The Properties panel on RHS of default 3D window which is activated with (N) became very small and hard to read. All other active Blender files are fine....but cannot restore/resize to normal settings and too small to read.

I zoomed in / out of one of my UI panels and I can't figure out how to zoom back out/ in to get it normal size.   How can I reset the zoom level of UI panels?


For optimal battery health, should I charge my Mac most of the time, apart from letting it run through a full battery discharge once a month?

My friend told me that I need to disconnect the power cord when the battery is fully charged. Otherwise, I will shorten the life of the battery.  Other people say you should drain it once a month or point out that for long term storage, you should charge it to 50% and then periodically (3 to 6 months) bring it back to 50% and store it again.  I am going to use my laptop at home 90% of the time. So, I plan to have the power cord connected all the time.  I'd prefer to just plugging in my MacBook Pro and letting it be on charge long term and occasionally taking it away from the charger when I'm not at home or my desk.  Are these specific recommendations worth the inconvenience?


I am working an an imitation of a Pac Man game, currently I'm trying to implement an algorithm that searches for a path to a certain goal. The algorithm checks available paths and adds every step to an ArrayList containing int[] named stack. My problem is that every time it has found a new available step and tries to add it to the arraylist using the .add method it replaces all current data with what i am trying to add.  I have tried all kinds of solutions but they won't work (that's also why my code is so messy)  private Position tempPos; private int distanceFromRoot = 0; private int[] toStoreInStack = new int[3]; private int[] tempStore = new int[3]; private ArrayList<int[]> stack = new ArrayList<>();   if (findValidPosition(tempStore[0], tempStore[1]))     {         distanceFromRoot++;         toStoreInStack[0] = tempPos.getX();         toStoreInStack[1] = tempPos.getY();         toStoreInStack[2] = distanceFromRoot;         stack.add(toStoreInStack);         System.out.println(Arrays.toString(stack.get(distanceFromRoot)));         System.out.println(Arrays.toString(stack.get(0)));     }   The print should then show what i just entered and what i initially entered something along the lines of   [1, 2, 1] [1, 2, 1] [1, 3, 1] [1, 2, 1] [1, 4, 1] [1, 2, 1]   but in reality it just prints  [1, 2, 1] [1, 2, 1] [1, 3, 1] [1, 3, 1] [1, 4, 1] [1, 4, 1]   i tested a few different positions in the arraylist and seems to replace all other data with the same that was just entered.

I always thought Java uses pass-by-reference. However, I've seen a couple of blog posts (for example, ) that claim that it isn't (the blog post says that Java uses pass-by-value). I don't think I understand the distinction they're making. What is the explanation?


Let $x, y \in G$, where $G$ is a group, $\operatorname{ord}(x), \operatorname{ord}(y) \in \mathbb{N} < \infty$, and $xy=yx$ (seems like it's very important). I want to prove that there exist integers $k, l \in \mathbb{N}$ such that $\operatorname{ord}(x^ky^l) = \operatorname{lcm}(\operatorname{ord}(x), \operatorname{ord}(y))$. I know these two facts:  If $\operatorname{gcd}(\operatorname{ord}(x), \operatorname{ord}(y)) = 1 \Rightarrow \operatorname{ord}(xy) = \operatorname{ord}(x)\operatorname{ord}(y)$. For $g \in G$ and $n \in \mathbb{N}$, $\operatorname{ord}(g^n) = \frac{\operatorname{ord}(g)}{\operatorname{gcd}(\operatorname{ord}(g), n)}$.  Looks like these two facts can help me, but I have no idea how. And why is $xy=yx$ so important? I tried to consider infinite non-abelian groups (For example $2\times2$ matrices), but I couldn't find any counterexamples. Maybe you can help me.

How can I prove that if $G$ is an Abelian group with elements $a$ and $b$ with orders $m$ and $n$, respectively, then $G$ contains an element whose order is the least common multiple of $m$ and $n$?  It's an exercise from Hungerford's book, but it's not homework. I could not solve it when I take the course on groups and I think it should be easy. There is a hint that says to first prove when $m$ and $n$ are coprimes. I did this part. But I have no idea how to solve the general case.  Thanks.


I have read that you should not store /tmp on a SSD, because the frequent writes will shorten the lifetime of the SSD.  But what about /var/tmp?  Is it reasonable for /var/tmp to be stored on a SSD?  Or should we avoid having /var/tmp stored on a SSD, to avoid killing the SSD prematurely?

I bought an SSD and I am going to set up my desktop system with a completely fresh Linux installation. SSDs are known to be fast, but they have a disadvantage: The number of writes (per block?) is limited. So I am thinking about which data should be located at the SSD and which at the HDD drive. Generally I thought that data that changes frequently should be placed on the HDD and data that doesn't change frequently can be put on the SSD.  Now I read  question, with a similar scenario. In the answers there is written: "SSD drives are ideally suited for swap space..." Why are SSDs ideally suited for swap space? OK, I see high potential for raising the system's performance, but doesn't swap data change frequently and hence there would be many writes on the SSD resulting in a short SSD lifetime?  And what about the /var directory? Doesn't its contents change frequently, too? Wouldn't it be a good idea to put it on the HDD?  Is there any other data that should not be located on an SSD?


I looked through the other questions and didn't really see anything specific to this.  My boss bought a QNAP NAS server for our office and up until now it's been great to use. Up until I needed to start testing out some eCommerce site.  I can't get my server to accept my OpenSSL certificate with *.redefine.dynalias.com  The structure of the workspace is that I have virtual hosts set up so that a directory 'www.site1.com' will be accessed as 'www.site1.com.redefine.dynalias.com'. Simple enough.  , if you look at the information, it states it still is a wrong site, with an unknown identity. What could I possibly be doing wrong? Even adding an exception causes an error that prevents me from testing the eCommerce site.  Any ideas?

We already have a wildcard certificate for *.mycompany.com. Our network has hosts that are only reachable internally. All of them belong to the internal.mycompany.com subdomain. There is a private server with the host name server.internal.mycompany.com on which I deployed our wildcard certificate.  When I visit the web server I get a host name mismatch error. Do I really have to get another wildcard certificate for *.internal.mycompany.com or is there another (free!?) way to use our wildcard certificate for all of our subdomains and its subdomains without getting an error in the browser?


I wanted to email a group of students to check how they are going with their assignment and it occurred to me that "how is everyone going with their assignment" does not seem grammatically correct. Matching a singular subject "everyone" with a plural word "their" seems a bit odd. However, "how is everyone going with his/her assignment" sounds more off.  Thanks heaps! Any comment would be highly appreciated.   Wen

Is there a pronoun I can use as a gender-neutral pronoun when referring back to a singular noun phrase?  Each student should save his questions until the end. Each student should save her questions until the end.


Hi, I wondered what was a good setup for AWS/MongoDB in terms of machines and the sizes of their disks.  Current setup   3 micro machines for the config servers, 1 mongos and arbiters. The 8Gb limit is almost reached. (and I ran the arbiters with --nojournal) per shard : a replica set of 2 machines m1.large with 8Gb for system + 20Gb for data everything is on EBS.   Questions   is 20Gb too big or too small ? Should I go with 100Gb for example ? Am I supposed to inform mongodb about the 20Gb (or other) disk limit ? Do you see anything wrong that I don't see ? Im new to mongodb and aws but Im an ok experienced SWE   Plan of use  My database should allow a 100 qps (mostly writes), and should grow up to 1Tb over the next 3 years. The plan is to add as many shards as needed, more or less manually (with scripts), when we see that more memory is needed on the database.  We will also run a few mapreduce over this and have some scripts that do aggregates with the data over the past 15 minutes, every 15 minutes.  We are a very small company, spending up to a few hundred $ per month on our servers would be ok but we can't go crazy on cash.  We hope that we won't have to manually take care of too many machine failures, manually taking care of things once a month would be fine.  Thanks for telling me what you think about that.  Thomas

This is a  about capacity planning for databases. Related:      I'm looking to create a canonical question of tools and methods of capacity planning for databases. This is intended to be a canonical question. Obviously, the general workflow is:  Put your scenario in place Add monitoring Add traffic Evaluate results Remediate based on results Rinse, repeat until reasonably happy  Please feel free to describe different tools and techniques for different web-servers, frameworks, etc., as well as best-practices.


While installing Ubuntu 18.04 LTS I created swap in hard drive which is leading me hang for heavy applications because I have 8 GB of RAM.

I have a Samsung 960 Pro SSD with Ubuntu 18.04  is it safe to put the swap file on there or would it hurt it in the long run,  I heard some people saying that new SSDs don't suffer from that issue anymore, is this true?


Let $X_1,X_2,...,X_n$ be independent normal distributions with a common variance $\sigma^2$. The usual definition of sample variance is $S^2:=\frac{\Sigma_{i=1}^{n} (X_i-\bar{X})^2}{n-1}$.   I want to show that $E[S^2]=\sigma^2$, i.e. the population variance.  My attempt at proof:  $\frac{n-1}{\sigma^2}E[S^2] = E[\frac{(n-1)S^2}{\sigma^2}] = E[\frac{\Sigma_{i=1}^{n}(X_i-\bar{X})^2}{\sigma^2}]=n$,  This is because for each $i$, $\frac{(X_i-\bar{X})}{\sigma}$ has a $N(0,1)$ distribution, so $\frac{(X_i-\bar{X})^2}{\sigma^2}$ has a Chi-squared distribution, each has an expected value of $1$.  But then $E[S^2]=\frac{n}{n-1}\sigma^2\neq 1$.

If $X_1,...,X_n$ are iid, what is the mean of the following variable:?  $ \sum (X_i - \bar{X})^2$  I know the answer is $\sigma^2(n-1)$, but how is this calculated in general? If I expand, I get the variables squared, and that turns quite ugly. What's the trick here?


I'm creating a simple level-up system and I'm looking to base the stats gain on curves so I can tweak them easier, I know it's a math function, but I have no idea what to search for.    I need to create this curve and get the value every x increment.    the engine I'm using is Ren'py and the language python. if you can tell me the terms to search for, I might be able to find something on the topic.

Problem  Player obtains 5 points per level up to level 80 with a maximum of 400. There are 5 stats to be distributed to and no maximum limit to how much you can add to a stat.   Strength Endurance Intelligence Agility Luck - Grants critical chance and critical damage   I would like to implement a diminishing return equation on let's say Luck. For critical chance, I do not wish for the player to be able to hit 100% critical chance.  There will be a ceiling to which it will reach as the increasingly decreasing growth reaches towards 0 per point added.  Example if the maximum critical chance I want the player to have is 40%, Each point into luck will increase critical chance lesser and lesser, until the critical chance reaches around 40%. By which 1 luck will give a very very miniscule amount.  Any solutions? Thank you and your help is greatly appreciated!


