I used to play this game on my PC ,but after a complete reboot of PC it won't launch the game anymore. When it is supposed to launch it, it sends me a crash report. I have no idea how to post it over here, so here you go, the whole copy of it:  ---- Minecraft Crash Report ---- // Sorry :(  Time: 29.10.16. 16.37 Description: Initializing game  org.lwjgl.LWJGLException: Pixel format not accelerated     at org.lwjgl.opengl.WindowsPeerInfo.nChoosePixelFormat(Native Method)     at org.lwjgl.opengl.WindowsPeerInfo.choosePixelFormat(WindowsPeerInfo.java:52)     at org.lwjgl.opengl.WindowsDisplay.createWindow(WindowsDisplay.java:247)     at org.lwjgl.opengl.Display.createWindow(Display.java:306)     at org.lwjgl.opengl.Display.create(Display.java:848)     at org.lwjgl.opengl.Display.create(Display.java:757)     at org.lwjgl.opengl.Display.create(Display.java:739)     at bcx.ap(SourceFile:598)     at bcx.an(SourceFile:434)     at bcx.a(SourceFile:381)     at net.minecraft.client.main.Main.main(SourceFile:124)   A detailed walkthrough of the error, its code path and all known details is as follows: ---------------------------------------------------------------------------------------  -- Head -- Thread: Client thread Stacktrace:     at org.lwjgl.opengl.WindowsPeerInfo.nChoosePixelFormat(Native Method)     at org.lwjgl.opengl.WindowsPeerInfo.choosePixelFormat(WindowsPeerInfo.java:52)     at org.lwjgl.opengl.WindowsDisplay.createWindow(WindowsDisplay.java:247)     at org.lwjgl.opengl.Display.createWindow(Display.java:306)     at org.lwjgl.opengl.Display.create(Display.java:848)     at org.lwjgl.opengl.Display.create(Display.java:757)     at org.lwjgl.opengl.Display.create(Display.java:739)     at bcx.ap(SourceFile:598)     at bcx.an(SourceFile:434)  -- Initialization -- Details: Stacktrace:     at bcx.a(SourceFile:381)     at net.minecraft.client.main.Main.main(SourceFile:124)  -- System Details -- Details:     Minecraft Version: 1.10.2     Operating System: Windows 7 (x86) version 6.1     Java Version: 1.8.0_111, Oracle Corporation     Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation     Memory: 80026872 bytes (76 MB) / 148910080 bytes (142 MB) up to 523501568 bytes (499 MB)     JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M     IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0     Launched Version: 1.10.2     LWJGL: 2.9.4     OpenGL: ~~ERROR~~ RuntimeException: No OpenGL context found in the current thread.     GL Caps:      Using VBOs: Yes     Is Modded: Probably not. Jar signature remains and client brand is untouched.     Type: Client (map_client.txt)  Resource Packs:  Current Language: ~~ERROR~~ NullPointerException: null Profiler Position: N/A (disabled) CPU: <unknown>   PLEASE someone try to answer to this, my knowledge of doing something on PC is complete 0.

Similar to  on the bugs in Minecraft, I would like a complete list of what error codes exist in Minecraft and how they occur, as well as how they can be resolved.


I recently bought a 7mm SSHD . I wasn't sure if my laptop had a 9mm or 7mm so I bought 7mm just to be safe. Do I have to buy any kind of adapter to place the 7mm SSHD in my laptop?

I'm planning to purchase a Crucial M4 256G SSD.  There are 2 versions though, 7mm and 9.5mm, at the same price on Newegg.com  My current laptop is 9.5mm SATA II. However, I plan to purchase a new laptop as soon as Ivy Bridge quad-core laptops (the 35W i7-3612QM interests me most) are available, which will certainly have SATA III (and I plan to use a legacy HDD in optical bay). However, I'm not sure if it will come with a 7mm or 9.5mm slot.  My question is, will a 7mm SSD fit in a 9.5 mm slot? Is there any disadvantage?  (BTW, comments are welcome if you feel Crucial M4 is not a good choice. I chose this after I read rumors about SandForce. I also do not see any reason to switch to Intel 320 Series as Crucial seems to have good reliability as well.)


I was recently reading axioms of real numbers, is there any proof that any other mathematical quantity will not satisfy those axioms? By mathematical quantity I mean a matrix or a complex number,etc.

For a frame of reference, I'm an undergraduate in mathematics who has taken the introductory analysis series and the graduate level algebra sequence at my university.   In my analysis class, our book lists axioms describing the structure of the reals. This seemed unnatural to me, as we can often write definitions or lists of rules that no set actually satisfies. So the axiomatic approach doesn't reassure me that the thing we are discussing can actually exist.  Our teacher talked to us about dedekind cuts as a way of explicitly constructing reals, which seemed more useful to me.  In my modern algebra class we discussed completion of the rationals as a way to construct the real numbers.  But this leads me to wonder - How do we know that all of these approaches and constructions result in the same structure, namely $\mathbb{R}$? Also, are the real numbers  the only complete, totally ordered field? If so, why?


I imported an OBJ character model and the image textures showed up as black in the Render View when using Cycles. They looks fine in the Material Preview. I tried removing the image texture and just used a Principle BSDF Shader with the color set to red and I'm having the same issue. I flipped the normals on the model and confirmed that the model is unwrapped but the outcome is the same. I'm fairly new to Blender but have never come across this issue before.  Material Preview Render Preview

I tried to assign different materials to face - they work correctly only on Eevee rendering.  When I tried to render using Cycles - the surface always black - doesn't matter what the material or base color, only 2 properties have value - Emission and Alpha, they work correctly, face orientation is ok on this face.    And the blend file


ok i am not sure why is this happen, can someone tell me the answer to this?   this is my code on my html.  i created a link  Card List   from this link, it will lead to this jquery code when click  $("a#configPage").click(function(){ var request = $.get('controller.php',{ action: "configView", subaction: "" }); request.success(function(result) {   $( "#resultContent" ).html(result);   console.log(result); });  request.error(function(jqXHR, textStatus, errorThrown) {   if (textStatus == 'timeout')     console.log('The server is not responding');    if (textStatus == 'error')     console.log(errorThrown);    // Etc });  return false;   });  from the .get, i will go to my php script and return a set of HTML code with forms in it and populate to #resultContent div.  this is working fine. But after my form has been populated in #resultContent div, i have another same link inside that html   Card List   this time, that link above is not firing the jquery anymore. I found out that the html return is not showing in my view source code. Is this the reason why is not firing? how to solve this? or i am doing it wrong?  edit: everything from the return HTML is not firing any jquery at all such as form on submit button etc. Is like that whole div with the returned html code is not exist

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.


I was reading The Sorcerer's Stone when I noticed that Hagrid was very hard on the Dursley's for not telling Harry about Hogwarts, which is fair enough. However, this made me think. What if a student or a family who considered everything didn't want their child to come, similarly to how Mr. and Mrs. Durlsey said they didn't want Harry associated with magic. Obviously, the Dursleys are a bit of a special case because the way they treat Harry is horrendous, but what if an actual decent family said something similar? What if a parent wanted to put a "stop" to it as well? Would it be treated similarly? What if a student didn't want to go? Would they (the child) still be forced to go to Hogwarts, even if they didn't want to attend?

In the Harry Potter universe, young wizards and witches are sometimes born to Muggle parents. In this case, someone from the wizarding world visits them to offer the child their place at Hogwarts.   Anyway, attendance at Hogwarts isn't mandatory because parents can home school their children, but is this true for all children, or only those whose parents can teach them magic?  Would a Muggle-born wizard or witch be left to their own devices, not taught magic or integrated in the wizarding community, basically be left to live as a Muggle?   The only example I know of is Harry (the Dursleys didn't want him to go, but they were intimidated into letting him) but then again he is Harry Potter and there is no other way (even for Dumbledore in-universe) than to make an exception for him.   Do we know what the general rule would be for muggle born wizards and witches, or do we have any clues?


Let $F_n$ be the $n$-th Fibonacci number, defined recursively by $F_0 = 0$, $F_1 = 1$ and $F_n = F_{n−1} + F_{n−2}$ for $n ≥ 2$. Prove the following by induction (or strong induction):  $(a)$ For all $n ≥ 0$, $F_{n+1} ≤ \left(\dfrac74\right)^n$. $(b)$ Let $G_n$ be the number of tilings of a $2 × n$ grid using domino pieces (i.e. $2 × 1$ or $1 × 2$ pieces). Then prove $G_n = F_{n+1}$.  For question $(a)$, I've done the proof but the result I kept getting was $$\left(\frac74\right)^{k+1}\left(\frac{11}7\right)≤\left(\frac74\right)^{k+1}$$ which is wrong.

Recall that the Fibonacci sequence is defined by $F_0 = 0$, $F_1 = 1$, and $F_n = F_{n−1} + F_{n−2}$ for $n ≥ 2$. Prove that:  $$\forall \,\, n ≥ 1 ,\,\, F_n < \left(\frac 74\right)^n$$   In this question I understand how to do the basis step. In the induction step I know that you have to assume that n=k but I am having trouble figuring out on how to do that. Could someone please explain how to do this question.


I have written a program that is supposed to go through each character in a string and prints it out. However, something isn't working... #!/bin/bash  function name {   read -p "Enter your name: " username   for i in {0.."$(( ${#username} -1 ))"}; do     echo "${username:0:i}"   done }  name  However whenever I run it I get the error: line 7: username: {0..2}: syntax error: operand expected (error token is "{0..2}")  (By the way the input was Bob but it doesn't work with other cases either) Is there a way to fix the code? Is there a more efficient way to do this? (I intend to use the "${username:0:i}" part later, so just printing the characters to the terminal is not what I'm looking for!) Cheers!

I have the following bash script:  #!/bin/bash  upperlim=10  for i in {0..10} do echo $i done  for i in {0..$upperlim} do echo $i done   The first for loop (without the variable upperlim in the loop control) works fine, but the second for loop (with the variable upperlim in the loop control) does not.  Is there any way that I can modify the second for loop so that it works?  Thanks for your time.


The past couple of days I've been periodically getting this pop up through my antivirus. I'm not familiar with what to do with malware but I have made sure there are no recently installed apps- I have uninstalled and reinstalled my Chrome- 'reset' and 'repaired' the automatic windows edge and yet it still pops up.  I don't know what to do from here and I'm really hoping someone can help me.

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.


