance.


This may (and probably will) sound very silly, but I rather ask first than destroy my childhood memories - I found my old sega mega drive at my parents home, but it had no psu. I knew I had some psu's laying around at home so I found one that supplies 5V2A, but the console requires 10V1A.  I guess I should get an universal psu somewhere, but maybe, by some chance, the one I got at home won't burn my console and will actually work?  Thanks.


Story about a guy living same day over again until he falls asleep under an aluminum boat?

I have a strong recollection of reading a short story sometime in the '70s (maybe in Analog magazine) roughly about a man who was living in some kind of experiment run by aliens, in which the same day was repeated over and over... (shades of Groundhog Day) - until he accidentally passed out under a metallic boat hull in his garage, and he was able to then realize he was in this experimental world where the same day repeats.  I think the title contained the word "Tuesday" (or some other day of the week); IIRC the author mentioned that he considered using the title "The Ides of March" but decided against it.  Sound familiar to anyone?


What size standard deviation is considered uncommonly large or small?

What does the size of the standard deviation mean?  For example, if I want to study human body size and I find that adult human body size has a standard deviation of 2 cm, I would probably infer that adult human body size is very uniform, while a 2 cm standard deviation in the size of mice would mean that mice differ surprisingly much in body size.  Obviously the meaning of the standard deviation is its relation to the mean, and a standard deviation around a tenth of the mean is unremarkable (e.g. for IQ: SD = 0.15 * M).  But what is considered "small" and what is "large", when it comes to the relation between standard deviation and mean? Are there guidelines similar to the ones that Cohen gives for correlations (a correlation of 0.5 is large, 0.3 is moderate, and 0.1 is small)?


I'm looking for help regarding how to edit an object's style in a separate CSS file via JS. For example, if I have an object that I style with #objectid {left: 0%;} in my CSS file, how would I go about changing that left property via JavaScript? I'm aware you can do object.style.property but that hasn't been working for me as of late. What's the most efficient/easy method of doing this? Thanks in advance.


When should I watch the two latest Naruto movies?

I have completed watching all the currently released Naruto Shippuden episodes. I have completed the Naruto original series, and am on episode 436 of the subbed Naruto Shippuden series. My question is, when should I watch The Last: Naruto the Movie and Boruto: Naruto the Movie? Should I wait until I am completely done with the Shippuden series, or do I watch them now?   I have seen other answers, but none have been definitive for me. I have not read any of the Manga, nor do I plan to at this point. However, I do not want these movies to spoil any of the plot lines from the Shippuden series for me. How many episodes are left in the Shippuden series? Can someone please give me some guidance and/or information on these topics? Thank you so much!


Why is my previous history command in the terminal overwriting other text?

Here is my .bashrc config for ps1 i believe ive done it correctly but any time i press up for a previous command it gets all jumbled up. I can write long lines of commands without it wrapping only the "previous history" is giving me trouble.  PS1='\[\e[38;5;9m[\]\[\e[38;5;214m\u\]\[\e[38;5;41m@\]\[\e[38;5;4m\h\] \[\e[38;5;9m\W]\]\[\e[38;5;254m\$ \]'


I want to add a string to a specific place

I have these commands :       address=`tail -1  address.txt`      address="\"0x$address\" : {      \"balance\": \"1000000000000000000000000000\"}"   I want to execute this        sed -i  "/{/a $address" genesis.json   but it crashs with this error        sed: -e expression n°1, caractère 61: commande inconnue: `"'   When i execute the same command whith $c avec $c=abs it works .  Do anyone have an idea about the problem?


Is a confidence interval the inverse of a p-value?

I've recently encountered the claim that a confidence interval is 1-$\alpha$, (where I assume $\alpha$ is a p-value).  e.g. that a p-value of 0.05 is equivalent to a 95% confidence interval.  I believe this claim to be false, as I've recently read that p-values are not predictive, but I wonder if a statistician (which I am not) could shed some light on this?  Thanks


Wifi not working on Ubuntu Dual Boot with windows 8.1 ( ASUS X550LD )

Hey guys i recently dual booted Windows 8 and Ubuntu 14.04 LTS on my laptop ASUS X550LD. The dual boot works perfectly but wifi doesnt connect in Ubuntu.  It connects on Windows 8 perfectly. Any help on this would be greatly appreciated.  3:00.0 Network controller [0280]: Broadcom Corporation BCM43142 802.11b/g/n [14e4:4365] (rev 01)  Subsystem: Lite-On Communications Inc Device [11ad:6605]  Kernel driver in use: bcma-pci-bridge


Installing Orange Package with older Python Version?

I am trying to install an Add-on package from GitHub that contains prototype widgets for Orange Data Mining. I am trying to install it from the GitHub page found . I am using the following Terminal code to install this: git clone http://github.com/biolab/orange3-prototypes.git  Everything then appears to install correctly and the download shows 100%. Then, however, it throws an error and says:  Orange requires Python >= 3.4  I am using Mac OS. Clearly, it is suggesting that I need to use a different version of python to install, however, I already updated my pip install. Any insight into how I can fix this?


When was the expression "Indian file" first used in English?