I want to prove that $2^{n+2} +3^{2n+1}$ is divisible by $7$ for all $n \in \mathbb{N}$ using proof by induction.  Attempt  Prove true for $n = 1$  $2^{1+2} + 3^{2(1) +1} = 35$  35 is divisible by 7 so true for $n =1$  Induction step: Assume true for $n = k$ and prove true for $n = k+1$  $n = k$  $2^{k+2} + 3^{2k +1} = 2^k \cdot 2^2 + 3^{2k} \cdot 3^1 = (4) 2^k + (3) 3^{2k}$  $n = k+1$  $2^{k+3} +3^{2k+3} = (8) 2^k + (27) 3^{2k}$  Thoughts:  I know I need to use the expression for $n = k$ to prove that it is true for $n = k+1$ but I am not sure where to start. I think that using modular arithmetic would be too complex.  Any ideas would be greatly appreciated!  Update  Thanks for all of the useful answers/suggestions. I understand the approach to take now!

I want to prove that $2^{n+2}+3^{2n+1}$ is divisible by 7 using induction. My first step is replace $n$ with $1$.   $2^{1+2}+3^{2(1)+1}$ $2^3+3^3$ $8+27$ $35 = 7\times 5$   The next step is assume that $2^{n+2}+3^{2n+1}$ is divisible by 7. And the last step is to prove that $2^{(n+1)+2}+3^{2(n+1)+1}$.   $2^{(n+1)+2}+3^{2(n+1)+1}$ $2^{n+3}+3^{2n+3}$ I got stuck here.   How can I prove it using induction?


Given an equation $\frac{a}{b+c} + \frac{b}{a+c} + \frac{c}{a+b} = 4$, how to solve this problem in positive integers?  I've tried to assume $a\le b\le c$ and that $b=a+k_1, c=a+k_2$. So the equation become  $$\frac{a}{2a+k_1+k_2} + \frac{a+k_1}{2a+k_2} + \frac{a+k_2}{2a+k_1} = 4$$  or equivalently,  $$\frac{1}{2+\frac{k_1}{a}+\frac{k_2}{a}} + \frac{1+\frac{k_1}{a}}{2+\frac{k_2}{a}} + \frac{1+\frac{k_2}{a}}{2+\frac{k_1}{a}} = 4$$  Now let $x= \frac{k_1}{a}, y= \frac{k_2}{a}$, it is sufficient to find all positive rational solutions of $\frac{1}{2+x+y} + \frac{1+x}{2+y} + \frac{1+y}{2+x} = 4$.

If I had a very shallow question, then I am sorry. $x,y,z\in\mathbb{N}^{+}$ and$$\frac{x}{y+z}+\frac{y}{x+z}+\frac{z}{y+x}=4$$find $x,y,z$.  I try with AM-GM, just get$$ \frac{x}{y+z}+\frac{y}{x+z}+\frac{z}{y+x}\geq\frac{3}{2}$$  This means that the equation must have a real solution, but can not be sure there is an integer solution.  Let: $x=ay=abz$, then the equation becomes:$$\frac{ab}{a+b}+\frac{b}{ab+1}+\frac{1}{a^2+ab}=4$$  Which makes the problem become non-homogeneous, and seems to become more difficult. I have no more ideas. Could anyone help me? Thanks a lot.


For any numbers a, b and and an even natural number n that the equation  $$x^n+ax+b=0$$ has at most 2 solutions.  My attempt: $f'(x)=nx^{n-1}+a$, $n \text{ is even} \implies n-1 \text{ is odd} \implies f'(x) \text{ is strictly increasing}$.   Now I want to show that $f'(x)$ has exactly 1 root, so that I can apply Rolle's theorem to get the desired result. I think I need to use IVT, but which endpoints of the interval (c,d) should I take?  P.S. Is this still true if n is odd?

For any real numbers $a$ and $b$ and even natural number $n$, Show $x^n+ax+b=0$ has most two solutions for all $x$ in $\mathbb{R}$.   let $f(x)=x^n+ax+b$. Set $f(x)$ and $a$ be $0$, then we have $x^n+b=0$. So $x=\pm b^{1/n}$. $f$ has two solutions. To yeld a contradiction. Now assume that $f$ has more than two solutions. As $f$ is a polynomial on $\mathbb{R}$, it is differentiable on $\mathbb{R}$; thus $f'(x)=nx^{n-1}+a$. Set $f'(x)=0$, then $0=nx^{n-1}+a\Rightarrow x=\left(\frac{-a}{n}\right)^{1/(n-1)}$. At $x=\left(\frac{-a}{n}\right)^{1/(n-1)}$, $f(\left(\frac{-a}{n}\right)^{1/(n-1)})$ is the only extreme value of $f$ which contradicts with $f$ has more than two solutions.    Can someone check this solution? I am not sure right or not. If not right, please give me a hint or suggestion. Thanks


If a piece of matter is released along the tunnel extended between one end to the opposite end through the diameter of the earth, what will be the nature of motion?

...And you jumped in.  What would happen when you got to the middle of the Earth? Would you gradually slow down, until you got to the middle and once you were in middle would every direction feel like it was up?


I am approaching the 15GB limit of Google's free storage for Gmail and Drive. I have a lot of screenshots that I have sent with Gmail. I want to free up space but I don't want to delete any emails. Given that Google Photos will start counting newly added photos and videos towards this common Google storage quota, but not for the items uploaded prior to 2021-06-01, I want to move the images embedded within my Gmail messages to Google Photos and leave a link to the photo in Google Photos in the email. I have searched for quite long for a solution to automate this but so far I haven't found any solution. How to migrate embedded/attached images in Gmail to Google Photos and leave a link in the email to the moved location? Ideally I would love to see images in the emails as they are now by using <img src="https://photos.app.goo.gl/someRandomString"/> in the emails.

Is there a more intuitive way to add an attachment from GMail (either standard or Inbox) to Google Photos than saving it into the Google Photos folder in Google Drive?


I want to reduce spacing b/w labels and figures. But after the label to be very close to subfigues but with the following setting I can't reduce it less than 1cm.  \documentclass[aps,twocolumn,amsmath,amssymb,]{revtex4} \usepackage{graphicx} \usepackage{subfig} \usepackage{floatrow} %\floatsetup[figure]{style=plain,subcapbesideposition=top} \setlength{\labelsep}{1cm} \begin{document} \begin{figure*}[!htb]      \sidesubfloat[]{\includegraphics[width=\textwidth]{Fig1.png}}      \sidesubfloat[]{\includegraphics[width=\textwidth]{Fig2.png}}      \sidesubfloat[]{\includegraphics[width=\textwidth]{Fig3.png}}     \sidesubfloat[]{\includegraphics[width=\textwidth]{Fig4.png}} \end{figure*} \end{document}

I'm usin minipage to plot subfigures. I used figuresize (8 by 6) in matplotlib for all subfigures, But when I compile then in Latex their boudries don't appear at the same position (e.g top right and bottom right figure's boundry should start from same place). I'm not sure if it is due to spacing or anything else. I tried to use centering for all subfigures but it didn't work.How can I fix this issue?  `\begin{figure*}[!htb]     \begin{minipage}{\columnwidth}         \centering         \includegraphics[width=\textwidth]{Fig14.png}     \end{minipage}%      \begin{minipage}{\columnwidth}         \centering         \includegraphics[width=\textwidth]{Fig2.png}     \end{minipage}     \begin{minipage}{\columnwidth}         \centering         \includegraphics[width=\textwidth]{Fig3.png}     \end{minipage}%     \begin{minipage}{\columnwidth}         \centering         \includegraphics[width=\textwidth]{Fig4.png}     \end{minipage}`


I tried installing Ubuntu (successfully) on my Windows 8 machine so i could develop in c and it worked decently for a while. I did this without wubi. However, I later got a virtual machine to run Ubuntu and didn't need the full dual boot install anymore. Following a guide I found online (I dont remember where), I simply deleted the 2 Ubuntu partitions (1 was a main partition and the other was a swap area). When I rebooted my computer I was greeted with a grub rescue prompt. I have tried using  both Ubuntu's boot-repair (but only on recommended settings since I am kind of afraid to mess around with options I don't know about) and boot repair from my Windows install disk (both the automated repair and the bootrec command line options). The linux boot repair said it completed successfully but gave me a warning midway through which said something like "EFI detected. check the options." The both Windows boot fixes said they completed successfully. I have also tried using supergrub to fix my bootloader. All of these wind up back at the grub rescue prompt.   Things that make this complicated: I have a lenovo y580 laptop which comes with 2 disks: a 30gb ssd (I was told this was for booting and caching) and a 750 gb hdd. The computer also came with Windows 7. I have since replaced the hdd with a 250gb ssd. and upgraded to Windows 8. As a result I am not entirely sure which drive Windows 8 is stored on. can anyone help me fix my boot?  UPDATE: after trying to run Windows bootrec commands again bootrec /fixmbr completes sucessfully, but bootrec /fixboot fails because "Element not found."

I have absolutely no experience with Linux, and I desperately need to get my computer back up and running again with Windows.  How do I remove Ubuntu and reinstall Windows?    Editor's note: many of the answers are about removing Ubuntu from dual-boot but keeping Windows (which is a bit complicated), while other answers are about removing Ubuntu from single-boot (which is easy: basically just format the disk while installing Windows). The question as written is ambiguous between dual-boot or single-boot.


I have the following code:  \documentclass{article} \usepackage[utf8]{inputenc} \usepackage{caption} \usepackage{graphicx}  \begin{document} \listoffigures  \begin{figure}   \caption{Example picture}   \centering     \includegraphics[width=0.5\textwidth]{example-image-b}  \end{figure}   \end{document}   Is it possible to get Figure prefix in list of figures like shown in this image:    Thank you

I have a problem when trying to add the word "Figure" before the actual number in the list of figures. I guess it will be the same for all languages, since the langauge setting will make it in my language automatically. But what I have so far is only the number like the upper line, and it should be like the second line (which was poorly made with paint, just in case you wonder).    Here is the code I am using for figures so far:  \begin{figure}[ht] \centering \includegraphics[width=1.0\textwidth]{imageName.png} \caption[CaptionText]{CaptionText\footnotemark.} \end{figure} \footnotetext{CaptionTextn. Available under \url{www.nowhere.com}, seen on Date.}


I am just wondering if this is possible. I have almost 50 html files in my project and have almost common include files like bootstrap, angular, jquery ui etc.   Can I write a common file say include.html that is similar to say import java.util.*. my include.html will contain 3-4 entries of my common JS and CSS files and then I can include that file in my each html page?  like say user.html:  <!DOCTYPE html> <head> import include.html (or any other appropriate name or file format) </head>....   I do not want common header and footer files I want to include required files in one shot by including one html file.

Is there a decent way with static HTML/XHTML to create common header/footer files to be displayed on each page of a site? I know you can obviously do this with PHP or server side directives, but is there any way of doing this with absolutely no dependencies on the server stitching everything together for you?  Edit: All very good answers and was what I expected.  HTML is static, period.  No real way to change that without something running server side or client side.  I've found that Server Side Includes seem to be my best option as they are very simple and don't require scripting.