I would like to have the #Midori Tag. Since this browser comes with the common Raspian OS for Raspberry-Pi and there are many tutorials using #Midori . I think it makes sense to create the tag.

Can someone please create the tag  on our site? We need to have it because        Foo is a recent/upcoming release / edition / model / episode of a popular, established OS / board game / bike brand / TV show   Foo is a hot new language / ingredient / game   we're currently using some other tag for questions about Foo, but it's causing ambiguity with a separate thing that's also named Foo      This is not a joke post. We get a lot of feature requests that ask for this or that tag to be created, and every time, a discussion ensues wherein people explain that there is no "tag creation department" and that community members create tags just by using them. I'm posting this "question" so that future requests of that type can be closed as a duplicate of this, saving time and eliminating redundant conversations for everyone involved.     See also:


My iMac running High Sierra has become painfully slow. I suspect photoanalysisd, as it's using a lot of CPU time, but I can't figure out how to get rid of it. There's at least one other question () here about photoanalysisd, but my scenario is different and none of the suggestions in the other thread were helpful to me. Looking in the Console log, I see odd errors for photoanalysisd, e.g.: "seekAndRead -- Input/output error" "error: (266) I/O error for database -- CLSBusinessCategoryCache.sqlite.  SQLite error code:266, 'not an error' errno:5" "error: -executeRequest: encountered exception = I/O error for database at ... CLSBusinessCategoryCache.sqlite.  SQLite error code:266, 'not an error' errno:5"  Error code "not an error" -- huh? Using the Terminal, I've tried all of the following: sudo launchctl remove com.apple.photoanalysisd sudo launchctl kill -TERM gui/$UID/com.apple.photoanalysisd launchctl disable gui/$UID/com.apple.photoanalysisd launchctl kill -STOP gui/$UID/com.apple.photoanalysisd launchctl kill -TERM gui/$UID/com.apple.photoanalysisd  BUT photoanalysisd is still running, according to the Activity Monitor. Even after I issue commands to kill the process(!?), it's still there. Of course it also comes back when I restart, and slows the machine horribly again. First question, then: why don't these commands get rid of photoanalysisd? Next, I have tried starting in safe mode, but it makes no difference: the iMac is still unusable, until I issue commands to kill photoanalysisd. Also, the screen updates are incredibly slow in safe mode. The desktop appears very slowly and is painted in bands like venetian blinds opening up from the bottom. Never seen this before. Again, there is nothing in the Activity Monitor that is obviously eating up CPU or memory. Activity Monitor consistently reports over 90% idle, though the system is beachballing constantly. Finally, I have already re-installed High Sierra once, but it made no difference. I really don't care if the Photos app does the person recognition thing or not. I just want my Mac to be useable again. Any suggestions? EDIT: 25 days later, I still have no solution to this. My basic question about photoanalysisd (above) remains unanswered.

We got a new iMac for Christmas and it has seemed really slow for the past couple of days. In desperation I checked out Activity Monitor and it shows photoanalysisd as the guilty process that is hogging my CPU. I assume this is related to the Photos app, but that's not even running!  What is "photoanalysisd", why is it using 77% of my CPU, and can I safely stop the process?


The main screen before clicking "render image":    Page 1 of the options (pages made by scrolling):    Page 2 of the options (pages made by scrolling):    I am very, very new to Blender, so bare with me.  I had a friend make a model for me.  He assigned two textures to two objects called "Cube" and "white."  Each works properly when the render view is closed, but when I generate a render, no matter what pose, all textures disappear, and the model is solid black without shading.  How do I fix this?

I've imported an .OBJ file to my scene and it looks good in viewport, but when I try to render with F12 it's completely black.  Clearing custom split normals data (in object data panel) removes black rendering issue, but also completely destroys the shading in viewport and render.  Is there a way to somehow retain the viewport like shading in render?


What is a simple way to prove that two annuli $A_1 = {z: r_1 < |z| < R_1}$ and $A_2 = {z: r_2 < |z| < R_2}$ are conformally equivalent if and only if $R_1/r_1 = R_2/r_2$, using standard results of complex analysis?  I'm not looking for a concise proof so much as one that uses elementary concepts.

I'm self-studying some complex analysis, and apparently holomorphic bijections between two annuli exist precisely when the ratios of the radii are the same. More exactly, if $A_{\sigma,\rho}=\{z\in\mathbb{C}:\sigma&lt|z|&lt\rho\}$, then there is a holomorphic bijection between $A_{\sigma,\rho}$ and $A_{\sigma',\rho'}$ iff $\rho/\sigma=\rho'/\sigma'$.  Is there a reference where this fact is proven? Or can a proof be included here if it's not overly involved? Thanks.


I first tried to install the Wacom driver by following this:   When I ran ./configure, I saw this   checking for doxygen... no configure: WARNING: doxygen not found - documentation targets will be skipped   I wasn't sure if that was a problem or not. I decided to follow this:   so I typed   sudo apt-get install xutils-dev libtool xserver-xorg-dev libx11-dev libxi-dev libxrandr-dev libxinerama-dev libudev-dev   I then ran make and got  make[1]: Entering directory '/home/Downloads/xf86-input-wacom-0.33.0' Making all in conf make[2]: Entering directory '/home/Downloads/xf86-input-wacom-0.33.0/conf' make[2]: Nothing to be done for 'all'. make[2]: Leaving directory '/home/Downloads/xf86-input-wacom-0.33.0/conf' ... Making all in tools make[2]: Entering directory '/home/Downloads/xf86-input-wacom-0.33.0/tools' make[2]: Nothing to be done for 'all'. make[2]: Leaving directory '/home/Downloads/xf86-input-wacom-0.33.0/tools' Making all in test make[2]: Entering directory '/home/Downloads/xf86-input-wacom-0.33.0/test' make[2]: Nothing to be done for 'all'. make[2]: Leaving directory '/home/Downloads/xf86-input-wacom-0.33.0/test' make[2]: Entering directory '/home/Downloads/xf86-input-wacom-0.33.0' make[2]: Leaving directory '/home/Downloads/xf86-input-wacom-0.33.0' make[1]: Leaving directory '/home/Downloads/xf86-input-wacom-0.33.0'   This seemed ok, so I then tried sudo make install  ...  /bin/mkdir -p '/usr/bin' /bin/bash ../libtool   --mode=install /usr/bin/install -c xsetwacom isdv4-serial-debugger isdv4-serial-inputattach '/usr/bin' libtool: install: /usr/bin/install -c xsetwacom /usr/bin/xsetwacom libtool: install: /usr/bin/install -c isdv4-serial-debugger /usr/bin/isdv4-serial-debugger libtool: install: /usr/bin/install -c isdv4-serial-inputattach /usr/bin/isdv4-serial-inputattach make[2]: Nothing to be done for 'install-data-am'. make[2]: Leaving directory '/home/Downloads/xf86-input-wacom-0.33.0/tools' make[1]: Leaving directory '/home/Downloads/xf86-input-wacom-0.33.0/tools' Making install in test make[1]: Entering directory '/home/Downloads/xf86-input-wacom-0.33.0/test' make[2]: Entering directory '/home/Downloads/xf86-input-wacom-0.33.0/test' make[2]: Nothing to be done for 'install-exec-am'. make[2]: Nothing to be done for 'install-data-am'. make[2]: Leaving directory '/home/Downloads/xf86-input-wacom-0.33.0/test' make[1]: Leaving directory '/home/Downloads/xf86-input-wacom-0.33.0/test' make[1]: Entering directory '/home/Downloads/xf86-input-wacom-0.33.0' ... make[1]: Leaving directory '/home/Downloads/xf86-input-wacom-0.33.0'   I assumed this meant there were no errors. However, I don't see Wacom anywhere. I even typed   xsetwacom --list devices sudo find . -name wacom\* | grep modules   but there was no output for either of those commands.   lsmod | grep wacom just gave  wacom                  81920  0 hid                   118784  3 wacom,hid_generic,usbhid   I then followed this:   However, after sudo apt-get install wacom-dkms  I got   Error! Bad return status for module build on kernel: 4.2.0-36-generic (x86_64) Consult /var/lib/dkms/wacom/0.30.0/build/make.log for more information.   I then checked /var/lib/dkms/wacom/0.30.0/build/make.log and its contents are  DKMS make.log for wacom-0.30.0 for kernel 4.2.0-36-generic (x86_64) Building input-wacom drivers for 2.6 kernel. make -C /lib/modules/3.13.0-68-generic/build M=/var/lib/dkms/wacom/0.30.0/build/3.7 make[1]: *** /lib/modules/3.13.0-68-generic/build: No such file or     directory.  Stop. Makefile:24: recipe for target 'all' failed make: *** [all] Error 2   Can anyone help?

Recently I have installed an older version of Ubuntu on my old machine. Whenever I try to install any software, I get an error saying it couldn't be found:  $ sudo apt-get install vlc Reading package lists... Done                Building dependency tree        Reading state information... Done     E: Couldn't find package vlc


Hello thanks for looking into this, I need to extract text output of system function in std c++, I want the below program to return the text output that it prints in terminal, #include <bits/stdc++.h> using namespace std;  int main(int argc, char const *argv[]) {     system("git remote -v");     return 0; }   this gives on terminal origin  https://github.com/pawan-nirpal-031/Graphics-Lab.git (fetch) origin  https://github.com/pawan-nirpal-031/Graphics-Lab.git (push) orign   https://github.com/pawan-nirpal-031/Graphics-Lab.git (fetch) orign   https://github.com/pawan-nirpal-031/Graphics-Lab.git (push)  I want it to return this text output as a c++ string datatype.

I am looking for a way to get the output of a command when it is run from within a C++ program.  I have looked at using the system() function, but that will just execute a command. Here's an example of what I'm looking for:  std::string result = system("./some_command");   I need to run an arbitrary command and get its output. I've looked at , but I have not found anything that will give me what I need.


If all of humanity (and perhaps the animal kingdom too for good measure) were to run East at the same time for a prolonged period of time, would the equal and opposite force of their feet pushing the ground west behind them slow down the Earth's rotation?

I'm a class 12th student and this thought just struck me from nowhere.  Assume a situation where every human on this planet turns towards west. All of them start walking simultaneously in west direction (exactly west i.e. antiparallel to Earth's rotation and none of their paths cross each other).  As Earth spins from west to east would this activity cause the earth's rotation speed to increase?   (There is frictional force acting on the earth due to motion by nearly a billion people which should produce enough torque to increase angular velocity of the earth.)   p.s. If the magnitude of friction force not enough to rotate the earth then assume each person to weigh more than 100 kg.  Also if it does happen would earth remain in the same orbit around the sun with just increased angular velocity about axis? (or would path around the sun also change due to this? )  I would really appreciate an easy solution cause I am still in class 12th.