I have just discovered that the Spanish expression  translates word by word to a valid English expression: . And seemingly it is also valid at least in French (file indienne) and Portuguese and Italian (fila indiana).  The linked question discusses the reason why it is called Indian file, but I would like to know which language came up with the expression first, so what are the first texts registered in English that use this expression? So far I have found a text in Spanish from 1799 that uses the Spanish version of the expression. But I have also found  from 1760 in the American English corpus of Ngram:     You will march your Party in an Indian File along the River side, opposite the Battoes, keeping the men at 5 or 6 yds distance from each other [...].   If I select the British English corpus, the first result is also from 1760.  Are there any other previous English texts that used this expression?


how to get <?php wp_title(''); ?> only in lowercase letters ?  I tried a lot but cant get it ! Perhaps one of you can tell me how to proceed ?


Does a Yemeni citizen need a transit visa for India?

I will travel from Aden to Mumbai by Yemen Airways, and then I will travel to Kuala Lumpur by Malaysia Airlines. Do I need an Indian visa for the connection?


I'm trying to iterate through a Linked HashMap keySet however I am having difficulties in getting it to work.  Essentially I am searching the keySet to find  a word, and another word. If the second word is immediately after the first word I wish to return true. This is the progress I have made so far.  for (String word : storedWords.keySet()) {          value0++;          if(word.equals(firstWord)){             value1 = value0;         }          if(word.equals(secondWord)){             value2 = value0;         }          int value3 = value2 - 1;         if(value1 == value3){             result = true;             break;         }     }   EDIT:  I've solved my problem and am thankful for all of those who helped. I apologise for making a post when there was a lot of information available on the website however I just lacked the understanding of the logic behind it.


Gimp won't allow me to copy and paste a transparent image

On the latest version of GIMP on my PC, whenever I try to copy a transparent image from the internet, GIMP will automatically fill in the transparent areas with the background color I have selected.  This is a non-issue on my Mac, but I need to do this work on my PC, so how can I make it recognize the alpha of the image and not fill it with the background color?  The image canvas that I'm working with does have an alpha channel, but that does not seem to make a difference.


How can I convince my 28-month-old it's ok to poop?

My 28-month-old girl absolutely refuses to poop. We started potty training a week ago and she does perfect with pee. But she went to poop and freaked out. Crying and gagging is all I got... That was on a Monday, it's now Saturday morning and not more poop. She even told me I don't want to poop ever never...   Please help! I figured by now it would have to come out... Apparently not... We've tried everything big potty little potty rewards... I hate to give her something to go and her have diarrhea.


Hi I saw lots of posts here regarding Ubuntu eye strain issue. But none could answer my question. I use Intel i5 processor, AMD radeon Graphics card.  When I use my Win 7, there is no issue with my eyes for long time, but as soon as I use Ubuntu for even less than 1.5 or 2 hours, it makes my eyes dull. It makes eye strain, causes dryness of eyes.  UPDATE :  When I try the xrand -r 120, it says that the refresh rate is not available for the size.  I use a sony vaio 15 inch led laptop


Disable automatic reboots in Windows 10 professional - 2017

Wait! Please do not mark this as a duplicate until you have read this entire question. I know full well there is supposed to be a highly upvoted solution  but it is problematic because there have been many important changes to windows since the question was first answered. Some of these changes completely invalidate aspects of the solution (for example see ramhound's first comment in this question ). Also there are now 27 comments below the top answer so any additional comments are unlikely to be read.  So now my question: I wish to prevent windows from rebooting after doing an update because sometimes I want to leave my PC performing a task unattended for up to a week at a time. Can it be done?  SOLUTION FOUND: :     A simple Windows-Service that will update this "active hours" timeslot   in the background.   It is free, simple and it works.  March 2019: Still no unwanted reboots.  March 24th 2019: Windows 10 reboot blocker has now been marked as the correct answer in the duplicate question.


Does a function exist so that  f(x) = 0    x <= 0 f(1) = 1   under the additional constraint that all derivatives of f shall be continuously differentiable in [0;1]?  I strongly suspect that this is impossible, but I can't come up with a proof.  Constructing an f(x) which is continuous up to its nth derivative (for arbitrary finite n) is obvious, but not what I'm looking for.


Checking the available .NET framework on a client using C++

Is there a way to check and see what version of the .NET framework is available on a machine, without manually digging through the registry, etc.?  Ideally, from C++. How can this be solved it?


I was trying to make a really low poly flower, basically using 2D planes and applying textures with an alpha channel (Targa, 32 bit).  However when doing the UV mapping and applying the texture as usual doesn't yield the expected results. The render either shows the image with the alpha being white, or it doesn't show anything at all (an empty/completely transparent square).  I've tried several settings, but without any results. If I drag the "alpha" down to 0, it makes the whole texture transparent which is not what I want. I've tried selecting Z transparency, and also Mask, but nothing. Is there something I'm missing? It'd be nice to know the basic workflow to get it to work.


I wanted to make a desktop shortcut that performed an operation on multiple files matched by a wildcard pattern. However, it seems the desktop shortcut Exec option doesn't acknowledge globbing. For example, this desktop shortcut is supposed to remove all .png files in the home directory. However, it instead tries to remove a file literally named *.png (I think). [Desktop Entry] Encoding=UTF-8 Version=1.0 Name=remove pngs Exec=rm *.png Terminal=true Type=Application  I also found that it wouldn't expand things such as ~ or $HOME, needing an absolute path instead. Is it possible to perform shell globbing in a desktop shortcut, and if so how?