I have a small doubt. Is $\sqrt{x^2}= |x|$ true? For, put $x=-1\implies x^2=1$. Now, $\sqrt 1=\pm 1$, whereas $|1|=+1$ only. $x\in\mathbb{R}$ P.S. This doubt came @Daniel's answer from  post. To quote-  The problem appears when you take square roots, since it is not still true that $\sqrt{(-1)^2}=-1$, in fact, $\sqrt{x^2}= |x|$ so in this case $\sqrt{(-1)^2}=|-1|=1$, which is not equal to $x-2$ when $x=1$.

Lets say I have a function defined as $f(x) = \sqrt {x^2}$. Common knowledge of square roots tells you to simplify to $f(x) = x$ (we'll call that $g(x)$) which may be the same problem, but it isn't the same equation. For example, say I put $-1$ into them:  $\begin{align} f(x) &= \sqrt {x^2} \\ f(-1) &= \sqrt {(-1)^2} \\ f(-1) &= \sqrt {1} \\ f(-1) &= 1 \end{align}$  $\begin{align} g(x) &= x \\ g(-1) &= -1 \end{align}$  thereby, we conclude that $f(x)$ and $g(x)$ do not produce the same results even though they are mathematically the same. This is also shown when we try to graph the functions:  :    :    :    From this, we can see that given $f(x) = \sqrt {x^2}$, when simplified is not the same as $f(x) = x$. So, is there any way to prove that $y = \sqrt {x^2}$ is not the same as $y = x$ for negative values, but is infact the same as $y = \mid x \mid$?


I'm wondering if someone can help: I'm trying to add Drupal Commerce into an existing Drupal site, so I've followed the steps  and managed to install all modules without problems.  The issue I'm having is when I view a product I've added. Please note that I've added the product type. I can also add the node, but every time I try to view it I get this error (in the reports/error):     EntityMetadataWrapperException: Unknown data property   commerce_product. in EntityStructureWrapper->getPropertyInfo() (line   336 of   /my/local/server/php/mysite/sites/all/modules/entity/includes/entity.wrapper.inc).   I did follow all the steps in the tutorial. When I tried to view the product like in the video I get the error.  Any ideas?

I have managed to create a product type and import my product data, so I now have a list of products.  then i follow ryan szrama instruction   After that i get this error. EntityMetadataWrapperException: Unknown data property commerce_product. in EntityStructureWrapper->getPropertyInfo() (line 339 of C:\xampp\htdocs\drupal7\modules\entity\includes\entity.wrapper.inc).  what i should do??


I have this:  local v="${name-$tag}"  # default is name, tag is backup   except it doesn't work if name is empty. So the long-way to do this would be:  local v="$name";  if [[ -z "$v" ]]; then    v = "$tag" fi   is there a shorthand way to do this?

I found this line in a korn shell script:  var=${var:-/temp}   I am able to figure it out what it is doing   $ var=/data $ var=${var:-/temp} $ echo $var /data $ var= $ echo $var  $ var=${var:-/temp} $ echo $var /temp   Does it have advantage over checking the value and then assigning?


so I did some stuff, and made a character. And then I had to go so I saved it and turned off my computer. The next day I woke up and then I opened the file and saw it looks like this          I did not do anything to make it purple when I was saving it. I am using blender 2.77

I made a character, and its one of my first times texturing, and I saved my character into a new folder, and when I came back to the model ALL the textures were pink, I used to know what to do, but I stopped texturing, how do I bring my textures back?


In most languages, gender plays a much more important role than in English. Nevertheless, it is possible to refer to a noun using its gender.     The ship was launched on 4 October 1853. Tayleur left Liverpool on 19 January 1854, on her maiden voyage.   How does one know that "ship" is feminine? Are there masculine nouns?

I read the following claim concerning pronouns referring to inanimate objects:      Anything that is meant to contain you, protect you or provide you with something beneficial is [often referred to as] a she; anything that is a perceived threat is a he. That's why cars, boats and some countries are she.    Is this really the case, or is it just a subjective claim? (According to the  using he/she for inanimate objects is not recommended and it should be used instead.) Is there a 'rule' for determining whether to use he, she or it based on the impression one would like to express? (I only know the 'rule' for animals: In the case where you know their gender and they are important to you, you refer to them using he/she. E.g. A dog attacked me in the street. It bit me. versus This is my dog Roger. He is 7 years old.) Have these practices changed over time?   Note 1: There is already a similar question (), but that considers only the feminine case and none of the answers offers an objective discussion of the matter.  Note 2: My native language is Czech, where the gender of the pronoun is based only on the grammatical gender of the noun. E.g. a cat (kočka) is always she, a dog (pes) is always he, a boat (loď) is always she and a car (auto) is always it.


I am trying to draw a very simple network diagram. My code:       \begin{tikzpicture}     \node[draw, shape=circle] (v0) at (0,0) {$v_0$};     \node[draw, shape=circle] (v1) at (1,0) {$v_1$};     \node[rectangle,minimum width=6em,draw] (v3) at (0.5,-1) {$v_3$};     \draw [thick] (v0) -- (v1)     (v0) -- (v3)     (v1) -- (v3);     \end{tikzpicture}   This produces the following figure:   I want the lines from the upper two nodes to go straight down towards the edge of the rectangle. Is there a simple way to do this?

When drawing a line between two nodes in TikZ, you can specify the anchors on the beginning and end nodes in order to control how the line is drawn.  I would like to specify the anchor on the beginning node, and the angle at which the line is drawn, and let TikZ figure out where it will intercept the end node.  The usual use case is when I'm connecting to a "big node" and I would like the lines to be vertical.  I can cheat by placing a coordinate behind the big node, drawing a line to the coordinate instead, and then drawing the big node so that it covers things up.  However this won't work if I need to put an arrow on the end.  I could try to calculate the intercept coordinate on the edge of the big node manually, but that seems against the TikZ spirit.  |- doesn't work in this case.  \documentclass[10pt]{minimal} \usepackage[active,tightpage,pdftex]{preview} \usepackage{tikz}  \begin{document} \begin{preview}  \tikzstyle{RectObject}=[rectangle,fill=white,draw,line width=0.5mm] \tikzstyle{line}=[draw] \tikzstyle{arrow}=[draw, -latex]   \begin{tikzpicture}   %%%%%%%%%%%%%%%%%%%%%%%%   %%  LEFT SIDE   %%%%%%%%%%%%%%%%%%%%%%%%   \draw (1,0) node[RectObject] (Small1A) {A};   \draw (3,0) node[RectObject] (Small1B) {B};   \coordinate (Cheat1A) at (1,2);   \coordinate (Cheat1B) at (3,2);   \path [line] (Small1A.north) -- (Cheat1A);   \path [line] (Small1B.north) -- (Cheat1B);    % need to draw Big Node last to cover up our cheating   \draw (2,2) node[RectObject, inner xsep=1cm] (Big1) {Big Node};    \draw (2,4) node[text width=4cm] (text1) {L: Cheating to control line orientation. Arrows would be hard.};    %%%%%%%%%%%%%%%%%%%%%%%%   %%  RIGHT SIDE   %%%%%%%%%%%%%%%%%%%%%%%%   \draw (7,2) node[RectObject, inner xsep=1cm] (Big2) {Big Node};   \draw (6,0) node[RectObject] (Small2A) {A};   \draw (8,0) node[RectObject] (Small2B) {B};   \path [arrow] (Small2A) -- (Big2);   \path [arrow] (Small2B) -- (Big2);    \draw (7,4) node[text width=4cm] (text2) {R: No cheating. Arrows easy. Can't control line orientation.}; \end{tikzpicture} \end{preview} \end{document}   Here's a side-by-side example of "cheating", which shows what I want to be able to do, and "not cheating", which does not do what I want.    The left side of this example shows what I want to be able to do, except I want to do it without cheating, and I'd like to put arrows on the end of the lines.


In Ubuntu 12.04 I had 3 choices of displaying my folders but now I have upgraded to 14.04 and there are only 2 choices to display my folders.  I don't like 'icon' view and I don't like 'list' where one folder is on top of the other. I like the folders to fill the whole window, on top of each other but also to the sides just like I had it in 12.04.  Is there anything I can do to get my preferrd folder view back?? Thanks

Ubuntu 13.04 have fully absent compact mode. Nautilus allows only icon view and list view.   List view isn't the same as compact mode - well, it's easy to switch off unneeded columns, but what about multicolumn files display?   Is it possible to return habitual compact mode back?


Trying to understand what it is in java.  method? Thank you   static {     String xxx;     try {         xxx = new File(".").getCanonicalPath();     } catch (final IOException e) {         e.printStackTrace();        xxx = ".";     }

My question is about one particular usage of static keyword. It is possible to use static keyword to cover a code block within a class which does not belong to any function. For example following code compiles:  public class Test {     private static final int a;         static {         a = 5;         doSomething(a);     }     private static int doSomething(int x) {         return (x+5);     } }   If you remove the static keyword it complains because the variable a is final. However it is possible to remove both final and static keywords and make it compile.   It is confusing for me in both ways. How am I supposed to have a code section that does not belong to any method? How is it possible to invoke it? In general, what is the purpose of this usage? Or better, where can I find documentation about this?


In , it says:  Stack Exchange is a fast-growing network of 112 question and answer sites on diverse topics from software programming to cooking to photography and gaming. We build libraries of high-quality questions and answers, focused on the most important topics in each area of expertise  Emphasis is mine, note the "high quality". Now, have a look in the Hot Network Questions, visible in the front page of every Stack Exchange site:    That's not high quality. For the occasional visitor or 99.999% of Stack Exchange users, this is useless nonsense. Only going to the the  will reveal:  Note: This is a code-trolling question. Please do not take the question and/or answers seriously.  OK, let them have a party but I don't want it to overflow to the whole network.  () Can Programming Puzzles & Code Golf site be excluded from the Hot Network Questions list until this party is over? Edit: and they even invaded this very question!!1    :D

Some sites appear far more often in the hot questions list than other sites. I don't have any hard data on that, as that kind of data is just not publicly available, but I'm pretty sure my subjective impression on that is reasonably accurate.  Those sites don't appear more often because they are inherently more interesting, but because they have certain voting and answering patterns that favor them in the hot questions algorithm. I would argue that the goal of the hot questions list is to present questions from a large variety of SE sites to the whole network, and to show possibly interesting questions to users that would not have found them otherwise.   To achieve this goal, the spots in the hot questions list should be distributed among all SE sites. The algorithm should try to get a good sampling of all sites, and it should try to normalize the results for varying voting behaviour. At the moment, sites that intrinsically get more votes and more answers per question seem favored in the algorithm.  So I think one part of the algorithm should try to identify questions that get an unusally high amount of votes and views for that site, and give the smaller sites a chance this way.  I'm not sure on how exactly this weighting should be done, as a complete normalization would likely not work across the huge difference in scale for all the SE sites.  As a specific example that the current algorithm is broken I'll present . I don't think any site should occupy a third of the whole list.   Here's another instance where one site is overrepresented at the top of the list:


It is rather straightforward to prove that the only continuous Ring homomorphism from $\mathbb{R}$ onto itself is the identity, as its restriction to rational numbers is the identity.  I wonder if that still holds if one gives up on the continuity hypothesis? In other words, are all Ring endomorphisms on $\mathbb{R}$ continuous?  My intuition would be no, because Ring axioms seem to put loose enough constraint on transcendental numbers. Yet I haven't been able to find a construction for a non-continuous endomorphism.  Technical precision: the definition of Ring homomorphism meant in this question is 1-preserving.