Lots of articles say that MLE is as same as minimizing cross-entropy.  I tried to prove this but failed.    This article has the same problem, but I could not understand it.  $\,$  For example, I have several data points $X_i\,(i=1,..., N)$  These points are distributed as $X \sim P_{data}(X)$  Let, I want to approximate $P_{data}(X)$ with some parameters.  Let this approximated model is $P_{model}(X;\theta)$.  $\,$  First, I tried MLE.  $\theta^*=argmax\,\,\prod_{i=1}^{N}P_{model}(X_i;\theta)$  $\,\,\,\,\,\,\,=argmax\,\,\log (\prod_{i=1}^{N}P_{model}(X_i;\theta))$  $\,\,\,\,\,\,\,=argmax\,\, \sum_{i=1}^{N}\log (P_{model}(X_i;\theta))$  $\,$  Second, I tried minimizing cross-entropy.  $\theta^*=argmin\,H(P_{data}(X),P_{model}(X_i;\theta))$  $\,\,\,\,\,\,\,=argmin\,\, E_{X\sim P_{data}(X)} [-log(P_{model}(X_i;\theta))]$  $\,\,\,\,\,\,\,=argmax\,\, E_{X\sim P_{data}(X)} [log(P_{model}(X_i;\theta))]$  $\,\,\,\,\,\,\,=argmax\,\, \sum_{i=1}^{N} P_{data}(X_i)\log (P_{model}(X_i;\theta))$  $\,$  OK. Here I have the different result.  In cross-entropy, $P_{data}(X_i)$ is multiplied.  Why does this happen?  And also, how can be cross-entropy calculated?  Because we do not know $P_{data}(X_i)$ in general case.  I'm really curious about this. Kind explanation will be greatly appreciated.

There is a statement that maximizing the likelihood is equivalent to minimizing the cross-entropy.  Are there any proof for this statement?


Question is precisely the title. I've been trying to come up with an example for an hour now and haven't found one. Do such matrices, $A$ and $B$ exist?

How to find two non singular matrices $B$ and $C$ such that $BC+ CB= 0$. Clearly $B$ and $C$ must be square matrices of same order and the order is even.so it is possible we can find some example of order 2. But I cannot find any. I would be happy if someone helps me in finding some matrices.Thanks in advance.


Take a system with two ideal, rigid spheres in vacuum, being under zero net external force. Now suppose I want to make the spheres collide, which I do by pushing one of them towards the other. Now consider the distance between the two spheres: let it be, say, $x$. As you can now obviously deduce, that as the 2 spheres come closer, $x$ will keep getting smaller and smaller, approaching $0$, taking every real value between its initial value and $0$ at different times. Now, well, I'm not sure if I should ask it here, but, if there are infinite real numbers before zero, and it's taking every one of them before getting equal to $0$, how are the balls colliding? What's really going on in there? A little quirky and philosophical, I know. I also asked the same on Physics Stack Exchange.

I heard Zeno's "Achilles and the Tortoise" paradox is resolved using the limit concept of mathematics, i.e., the time cost in every sub-race is added up, which has a limit, not limitless, so Achilles can catch up the Tortoise finally. That resolution is based on two assumptions:  the catch-up time equals to the sum of a series the series is convergent and the sum of the series is a limited number  The second assumption can be strictly proved in math. But how to prove the first assumption?


A probability density family for $x\in\mathbb{R}$ is  $$f(x) = k(\theta)\left[1 + (x/\theta)^2\right]^{-1}$$  parameterized by $\theta \gt 0$.  I am supposed to find $k(\theta)$ and then both $E(X)$ and $\text{Var}(X)$.  I have found that $k =1/(\theta\pi)$. When I try to evaluate $E(X)$ I get that the corresponding integral diverges. Is this possible and does it imply that the variance diverges too?

Many PDFs range from minus to positive infinity, yet some means are defined and some are not. What common trait makes some computable?


Let $$A= 1! \cdot 2! \cdot 3! \cdots 1002!$$  $$B= 1004!\cdot 1005! \cdots 2006!$$  Prove that $2AB$ is square. Help guys, I tried, I really did but I couldn't.

If :$A=1!2!\cdots 1002!$, and $B=1004 ! 1005!\cdots2006!$, how to prove that:  a) $2AB$  is a perfect square   b) $A+B$ is not a perfect square


I want this command to be executed automatically when my machine starts   xinput set-prop "AlpsPS/2 ALPS DualPoint Stick" "Device Enabled" 0   How can I do this?

I'd like to startup an Apache Spark cluster after boot using the following command:  sudo ./path/to/spark/sbin/start-all.sh   Then run this command when the system prepares to reboot/shutdown:  sudo ./path/to/spark/sbin/stop-all.sh   How can I get started? Is there a basic template I can build on?  I've tried to use an extremely simple (file: /lib/systemd/system/spark.service):  [Unit] Description=Spark service  [Service] ExecStart=sudo ./path/to/spark/sbin/start-all.sh   Which doesn't work.


The join() method for srings seems to work just fine for lists of strings and other built-in iterables. However, when I define my own iterables, join() cooperate. How can be write an iterable which join() is happy to have?  class IterATOR: # iter-ATOR     def __init__(self):         self.x = 0     def __next__(self):         self.x += 1         if self.x > 4:             raise StopIteration()         return 'hello world'  class IterABLE: # iter-ABLE     def __iter__(self):         return IterATOR()   print(30 * '#', 'BEGIN TEST ONE', 30 * '#') gable = IterABLE() gator = iter(gable) try:     while True:         print(next(gator)) except StopIteration as exc:     print(exc)   print(30 * '#', 'BEGIN TEST TWO', 30 * '#') gable = IterABLE() for elem in gable:     print(elem)   print(30 * '#', 'BEGIN TEST THREE', 30 * '#')  lyst = [str(x) for x in range(0, 5)] # tcs: test cases tcs = [lyst, IterABLE(), iter(IterABLE()), IterATOR(), lyst, iter(lyst)]  for tc in tcs: # for test case in test cases:     try:          print(type(tc).__name__.ljust(20), end ='')          merged_str = ''.join(tc)          print(" was a success:".ljust(20), repr(merged_str))     except Exception as exc:         print(" was a failure:".ljust(20), str(exc))   The output for test three is:  ############################## BEGIN TEST THREE ############################## list                 was a success:      '01234' IterABLE             was a failure:      'IterATOR' object is not iterable IterATOR             was a failure:      can only join an iterable IterATOR             was a failure:      can only join an iterable list                 was a success:      '01234' list_iterator        was a success:      '01234'

How would one create an iterative function (or iterator object) in python?


Usually when I try to get object:  buffering = processing.runalg('qgis:fixeddistancebuffer', in_layer, 100, 10, False, None) buf_layer = processing.getObject(buffering['OUTPUT']) QgsMapLayerRegistry.instance().addMapLayer(buf_layer)   But when I do the following it does not work:  saving = processing.runalg('qgis:saveselectedfeatures', in_layer, None) output_layer = processing.getObject(saving['OUTPUT']) QgsMapLayerRegistry.instance().addMapLayer(output_layer)   The error is   KeyError: 'OUTPUT'   Anyone knows how to get this object?

Calling the results of Processing algorithms in order to plot them to the screen differs depending on the provider used.  An example with QGIS provider:  tmpggis = processing.runalg("qgis:reprojectlayer",vektor,"EPSG:4326",None) out = tmpggis["OUTPUT"] qgisLyr = QgsRasterLayer(out, "Orfeo") QgsMapLayerRegistry.instance().addMapLayer(qgisLyr)   So, for QGIS it is: ["OUTPUT"]    - capital letters  For GRASS it is: ["output"]   - lower case letters  What is the Output name for other providers such as Orfeo Toolbox, SAGA, etc.?


This will probably be a long shot, but I read a novel about twenty years ago that I'm sure is from the late sixties.    I can only really remember the main plot point: There's a man in it who can change reality at will with only his mind.  A medical doctor studies him and uses this to his own ends.  Two more things: there was an alien invasion and people were preoccupied with a volcano at some point.  Don't remember any character names or locations.  Sorry about that.  If I knew those, I'd probably be able to find this myself.  My son and his wife are really getting into sci-fi books and stories and I'd like to be able to recommend this one to them, since I remember enjoying it at the time.

I saw a science fiction anthology series episode in which when a man manipulated by a doctor, I think a psychiatrist, slept and dreamed he would wake up to a world affected by what he had dreamed.  When I saw it, I looked it up and found that it was based on a book, and that a movie had also been made based on it.  I cannot remember the names of any of them.


I bought a Dell Vostro 3558 laptop with preinstalled ubuntu 14.04  It is only showing guest account log in. Not able to generate my personal account.it is not even taking password  to unlock account. Please guide. Mahen

I bought a New Dell Vostro 3558 Laptop today. Ubuntu was pre-installed in that. However, i am facing the below 2 issues in it.   Only Guest user login is available. Linux Terminal is not working in Guest user login   Could someone please advise what i should do now.


now, I have read a lot of explanations on that but still can't really understand why it would happen so if you can give some examples for a such a thing happening. I mean lets say gravity attracts the air and due to air viscosity all of the air gets carried with the Earth but why will the speed be same ?

I was reading somewhere about a really cheap way of travelling: using balloons to get ourselves away from the surface of the earth. The idea held that because the earth rotates, we should be able to land in a different place after some time. As we all know, this doesn't happen.  Someone said that the reason why this doesn't happen is because the atmosphere (air, clouds etc.) also revolves around the earth (with the same angular velocity as the earth's rotation). Since we are also part of the atmosphere, our position doesn't change relatively.  Well, I'm not convinced with that answer. Why does the atmosphere rotate along with earth?  Gravitational force is towards the centre of the earth, but I don't see how it's making the atmosphere rotate.


I maintain a large folder, and this folder is regularly rsync'ed to another folder far away.  Sometimes I change a name on my local folder, and then the next time I rsync to the remote folder the whole file needs to be sent, even though the only thing that needs to be sent really is the information that the filename has changed.  Is there any way to get rsync to figure out name/path changes?  I looked through here: , and couldn't find anything like that.