You have a flashlight that uses two batteries and you have a package of three new batteries. Suppose that each battery has an independent lifetime (in hours) with exponential(1/50) distribution. Find the distribution of the number of hours T that you can use the  flashlight.  Attempt for solution: denote by T the number of hours you can use the flash light let B1, B2 and B3 be the batteries respectively (B1\B2\B3) ~ exp(1/50)  I have the thought that if we use the first two batteries and the first one runs out first, then we have the second and third one once the second one runs out we can't use the flash light so the maximum life of the flashlight would be the amount of time the second battery runs  But i don't exactly know how to put this in terms of probability  I would really appreciate if there is someone out there willing to share ideas  Thanks alot!!


H is a subgroup of G and G' is a subgroup of H. Prove H is normal in G.

Question: Let G be a group and let G' be the subgroup of G generated by the set $S=\left \{ x^{-1}y^{-1}xy \mid x,y \in G \right \}$  $\space$  Prove that G' is normal in G. Solved  $\space$  Prove that G/G' is abelian. Solved  $\space$  Prove that if H is a subgroup of G and G' is a subgroup of H, then H is a normal subgroup of G.  I cannot even begin to start on this question. Any hint is appreciated.


How do I summon something with velocity in Minecraft? I tried searching it on google and click the links I can find. When I tried them, it didn't work. How do I do it?


Prove $1 + \frac{1}{4} + \frac{1}{9} + \cdots + \frac{1}{n^2} < 2 - \frac{1}{n}$ by Induction

The Question  Prove $1 + \frac{1}{4} + \frac{1}{9} + \cdots + \frac{1}{n^2} < 2 - \frac{1}{n}$ where $n\ge2$ and $n$ is an integer by Induction  My Work  Basis Step:  1 + $\frac{1}{4} = \frac{5}{4}$  $2-\frac{1}{2} = \frac{3}{2}$  $\frac{5}{4}<\frac{3}{2}$  Inductive Hypothesis:  $1+\frac{1}{4}+\frac{1}{9} + \cdots + \frac{1}{k^2} < 2 - \frac{1}{k}$  Induction Step  We must show $1+\frac{1}{4}+\frac{1}{9} + \cdots + \frac{1}{k^2} + \frac{1}{(k+1)^2} < 2 - \frac{1}{(k+1)}$  $1+\frac{1}{4}+\frac{1}{9} + \cdots + \frac{1}{k^2} < 2 - \frac{1}{k}$  $2 - \frac{1}{k} + \frac{1}{(k+1)^2} = 2 - \frac{(k^2+2k+1)+k}{k(k+1)^2} = 2-\frac{k^2 + 3k + 1}{k^3 +2k^2+k}$  My Problem  I can't seem to complete the proof. Any hints on how to change my approach for success?


I would like to reorder a whole file.  file.txt looks like this:   1 10 1 10 2 10 1 11 2 11 2 10   I would like it to look like this:   1 10 1 10 1 11 2 10 2 11 2 10


How to find $\lim_{x\to 0}\frac{\tan 3x}{\tan 5x}$?

I am asked to find the following limit:  $$ \lim_{x \to 0} \frac{\tan 3x}{\tan 5x}$$  My problem is in simplifying the function. I followed two different approaches to solve  the problem. But both seems incorrect.  Apprach 1) Since $\tan \theta = \frac{sin \theta}{cos \theta}$ and $\cot \theta = \frac{\cos \theta}{\sin \theta}$, we have:  $$\frac{\tan 3x}{\tan 5x} = \frac{\sin 3x \times \cos 5x}{\sin 5x \times \cos 3x}$$  This approach does not work well, because I cannot simplify more.   Approach 2) Since $\tan(x+y) = \frac{\tan x + \tan y}{1 - \tan x \times \tan y)}$, we have:  $$\frac{\tan 3x}{\tan 5x} = \frac{\tan 3x}{\tan 3x + \tan 2x} = \frac{\tan 3x}{\frac{\tan 2 + \tan3}{1 - \tan 2 \times \tan 3}}$$  What am I doing wrong?


Can one do the maths of physics without using $\sqrt{-1}$?

The use of imaginary and complex values comes up in many physics and engineering derivations. I have a question about that: Is the use of complex numbers simply to make the process of derivation easier, or is it an essential ingredient, without which it would be impossible to derive some results?   I can identify two different settings where the answer may be different:   It doesn't look like it is mandatory for results in Newtonian mechanics, General Relativity and classical electrodynamics. Can we say the same thing about quantum mechanics either way for sure?   Could this be a difference in quantum mechanics over the classical picture?


complex numbers - dealing with the square root of i

I have the following quadratic equation: $$(1-i)x^2 +ix - \frac{1}{4}i = 0$$ when I tried to solve for $x$ and get the complex solutions I got $ \sqrt{i}$ in the determinant. I know that $$ i^2 = -1 \implies \sqrt{i} = (-1) ^{\frac{1}{4}}$$ but don't come any further with it. Thanks in advance for your help


Can we derive  from the theory of elasticity? I know it is not a fundamental law and therefore can be derived from more basic considerations.


Is every discrete absolute value non-archimedean?