Is an automorphism of the field of real numbers $\mathbb{R}$ the identity map? If yes, how can we prove it?  Remark An automorphism of $\mathbb{R}$ may not be continuous.


I need to translate the following sentence:  Whenever the alarm sounds the fan must be on and the building empty  into a logical proposition.  So I defined variable as follow:  $p$ = "The alarm sounds" $q$ = "The fan is on" $r$ = "The building is empty"  The answer: $p \to (q ∧ r).$   I'm confused by this question because if the alarm does not sound and the fan is not on and the building is not empty then by implication doesn't this mean the statement is true?

I am studying entailment in classical first-order logic.  The Truth Table we have been presented with for the statement $(p \Rightarrow q)\;$ (a.k.a. '$p$ implies $q$') is: $$\begin{array}{|c|c|c|} \hline p&q&p\Rightarrow q\\ \hline T&T&T\\ T&F&F\\ F&T&T\\ F&F&T\\\hline \end{array}$$  I 'get' lines 1, 2, and 3, but I do not understand line 4.      Why is the statement $(p \Rightarrow q)$ True if both p and q are False?  We have also been told that $(p \Rightarrow q)$ is logically equivalent to $(~p || q)$ (that is $\lnot p \lor q$).  Stemming from my lack of understanding of line 4 of the Truth Table, I do not understand why this equivalence is accurate.       Administrative note. You may experience being directed here even though your question was actually about line 3 of the truth table instead. In that case, see the companion question  And even if your original worry was about line 4, it might be useful to skim the other question anyway; many of the answers to either question attempt to explain both lines.


I created an animated outer glow around a shape like shown below:    But when I save it the outer glow shape changes to dotted instead of clear glow.

I took the loaders from  then exported them with the help of the included action to a GIF. But I have some white pixels around the loader which are really annoying when displayed on a dark background. You can see it here, in a frame I extracted from the gif:    How can I prevent those white pixels and maintain the transparent background?


I have a clean install of PostGIS 2.1 in Postgres 9.3 on Ubuntu, using apt-get and postgres extensions.   Ran the data loading scripts from .   normalize_address works well, but geocode returns no result.    Interestingly, reverse_geocode is able to find the state, but no finer detailed information.      SELECT pprint_addy(r.addy) As st1, pprint_addy(r.addy[2]) As st2,    pprint_addy(r.addy[3]) As st3, array_to_string(r.street, ',') As   cross_str FROM reverse_geocode(ST_GeomFromText('POINT(-71.06941   42.34225)',4269)) As r;   returns:     st1   st2 st3 cross_str      MA               Is this a data loading issue or a software install issue?

I am trying to install the tiger geocoder for postGIS. I am using the 2.1 version of postGIS on Windows 7. I am using  to do so.  I am confused by what they mean be edit the paths in the declare_sect column to those that fit your pg, unzip,shp2pgsql, psql, etc path locations.   Here's the code that I am using to do this.  INSERT INTO tiger.loader_platform(os, declare_sect, pgbin, wget, unzip_command, psql, path_sep,             loader, environ_set_command, county_process_command) SELECT 'ravimehta', declare_sect, pgbin, wget, unzip_command, psql, path_sep,         loader, environ_set_command, county_process_command   FROM tiger.loader_platform   WHERE os = 'windows';   @RyanDalton - I tried to do what you suggested. However, I got the following error.      ERROR:  unrecognized configuration parameter "unziptool." I'm not sure   what I am doing wrong.   Fixed problem by using:  UPDATE tiger.loader_platform SET unzip_command = 'C:\Program Files\7-Zip\7z.exe' WHERE os = 'ravim';


Let $A$ be a $2×2$ matrix and $n$ be an integer exceeding $2$. Show that $A^n=0$ if and only if $A^2=0$ where $0$ denotes null matrix of second order.   Proving the 'if part' is easy.  Given, $A^2=0$  Then, pre-multiplying(or post-multiplying) both sides by $A$ for $n-2$ times consecutively, we get  $A^n=0$.  But I cannot prove the 'only if' part, i.e., given $A^n=0$, how can I show that $A^2=0$?   Please anyone help me solve it. Thanks in advance.

I have problems to show that if $A$ is a $2 \times 2$ matrix and if there exists some positive integer such that $A^{n}=0$ then $A^{2}=0$. I only showed that $A$ is a singular matrix but nothing else. Thanks any help will be appreciated.


In the Star Wars universe, time is measured by using "BBY": before battle of Yavin... however, seeings as there was a lot of history before that, including but not limited to:   The Old Republic The New Republic (prequels) The First Galactic Empire- & the events of a New Hope incl. battle of  Yavin.   How was time measured in that (thousands of years) time period before the battle of Yavin?

Much like we use B.C.E and A.D, in the Star Wars universe they use B.B.Y and A.B.Y, standing for Before Battle of Yavin and After Battle of Yavin respectively.  But what date system had the galaxy used before the events of Episode 4?


OK, so I know that other people asked exactly the same... but I just moved from Nouveau to Nvidia using , and the new drivers are really, really, really slow. How can I remove Nvidia drivers and recover the open ones?

I always seem to have grief with Nvidia drivers and have often had to re-install Ubuntu: is there a better way to remove them? When I first installed the drivers, the display came up on 640 by 480.  I managed to set 2 screens to 1024 by 780 which was usable, but then Ubuntu recommended installing proprietary drivers (nvidia-current-updates 295.40-ubuntu1). After doing this and re-booting it shows LAPTOP and offers only 640 by 480 on a single screen.   Is there any way to revert to the original driver? Is there any way to find out if the new drivers work before installing them? - For years I have been hoping that it would be all fixed in the latest release… I always seem to fall for this!


I have a part of a bigger program here:  from random import randint  def computerChooses():     import random     choices = ["rock", "paper", "scissors"]     computerChoice = choices[randint(0,2)]     def whoWins():     if computerChoice == "rock":                 print("DO THIS")     elif computerChoice == "paper":                 print("DO THIS")     elif computerChoice == "scissors":                 print("DO THIS")  computerChooses() whoWins()   I always end up with:  NameError: name 'computerChoice' is not defined   (even though I believe it is!)  This, the error message states, is for line 20, and line 12.  What did  I do wrong and where, specifically?  Thanks, Khy

What exactly are the Python scoping rules?  If I have some code:  code1 class Foo:    code2    def spam.....       code3       for code4..:        code5        x()   Where is x found?  Some possible choices include the list below:   In the enclosing source file In the class namespace In the function definition In the for loop index variable Inside the for loop   Also there is the context during execution, when the function spam is passed somewhere else. And maybe  pass a bit differently?  There must be a simple reference or algorithm somewhere.  It's a confusing world for intermediate Python programmers.


I'm trying to install Ubuntu 18.04 on my Seagate 1 TB (external hard drive). I created one partition for my files leaving about 100 GB unallocated for Ubuntu's installation. I followed steps in this tutorial (in the link below) used to install Ubuntu    except that I set the boot loader to my external hard drive. Everything went so well but whenever I restart my computer and choose to boot from external HDD, I get unknown file system error  Update  Solutions suggested in the AskUbuntu community are all about fixing grub and it seems not working for me since it based on locating root partition, In my case I tried every partition listed all of them gave "error: unknown filesystem "    Here is the method i used  ls ls (hd0,msdos6)/ set root=(hd0,msdos6) ls / set prefix=(hd0,msdos6)/boot/grub insmod /boot/grub/linux.mod normal   I spend too much time trying to install different distributions of Linux such as Centos but I got the same error. I think rather than fixing grub I need to know what causes this issue in the first place. Is there something wrong with installation, or something else?  How do I find out?  Update 2  I tried Boot-Repair ISO to fix boot issue and report says the following:  The boot files of [Ubuntu 18.04.3 LTS] are far from the start of the disk.  Your BIOS may not detect them. You may want to retry after creating a /boot  partition (EXT4, >200MB, start of the disk). This can be performed via tools  such as gParted. Then select this partition via the [Separate /boot  partition:] option of [Boot Repair]   is that means i need to create /boot just before root partition or at the start of the entire hard disk   The last update   At last, Finally it works  Problem was in bios (can't detect boot files), boot-repair ISO report suggested adding /root partion at the start of hard disk     the most important remark as the help article says boot partition must be located inside the first 100 Gb of the disk     - Reduce one of the first partitions of the disk in order to create 1GB    (=1000MiB) of free space at the start of the disk where Ubuntu is    installed. This free space must be located inside the first 100GB of the    disk (its end must not be located at more than 100GB from the start of the    disk).   Thanks for all of you guys. I really appreciated your help, I hope AskUbuntu won't delete this question because as far i know it can't be a duplicate of this

OS: Windows 7. I want install Linux Ubuntu on portable external Hard Drive USB 2.0. I read a variety of methods, but I'm confused by contradictory advices and methods. Actually, installing Ubuntu on anything other than clean PC looks much more complicated than installing Windows. I need to have Ubuntu package + Python 2.7 + C compiler installed. My external hard drive is partially filled, I need to keep all files.   Will Ubuntu run entirely on external hardrive, without writing anythinhg to Windows system folders and to registry?  Can anyone post detailed guide how install Ubuntu on external hard drive?


So I recently came across this problem:  $\large{x^{3}+ (x+1)^{3}+\cdots\cdots+(x+15)^{3}=y^{3}}$  Find how many ordered pairs for $\large{(x,y)}$ satisfy the above equation. Both $x,y$ are positive integers.  I can do it using computer program but this problem was supposed to be solved by hand and I have no idea how. How can I do it?  EDIT: The other question doesn't have any answer either.

Find all pairs of integers $(x, y)$ such that    $$x^3+(x+1)^3+ \dots + (x+15)^3=y^3$$   What I have tried so far:  The coefficient of $x^3$ is $16$ in the left hand side. It is not useful then to trying bound LHS between, for example, $(ax+b)^3$ and $(ax+c)^3$ and then say that $ax+b<y<ax+c$.   I also tried to use modulo a prime. But it seems unlikely to bound variables this way.  EDIT : Though, it can be factored as $(2x+15)(x^2+15x+120)=(y/2)^3$. LSH factors are almost co-prime and we can say that $x^2+15x+120=3z^3$ or $x^2+15x+120=5z^3$. These are still too difficult to solve!  Any ideas?