I have two drives with the same files, but the directory structure is totally different.  Is there any way to 'move' all the files on the destination side so that they match the structure of the source side? With a script perhaps?    For example, drive A has:    /foo/bar/123.txt /foo/bar/234.txt /foo/bar/dir/567.txt   Whereas drive B has:  /some/other/path/123.txt /bar/doo2/wow/234.txt /bar/doo/567.txt   The files in question are huge (800GB), so I don't want to re-copy them; I just want to sync the structure by creating the necessary directories and moving the files.  I was thinking of a recursive script that would find each source file on the destination, then move it to a matching directory, creating it if necessary. But -- that's beyond my abilities!  Another elegant solution was given here:


Does anyone have any idea how to create this realistic "skewed"/inclined 3D Style Tile?:    Things to note from this design:   The image "wraps" around the slab. The image has a light source that helps create the realistic look to it. Look at how the lighting in the upper right side is lighter than the lower left side. The location of the shadow is perfectly aligned with the tile. The spread/blur of the shadow "fits" the distance of the slab from the surface.   I found  from 2012, but the steps described by the author are to vague and can't enlarge his screenshots either.  I've been looking all over the web for a more helpful tutorial about how to accomplish this, but haven't been able to find anything.  Any help or pointers accomplishing this is GREATLY appreciated.  Image taken from Jonathan Quintin's:   EDIT-9/25/14  I was able to find the answer to my own question, but was unable to add it here. So I answered these two other very similar questions:

How do I create this type of effect with an image? I'm wondering how to get the thick edges and the tilted look. Is there an online tool that will convert a flat image to look like this?


I know this sounds like a general question and I've seen many similar questions (both here and on the web) but none of them are really like my dilemma.  Say I have this code:  void GetSomeData(char* buffer) {     // put some data in buffer }  int main() {      char buffer[1024];      while(1)      {           GetSomeData(buffer);           // do something with the data      }      return 0; }   Would I gain any performance if I declared buffer[1024] globally?  I ran some tests on unix via the time command and there are virtually no differences between the execution times.  But I'm not really convinced...  In theory should this change make a difference?

This question may sound fairly elementary, but this is a debate I had with another developer I work with.  I was taking care to stack allocate things where I could, instead of heap allocating them. He was talking to me and watching over my shoulder and commented that it wasn't necessary because they are the same performance wise.  I was always under the impression that growing the stack was constant time, and heap allocation's performance depended on the current complexity of the heap for both allocation (finding a hole of the proper size) and de-allocating (collapsing holes to reduce fragmentation, as many standard library implementations take time to do this during deletes if I am not mistaken).  This strikes me as something that would probably be very compiler dependent. For this project in particular I am using a  compiler for the  architecture. Insight on this combination would be most helpful, but in general, for GCC, and MSVC++, what is the case? Is heap allocation not as high performing as stack allocation? Is there no difference? Or are the differences so minute it becomes pointless micro-optimization.


I am poly modeling a head and I was wondering if there was a shortcut to insert poly's into this blank space. I have tried watching video tutorials but I dont see anything useful.

I have a large hole in a mesh that I'm trying to fill:    I've been trying an approach like this:    I'm finding it quite tough, since the number of vertices around the perimeter of the hole don't match a grid.  Is there a better approach to filling a hole like this?


Recently I installed Ubuntu 15.04. It's really fantastic but I don't want to use the GUI. I want to practice commands.  How can I make Ubuntu CLI only?

Hi I have ubuntu server 10.04 installed and I also installed the following:  su aptitude install xorg xfce4 aptitude install <name of GUI browser, I use firefox> aptitude install gedit aptitude install gnome-terminal   Now when I restart the system it goes to the GUI login, what I am really after is a system that loads the CLI by default and then I can use startx to load the GUI when really necessary. I am trying to learn CLI but I would like to retain access to the GUI for now. And, how can I switch between CLI and GUI anytime?


I came across $\int _0^{\infty }\frac{\left(\ln x\right)^2}{\sqrt{x}\left(1-x\right)^2}\text{dx}$, how should i approach it and what techniques can i use to solve it?

$${\dfrac{1}{\pi^2}}\int_{0}^{\infty}\dfrac{{(\ln{x}})^2}{\sqrt{x}{(1-x)^2}} \mathrm d x$$   I tried substituting $1/x$ for $x$ but the the only change in the integral is that the $\sqrt{x}$ moves in the numerator from the denominator. I don't understand what to substitute. $\tan{x}$ doesn't seem to work.


Assume you are an invincible observer who falls into a blackhole...  Your time runs slower than the universe outside, as you get closer and closer to the singularity, the ratio between your time and the time of the universe outside the blackhole increases exponentially.  Ergo, you will see the universe in a very rapid "fast-forward" (ignore the fact that you'll get fried by the immense amount of radiation that accumulates due to the time dilation).  Does this also not mean that the event horizon is aging much faster than you, and thus evaporating, and as you get closer and closer to the singularity, it evaporates more and more per second, according to you and at some point it will catch up to you?  Also by the time you reach infinitesimally close to the singularity, the universe outside has experienced such a long time, that the heat death or the big crunch has happened, in which case the black hole is also gone?  TLDR; As you approach the singularity, the event horizon will start moving towards you as it shrinks, at some point it will catch up right?

I am not a professional physicist, so I may say something rubbish in here, but this question has always popped in my mind every time I read or hear anyone speak of particles hitting singularities and "weird things happen".   Now to the question at hand, please follow my slow reasoning... As far as I've learned, to reach a black hole singularity, you must first cross an event horizon. The event horizon has this particular property of putting the external universe on an infinite speed to the falling observer. Now due to the Hawking radiation, and knowing that the cosmic background radiation is slowly dimming, sooner or later every black hole in this particular instance of inflation we are living in will evaporate, according to an external observer of said black holes.  This means that every black hole has a finite timespan, as long as this universe survives that long. Now if we go back to the falling observer, we had already established that such an observer would see the outside universe "speed up" infinitely. This means that when the falling observer "hits" the event horizon, he will (or it if we speak about particles, which is clearer in this case), be immediately transported in time towards the final evaporation moment of the black hole. Either this or the particle gets some weird treatment. My point is, such a particle never gets to the singularity, because it has no time to get to it. The moment it crosses the event horizon, the black hole itself evaporates.  Where am I wrong here?


In Pokemon Alpha Sapphire and Omega Ruby, If You catch Thunderous in the Storm Clouds Mirage Spot using the Eon Flute, than will the Storm Clouds come back so you can catch Landerous, or Tornadous?

There are a lot of legendaries available in ORAS, however a lot of them will only show up/be available if certain prerequisites are met.  I know Groudon/Kyogre are available through the Story, and      Rayquaza & Deoxys   through the postgame Delta episode, but what about the other available legendaries? What do I need to do to catch them?


When I run the following code:  double x = 4.35; double y = x * 100; System.out.println(y);   I get 434.99999999999994 which is expected due to the nature of floating point precision. However when I run:  double x = 4.35; double y = x * 1000; System.out.println(y);   I get 4350.0 in the console. Similarly when I replace the 1000 with 10, I get 43.5, which is peculiar, since there is no rounding error for these numbers. It seems that there is only rounding error when I mulptiply the double by 10 to the power of the number of decimal places. Why is it like that?  Also, when I tried running the three blocks of code using 4.25 as my value for x, I got a nice 425.0 in the console. Does rounding error only apply to some decimal values?  EDIT: Dividing 4.35 by 10 also gave me a wacky decimal (0.43499999999999994 to be exact). Also, if I set x to 43.5, there were no rounding errors at all. Multiplying by 10 gave me 435.0.  EDIT 2: I think some people are misinterpreting my question. I'm asking why this happens and not how to avoid running into these errors.

Consider the following code:   0.1 + 0.2 == 0.3  ->  false   0.1 + 0.2         ->  0.30000000000000004   Why do these inaccuracies happen?


Recently I have done some simulations with a linear system that behaves similarly to the wave equation. Now I have a bit of trouble understanding when interaction is possible in linear theories, especially in the context of quantum mechanics. If we, for instance, consider a linear theory like the maxwell equations we have no interaction between two light waves (as far as I recount). I have read the general answer , however I still do not get how one would formulate the interaction between e.g. two electrons described by a wave function. If we take the time dependent Schrödinger Equation: $$i \hbar \frac{\partial}{\partial t} | \psi \rangle = \hat{H} | \psi \rangle $$ How would the Hamiltonian be formulated to incorporate interaction and still be linear? The often seen expression $$\hat{H} = \hat{T} + \hat{V}$$ where $$\hat{V} = \frac{e^2}{4 \pi \epsilon_{0}} \frac{1}{\left| \vec{r}_{1} - \vec{r}_{2} \right|} $$ does not make so much sense to me here, because I do not understand how $\vec{r}_1 , \vec{r}_2$ would be defined at different times in the time dependent Schrödinger equation without involving the wave function itself in a non linear fashion.

I'm having trouble finding a simple answer to this question (maybe because there isn't one), but I'm just confused about how the Schrödinger Equation would look for two electrons. I understand that it would exist in 6 dimensional configuration space, but how does the potential look? It's confusing that the potential would be different for each electron depending on where the other one is.


Background  Currently all suggested edits with code changes are rejected. Some people belive that a suggested edit that fixes the code should not be rejected, I don't see any other option because:   If everybody would skip edits in code that he does not understand it would fill up the queue and waste the time of much more reviewers. For the same reasons we already reject minor edits. Reviewing other queues does NOT require special expertise to review. Why should suggested edits different?   Suggestion  But there is a user that should have the nessecary expertise: the original poster (OP). The OP has already a binding vote on suggested edits, but if the edit was rejected in the mean time, he has to edit the post itself, while the edit is still rejected.  So my suggestion is to let the OP override the suggested edit AFTER it was aproved/rejected if there were no other edits in the mean time*.  * How should a suggested edit be done if someone else edits the post after it was rejected?