I've been reading Milne's notes on absolute values and local fields (Chapter 7 of the book on algebraic number theory), and a possibly minor point is confusing me.   On page 126, Milne writes, "$K$ is a field complete with respect to a discrete absolute value $|\cdot|$..." and then he talks about things that only make sense for non-archimedean absolute values, like the ring of integers and its maximal ideal.   Is every discrete absolute value on a field $K$ also non-archimedean? This would explain a lot, but I also suspect that it is not true, because I can't find any statement of this fact anywhere.  EDIT: An absolute value is discrete if the value group $|K^\times|$ is a discrete subgroup of the multiplicative group $\mathbb{R}_{>0}$. An absolute value is non-archimedean if it satisfies the stronger triangle inequality $$ |x+y| \le \max (|x|,|y|) $$ or equivalently if the set $\{|1|,|1+1|,|1+1+1|,\ldots\}$ is a bounded subset of $\mathbb{R}$.


Will the CMB eventually recede outside our observable universe?

As I understand it, some billions of years ago, the universe used to be opaque (edge of the sun - orange colored). Due to the expansion of the universe, photons emitted billions of years ago from billions of light years away are just now reaching us with their wavelengths now shifted into the microwave spectrum. This is what we perceive as the CMB. It seems that the origin of CMB photons just barely lies inside our observable universe. Is this coincidence? Or is there some reason why it should be inside our observable universe? Will it eventually recede outside our observable universe, so that future physicists will look out into space and see no CMB?


How to calculate the number of days one can stay in the Schengen area?

Valid for: Schengenstater (Issued by Sweden) valid From: 26-09-16 to 16-10-16 Type of Visa: C Number of Entries: 1 Duration of Stay: 6 days  1st entry in Greece on 10-10-16 and exit on 13-10-16 2nd entry in Belgium on 13-10-16 and exit on 14-10-16 3rd entry in Norway on 14-10-16 and exit on 16-10-16   My stay at Schengen countries in total of 6 Days (from 10-10-16 to 16-10-16). This is how the calculation or I am over staying? Please Advise.


I am learning to make an alarm clock but the problem is my scaling is not happening like the one in the youtube video am learning from. My scaling was supposed to be like this  , but it's coming out like this, all selected lines r scaling together it seems


Can a similar Add Row functionality as shown above be implemented in Salesforce? I don't necessarily want to create new custom fields each time, but at least make them visible when the button is pressed.


I'm trying to extract climate variables in QGIS 3.10.2 for sample points with a raster dataset. The raster comes from ClimateNA () and is available as in ASCII grid (.asc) and NetCDF (.nc) formats.  The raster uses the Projection: Lambert Conformal Conic and Datum: D WGS 1984. The best matching CRS seems to be North_America_Lambert_Conformal_Conic, EPSG:102009  I've set the project CRS to this and verified it for all layers. The raster loads with the CRS undefined and must be set manually, and the sample points, which are actually located in California, are displayed at (0,0). The Google base map appears to be correct.    Does anyone know how I can resolve this?   Another user was able to load it correctly, so hopefully its just a simple step I'm doing incorrectly.


Have the character automatically slide around obstacle corners

Like this:    The player is only holding right, however the character still moves up a bit to go around an obstacle.  My current collision system has access to:   The entity's previous position The entity's current position The entity's (axis-aligned) bounding box All the obstacles and their (also axis-aligned) bounding boxes   Also it proccesses each axis separatelly.  How can I implement this?


Forcing area calculation into miles in QGIS (without changing the PCS)

I'm working on an assignment that requires me to create an area column in miles without changing the projected coordinate system. ArcGIS has a tool that can do this ('Calculate Geometry')-- does QGIS have anything analogous? I know about using $area in the Field Calculator but I cannot tell what units the resulting answers are in.


Calling an object's function - Undefined is not a function

I'm trying to call a function of the object from another function and I get "Undefined is not a function" error. I think there's some silly mistake but I can't figure it out.  function dataProvider() {      var self = this;      self.loadData = ko.computed(function(){          var data = new Data(self.getJson().data); //here comes the error         ...       });      self.getJson = function(){         if(typeof jsonVar !== 'undefined')             return jsonVar;         else {             ...         }       };  }   The jsonVar is defined and it is a valid JSON. Data is an object, but self.getJson() just doesn't work.   EDIT: It is not about calling private or public method. The problem is that I can't call the method of the object.


If we are installing Ubuntu by flash drive can we generate the flashdrive with poweriso in another laptop?


Let $(c_0,\|\space.\|_{\infty})$ be the space of sequences $(x_k)_{k=0}^{\infty}$ such that $x_k\in{}\mathbb{K}$ and $x_k\rightarrow{}0$. I want to show that this space is complete.  I understand this requires me to take a Cauchy sequence in $c_0$ and showing it not only converges, but converges to a limit point (a sequence) in $c_0$.  I am comfortable with the definitions, but I am not sure how to approach the proof. This is how I tried to break down the problem:  Clearly a Cauchy sequence is bounded and I believe it does converge but can't show why (I can easily show that a convergence implies Cauchy).  After this, knowing it converges, I must show it converges to a sequence that itself converges to 0.  I did find a similar question someone else has posted but didn't find the solution very helpful.