According to :     Downvoting should be reserved for extreme cases. It's not meant as a   substitute for communication and editing.   I happen to take this seriously, and always make sure to offer an explanation with every downvote I dish out. By the same token it bothers me quite a bit when I get an anonymous, no-explanation downvote on a question I've carefully crafted. While I think it's more than fair to ask for an explanation, I usually get heat for it- the prevailing attitude seems to be that questioning a downvote is "noise", "pointless", and generally bad form.   I would prefer the system required a comment on every downvote- it would be more constructive than the current "you know what you did" approach. But seeing as how we're relying on ettiquete, is asking for an explanation off limits?  P.S. I'm ready for the rain of ironic downvotes- I'm taking this for the team...

Note: If you're looking for a simple explanation as to why comments aren't required on downvotes, see .   I used to get "upset" (though that is too strong a term) when I got downvoted without comment. If my answer isn't good enough then I'd like to know why. Not only does it improve the answer for the OP but it improves my knowledge too.  Where the down-vote has been explained I've found it useful & it has improved my answer, or forced me to delete the answer if it was totally wrong.  So is there any way we can encourage people to leave a comment? Perhaps they don't lose rep if they explain their down-vote?  I must admit though that I haven't always explained my down-vote either so you could call me a hypocrite. I've also grown a thicker skin over the months of using SO (it seems to have come with the higher rep score ;-)), so I'm less bothered about this now.


I am new, just installed Ubuntu and trying to see the output of commands. I can't open/don't know how to open a terminal window.

What is a terminal? How do I open a terminal window? How do I use the terminal?


I think, I got an error in this part, but I don't know to repair it. The result of error is   Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException     at bismillahpata.View.hitungHPP1.selanjutnyaActionPerformed(hitungHPP1.java:381)     at bismillahpata.View.hitungHPP1.access$800(hitungHPP1.java:28)     at bismillahpata.View.hitungHPP1$9.actionPerformed(hitungHPP1.java:330)     at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)     at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)     at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)     at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)     at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)     at java.awt.Component.processMouseEvent(Component.java:6505)     at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)     at java.awt.Component.processEvent(Component.java:6270)     at java.awt.Container.processEvent(Container.java:2229)     at java.awt.Component.dispatchEventImpl(Component.java:4861)     at java.awt.Container.dispatchEventImpl(Container.java:2287)     at java.awt.Component.dispatchEvent(Component.java:4687)     at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)     at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)     at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)     at java.awt.Container.dispatchEventImpl(Container.java:2273)     at java.awt.Window.dispatchEventImpl(Window.java:2713)     at java.awt.Component.dispatchEvent(Component.java:4687)     at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:707)     at java.awt.EventQueue.access$000(EventQueue.java:101)     at java.awt.EventQueue$3.run(EventQueue.java:666)     at java.awt.EventQueue$3.run(EventQueue.java:664)     at java.security.AccessController.doPrivileged(Native Method)     at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)     at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)     at java.awt.EventQueue$4.run(EventQueue.java:680)     at java.awt.EventQueue$4.run(EventQueue.java:678)     at java.security.AccessController.doPrivileged(Native Method)     at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)     at java.awt.EventQueue.dispatchEvent(EventQueue.java:677)     at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:211)     at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:128)     at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:117)     at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:113)     at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:105)     at java.awt.EventDispatchThread.run(EventDispatchThread.java:90)   and this my code   private void selanjutnyaActionPerformed(java.awt.event.ActionEvent evt) {                                                     String namaProduk = this.fieldNamaProduk.getText();         double totalProduk = Double.parseDouble(fieldTotalProduk.getText());          produk p = new produk();         p.setNamaProduk(namaProduk);         p.setJumlah(totalProduk);          produkController pc = new produkController();          int res = pc.insertProduct(p);         if (res > 0){             new hitungHPP(namaProduk, totalProduk).setVisible(true);             this.dispose();         }else{             JOptionPane.showMessageDialog(null, "Perintah Gagal, silahkan isi ulang!");         }         totalHargaBahan = totalHargaBahan + total;         System.out.println(totalHargaBahan);      }

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


$B$ is an Hermitian operator in Hilbert space, and $|b\rangle$ is the eigenstate of $B$. We can have $[A, B] = 1$ where A is arbitary operator. Then we can calculate as below:  \begin{align} &\phantom{=}\langle b | [A,B] | b \rangle \notag\\ &= \langle b | b \rangle\notag\\ & = \langle b | AB | b \rangle - \langle b | BA | b \rangle \\ &= b \langle b | A | b \rangle - \langle b | A^\dagger B^\dagger | b \rangle ^* \notag\\ &= b \langle b | A | b \rangle - \langle b | A^\dagger B | b \rangle ^* \\ &= b \langle b | A | b \rangle - b^* \langle b | A^\dagger | b \rangle ^* \notag\\ &= b [ \langle b | A | b \rangle - \langle b | A | b \rangle ] \notag\\ &= 0. \end{align}  So it is shown that $1 = \langle b | [A,B] | b \rangle = 0$ which is clearly not right. But where does the problem in the process lie?

Let $\hat{x} = x$ and $\hat{p} = -i \hbar \frac {\partial} {\partial x}$ be the position and momentum operators, respectively, and $|\psi_p\rangle$ be the eigenfunction of $\hat{p}$ and therefore $$\hat{p} |\psi_p\rangle = p |\psi_p\rangle,$$ where $p$ is the eigenvalue of $\hat{p}$. Then, we have $$ [\hat{x},\hat{p}] = \hat{x} \hat{p} - \hat{p} \hat{x} = i \hbar.$$ From the above equation, denoting by $\langle\cdot\rangle$ an expectation value, we get, on the one hand $$\langle i\hbar\rangle = \langle\psi_p| i \hbar  | \psi_p\rangle = i \hbar \langle \psi_p | \psi_p \rangle  = i \hbar$$ and, on the other $$\langle [\hat{x},\hat{p}] \rangle = \langle\psi_p| (\hat{x}\hat{p} - \hat{p}\hat{x}) |\psi_p\rangle =  \langle\psi_p|\hat{x} |\psi_p\rangle p - p\langle\psi_p|\hat{x} |\psi_p\rangle = 0$$ This suggests that $i \hbar = 0$. What went wrong?


I have transferred photos from my camera SD card to my computer (using a card/ram reader) and deleted the original photos. Now I have just realized there are color bars overlaid in photos. Here is an example:    You can download the original image (which includes metadata) here. Note that the colorbars are not present in the thumbnail!:     The blame seems to be on the transfer. Do you agree? Why transferring a photo can potentially corrupt it? I haven't seen this problem with other file types.  As I don't have the original photos, there any way to fix/reduce this corruption?

I have had my Nikon D40 for a while, and some of the pictures are coming out distorted. Two examples are below:   So my questions are:    How do I fix them after the fact? - i.e. after they have been imported from the camera - if possible How do I prevent future pictures from being distorted like this?   Thanks   and


I've read (in the Elements of Style) that, while genitives of names ending in ‘s’ may have an additional ‘s’, as in "Ross’s", this oughtn't to be done with :     Exceptions are the possessives of ancient proper names in -es and -is, the possessive Jesus', and such forms as for conscience' sake, for righteousness' sake. But such forms as Achilles' heel, Moses' laws, Isis' temple are commonly replaced by      the heel of Achilles      the laws of Moses      the temple of Isis   What is known about the origin of and reasoning behind this distinction?

Many questions already ask about this topic ( , , etc.) and their answers vary, but they always give exceptions to the apostrophe-s rule, for example:      6.24 The general rule for the possessive of nouns covers most proper nouns, including most names ending in sibilants."   Examples they give include Kansas’s, Ross’s land, and Jones’s reputation. Exceptions include Jesus’  and Moses’.  Which names does this apply to?  Is the Aeneas’  form correct, or is it Aeneas’s instead?


How can i select multiple items in Google's Earth sidebar "places" menu to delete or to move to a folder?

I've got a Google Earth .kmz file opened in my copy of Google Earth 6.0.1.2032 running on Mac OS X 10.6.7. There are about 5000 points/"places" in the file and they show up fine.  What I would like to do is create folders in Google Earth for those points to categorise them. Unfortunately, I noticed that the Google Earth interface does not let me select more than one place at a time!  Is there another solution for me to manage and categorise those 5000+ places in the .kmz file other than drag and dropping them individually into folders in Google Earth?! (I really don't want to have to do that!) Thanks.


I created my Stack Overflow account using company email. When I leave this company, that email will no longer exist. So can I change the login email to my personal email? Because I don't want to loose my reputation.

I no longer use the service that I originally used to register, and would like to change the service I use to log in, or at least add a second account.  Is this possible? How do I change my login provider or associate a backup method to log in?     For more information, see "" in the .


I am on another computer, also running Ubuntu 16.04, and need to access my old HDD (a 120Gb SSD) to get some files for backup.  When inserting the USB (the HD as an external drive) the graphic Ubuntu interface shows a folder, but it is only the 511Mb boot-partition. The path is  something like  /media/myname/9bee303f-0713-48bb-b897-fee19a1de800  So, perhaps, I need to mount the other 2 partitions to see my files?  With the Disks application, I can see something like   /dev/sdb1 = 511Mb. Content Ext2 (v 1.0) mounted at  /media/myname/9bee303f-.... /dev/sdb2 = 120Gb. No mount.. only says "extended"  /dev/sdb5 = 120Gb. No mount.. only says "Linux LVM"   PS: all = "Master Boot Record"  Does it make sense to have 120Gb twice, what can I mount, sdb2 or sdb5?    I would really like a command line answer with warnings about any possible risks of running the commands. If I can apt install a reliable and safe graphical application to help me, that would also be OK.    This isn't a duplicate of the linked post because it doesn't have a direct solution for my context:   I don't need a clone; I only need some files off the old filesystem.  I am not using Fedora in 2014, I am using Ubuntu 16.04 in 2017     Trying suggestions:  After sudo apt install lvm2  I ran sudo vgscan but:   /run/lvm/lvmetad.socket: connect failed: Arquivo ou diretório não encontrado  WARNING: Failed to connect to lvmetad. Falling back to internal scanning.  Reading all physical volumes.  This may take a while...  Found volume group "ubuntu-vg" using metadata type lvm2

Yesterday I decided to upgrade my laptop hard drive to an SSD. I was previously running Ubuntu 14.04 on the HDD that came with it. I have installed Ubuntu 14.10 on the SSD.  I would like to mount the old HDD so that I can copy over all my files. So I purchased an enclosure that lets me treat it like an external USB drive. I put the HDD into the enclosure and plugged it in. It is detected and it sees all of the volumes. But it only mounts the boot volume for read/write.  The HDD is 750GB and the SSD is 120GB. When I inspect it in the "Disks" utility I see both hard drives and can easily tell the difference between the two. When I inspect the HDD I see: Partition 1 Ext2 (boot volume), Extended Partition 2, and Partition 5 LVM2 PV.  So clearly it can see the volumes as well. It reports that the disk is ok but has one bad sector. The drive is not encrypted. I am not sure why it shows two volumes of the same size. Probably has to do with it being an LVM volume.  How do I get it to let me read the files from my old installation of Ubuntu?  $ sudo fdisk -l Disk /dev/sda: 223.6 GiB, 240057409536 bytes, 468862128 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: dos Disk identifier: 0x7f79a18e  Device     Boot  Start       End   Sectors   Size Id Type /dev/sda1  *      2048    499711    497664   243M 83 Linux /dev/sda2       501758 468860927 468359170 223.3G  5 Extended /dev/sda5       501760 468860927 468359168 223.3G 8e Linux LVM  Disk /dev/mapper/ubuntu--vg-root: 215.6 GiB, 231479443456 bytes, 452108288 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk /dev/mapper/ubuntu--vg-swap_1: 7.8 GiB, 8317304832 bytes, 16244736 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk /dev/sdb: 596.2 GiB, 640135028736 bytes, 1250263728 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: dos Disk identifier: 0x0004f632  Device     Boot  Start        End    Sectors  Size Id Type /dev/sdb1  *      2048     499711     497664  243M 83 Linux /dev/sdb2       501758 1250263039 1249761282  596G  5 Extended /dev/sdb5       501760 1250263039 1249761280  596G 8e Linux LVM


I am a Minecraft pocket edition player. Can I use redstone for things?