A user  which added useful information to one of my answers. However, because it was a substantial edit, it was rejected by the reviewers. That's fine. However, as the owner of the post I would like to be able to overrule their decision after reviewing the edit myself (as I was encouraged to do by the notification in my inbox).  Currently, I had to open the edit suggestion in a different tab and manually copy and paste over the changes from the markdown diff to apply the changes. This seems laborious and doesn't give credit to the user who suggested the edit.  Request:  I would like a button on the suggested edit page, visible to the owner of the post, which applies the suggested changes, preferably just as if it had been accepted by the reviewers (i.e. giving credit to the editor and the +2 reputation for editing, if applicable).  Related discussions: (note that since this is a feature request, these are not duplicates)


I tried to install Times New Roman font on my Ubuntu. I used this code formulation: sudo apt-get install msttcorefonts. Everything looked fine, until the screen showed a kind of agreement statement. I tried to enter the 'OK' there, but it didn't work. So, I thought the process of installing the font is done. Then, I restarted the computer. But, the font, I could find it in my Libreoffice. I wrote the same formulation again for installing it. But I got this notification:   dpkg was interrupted, you must manually run 'sudo dpkg --configure -a' to correct the problem.   Can somebody help me to fix this? Thanks

I was running an upgrade with the apt-get command, and it was taking an exceptionally long time because half way through my ISP hit me in the face with their fair usage policy.   After sitting outside & watching the rain for awhile my electronics regained consciousness, so I went back to complete the upgrade and my terminal scolds me with   "E: dpkg was interrupted, you must manually run 'sudo dpkg --configure -a' to correct the problem."   The last bit of legible info was all this:  Installing (ri/RDoc) documention for (stuff and such) ERROR:  Could not find a valid gem 'watobo-0.9.8.724.gem' (>= 0) in any repository rm: cannot remove `watobo-0.9.8.724.gem': No such file or directory  Setting up metasploit (4.3.0-bt1) ... Upgrading Pre-Existing Installation... /opt/metasploit/postgresql/scripts/ctl.sh : postgresql  (pid 1191) already running prosvc is running metasploit is running [*] [*] Attempting to update the Metasploit Framework... [*]   So on it goes for miles, talking about gem caches, rubies, & stuff I wish I had. All up until:  A    lib/gemcache/ruby/1.9.1/gems/state_machine-1.1.2/gemfiles/active_record-2.1.2.gemfile.lock   ...and there it has sat, all night.    If I stop it, will I still get the dpkg error (on the off chance that I won't), or if so what do I need to to resume using apt-get commands and its Super Cow Powers?


On , I notice that if I use the lower "unanswered" tab (the one in line with "All Questions"), the count is 1,432 questions. If I use the upper "Unanswered" tab (in line with the site title), I get 1,383 "questions with no upvoted or accepted answers".  This changes the options in the lower tab, one of which is "no answers".  Clicking here, I now get 1,083 "questions with no answers". If I run select Id from Posts where PostTypeId=1 and AnswerCount=0;  in the , I get 1158 rows back. Which of these is correct, and why is the first one (1,432) so much higher than the others?  I understand that the numbers may only be updated periodically, but that difference in particular seems much too great for this to be the reason. To clarify:  1,432 is the number of "unanswered questions". 1,383 is the number of "questions with no upvoted or accepted answers". 1,083 is the number of "questions with no answer" 1,158 is the number of questions with no answer in the data explorer.  This is not live data, but that means it should be smaller, not larger, than 1,083.  I promise we did not offset this with answers to the tune of 80 questions this week.  The first three are obviously live because they fluctuate. The difference between the first two is ~50, implying they actually don't refer to the same thing, and the difference between the last two seems too great (and in the wrong direction) to be explained by the a live vs. data explorer source.

Is it possible that I am not using this feature correctly?  Or perhaps I should be modifying my expectation, but when I click on the 'Unanswered' button I get a list of results that contain perhaps one or two unanswered questions at the top, followed by many more already answered questions.  Another strange thing is that interspersed with the results are random unanswered questions within and around the answered ones, so that we are not only seeing answered questions in with the unanswered ones, but they are not sorted so that the unanswered ones stack up at the top.  Am I the only one to be seeing this?  Am I not using the feature correctly or is there some way that I am supposed to sort the results on my own?


I saw on Google the formulation: "the maverick of the sea scrolls…".  Would it be better, equivalent or incorrect, instead of saying for example "the maverick of frameworks", to say "the maverick framework" or the "the frameworks' maverick"?  EDIT Actually I want to know if I can use correctly the shorter sentence: "the maverick framework", as it is using maverick as an adjective?  Thanks!

I would be very grateful for some advice on how to decide whether to use an attributive noun or the "of genitive" (periphrastic genitive).  It seems to me that an attributive noun is generally preferable, except when it leads to ambiguity, often due to the combination of several modifiers with mixed dependent relationships.  Additionally, the of-genitive, when used stand-alone, seems to impart a more formal tone, a higher register.  Simple examples (preferred first, less-preferred second):  The department secretary vs. the secretary of the department.  But:  The excellent secretary of the department vs. the excellent department secretary.  Any additional guidelines would be most welcome.


I am 5'5" tall and weigh 250 lbs. I have never flown before but am flying to visit my son who is in the Navy serving in Japan this month. I will fly American AirlinesExpress to Chicago and then ANA Premium Economy to Japan. I am sick worrying about it.    Do you think I will fit and do you think I will need an extension?    I have lost 80 pounds but still have more to lose. I'm sad I cannot get excited about my trip for worrying about fitting in my seat.

As I said in another question, I'm bringing my parents to visit me here in Sweden next year.  My mother is around 280-300 pounds and 5'6" (130-135kg, 1.67m). I am concerned that she might be asked at the airport to buy a second seat. If it's likely I would rather just buy the second seat in advance, because I don't want her to be embarassed/humiliated by some random employee. As well, I won't be there, they will be travelling alone and aren't used to dealing with airports and they won't know what their rights are.  In terms of how it will affect other passengers, it's not important, she will get a window seat and my dad will sit in the middle seat, so I don't see it affecting anybody.   She insists it's fine, "the last time I flew I fit easily!" but that was 20 years ago when she was half the size.   They will be flying BA or SAS, definitely not Ryanair.  So - where is the cutoff? Is a 300 pound 5'6" woman going to be too big to fit in a single airline seat? Or am I worrying about nothing?


I'll start off by prefacing this with the fact that I'm not even sure if I'm asking the right question and what I'm really looking for is some guidance to dig in the right direction. I have a set of 3D spatial data (latitude, longitude, time) on a regular spatial grid. I expect there to be anomalies/outliers in this data that are of interest. They may be spatial or temporal in nature. Are there machine learning or statistical methods that are tailored towards identifying such anomalies? I think I'm struggling as it's such a vague question so some direction (even just the name of a method to go and google) would be really helpful.


I have dual boot Windows 7 and Ubuntu 16 with grub. They were working very well until I installed the last Windows update. The update had to restart at some point but as Ubuntu is listed first in the grub menu Windows didn't complete the update process. Right now I can neither access Windows partition nor access Windows OS. When I select windows in the grub I get only black screen and when trying to open the windows disk from Ubuntu I got the message in the attached screenshot.    I tried ntfsfix but never succeeded. please advise.

I am having trouble mounting my external hard drive, every time I try and do so I get the following message:    "Error mounting /dev/sdb1 at /media/fuzzy27/My Book: Command-line `mount -t "ntfs" -o "uhelper=udisks2,nodev,nosuid,uid=1000,gid=1000,dmask=0077,fmask=0177" "/dev/sdb1" "/media/fuzzy27/My Book"' exited with non-zero exit status 13: $MFTMirr does not match $MFT (record 0). Failed to mount '/dev/sdb1': Input/output error NTFS is either inconsistent, or there is a hardware fault, or it's a SoftRAID/FakeRAID hardware. In the first case run chkdsk /f on Windows then reboot into Windows twice. The usage of the /f parameter is very important! If the device is a SoftRAID/FakeRAID then first activate it and mount a different device under the /dev/mapper/ directory, (e.g. /dev/mapper/nvidia_eahaabcc1). Please see the 'dmraid' documentation for more details."   How do I go about or what do I need to do in order to fix this error/problem without losing any of the data on my hard drive?  Is there no other way of fixing it without having to reinstall windows or finding someone using windows?


I've tried a lot of the videos, how to's answers in here on how to get the smoke to run past ~150 frames, nothing works, bake I tried too. using cycle render and particles, Domaine smoke cache set to ~5000 frames

I've set up the physics of a swinging wrecking ball and set the animation to run for 240 frames.  This was not long enough for the entire "swing" of the ball-and-chain.   I'm unable to reset the timeline, but I can set the end frame to (say) 1000 frames, but when I try to play the animation, the animation progress halts at frame 240 and I cannot get it to go any further.   There are no markers or keyframes in the timeline.  What should I do to "force reset" the animation-timeline, to allow changes to the length?


I created a file using TeXstudio, I have lots of comments in the document. I want publish the document one version with the comments and the other without it. Is three a way to put on and off comments when publishing a PDF file in LaTEX? Will be of great help if some one can help me on this.   P.S I am not sure where to tag since I am a new user of latex and also this forum

This is kind of similar to some of the pdf to latex questions but from a different angle.  I'm not looking for a complete LaTeX reconstruction method, I want to know if the comments are safely hidden.  My scenario is that I would like to distribute a sample test to my students which includes the real test or some variation of it commented out---that way I can keep the same file from year to year without having to manage multiple documents.  I'm pretty sure that what's commented out is dropped entirely from the compiled document but I'd like to be absolutely certain before I distribute such a pdf.  Is there any way whatsoever to extract commented lines from the final pdf? If it makes any difference, I'll probably be using XeLaTeX.


I have an installation of Postfix & Dovecot on a Centos 7 server. While being logged into the server via ssh I am able to use telnet and openssl to connect to localhost like  openssl s_client -starttls smtp -crlf -connect localhost:25   authenticate myself, and send an email. However, when I try to connect to the server from my local Computer, replacing localhost with the server name, I get the error message  connect: Connection refused connect:errno=61   Using telnet I get the error  Trying XXX.XXX.XXX.XXX... telnet: connect to address XXX.XXX.XXX.XXX: Connection refused telnet: Unable to connect to remote host   The file /etc/postfix/master.cfcontains the lines  smtp      inet  n   -   n   -   -   smtpd submission inet n   -   -   -   -   smtpd   The command netstat -tpnl | grep :25 results in  tcp        0      0 0.0.0.0:25              0.0.0.0:*               LISTEN      10327/master         tcp6       0      0 :::25                   :::*                    LISTEN      10327/master    Calling systemctl status iptables.service on the server yields  ● iptables.service Loaded: not-found (Reason: No such file or directory) Active: inactive (dead)   Entering my mail server at mrtoolbox.com results in the message  Connecting to XXX.XXX.XXX.XXX 1/20/2016 3:43:42 PM Connection attempt #1 - Unable to connect after 15 seconds. [15.01 sec]  PWS3v2 15193ms   Can you give me some hints what I might have missed or how to check what is going wrong, here?