Find all ways to partition a set into given-sized subsets

It isn't really complicated, but I just can't figure out how to do it. I have one set with objects, let's say they are numbers. I need to check all the possibilities of N groups (we can assume there are 3 groups, 9 objects in set), where order inside group doesn't matter ({1,2,3}, {2,1,3}, {3,2,1}, etc. are the same) and order of groups doesn't matter ([{1,2,3},{4,5,6}] is the same as [{5,4,6},{2,1,3}]).  I'm writing code in C#, but there really isn't anything I could show. The closest idea I had contained a lot of fors and ifs 😞


when do the stargate Atlantis seasons take place in SG-1

I'm going to start a Stargate marathon where I watch all of SG-1 and Atlantis. I know the 2 series take place roughly in the same timeframe but I am wondering at what points in SG-1 do each seasons of Atlantis takes place.  While I am only asking about when each season of Atlantis takes place in regards to SG-1 if there are key mid-season moments in Atlantis that should be seen before a particular point in SG-1 (ie. the Replicators beginning their attack on the Wraith) then I am interested in these as well.


In the phrase beginners guide to …,  where should the apostrophe go?   Beginner’s Guide to […] Beginners’ Guide to […]   In my particular case, this is the title for a presentation so there are multiple beginners that are being addressed.


Peter and Susan are facing each other in outer space. Both of them ignite their their incredibly powerful jet pack thrusters and accelerated away from each other to just over half the speed of light. From their original position they would appear to moving at just over half the speed of light, yet from Peter perspective, Susan will be moving faster than the speed of light, and vice versa. So whats going on here?


Representing a countable field by $\Bbb N$ [transport of algebraic structure]

To make sure that we are talking about the same, I would like to post the relevant definitions I know first.  Definitions:  A pair $(G, +)$ where $G$ is a set and  $+: G \times G \rightarrow G$  is called a commutative group if it has all of the following three characteristics:   (associativity): $\forall x,y,z \in G: (x+y)+z=x+(y+z)$ (identity element): $\exists e \in G \forall x \in G: e + x = x = x +e$ (inverse elements): $\forall x \in G \exists x^{-1} \in G: x^{-1} + x = e = x + x^{-1}$ (commutativity): $\forall x,y \in G: x+y=y+x$.     A triple $(\mathbb{K}, +, \cdot)$, where $\mathbb{K}$ is a set and  $+: \mathbb{K} \times \mathbb{K} \rightarrow \mathbb{K}$  $\cdot: \mathbb{K} \times \mathbb{K} \rightarrow \mathbb{K}$  is called a field if it has all of the following three characteristics:   $(\mathbb{K}, +)$ is a commutative group $(\mathbb{K} \setminus \{0\}, \cdot)$ is a commutative group distributive properties: $\forall x,y,z \in \mathbb{K}: x \cdot (y+z) = (x \cdot y) + (x \cdot z)$ and $\forall x,y,z \in \mathbb{K}: (y+z) \cdot x = (y \cdot x) + (z \cdot x)$     $\mathbb{N^+} := 1, 2, 3, 4, 5 ...$ (all positive integers)  $\mathbb{N}_0 := \{0\} \cup \mathbb{N}$ (the natural numbers with zero)  $\mathbb{N}$ can be both: $\mathbb{N^+}$ or $\mathbb{N}_0$.    My question: Does a field exist that has $\mathbb{N}$ as its set?  I know that $(\mathbb{Q}, +, \cdot)$ is a field and I know that $(\mathbb{N}, + )$ is only a commutative semigroup.   But maybe it's possible to define two mappings $\circ, *$ for $\mathbb{N}$ in such a way that $(\mathbb{N}, \circ, *)$ is a field.    Related:     The smallest field containing the integers is the field of rational   numbers.   Source: en-Wikipedia:   I don't know if this is true. If somebody can prove (or at least scribble the proof of) the quote it would be a good answer, I guess.


How can I use a function to turn a list of 25 into 5 chunks of 5 on 5 separate lines

I need to turn my random list of 25 integers into 5 chunks of 5 that go on 5 different lines.  I have found a way to turn the list in to chunks of 5 but I am unsure of how to separate them onto 5 different lines.  import random def fill(nx, x, y):     lx = []     j = 0     while (j < nx):         r = random.randint(x, y)         if r not in lx:             lx.append(r)             j = j + 1     return lx   def chunks(l, n):     for i in range(0, len(l), n):         yield l[i:i + n]   def display(lx):     lx = list(chunks(lx, 5))     print(lx)  n = 25 a = 10 b = 50 # myList = [] myList = fill(n, a, b) display(myList)   That is just the code to get the chunks of 5. I know lx.split wouldn't work because it is a list and I can't use \ to split them line by line. So I am unsure of how to get the 5 chunks onto 5 separate lines. Unless I am missing it the difference between mine ( potential duplicate) and the other question is that I have a list of random numbers already generated instead of trying to list out all of the numbers I am turning the 25 I have into chunks separated onto 5 different lines.


I have come across at a proof in the book (I'm not writing it all down) but at the last lines it says: $9(73+8)^n + (73-9)8^n$ Is congruent to $9x8^n - 9x8^n$ is congruent to 0 (mod 73). What i don't get is that how is $9(73+8)^n + (73-9)8^n$ when divided by 73 leaves the remainder $9x8^n - 9x8^n$ Or zero? I mean the value of n can be any and its binomial expansion can be bigger so how to know its really divisble by 73. Is there any simpler expression of above line so that i can understand it clearly. Or with other similar example which can be helpful to understand the concept. Thanks


What should the relationship between significance and correlation be?