I have Minecraft Pocket Edition and I have collected a lot of redstone dust. For some reason, I couldn't use it for things such as iron doors. Why?


In case of malware infection in latest windows OS, like win 10, which is the best course of action for complete disinfection - a factory reset using troubleshoot and recovery, a format of entire drive done with Windows built-in disk management tool, or a disk wipe done with third party data erasure softwares?  What are the differences between these three? If the infection has spread to the master boot record, which of these three, if any, should be able to fix that as well alongside OS infection?  Also, if I understand correctly, disk wipe and low level format are the one and the same for modern machines?  (Not taking any firmware or hardware malware into account, just OS and MBR infections.)  EDIT: I do not want to know how to run antivirus tools to remove the malware, or IF I should format, as the answers to other similar looking questions have stated. I want to know the differences between the three different processes of starting over and reinstalling Windows, and which one is the best bet for malware. I have seen the words formatting and wiping being thrown around somewhat interchangeably on the threads and forums, and I feel that the two processes are actually a little different, but I'm not sure. Can malware which isn't firmware/hardware and is limited to OS/MBR actually survive a format, such that I would need to use third party tools to perform complete disk erasure? Because from what I understand, after formatting, the data is pretty much gone until you run special recovery tools on it and even then it might be uncertain. What are the odds of OS infections persisting after format and not wipe? I am looking for an explanation on the difference a full drive format with disk management tool, and a disk wipe with third party tool can have on various types of malware, whether those differences are theoretical or low odds.

What should I do if my Windows computer seems to be infected with a virus or malware?  What are the symptoms of an infection? What should I do after noticing an infection? What can I do to get rid of it? how to prevent from infection by malware?   This question comes up frequently, and the suggested solutions are usually the same. This community wiki is an attempt to serve as the definitive, most comprehensive answer possible. Feel free to add your contributions via edits.


how to solve the following equation?  $x+\log(x)=n+c$,where $c$ is constant, and $n$ is positive number and allow to be infinity.  Intuitively, if let $n \to \infty$， the approximate solution will be  $x=n+c-\log(n)$, can any one help with the exact solution?

Is there any "superlogarithm" or something to solve an equation like this:  $$x^x = 10?$$


So I changed my Google email address, and now when I log in with Google, I'm a new user - how do I get my old account back ?

I accidentally posted a question without being logged in. Is there a way to associate that question with my account?   For more information, visit "" in the .   a.k.a. How can you link a registered account to a cookie-based account? a.k.a. How do I merge an unregistered account with a registered account a.k.a. Merging users a.k.a. How do I associate anonymous questions I’ve asked with my registered account? a.k.a. Is there a way to claim an unregistered user? (in case anyone searches with those terms)


are Independently and Identically Distributed.     Z=|X-Y|.  Find the PDF of Z. The joint PDF of this function is 1 as well. Through the graph, I found that the CDF of Z is  and PDF is . However, I am not able to solve it through the joint density function of x,y. What are the limits in which the joint function should be integrated to get the CDF of Z?

Let $X_1$ and $X_2$ be two independent random variables with distribution $U(0,1)$. Let $Y=|X_1-X_2|$. Find the distribution function and density of $Y$.   Solution:  f(x1)=1 whenever x1 between 0 and 1          =0 Else where f(x2)=1 whenever x2 between 0 and 1          =0 Else where f(x1,x2)=1 whenever x1,x2 between 0 and 1           =0 Else where G(y)= P[-y <= x1-x2 <= y]       =\int_{-y}^y \int_{x1_y}^{y+x1} 1 dx2 dx1       =\int_{-y}^y -2y dx1       =4y^2 when y between 0 and 1       =0 when y less than 0       =1 when y greater than 1 Thus, g(y)= \diff G(y) =8y  Is it correct?


Seems to me it is so general question I wanted to ask on Computer Science site but could not find proper tags, so asking here. Mods please move if appropriate.  As I've read in many places, e.g. here  to run a program parent process in Linux forks (copies all info) itself then replaces in that fork itself by calling  with needed program.    Why not just make/start a new process? How is it better (as it was implemented that way, looks like it is better by some criteria)?    I could not find an answer by web search for Linux: why to execute a program first we need to copy (fork) current one? and here on SE questions on exec fork are about technical details, not why type.

In Unix whenever we want to create a new process, we fork the current process, creating a new child process which is exactly the same as the parent process; then we do an exec system call to  replace all the data from the parent process with that for the new process.  Why do we create a copy of the parent process in the first place and not create a new process directly?


If I install Linux on a USB stick using computer A, then plug it into computer B with different hardware and try to boot and work on it, should I generally expect it to work? Or should I rather accept that Linux, when installed (as opposed to using Live CD/USB), gets tied to the hardware and is generally not supposed to work seamlessly on different hardware?  If the answer is "it depends", let's narrow the question:   All hardware is x86. Nothing fancily customized, just stock laptops/desktops currently available on the market; Distros: latest OpenSUSE, Ubuntu or Cubes OS with default settings; No fancy software, just web/office etc.   The background behind this question is that I am deciding whether to have separate USB stick Linux installations for each computer I have, or just clone the same one.

I was given a laptop with a totally dead display. I do not want to pay to replace the broken display, but I would like to use the laptop as a server and connect to it via SSH to control it.  I have pulled out the internal hard drive from the broken laptop, and I want to install Debian GNU/Linux and the SSH server onto this HDD using a working Debian laptop.  However, the hardware in the two laptops is very different, and I am wondering what kind of problems I would run into when I plugged the drive back in to the laptop with the broken display because of this?  How would I make this work? What is the proper way for me to install a bootable copy of Linux onto a HDD that will be used by a computer with different hardware?


Let's say I have a multi-line string like this:  STARTFRUIT banana ENDFRUIT  STARTFRUIT avocado ENDFRUIT  STARTVEGGIE rhubarb ENDVEGGIE  STARTFRUIT lime ENDFRUIT   I want to search for all fruit, no veggies. I try this:  MatchCollection myMatches = Regex.Matches(tbBlob.Text, "STARTFRUIT.*ENDFRUIT", RegexOptions.Singleline);  foreach (var myMatch in myMatches) {     Forms.MessageBox.Show(String.Format("Match: {0}", myMatch), "Match", Forms.MessageBoxButtons.OK, Forms.MessageBoxIcon.Information); }   The problem is, instead of returning me an array of three matches, it gives me a big match encompassing the first STARTFRUIT at the beginning and the last ENDFRUIT at the end. Is there a way to "minimalize" the match search? I don't see any help in RegexOptions.

I have this gigantic ugly string: J0000000: Transaction A0001401 started on 8/22/2008 9:49:29 AM J0000010: Project name: E:\foo.pf J0000011: Job name: MBiek Direct Mail Test J0000020: Document 1 - Completed successfully  I'm trying to extract pieces from it using regex. In this case, I want to grab everything after Project Name up to the part where it says J0000011: (the 11 is going to be a different number every time). Here's the regex I've been playing with: Project name:\s+(.*)\s+J[0-9]{7}:  The problem is that it doesn't stop until it hits the J0000020: at the end. How do I make the regex stop at the first occurrence of J[0-9]{7}?


I have a netbook MSI U135 DDR 2 1GB with Windows7 Starter. I want to install, alongside it, a Ubuntu version which is stable and fast running. Can anyone tell me which one to install?And to install Ubuntu alongside windows7 Starter, how to procede?  Greetz Chris.

For a given hardware configuration, how do I find out if Ubuntu will run on it? What considerations should I take into account when choosing an Ubuntu version and  such as:    with a lighter desktop than the usual Gnome and Unity  with the even lighter LXDE desktop   Obviously Ubuntu does not run on some processor architectures. So how do I go about choosing the right version and derivate. How can I find out the minmal system requirements?


What is different between CentOS 7 DVD ISO and Everything ISO in  ?  CentOS 7 DVD ISO 3.86 GB  Everything ISO 6.58 GB

What is the difference between the DVD ISO and the Everything ISO?  These options are presented on the CentOS  but there is no explanation as to what the difference is.


I am working with Java and trying to write a very simple test code like this to test and I thought that there was no problem but there was one problem.  public class EmployeeTest {     public static void main(String[] args){         Employee[] staff = new Employee[1];         staff[0] = new Employee("Carl Cracker", 75000);         for (Employee e : staff)             System.out.println("name=" + e.getName() + ",salary=" + e.getSalary());     }      class Employee {     private String name;     private double salary;     public Employee(String n, double s)     {         name = n;         salary = s;     }     public String getName()     {         return name;     }     public double getSalary()     {         return salary;     } } }  Unfortunately, when I ran my code, the result is No enclosing instance of type EmployeeTest is accessible. Must qualify the allocation with an enclosing instance of type EmployeeTest (e.g. x.new A() where x is an instance of EmployeeTest).  I am sure that my code is very simple and easy to understand, so I am very confusing that why I had that error? Could you please give me some comments ? Thank you very much!

What is the main difference between an inner class and a static nested class in Java? Does design / implementation play a role in choosing one of these?


How do we prove that for every prime $p\neq2,5$ there exists a positive integer $n$ such that $(10^n-1)/9$ is divisible by $p$?  BTW, I suspect that it holds not only in base $10$, but also in every other base $b$, for every prime which is not a factor of $b$.  My work so far - not much, except for manually testing the first few numbers of the form $111\dots1$:   $11=11$ $111=3\cdot37$ $1111=11\cdot101$ $11111=41\cdot271$ $111111=3\cdot7\cdot11\cdot13\cdot37$ $1111111=239\cdot4649$ $11111111=11\cdot73\cdot101\cdot137$   Thanks

How can I prove that every prime except 2 and 5 divide infinitely many of the following integers $11, 111, 1111, ...$ ?