This is a  about Connection Refused    We see a lot of questions to the effect      When I try to connect to a system I get a message      Connection refused      Why is this ?


How do I install Ubuntu on Samsung Galaxy A01 ? Platform OS Android 10,One UI 2 Chipset Qualcomm SDM439 Snapdragon 439 (12 nm) CPU Octa-core (4x1.95 GHz Cortex-A53 & 4x1.45 GHz Cortex A53)GPU Adreno 505 Thank you

With the announcement of the Ubuntu Phone OS I'd like to know what phone (and tablet) models are supported at this time.  Note from foss & Oli: We are making this the master question for all future "Will this work on <insert random tablet/phone/device here>?!" questions


I was wondering what are the main tricks one can try when dealing with a functional equation, like trying values, checking injectivity, surjectivity, bijectivity... In particular, how is one sure generally to know every function that satisfies a functional equation (that is there are no more)? What I am asking for are links or reference materials from the internet; but if you have a list, I'd be grateful to read it!

Could you help me please with some functional equations? I need some online books with exercises and some explanations. I'm interested in the Cauchy functional equation and Jensen functional equation.


I'm a programmer looking at implementing the WASP predictor for cricket in python. I could find one formula for calculating the target score in the first innings, in the blog:  I found one implementation in R:  However, none of these describe the actual calculations involved in getting a win probability percentage in the second innings. I did find one question asking for similar details, but at a non-programmer level.  That question has no satisfactory answer either. Also, there's almost no literature about this elsewhere. Can you please tell how are the wasp scores -  win probability in second innings are calculated? Please provide the details: formulae involved and how each of the input variables are individually calculated.

We know that in the first innings the predicted score and in the second innings the predicted winning percentage will be calculated in the WASP.   But there is only one formula for calculating both score and percentage.  V(b,w) =r(b,w) +p(b,w) V(b+1,w+1) +(1-p(b,w)))V(b+1,w)  How is this one formula enough to get two results?  This question is not related to the . I’m not asking about logical explanation here; I just want to know, what is the change that they do in the formula to get the percentage for the second innings?  Providing an example is a great thing for this type of question.


How can I send the Return key in a script file? I am installing all the PPAs from a script, and while it works, currently the addition of each PPA requires user input of the carriage return.  #!/bin/bash add-apt-repository ppa:yannubuntu/boot-repair  add-apt-repository ppa:libreoffice/libreoffice-5-1

I am working on a simple bash script that configures new servers how I want them. It's nothing special but it will hopefully save me quite a lot of time in the future.  How do I prevent prompts like this:    You are about to add the following PPA to your system:     Stable version of nginx.     More info: https://launchpad.net/~nginx/+archive/stable   Press [ENTER] to continue or ctrl-c to cancel adding it   When running commands like this from a script:    sudo add-apt-repository ppa:nginx/stable    sudo apt-get update   sudo apt-get -y install nginx   Is there an auto accept flag that I can set or something like that?


Apparently the whole cumin seed contains oil which the ground version doesn't.  However when I crunch one down I never notice any oil coming out.  Where is it? I would like it to mix with my cooking oil.

I am referring to things like cumin seeds or others which are meant to contain oil.  When they are ground does it loose the oil?  Or does the oil exist but it deteriorates due to oxidation?  I also understand raw tumeric contains oil.  Does that also go once it's ground or does that oxidise too?  I am asking about if you ground at home and store bought powders.


Just wondering if there is any difference between:    echo "running the npm patch" >&2;   and   echo "running the npm patch" &>2;   I have actually never really understand that syntax.

I often see tutorials online that connect various commands with different symbols. For example:  command1 |  command2 command1 &  command2 command1 || command2     command1 && command2   Others seem to be connecting commands to files:  command1  > file1 command1  >> file1   What are these things? What are they called? What do they do? Are there more of them?    .


Suppose it is required to test the fitting of binomial distribution to the following data ( at level $\alpha =0.05$) :    the parameter p is estimated as p = 0.494 , and the expected frequencies (given in red ) are also calculated .  let the claculated value of chisquare statistic (using the formula $\sum\frac{(O_i - E_i)^2}{E_i}$ ) be  $\chi_{cal}^2 $ (say)  my question is : what  type of hypotheses does "goodness of fit" signifies , i.e is it single tailed or two tailed ?  in other words ( or expressing my question more clearly by showing the way i attempt it)  $ H_0 : $ $ P = 0.494 $ or fit of the model is good   $ H_1 : $ $ P \ne 0.494$ or fit of the model is not good   then the test criteria should be to  accept $ H_0 $ iff  $\chi_{0.025}^2 \le \chi_{cal}^2  \le \chi_{0.975}^2 $  but thats not the actual story  , every source that i reffered , says that test criteria should be to  accept $ H_0 $ iff  $ \chi_{cal}^2  \le \chi_{0.05}^2 $ , why is this happening , if its a two tailed hypotheses then both ends should be reffered ? please correct me where i am wrong

A published article () contains these 2 sentences:     Moreover, misreporting may be caused by the application of incorrect rules or by a lack of knowledge of the statistical test. For example, the total df in an ANOVA may be taken to be the error df in the reporting of an $F$ test, or the researcher may divide the reported p value of a $\chi^2$ or $F$ test by two, in order to obtain a one-sided $p$ value, whereas the $p$ value of a $\chi^2$ or $F$ test is already a one-sided test.    Why might they have said that?  The chi-squared test is a two-sided test.  (I have asked one of the authors, but gotten no response.)  Am I overlooking something?


If I reduce the Lorentz group to the representation $\mathfrak{su}(2)\oplus \mathfrak{su}(2)$, I can write left and right-handed Weyl spinors respectively as $\left( \frac{1}{2},0 \right)$ and $\left(0, \frac{1}{2} \right)$. I can get a Dirac spinor by summing them, i.e. $\left( \frac{1}{2},0 \right) \oplus \left(0, \frac{1}{2} \right)$.  In my lecture notes, it is said that one can obtain higher representations by taking the tensor product. As an example, my prof gives $\left( \frac{1}{2},0 \right) \otimes \left(0, \frac{1}{2} \right) = \left(\frac{1}{2}, \frac{1}{2} \right)$, and he says that this corresponds to spin $1$ with $4$ components. I don't really understand what are the numbers on the right-hand side, and how I can relate this object to spin $1$. What does this notation mean, and how does the calculation work?

EDIT:  The vector space for the $(\frac{1}{2},0)$ Representation is $\mathbb{C}^2$ as mentioned by Qmechanic in the comments to his answer below! The vector spaces for the other representations remain unanswered.  The definition of a representation is a map (a homomorphism) to the space of linear operators over a vector space. My question is: What are the corresponding vector spaces for the   $(0,0)$ Representation $(\frac{1}{2},0)$ Representation  $(0,\frac{1}{2})$ Representation $(\frac{1}{2},0) \oplus (0,\frac{1}{2}) $ Representation $(\frac{1}{2},\frac{1}{2})$ Representation infinite dimensional Representation?


I moved to a new apartment and under the far left burner is a hole into the oven:    That is my pizza stone you are seeing through the hole.   I understand that the oven needs some ventilation, but this seems like it would cause a lot of heat loss. Indeed the burner and any pan sitting there get quite warm while the oven is in use, I can boil water with the excess heat if a kettle is left there long enough (and the oven is very hot, like when I bake bread).

I'm staying in a hotel and have access to a "electric coil stove" for one of the first times.  I accidentally turned on the oven light and saw that the light was shining up through only one of the stoves:    There's only a port from the oven into the top right stove, and note that the stove is not on.  Here's a view from within the oven:    Is there a hole here as a vent for the oven for some reason, or is this for the stove? I typically use a glass "flat-top stove" that doesn't have an oven underneath it. I've never seen a direct hole from a stove to the oven before, and have to wonder what the purpose is.


Can I use Ubuntu 20.4 on a laptop with a 2GB ram and 1.9GHz processor? It is a x64 bit processor with 2 cores. I have not tried anything due to financial deficits.

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?


I can buy Dell Latitude E7270 through my employer. It will come with Windows, but I would like to install Ubuntu (most likely 14.04). This model does not appear on the list of certified hardware, however. Does anyone know whether I should anticipate any problems with his laptop? Thanks!


Prove that the elements $b_{1} = (x_{1}, y_{1})$ and $b_2 = (x_{2}, y_{2})$ form a basis of $\mathbb{Z} \oplus \mathbb{Z}$ if, and only if, $x_{1}y_{2} - x_2y_1 = ± 1$  I was able to show that these vectors are linearly independent because the determinant between them is by hypothesis $\pm 1$. But I could not show that they generate all $\mathbb {Z} \oplus \mathbb {Z} $. How to proceed?

Let $x = (a, b), y = (c, d) \in \mathbb{Z}^2$. What is the condition on $a, b, c, d$ so that ${x, y}$ is a basis?   My answer: $ad\neq bc$ and $gcd(a, c) = gcd(b, d) = 1$.  The first condition ensures that they aren't the same vector; the second ensures that we can actually "get" all of the integer values/lattice points.  Is this correct?  Thanks.


By "sponge" I mean anything used to suck up liquids from surfaces, such as kitchen towels etc. I assume capillary action is a factor, and also maybe surface area and surface energy. What are the factors involved and what makes a good sponge?  In other words, how can one predict the best materials for creating a sponge?

If I take a sponge and place it in a shallow dish of water (i.e. water level is lower than height of sponge), it absorbs water until the sponge is wet, including a portion of the sponge above the water level. In other words, it seems the sponge pulls some water from the bath up into itself, doing work, and the water gains some gravitational potential energy.  Where does the energy required to do this work come from? My suspicion is that the answer involves physical and/or chemical bonds between the water and the sponge, or possibly the change in the surface area to volume ratio of the water.


How can I use Cisco AnyConnect on Rasbian OS? apt-get install anyconnect is not possible.

I am currently using Windows XP with Cisco VPN Client version 5.0.01.0600  I would like to replace Windows XP with Linux, either Red Hat version 5.x or 6.x  My question is, what equivalent VPN software can I install on Linux machine in order to get full compatibility with the same VPN network that the Cisco VPN client uses.  Where can I download Cisco VPN Client version 5.0.01.0600 for Linux?