Is it possible to have a very significant Chi-squared test, but a terrible correlation (I'm talking around 0.2)??


Number of graphs with vertices of only even degree.

This is an exercise I don't know how to solve, as I am preparing for an exam it would be great if you could help me with it.     Show that for $n > 0$ a number of graphs with vertices from set $\left\{1, 2, ..., n\right\}$ in which every vertice has even degree equals $2^{\binom{n-1}{2}}$   Thanks in advance!


What are efficient ways to find duplicates on trilogy sites?

Too many times I just know something's a dupe but can't for the life of me find the original question that is duplicated.  I search the sites from Google to find things, but in coming up short there I usually leave it and rely on someone else to clean it up [sigh].  What are other ways to do it better?  (or maybe this is one that gets closed employing said techniques...)


want to switch from ubuntu 14.04 to windows7 using usb

I was using windows7 and installed ubuntu 13.04 which became the only os of my laptop. Now i want to reinstall windows7 again.I am unable to do so. please help


Best practice for a query inside a batch and Mapping

I'm working on a batch which getting a params from another batch in the finish method.  The Params are :    A Map - Map<Sobject,Set<String>> A Set -  Set<String>   I lost the values of my Map on the second run of the execution method - Means - Map.get(Sobject) returned with null although it had values in it.  That happened only within the second to the last run of the batch (from the second till the end of the chunks).  The first chunk getting the values as expected.  I guess it could be because defined a Sobject as a Key in a Map is not Best Practice because Hashing issue - Because the second param that I'm sending to the batch is a Set<String> - And it keeps its values for all the chunks.   Because of this issue, I decided to send a Set<Id> of all the Sobjects from the first batch, and retrieve the records in the second batch with SOQL query. and I wanted to know what are the best practices to do so.  the queryLocatoer in the Start method is needed to go over another Sobject without any related to the Sobject that I sent.  Where can I put this Query? Can I put it inside the Constructor and assign it to a global variable? Inside the Start method before I set the query for the queryLocator? - since it always will be the same results, I don't want to put it on the execute method.  What do you think? Why we have hashing issue when the key of a Map is a Sobject?  Thanks!


I want to really put an emphasis on some central piece of text I'm using in a Beamer slide.  I'm using tikz and overlay to put it, enlarged, on the center of the page, using the following code:  \begin{tikzpicture}[remember picture,overlay]   \node[at=(current page.center)] {     \scalebox{2}{\Huge\texttt{{This is important!}}}   }; \end{tikzpicture}   Can I add a drop shadow to the letter themselves, so they would look even more emphasized?  Is there some other decoration that can be added to the text itself, like a glow, etc.?  Or does PGF ignores node text altogether?  The text should be in typewriter style, so using special fancy fonts is probably not the solution.


How do I get the first element from an IEnumerable in .net?

I often want to grab the first element of an IEnumerable<T> in .net, and I haven't found a nice way to do it.  The best I've come up with is:  foreach(Elem e in enumerable) {   // do something with e   break; }   Yuck!  So, is there a nice way to do this?


So I have the following integral:  $$\int_0^2 \frac{dt}{4+t^2}$$  In order to solve it am I able to say it is equivalent to the following integral?  $$\int_0^2 \frac{1}{4+t^2} dt$$  If not how can I go about solving it. Thanks!


Somewhere I can put thinking problems? If you don't know what I mean by that, an example is . I'm not asking a place to put riddles or math problems, rather to put long problems (that are most words) that can be put in an Computer Science Olympiad for example. Not actually coding, rather logical and algorithmic problems.  I hope you understand what I mean...


Problem printing LaTeX from lua in lualatex

I am having difficulty printing LaTeX from a lua function in a LaTeX document processed with lualatex (version 0.70.2). I have a sample that works (if I remove all newlines from the code) and a case that fails. I don't know why these get different results. Here is the sample that fails:  \documentclass{report} \usepackage{luacode} \begin{document}  \begin{luacode*} tex.sprint([[ \begin{tabular}{ | l | l | p{4.in} | }  \hline  {\bf File} & {\bf Cards} & {\bf Summary} \\ \hline  \end{tabular} ]]) \end{luacode*}   \end{document}   I get an error saying:  ! Misplaced \noalign. \hline ->\noalign               {\ifnum 0=`}\fi \hrule \@height \arrayrulewidth \futurelet... l.22 \end{luacode*}   When I put all of the LaTeX code printed from lua on one line the code works fine:  \documentclass{report} \usepackage{luacode} \begin{document}  \begin{luacode*} tex.sprint([[ \begin{tabular}{ | l | l | p{4.in} | } \hline {\bf File} &{\bf Cards} & {\bf Summary} \\ \hline \end{tabular} ]]) \end{luacode*}   \end{document}   So I have a few question.  First, why does the first example shown above fail? It seems like something I am not aware of is being inserted into the generated LaTeX.  Also is there a way for me to see the actual LaTeX that is generated and processed so that I can debug issues like this better?  Is there a way to tell the lualatex to log the actual LaTeX it tries to process?  Any other suggestions for how to debug a problem like this?