I know that some Jedi had relationships (include Qui-Gon), and some even married in opposition to Jedi customs and contrary to Council will (that's a stone in your backyard, Mrs Anakin Skywalker!)  But was there ever a case where Jedi Council reversed its position and officially OKed for a Jedi to marry while remaining an active member of the order?  I don't know if the Council existed or had marriage prohibition during Old Republic era, so the scope of the question is 1000BBY-0ABY.

There is a vague idea that Obi-wan and Queen of Mandalore had a thing, but this isn't properly addressed in the Clone Wars series AFAIK.  But are there other instances of Jedi who go against the order for love/relationships?


In the Star Trek episode "The Squire of Gothos", Trelane suggested he was looking at Earth of 900 years ago, in the late 18th century, making Star Trek set in the 27th Century.   According to , it appears that the date when Star Trek was set in was made later than this episode.     Continuity      At the time episode was written there was no definite century in which Star Trek took place. It is stated that Gothos is 900 light years from Earth and that Trelane had "been looking in on doings nine hundred years past". However, Trelane references people and events of the late 18th and early 19th centuries putting Star Trek in the 27th century.   Which episode establishes the time Star Trek: TOS takes place is (roughly) the 2260s? Was it in the original series or ST:TNG?

The Original Series is set from 2265 to 2269, but as far as I can remember, the year was never given until much later, in The Next Generation, which arbitrarily started 100 years later.  Somehow, someone, most likely Mike Okuda or Gene Roddenberry himself, decided to make 2265 the start year, but how was that decided? What specific clue or line tied it down to that year? Perhaps in the last season of TOS someone said onscreen that it was 300 years since Apollo 11?


Let's say I have a nested dictionary that looks like:  { 'word1':     {'VERB': 129}     {'NOUN': 151}     {'DET': 26426} ... }   I want to get DET from the nested dict since it has the highest frequency. I tried to do it by iterating the dict[word1] but it seemed every inefficient. Is there an easy/simple way to do this?

I have a dictionary: keys are strings, values are integers.  Example:   stats = {'a':1000, 'b':3000, 'c': 100}   I'd like to get 'b' as an answer, since it's the key with a higher value.  I did the following, using an intermediate list with reversed key-value tuples:  inverse = [(value, key) for key, value in stats.items()] print max(inverse)[1]   Is that one the better (or even more elegant) approach?


Let $x_1,...,x_n$ be a natural numbers,      show that $\prod _{i<j}(x_i-x_j)$ can be divided wihout remainder in $\prod_{i<j}(i-j)$   I know $\prod \left(x_i-x_j\right)$ is the result of Vandermonde Determinant, so is related with Det?

let $a_{i},i=1,2,\cdots,n$ be postive integer ,show that $$1^{n-1}2^{n-2}\cdots (n-2)^2(n-1)|\prod_{1\le i<j\le n}(a_{i}-a_{j})$$  I know this $\prod_{1\le i<j\le n}(a_{i}-a_{j})$ is  Vandermonde  determinants,and I found $$1^{n-1}2^{n-2}\cdots (n-2)^2\cdot (n-1)=1!2!3!\cdots (n-1)!=\prod_{1\le i<j\le n}(j-i)$$ we only prove $$\prod_{1\le i<j\le n}\dfrac{a_{j}-a_{i}}{j-i}$$ is integer  maybe consider Vandermonde determinants ? But I can't prove this


Based off the question ""  How does Captain Jack Harkness become the Face of Boe?

After Jack Harkness was brought back to life by Bad Wolf Rose, he is unable to die, not even from old age.  At the end of Last of the Time Lords, the Doctor comments on the fact that he doesn't know how Jack will look when he gets older.  Jack mentioned that he was once nicknamed the Face of Boe and from there looking back there are subtle hints which prove he is the Face of Boe:   Since the Doctor meets the Face of Boe further in the future, the Face of Boe, having been Jack, knew about Yana being the Master. The Face of Boe has the distinction of being the oldest being in the universe, which fits with the side-effects of Jack's Immortality. In Gridlock, the Face of Boe welcomed death. I remember Jack indicating at one point he was growing tired of not dying after having watched human history from 1869 after escaping Satellite 5.   However, with that said, the Face of Boe died, even though Jack can't die. However, not even the Doctor knew whether Jack could die of old age, so I am wondering: is there anything more concrete on whether Jack does become the Face of Boe?


I have used the biblatex package and I created a bibliography in a .bib file. I've created a link to this file (\addbibresource{bibliography.bib}) and at the end of my document I've put the \printbibliography command.  The bibliography is not shown in the pdf...I receive the following errors:   Empty bibliography on input line ... Please (re) run Biber on the file ... and run Latex afterwards.   Can you explain me why is not working?

Running the minimal example  \documentclass{article} \usepackage{filecontents} \begin{filecontents*}{\jobname.bib} @ARTICLE{example,   author  = {Other, Anthony Norman},   title   = {Some things I did},   year    = {2014},   journal = {J.~Irrep. Res.},   volume  = {1},   number  = {1},   pages   = {1-10} } \end{filecontents*} \usepackage[backend=biber]{biblatex} \addbibresource{\jobname.bib} \begin{document} Hello\cite{example}. \printbibliography \end{document}   I get the warning There were undefined references.  I have read  and know that I need to run:   LaTeX Biber LaTeX   However, my editor is only set up to run BibTeX. How do I go about setting up my editor/IDE to be able to run Biber, and how do I run the LaTeX/Biber/LaTeX cycle?  Answers (sorted alphabetically by editor name)                    Answer guidelines   Each answer should be for one editor. If the editor is cross-platform, if possible give a single answer with notes covering the minor platform variations. Please edit the question to include new answers in the 'link list' Each answer should be 'stand alone', i.e. don't say 'It's almost the same as editor Y but ...' for the editor part Instructions for 'build tools' such as arara or latexmk are welcome but should explain how to set up the editor in question as not all editors allow simple addition of arbitrary tools


I have a batch script that runs some programs at once. One of them requires admin access, so it's fine to manually give it. But now I am adding another admin program. I would not like to manually give admin access to two programs.  The apparent solution is to run the whole script as admin. Works.  But, I'd also like to not give admin access to the other programs. What would be the best way to run those in user-mode?  I found , but trying to run any command tells me that the command is invalid.  EDIT: I tried to run different commands with the at command, but it did not work.  C:\Windows\system32>at notepad Invalid command.  <then prints out help for the command>   (I am not sure if the exact text is "Invalid command" as my Windows is in Finnish, but that is the closest translation I can think of. If someone knows better it's "Komento ei kelpaa." in Finnish.)  EDIT 2: I also tried adding the directory and quotes to the command. No effect.

Is there any way that I can force a program that normally requires administrator privileges (via UAC) to run without them? (ie: no UAC prompt and no system-wide access.)  Added: Without modifying the executable itself.    In spite of James's answer, I have found a few ways that it can almost be done:   By modifying the executable I can remove the trustInfo entry from the manifest (or the manifest entirely, so I can use an external one), allowing the program to start without UAC. Unfortunately this modifies the executable, so it exits shortly after due to an internal checksum test. By using Process Explorer I can launch it as a Limited User. However this seems to limit it significantly more than I would like (it runs like Protected Mode IE and so can access significantly less than what my standard un-elevated user can).


Good morning, Suppose that we have a set: $ L = \{ x_{1} ,..., x_{N} \} $ and a given function $ f(x) $ we need to find it's minimum $  x^{*}  $. The set $ L $ is belonging to an interval $ [a , b ] $ and represents a the first drawn sample in random search algorithm for a 1-dimensional function . My question is about the random search algorithm. Is there any rigorous proves of how this algorithm works? For example, why everyone say:  Random search has a probability of 95% of finding a combination of parameters within the 5% optima with only 60 iterations. I need some proofs/principles analyses for a work! Thank you a lot in advance for help !

I'm currently going through Bengio's and Bergstra's Random Search for Hyper-Parameter Optimization  where the authors claim random search is more efficient than grid search in achieving approximately equal performance. My question is: Do people here agree with that claim? In my work I've been using grid search mostly because of the lack of tools available to perform random search easily. What is the experience of people using grid vs. random search?


I have a function transpose declared in a header file global.h as shown below:  template <size_t M, size_t N> extern void transpose(array <array <float, N>, M>&, array <array <float, M>, N>&);   The function is defined in another file global.cpp as shown below:  template <size_t M, size_t N> void transpose(array <array <float, N>, M>& a, array <array <float, M>, N>& b) {     // This can be made faster     for (size_t i = 0; i < M; i++)     {         for (size_t j = 0; j < N; j++)         {             b[j][i] = a[i][j];         }     } }   However, the following function call:  transpose<dim, dim>(jacobian, jacobian_transposed);   throws the error:  undefined reference to `void transpose<23u, 23u>(std::array<std::array<float, 23u>, 23u>&, std::array<std::array<float, 23u>, 23u>&)'   The variable dim is defined in the global.h as shown below:  static constexpr const int marker_num = 10; static constexpr const int dim = (2 * marker_num) + 3;   I found . Are there any ways to keep the function definition in the global.cpp?  Edit: I read the  of which this question was marked as duplicate. That along with the answer from @Xirema helped me realize that I have three options: 1) Implement function in the header.  2) Implement function in a file with '.ipp' extension and include it inside the header.  3) Third option is explicit instantiations like:  template <size_t M, size_t N> void transpose(array <array <float, N>, M>& a, array <array <float, M>, N>& b) {     // This can be made faster     for (size_t i = 0; i < M; i++)     {         for (size_t j = 0; j < N; j++)         {             b[j][i] = a[i][j];         }     } } template void transpose(array <array <float, dim>, dim>& a, array <array <float, dim>, dim>& b); template void transpose(array <array <float, dim>, 2>& a, array <array <float, 2>, dim>& b);   Which of the above is the best method (I am trying to follow the best coding practice)?

Quote from :     The only portable way of using templates at the moment is to implement them in header files by using inline functions.   Why is this?  (Clarification: header files are not the only portable solution. But they are the most convenient portable solution.)


I have been using blender for a few weeks onw and i came across this viewport issue that happens whenever i go to wireframe or solid mode but not on material preview or rendered. this issue moves all the object in a sort of line pattern and makes other object vanish. this glitch makes it look as if any object not on the shadow was not there. I am using cycles on gpu compute with 256 samples on the render and 32 samples on the viewport and rendering tiles of 288x and y. I have a ryzen 5 2600 on the laetst driver, an rtx 2060 running on the latest game ready driver (aka Game ready driver Version 466.27), a b450M/ac on the newwest BIOS version, and a 480Gb SSD with only 50Gb of free storage left (dont know if it matters). I experienced this issue seemingly out of nowhere and i do not know what it caused it. I do have many modifiers active and some applied on several different objects. I also have many different objects as parents. any help is appreciated.

When looking at my objects in 3d view I'm seeing a gray cone that seems to be hiding other objects.   Can anyone help me turn this off and explain what it is please.  Screenshots attached.