If I have a domain with the URL example.com/section-1/abc, should there also be a dedicated web page for example.com/section-1 from a SEO point of view?   Assume that there is no bread crumb navigation or any links to this page.

Question, is it ok for one of the pages levels to 404? (SEO-wise)  Let's say I have a sitemap like this:  example.com --/services   --/foo   --/bar --/sectors   --/my-sector   --/another-sector   --/the-sector   --/stuff --/about-example --/contact --/etc --/etc   This makes a lot of structural sense. However, from a design point of view, I think having a page to show all the sectors (example.com/sectors) is pointless since all of the sector pages can be accessed from the home page, main navigation, and in each sector page.  Would there be any SEO consequences if the /sectors page were to 404?  Note: in the sitemap 'example.com/sectors' would not be included.


I installed applications such as : Stacer,Latte,Sweeper,ONLYOFFICE,easyTAG,Files,etc. through software center Discover. I noticed that some of them are not updated to the latest stable version. My question is if these applications will update automatically ? (or i will have to uninstall them and install again with the latest version)

Why are packages in the official Ubuntu repositories older than the latest (upstream) versions from Debian Sid, PPAs, the authors, etc.?


I am working on a project for school and I am having a little issue with an IF statement i have made.  it uses a Scanner input and looks for the answer to what the person typed. It doesn't seem to be working however.  public static void remove(){     System.out.println("Would you like to remove a student? (y/n)");     input = new Scanner(System.in);     String answer=input.nextLine();     if(answer == "y"){         Scanner idInput = input;         System.out.println("Please enter a student ID");         for(int i=idInput.nextInt();i<=studentlist.size();i++){             if(studentlist.get(i).getId().equals(i)){                 studentlist.remove(i);                 return;             }         }     }     return; }   When I enter 'y' (without quotes) into the console it just skips my if logic and returns to the main method.      Would you like to remove a student? (y/n) y Student ID  Recent Grades   Name        E-Mail          Age 1       [88, 79, 59]    John Smith  John1989@gmail.com  0 2       [91, 72, 85]    Suzan Erickson  Erickson_1990@gmailcom  0 3       [85, 84, 87]    Jack Napoli The_lawyer99yahoo.com   0 4       [91, 98, 82]    Erin Black  Erin.black@comcast.net  0 5       [79, 88, 91]    Joshua Selvidge jselvidge@wgu.edu   0

I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?


I have computers A, B and C. Every one of them has ssh enabled and I can use rsync.  A can ssh to B B can ssh to C A can't ssh to C  B has public ssh access, so A can connect B and C can communicate because they are in a vpn and A is not part of it. I would like to copy some files (and create a cronjob for this) from C to A. What is a good way to do this? UPDATE: I was able to ssh to C  via B as it was explained in the related answers that you suggest me but I was not able to rsync through serverB.     Consider that B is listening for ssh not on port 22.

Possible Duplicate:          For connecting to server B I have to first ssh to server A. What's the command line to access server B?


I like the noend option from algorithmicx because it makes the layout of the algorithm closer to the python syntax my students use. But to make it even clearer, i'd like to have left threads on the left to visually empashise the indented block. Like this:

I am using the algorithmicx package to write an algorithm. However I am using the noend option:  \usepackage[noend]{algpseudocode}   Is there anyway to get vertical lines for each block of code? This question has been answered here:    However, it does not work when using the noend option.  EDIT: I'm looking for something like the algorithms here:


Can I remove a bounty which I set on a question if none of the answers satisfy me?

It's possible to offer and award bounties of reputation on questions.   What is a bounty? How can I find questions that have a bounty attached? How do I start a bounty? When can I start a bounty? Why is the system requiring me to choose a bounty amount that's higher than the minimum? Can I use Markdown formatting in the bounty remarks? Can I edit the remark? How long is the bounty period? How do I award a bounty? Can I award a bounty to my own answer? Can I award a bounty to an old answer? If I offer a bounty on someone else's question, can I award the bounty to their answer? After awarding the bounty, can I remove it or move it to another answer at a later time? What happens if there's no answer after the bounty period? What happens if I feel my question is still unanswered? What is automatic awarding? Are bounty awards exempt from the 200 points/day reputation limit? How does Community Wiki mode affect bounties? How does user deletion or post dissociation affect bounties? Can I award a bounty to an answer from a deleted user or one where the author was dissociated? Can I offer a second bounty after the first one has expired? Can I raise my bounty? What happens if a bounty question is closed or deleted? Why can't I vote to close or migrate a bounty question? What happens if I delete my account while I have an active bounty? Do I keep an awarded bounty when I delete my answer? What happens if a question where I awarded a bounty later gets deleted or migrated? Can I cancel my bounty? Can I affect / divide / share part of my bounty to two (or more) users? How many outstanding bounties can a single user have?      See also:  in the Help Center


Just out of curiosity, I was wondering if anybody knows any methods (other than the integral test) of proving the infinite series where the nth term is given by $\frac{1}{n^2}$ converges.

I need to prove that the sequence $a_n=1+\frac{1}{2^2}+\frac{1}{3^2}+\cdots+\frac{1}{n^2}$ converges. I do not have to find the limit. I have tried to prove it by proving that the sequence is monotone and bounded, but I am having some trouble:  Monotonic:  The sequence seems to be monotone and increasing. This can be proved by induction: Claim that $a_n\leq a_{n+1}$ $$a_1=1\leq 1+\frac{1}{2^2}=a_2$$  Need to show that $a_{n+1}\leq a_{n+2}$ $$a_{n+1}=1+\frac{1}{2^2}+\frac{1}{3^2}+\cdots+\frac{1}{n^2}+\frac{1}{(n+1)^2}\leq 1+\frac{1}{2^2}+\frac{1}{3^2}+\cdots+\frac{1}{n^2}+\frac{1}{(n+1)^2}+\frac{1}{(n+2)^2}=a_{n+2}$$  Thus the sequence is monotone and increasing.   Boundedness:  Since the sequence is increasing it is bounded below by $a_1=1$. Upper bound is where I am having trouble. All the examples I have dealt with in class have to do with decreasing functions, but I don't know what my thinking process should be to find an upper bound.   Can anyone enlighten me as to how I should approach this, and can anyone confirm my work thus far? Also, although I prove this using monotonicity and boundedness, could I have approached this by showing the sequence was a Cauchy sequence?  Thanks so much in advance!


As the title says: Is there any guarantee from C++ Standard to be sure the left side of && (or and) operator always evaluated first? To be honest, I couldn't search in , I don't know which section I most look for. Sample of Problem: I want to do something like this: std::unordered_map<std::size_t, std::weak_ptr<T>> objects;  bool f (std::size_t const id) {   bool result = false;    if (not objects.at(id).expired()) {     auto const& object = objects.at(id).lock();      /* Here left side of `and` most be evaluated first */     result = object->parent->remove(id) and               objects.erase(id) == 1;   }    return result; }  And want to be sure there is no problem with the code.

Does the ANSI standard mandate the logical operators to be short-circuited, in either C or C++?  I'm confused for I recall the K&R book saying your code shouldn't depend on these operations being short circuited, for they may not. Could someone please point out where in the standard it's said logic ops are always short-circuited? I'm mostly interested on C++, an answer also for C would be great.  I also remember reading (can't remember where) that evaluation order isn't strictly defined, so your code shouldn't depend or assume functions within an expression would be executed in a specific order: by the end of a statement all referenced functions will have been called, but the compiler has freedom in selecting the most efficient order.  Does the standard indicate the evaluation order of this expression?  if( functionA() && functionB() && functionC() ) cout<<"Hello world";


I have a maps.conf with a lot of map blocks like  map $uri $page_redirect {   include /etc/nginx/maps/rewrites.map; }   ...and a lot of *.map files that redirect pages, for instance:  */homepage/* to *https://example.com* and */my-page/* to *https://example.com/page/*  Now I also have some sections of the site where I need to use a variable for a more dynamic redirect.  /dynamic-page/detail/o5u48i3u5 should redirect to https://example.com/show/page/detail/o5u48i3u5  What I have tried to far was this:  ~^/dynamic-page/detail/(?<location>.*)/$          https://example.com/show/page/detail/$location/;   The redirect itself works, but it won't replace $location in the URL so it looks like this: https://example.com/show/page/detail/$location/  I have even tried  ~^/dynamic-page/detail/(.*)/$          https://example.com/show/page/detail/$1/;   but the URL is https://example.com/show/page/detail/$1/  Can someone point me in the right direction?

The  states that:     Since 1.0.4, case insensitive regular expressions can be used by prefixing the pattern with ~*.   And gives the example:  map $uri $myvalue {     /aa                   /mapped_aa;     ~^/aa/(?<suffix>.*)$  $suffix; }   I updated to nginx/1.2.7 to make use of this, and naive regexes work okay, but variables don't. When I try the above syntax I get the error:  nginx: [emerg] pcre_compile() failed: unrecognized character after (?< in "^/aa/(?<suffix>.*)$" at "suffix>.*)$"   I also tried the following syntaxes, but none of them worked:  ~^(.*)$  $1; ~^(.*)$  \1;   but neither of them worked either.  Does anyone know how to get variables to work in regular expressions in HttpMapModule?


I must be making some silly mistake but I can't see it... I have a document with some objects on a layer (metaballs) and 1 cam. The layer is enabled, the objects have preview and render ticked. The objects have Max draw textured. The renderer is cycles. The objects have nodes shaders.  Two 3dviews are open. both are aligned to cam. The cam has been pointed at the objects. Both are in object view. One shows the objects in all draw modes. The other shows the objects in no draw modes. The objects do not render. I have restarted blender.  What am i doing wrong? (2.79b)  Another thing I notice is the working mballs seem to have an orange icon with their name that expands to a white icon with the same name. eg mball.005 contains mball.005.  the broken mballs seem to be mixed up - the names don't match. e.g. mball.010 contains mball.012. Renaming the child elements doesn't seem to fix things but maybe it indicates something got corrupted. Pure speculation...  Regards  update: I pushed it out to an obj, factory reset blender and brought it back in. apart from needing the nodes rebuilt all is back to normal. it's made all the metaballs into single objects which I couldn't work out how to do, so in fact it's actually done me a favour.  I'd still like to know what I did wrong to mess up the file...

This is meant to solve this problem once and for all. What is every reason an object isn't showing up in a render or viewport in when using the cycles render engine?