Please provide a mobile-optimized captcha page

When working with the mobile version of one of the mobile sites, my connection got really slow, and (I think this is what) caused Apple.SE to show me a captcha. I'm okay with that, but  I'd like to point out that the mobile site should have a mobile optimized captcha.  With slow internet connections in mind, I suggest to implement a mobile-optimized captcha page.


How do I upgrade from a rather old (17.04) version of Ubuntu to the current version?

I have had a old partition of Ubuntu running 17.04 that I haven't booted to in ages. I finally booted back into it the other day and wanted to know how do I upgrade? The software updater doesn't work anymore. I assume because the software sources are taken down. How do I update the sources? And which one should I update them to to have a safe upgrade? Perhaps I could set my sources to 18.04 first and do that upgrade?  christopher@Chris-Gaming-Linux:~$ sudo apt-get update [sudo] password for christopher:  Ign:1 http://security.ubuntu.com/ubuntu zesty-security InRelease Err:2 http://security.ubuntu.com/ubuntu zesty-security Release   404  Not Found [IP: 91.189.91.38 80] Ign:3 http://us.archive.ubuntu.com/ubuntu zesty InRelease Ign:4 http://us.archive.ubuntu.com/ubuntu zesty-updates InRelease Ign:5 http://us.archive.ubuntu.com/ubuntu zesty-backports InRelease Err:6 http://us.archive.ubuntu.com/ubuntu zesty Release   404  Not Found Err:7 http://us.archive.ubuntu.com/ubuntu zesty-updates Release   404  Not Found Err:8 http://us.archive.ubuntu.com/ubuntu zesty-backports Release   404  Not Found Reading package lists... Done E: The repository 'http://security.ubuntu.com/ubuntu zesty-security Release' does no longer 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://us.archive.ubuntu.com/ubuntu zesty Release' does no longer 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://us.archive.ubuntu.com/ubuntu zesty-updates Release' does no longer 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://us.archive.ubuntu.com/ubuntu zesty-backports Release' does no longer 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 would one solve for x in the following equation:  $x^{x^{x^{x^{\cdots}}}} = 4$  The exponent continues forever... So what is the value of x?  Thank you for helping


What is the correct form: " I can't bear the thought of YOUR going out" or "I can't bear the thought of YOU going out".


I've customized the prompt in my Mac terminal like this:  export PS1="\[\e[31;1m\] \w $ \[\e[0m\] "   This way I get the /working/directory $ in bold red, but I also want to get the command I execute in bold red. Nonetheless, I want the output of the command to be of default color.  Basically I want this:    Any help, please?    EDIT: I tried the code on  but at least for me it is not working. It makes the command bold, but also the command output. And in fact I'm getting an extra ${OFF} tag printed after the command output and even a crazy behaviour when I press up key to see previous executed commands...


I wonder how to edit the following two files, so that I can change the system keyboard layout. It seems they are binary resource files, but I'm not sure.  /System/Library/Keyboard\ Layouts/AppleKeyboardLayouts.bundle/Contents/Resources/AppleKeyboardLayouts-B.dat  /System/Library/Keyboard\ Layouts/AppleKeyboardLayouts.bundle/Contents/Resources/AppleKeyboardLayouts-L.dat   I could use  to create a custom layout, but I would like to know how Ukelele reads the current layouts, and more over whether it is posible to edit the system layout directly.


How to make Top Panel and Dock completely transparent? (Ubuntu 18.04)

I want to make the GNOME top panel and dock completely transparent so that desktop wallpaper is completely visible.  I already created my own theme and added the following css rules. My top panel turned transparent but there is still some kind of gradient from the bottom. In addition I cant get to work the dock transparency. Instead of transparent it gets black.   @import url("/usr/share/gnome-shell/theme/ubuntu.css");    #panel {   background-color: rgba(0,0,0,0); }  #dash {   background-color: rgba(0,0,0,0); }  #dash .placeholder {   background-image: none; }


Why isn't the service layer shape properly spread out?

I created a simple service layer polygon in network analyst (ArcGIS Desktop 10.2) with no hierarchies set in the street network. Now I don't understand why is this polygon created along some particular streets?   Why isn't is properly spread out? For example, why doesn't the polygon cover the areas/streets I have marked in red? Obviously those marked areas are also within 1 km.  The impedance is 1 km and 2 km respectively.   The streets are also well connected individual line elements as you can see the junctions.


How can I determine the OS of the system from within a Lua script?

Ok I need to determine the system's OS from a Lua script, but Lua as such has no API for this, so I use os.getenv() and query enviromental variables. On Windows checking the enviromental variable "OS" gives me the name of the system's OS, but is there some variable that exists on both Windows and most flavors of Unix that can be checked?


Should it be "there was supposed to be donuts" vs "there were supposed to be donuts"?

I'm probably overthinking this, but I can't decide if it should be "was" or "were" in this case. Can someone explain to me which is correct and why? I think part of my problem is that, assuming were/was is the verb, I'm not sure what the subject is. Should it be conjugated to match "donuts"? Thanks.


Complex numbers involve the square root of negative one, and most non-mathematicians find it hard to accept that such a number is meaningful. In contrast, they feel that real numbers have an obvious and intuitive meaning. What's the best way to explain to a non-mathematician that complex numbers are necessary and meaningful, in the same way that real numbers are?  This is not a Platonic question about the reality of mathematics, or whether abstractions are as real as physical entities, but an attempt to bridge a comprehension gap that many people experience when encountering complex numbers for the first time. The wording, although provocative, is deliberately designed to match the way that many people actually ask this question.