I need to use dynamic table names which can't be provided as parameters in prepared statements. I figured that if I restrict identifier names to alphanumeric + underscore only, then there is no way some sql could be injected, right?  here's the check function:  function is_safe_identifier($s) {     return preg_match('/^[a-zA-Z0-9_]+$/', $s) == 1; }

If user input is inserted without modification into an SQL query, then the application becomes vulnerable to , like in the following example:  $unsafe_variable = $_POST['user_input'];   mysql_query("INSERT INTO `table` (`column`) VALUES ('$unsafe_variable')");   That's because the user can input something like value'); DROP TABLE table;--, and the query becomes:  INSERT INTO `table` (`column`) VALUES('value'); DROP TABLE table;--')   What can be done to prevent this from happening?


I am trying to understand the background of why the following works:  def part_string(items):     if len(items) == 1:         item = items[0]         def g(obj):             return obj[item]     else:         def g(obj):             return tuple(obj[item] for item in items)     return g  my_indexes = (2,1) my_string = 'ABCDEFG' function_instance = part_string(my_indexes) print(function_instance(my_string)) # also works: print(part_string(my_indexes)(my_string))   how come I can pass my_string to function_instance object even though I already passed my_indexes attributes to part_string() when creating function_instance? why Python accepts my_string implicitly?  I guess it has something to do with the following, so more questions here: what is obj in g(obj)? can this be something other e.g. g(stuff) (like with self which is just a convention)? what if I want to pass 2 objects to function_instance? how do I refer to them in g(obj)?  Can You recommend some reading on this?

I've been reading a lot about closures and I think I understand them, but without clouding the picture for myself and others, I am hoping someone can explain closures as succinctly and clearly as possible.  I'm looking for a simple explanation that might help me understand where and why I would want to use them.


The speed of light is constant as long as you are measuring it from a reference frame moving at a constant velocity, such as earth  What do we have to measure it from a reference frame moving at a constant velocity ? Isn't the speed of light always constant?  I don't really understand..Please explain.  Also sorry if this question seems dumb, im a 10th grader..

The speed of light is the same in all inertial frames.  Does it change from a non-inertial frame to another? Can it be zero?  If it is not constant in non-inertial frames, is it still bounded from above?


Define $$ H_n = \sum_{k=1}^n \frac{1}{k} $$ I need to calculate the sum $$ S = \sum_{n=1}^{\infty} \frac{(-1)^{n+1}}{n+1} H_n $$ Using the following integral representation of $ H_n$ $$ H_n = -n \int_0^1 x^{n-1}\ln(1-x) dx $$ and exchanging the order of summation, I obtained $$ S = -\int_0^1 \left(\frac{1}{1+x}+\frac{\ln(1+x)-x}{x^2}\right) \ln(1-x) dx $$ Using Wolfram Alpha, I got $$ S \approx 0.240227 $$ so I guess $$ S = \frac{(\ln 2)^2}{2} $$ But I don't know how to calculate the integral. Any idea?

Finding $$\sum^{\infty}_{n=1}\bigg[\bigg(\frac{(-1)^{n+1}}{n+1}\bigg)\bigg(\sum^{n}_{r=1}\frac{1}{r}\bigg)\bigg]$$   Try: Let $\displaystyle H_{n} =\sum^{n}_{r=1}\frac{1}{r},$ then series $\displaystyle \sum^{\infty}_{n=1}\frac{(-1)^{n+1}}{n+1}\cdot H_{n}=\frac{H_{1}}{2}-\frac{H_{2}}{3}+\frac{H_{3}}{4}\cdots\cdots$  could some help me to solve it, thanks


I just installed Ubuntu. I wanted to load a software  to allow me to graphically manage media.   I got a Terminal. I entered the following: sudo apt-get install synaptic The screen prompt demanded a password. I entered my password (not the passphrase) result was   the system did not seem to be allowing keyboard input At least there was no movement of the  cursor and  the system did not recognize my password no matter how many times I entered it.    What am I doing wrong?    Also  I am getting the following when I use the command line   System-Product-Name-Invalid-entry-length-16-Fixed-up-to-11:~$     What's that?   I tried it again using UXterminal from the Dash this time it recognized my password and gave me a Y/n option and I chose Y

When I'm about to install a program in the terminal it wants the password:  [sudo] password for xxx:   But when I start to type my password nothing happens. What should I do?


I'm looking to keep a change in my python working directory; however, when I change the directory with the following code:  import os os.chdir('Path')   and exit out of python, the working directory reverts back to the default while attempting to run a script within this working directory.  How do I keep the changed working directory? I'm using a Mac (if that makes a difference). Any help is greatly appreciated for this novice looking to self teach python.

I'm trying to write a small script to change the current directory to my project directory:  #!/bin/bash cd /home/tree/projects/java   I saved this file as proj, added execute permission with chmod, and copied it to /usr/bin. When I call it by: proj, it does nothing. What am I doing wrong?


I have a professor who used the same lecture notes, same assignments, and same exam questions word for word from from another professor at a different university (who posts his notes, assignments, and exams online). She mentions she "makes her own exams", however the questions are identical to the online past exam and assignment questions.   It's a masters level class and the exam questions are quite specific. We are given an abstract to read and then asked to perform calculations/analyze the abstract.   Is this common or "allowed"?

I have a professor at my university who uses content from an un-cited textbook that he has never referenced anywhere, including his green sheet (syllabus), as an additional resource. At least some slides he has used include parts of content that have been re-worded and others that are 100% the same. I noticed this by Googling for textbooks on the material we're studying in class and found that examples given in one that I found were exactly the same as what he has provided.  Would this technically be plagiarism? Should he be given the benefit of the doubt in this situation?


It's time once again to support your favorite open source project through our Free Vote-Based Advertising for Open Source Projects. . Here is your chance to create a . Create a graphical ad for an open source programming project and post it as an answer to this question (in the right format), and it will feed live remnant ads on Stack Overflow. Ad Requirements It must be an advertisement soliciting the participation and contribution of programmers writing actual source code. This is not intended as a general purpose ad for consumer products which just happen to be open source. It's for finding programmers who will help contribute code or other programmery things (documentation, code review, bug fixes, etc). Your ad should be an original creation which has not previously appeared on Stack Overflow. Please do not resubmit entries that have appeared as ads on Stack Overflow in previous periods. In order to work, the answers you post to this question must conform to the following rules. Answer Template  [![Tagline to show on mouseover][1]][2]        [1]: http://image-url   [2]: http://clickthrough-url   Please do not add anything else to the body of the post. If you want to add any commentary, keep it in the comments. Image requirements  The image that you create must be 220px by 220px Can be hosted anywhere (tinypic, twitpic, your blog); we will mirror the image locally when we serve it. Must be GIF or PNG No animated GIFs Absolute limit on file size of 150kb  The output, which ultimately will be served in an ad slot on Stack Overflow, can be previewed by clicking through to this URL:  There is a minimum score threshold an answer must meet (currently 6) before it will be served up by that URL and shown on Stack Overflow. You can see all the ads that currently make the threshold and meet our criteria on this page:  Ad Scroller (by ): I created a nifty little tool you can use to view the ads that have met the criterion already:

Possible Duplicate:    It's time once again to support your favorite open source project through our Free Vote-Based Advertising for Open Source Projects. We are clearing the leader boards to start the first half of 2011 anew. Here is your chance to create a . Create a graphical ad for an open source programming project and post it as an answer to this question (in the right format), and it will feed live remnant ads on Stack Overflow. Ad Requirements It must be an advertisement soliciting the participation and contribution of programmers writing actual source code. This is not intended as a general purpose ad for consumer products which just happen to be open source. It's for finding programmers who will help contribute code or other programmery things (documentation, code review, bug fixes, etc.). Your ad should be an original creation which has not previously appeared on Stack Overflow. Please do not resubmit entries that have appeared as ads on Stack Overflow in previous periods. In order to work, the answers you post to this question must conform to the following rules. Answer Template  [![Tagline to show on mouseover][1]][2]        [1]: http://image-url   [2]: http://clickthrough-url   Please do not add anything else to the body of the post. If you want to add any commentary, keep it in the comments. Image requirements  The image that you create must be 220 pixels by 250 pixels Can be hosted anywhere (tinypic, twitpic, your blog); we will mirror the image locally when we serve it. Must be GIF or PNG No animated GIFs Absolute limit on file size of 150 KB  The output, which ultimately will be served in an ad slot on Stack Overflow, can be previewed by clicking through to this URL:  Score Threshold There is a minimum score threshold an answer must meet (currently 6) before it will be served up by that URL and shown on Stack Overflow. You can see all the ads that currently make the threshold and meet our criteria on this page:  You can also view the ads that meet the threshold using 's


My code:  document.querySelector('input[name=fos_user_registration_form[gender]]:checked')   it doesn't work because of [gender].   Do you have an idea to select this type of input ?

What characters/symbols are allowed within the CSS class selectors? I know that the following characters are invalid, but what characters are valid?  ~ ! @ $ % ^ & * ( ) + = , . / ' ; : " ? > < [ ] \ { } | ` #


How to remove \n in a string?  E.g.    Input : string s = "\n1234" Output I want (but I can't achieve) : string s = "1234"   What I've tried (and failed) :   s.Remove(0,1); s.Trim();   Additional notes :  I think \n counts as 1 char because, when I tried :  bool b = s[0]=='\n';      b = true.

How can I replace Line Breaks within a string in C#?


I am new to JQuery and I'm trying to write code that changes a clicked button both in text and function. Here is the code:  $('.button1').click(     function() {         $(this).val('Button2');         $(this).removeClass('button1').addClass('button2');     } );  $('.button2').click(     function() {         alert('Button 2 Clicked');     } );   The problem is, the second event does not fire and call the alert.  Thanks in advance

I have a bit of code where I am looping through all the select boxes on a page and binding a .hover event to them to do a bit of twiddling with their width on mouse on/off.  This happens on page ready and works just fine.  The problem I have is that any select boxes I add via Ajax or DOM after the initial loop won't have the event bound.  I have found this plugin (), but before I add another 5k to my pages with a plugin, I want to see if anyone knows a way to do this, either with jQuery directly or by another option.


Is it useful to include cross-level-interaction in multilevel (hierarchical) models without varying slopes (only varying intercept)?  A short example in R:  m1 <- lme(y~x_1+x_2+z_1+z_2+x_1:z_1, random = ~1|county, data = data)   Where:  y = Response variable  x = covariate from individual-Level  z = covariate from group-Level   Technically these models can be fitted in R without warnings. But is it useful from a theoretical point of view? I once read that cross-level-interactions are only possible with individual-Level variables that possess a varying slope. Is that correct?

I have a HLM model with significant variance in the level 1 intercepts across groups but no significant variance in the level 1 slopes across groups and find significant cross-level moderation effects. Does it make sense to interpret these or are random slopes a necessary condition for probing cross-level interaction effects?