Apparently I can't get apt-get, as well as the ubuntu software centre, connect to any repository. I also tried to look for a suitable mirror using the ubuntu software centre (software sources->ubuntu software->download from->other->select best server), but it says it can't find any. My internet connection is OK (I'm writing here using the same pc on the same ubuntu), and there is no proxy.  Any ideas about what's going on?


New terminal with command and continue using it

I would like to open a new terminal and run a command from another terminal. I would like to be able to re-use that terminal after.  I've tried:  xfce4-terminal --hold -x echo "Hello" &   But while --hold does keep the new window open, it's "blocked" and can't be used. Is there a way around this?  (I'd use either Gnome or XFCE terminals)


Is it possible create a not measurable set absence of axiom of choice?

While reading Analysis II- Terence Tao, he writes that almost all set we encounter are measurable (naturally), and if one wants to create non-measurable set, one need to consult the axiom of choice. Immediately, I think that can we create non-measurable set without the axiom of choice?  The question might seem stupid, I ask just out of curiosity.


Given $(G,*)$ a group. Show the function $f: G \to   G$ defined as $f(a)=a^{2}$ is an homomorphism if and only if G is abelian.  My attemp was:  $\to$ suposse $f$ and homomorphism, to show $a*b=b*a$ \begin{align}  f(a*b)=f(a)*f(b) \\  & = a^2*b^2 \\   & = (a*a)*(b*b) \\  & = (b*b)*(a*a) \\   & =f(b)*f(a) \\  \end{align}  I think it is wrong because I used commutative property.  For the last part:  $\leftarrow$ suposse G is abelian, to show $f$ is homomorphism  \begin{align}  f(a)=a^2 \\  & = a*a \\  \end{align}  Can you help me to clarify the proof?


I am currently studying Python at school. I don't understand what the book is trying to explain and my instructor isn't very helpful. The book gives the following example: usr_text = input('Enter a string: ') print()  first_half = usr_text[:len(usr_text)//2] last_half = usr_text[len(usr_text)//2:]  print('The first half of the string is "{}"'.format(first_half)) print('The second half of the string is "{}"'.format(last_half))  I don't understand what [:len(usr_text)//2]  & [len(usr_text)//2:]  does. Would anyone mind explaining what's happening there and why it's used? Thank you!


The set of real numbers contained in the interval (0,1) is countable. Here is my proof.

Here is the interval (0,1). Step 1 : Divide the interval by half. Then we get cut 1/2. Step 2 : Divede the intervals of Step 1 by half. Then we get cuts 1/4, 2/4, 3/4. ................... In this way, we get infinite cuts contained in (0,1). And we can correspond each cut to one of binary number. Like 1/2 -> 0.1      1/4 -> 0.01      3/4 -> 0.11        ...... In this way, the binary numbers in the interval (0,1) are in 1:1 correspondence with the cuts constructed in above manner. And we know the real numbers in (0,1) are in 1:1 correspondence with the binary numbers in the same interval. Thus, the cuts are in 1:1 correspondance with the real numbers. And the number of cuts is countable, because it's the countable sum of countable numbers. Thus, the set of real numbers in the interval (0,1) is countable set. Is it right?


Is there a difference between Clones and Shadow Clones?

In the first episode, Naruto failed the Graduation Test because he couldn't create a proper clone. Mizuki falsely tells Naruto that if he learns a Jutsu from the Forbidden Scroll, he can graduate. As such, Naruto studies, and successfully performs the Shadow Clone Jutsu, with Iruka commenting how Naruto was able to master an advance Jutsu with so many clones.  But what makes the Shadow Clone Jutsu more advanced than the Clone Jutsu that Naruto failed at?


Is two cars colliding at 50mph the same as one car colliding into a wall at 100 mph?

I was watching a youtube video the other day where an economist said that he challenged his physics professor on this question back when he was in school. His professor said each scenario is the same, while he said that they are different, and he said he supplied a proof showing otherwise.  He didn't say whether or not the cars are the same mass, but I assumed they were. To state it more clearly, in the first instance each car is traveling at 50mph in the opposite direction and they collide with each other. In the second scenario, a car travels at 100 mph and crashes into a brick wall. Which one is "worse"?  When I first heard it, I thought, "of course they're the same!" But then I took a step back and thought about it again. It seems like in the first scenario the total energy of the system is the KE of the two cars, or $\frac{1}{2}mv^2 + \frac{1}{2}mv^2 = mv^2$. In the second scenario, it's the KE of the car plus wall, which is $\frac{1}{2}m(2v)^2 + 0 =  2mv^2$. So the car crashing into the wall has to absorb (and dissipate via heat) twice as much energy, so crashing into the wall is in fact worse.  Is this correct?  To clarify, I'm not concerned with the difference between a wall and a car, and I don't think that's what the question is getting at. Imagine instead that in the second scenario, a car is crashing at 100mph into the same car sitting there at 0mph (with it's brakes on of course). First scenario is the same, two of the same cars going 50mph in opposite directions collide. Are those two situations identical?  PS: This scenario is also covered in an  of .


Subject verb agreement with collective nouns

In this sentence, which verb is correct?  (Is/Are) staff given discounts on supplies?