Is there a library to compare two XML files including all imported XSD files? I need to know differences through the whole tree.  I need to know the individual differences because I need to report on them, not just that the files are different.

I'm trying to write an automated test of an application that basically translates a custom message format into an XML message and sends it out the other end.  I've got a good set of input/output message pairs so all I need to do is send the input messages in and listen for the XML message to come out the other end.  When it comes time to compare the actual output to the expected output I'm running into some problems.  My first thought was just to do string comparisons on the expected and actual messages.  This doens't work very well because the example data we have isn't always formatted consistently and there are often times different aliases used for the XML namespace (and sometimes namespaces aren't used at all.)  I know I can parse both strings and then walk through each element and compare them myself and this wouldn't be too difficult to do, but I get the feeling there's a better way or a library I could leverage.   So, boiled down, the question is:  Given two Java Strings which both contain valid XML how would you go about determining if they are semantically equivalent?  Bonus points if you have a way to determine what the differences are.


I am trying to calculate the sides of a right triangle given an angle theta and the hypotenuse. I specify that the hypotenuse should be equal to five. Then I calculate the sides using cos and sin, as per standard trig. What I find after the side lengths are calculated is that the hypotenuse is actually 5.000000000002 long, or something as ever so slightly off from exactly 5. For the purposes of the code I am writing, I would prefer that if I can't get a perfect hypotenuse length of 5, I would rather the program return side lengths that corresponded with a hypotenuse length of 4.99999999999, or however close to 5 as possible on the lesser side. All of my numbers are doubles. Any idea if this can be done?  I am writing in Java.

Consider the following code:   0.1 + 0.2 == 0.3  ->  false   0.1 + 0.2         ->  0.30000000000000004   Why do these inaccuracies happen?


I came to notice that on the smart phone (using mobile web theme), some of the badges some have white lettering and some have blue/orange lettering:        The badges are hyperlinks, so the change of color means different color for the "visited" links. However, in the full site theme the color does not change, so it looks like a bug.

Now some random badges on the Profile page for the mobile web is now blue! This is seemingly weird as the default and now permanent color for Badge name text is white. Here's the problem here:     Ahhhh! Now it has invaded the desktop/computer version too! Now seemingly, every version has badges with blue text. Android app has the same issues too! Can the badge color be fixed from blue to white on the mobile version please?


I've been learning CSS and am now practicing by trying to replicate basic websites, but I've stumbled across a problem!  I'm trying to vertically align a box so that it is always in the middle, and will automatically scale if I make the browser vertically smaller. So far I've tried to replicate what I've done horizontally (normally margin: 0 auto;) but it isn't working.  My relevant HTML and CSS so far look like this:    *{   margin: 0;   padding: 0;   box-sizing: border-box; }  /* Global Values */  html{   font-family: "Arial";   font-size: 16px;   line-height: 1.2;   height: 100%; }  body{   background-color: #f9f9f9;   height: 100%; }  .container{   display: block;   min-width: 240px;   max-width: 768px;   width: 100%;      /*----------------------------------------------*/   /* This is to make sure that the container height is always the same size as the browser. */      min-height: 100px;    height: 100%;        /*----------------------------------------------*/   margin: 0 auto;   text-align: center;   border-style: solid; }   header{   border: solid;   min-height: 100px;   margin: auto 5%; }

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         I'm showing the borders so I can see what's going on, and am sure that (like horizontal centering) my margins need to be automatic. When I've done this horizontally, it's worked fine...  Does anyone have a recommendation on what to do??  Thanks in advance!

I want to center a div vertically with CSS. I don't want tables or JavaScript, but only pure CSS. I found some solutions, but all of them are missing Internet Explorer 6 support.
Div to be aligned vertically
   How can I center a div vertically in all major browsers, including Internet Explorer 6?


I dont want to know that we have two types of feedbacks and why it was invented,I just want an explanation in simple words of what feedback is.

We are teaching op amps in a high school class, before calculus.  So we can't use control theory to teach how op amps respond.  All the same, I would like to have an intuitive explanation for how a feedback circuit works.  Take the negative feedback, for instance.  Is there a clear way to show how an initial difference of delta between V+ and V- leads to a very large (G(V+ - V-)) difference in the output, which then leads to ...  I'd like to be able to take that argument and show how the voltage of the output converges in addition to the standard virtual short argument.  Can anyone explain it clearly?


I am looking for a simple method to change password with a script on macOS 10.12.6 (or newer).  I tried something like  sudo yes "mynewpassword" | sudo passwd myuser   But this is not working, apparently passwd is not reading from stdin.  I wonder if there is a official method to do so, like a command line tool.

I am trying to set a master password from the terminal (using a shell script). I see the passwd function and the master.passwd function, however I don't see any documentation on either of these to set the master password (AFAIK, these set the user passwords only).  I am pulling my information from these sources:      My question is:  Can you use the passwd or master.passwd commands to set the master password? If so, can you please provide an example for how to accomplish this?


I want to simplify things in my jQuery Backbone.js web application. One such simplification is the behavior of my menu and dialog widgets.    Previously I created the div boxes of my menus at start and hid them using display: none; opacity:0;.   When I needed a menu, I changed its style to display:block then used the jQuery ui position utility to position the div box (since elements with display:none cannot be positioned) and when it was done, finally changed its style to opacity:1.    Now I want to just hide them with visibility:hidden, and when I need one, I use the position utility and then change the style to visibility:visible.  When I begin using this new approach, I will have around 10 div boxes throughout the web application session that are hidden but occupy space, in contrast to the previous div boxes hidden with display:none.    What are the implications of my new approach? Does it effect browser performance in any regard?

The CSS rules visibility:hidden and display:none both result in the element not being visible. Are these synonyms?


I developed a plugin in QGIS and I have attached a function on button clicked but it is calling the function two times and I don't know the reason why.  I am registering click function in plugin run event:      def run(self):          """Run method that performs all the real work"""         AttachBtnClicked(self)          # show the dialog         self.dlg.show()         # Run the dialog event loop         result = self.dlg.exec_()  def AttachBtnClicked(self):     self.dlg.btnDataSourceEncodingChangeAllLayers.clicked.connect(lambda: btnDataSourceEncodingChangeAllLayersClicked(self))   while the method is:     def btnDataSourceEncodingChangeAllLayersClicked(self):         print 'DataSourceEncodingChanageAllLayers : '# + encodingName         LayerDataSourceChange()   it runs two times.

I have a plugin with a function (triggered by a button) that selects a specific layer by name, then shows its attribute table. When I close the plugin and open it again, the attribute table pops up twice, and repeating this keeps adding another table popup. What's wrong?  Code:  def showTable(self):     for lyrs in QgsMapLayerRegistry.instance().mapLayers().values():         if lyrs.name() == "TestFeatures":             lyrTest = lyrs     self.iface.showAttributeTable(lyrTest)


If $q\mid 2^x-1$ and $q\mid 2^y-1$ does $q\mid 2^{\gcd(x,y)} - 1$?    If the answer is yes, please show proof. By factoring $2^x - 1$ to ${2^{\gcd(x,y)}}^\frac{x}{\gcd(x,y)} - 1$ the converse must be true.

Possible Duplicate:        $b$, $x$, $y$, $z$, $\ldots$ are integers greater than 1. How can we prove that  $$ \gcd (b ^ x - 1, b ^ y - 1, b ^ z - 1 ,\dots)= b ^ {\gcd (x, y, z, \dots)} - 1\ ? $$


Using differentiation with respect to the parameter,show that for $|r|<1$  $$\mathbf{F}(r)=\int_{0}^{\pi}\ln\left(1-2r\cos x +r^2 \right)dx =0$$  my attempt is $$\mathbf{F}'(r)=\int_{0}^{\pi}{-2\cos x + 2r \over1-2r\cos x +r^2}dx$$  let $u=\tan{x \over2}$ then $\cos x = {1-u^2 \over 1+u^2} $ and $dx={2du \over 1+u^2}$  Now  $$\mathbf{F}'(r)=\int_{0}^{\infty}{-2{1-u^2 \over 1+u^2} + 2r \over1-2r{1-u^2 \over 1+u^2} +r^2}{2du \over 1+u^2}$$ $$\mathbf{F}'(r)= 4\int_{0}^{\infty}{r+ru^2+u^2-1 \over 1+u^2-2r+2ru^2+r^2}{du \over 1+u^2}$$ but I do not know how to continue, I tried with partial fractions but it becomes too tedious.

For $a\ge 0$ let's define $$I(a)=\int_{0}^{\pi}\ln\left(1-2a\cos x+a^2\right)dx.$$ Find explicit formula for $I(a)$.   My attempt: Let  $$\begin{align*} f_n(x) &= \frac{\ln\left(1-2 \left(a+\frac{1}{n}\right)\cos x+\left(a+\frac{1}{n}\right)^2\right)-\ln\left(1-2a\cos x+a^2\right)}{\frac{1}{n}}\\ &=\frac{\ln\left(\displaystyle\frac{1-2 \left(a+\frac{1}{n}\right)\cos x+\left(a+\frac{1}{n}\right)^2}{1-2a\cos x+a^2}\right)}{\frac{1}{n}}\\ &=\frac{\ln\left(1+\dfrac{1}{n}\left(\displaystyle\frac{2a-2\cos x+\frac{1}{n}}{1-2a\cos x+a^2}\right)\right)}{\frac{1}{n}}. \end{align*}$$ Now it is easy to see that $f_n(x) \to \frac{2a-2\cos x}{1-2a\cos x+a^2}$ as $n \to \infty$. $|f_n(x)|\le \frac{2a+2}{(1-a)^2}$ RHS is integrable so $\lim_{n\to\infty}\int_0^\pi f_n(x)dx = \int_0^\pi \frac{2a-2\cos x}{1-2a\cos x+a^2} dx=I'(a)$. But  $$\int_0^\pi \frac{2a-2\cos x}{1-2a\cos x+a^2}=\int_0^\pi\left(1-\frac{(1-a)^2}{1-2a\cos x+a^2}\right)dx.$$ Consider $$\int_0^\pi\frac{dx}{1-2a\cos x+a^2}=\int_0^\infty\frac{\frac{dy}{1+t^2}}{1-2a\frac{1-t^2}{1+t^2}+a^2}=\int_0^\infty\frac{dt}{1+t^2-2a(1-t^2)+a^2(1+t^2)}=\int_0^\infty\frac{dt}{(1-a)^2+\left((1+a)t\right)^2}\stackrel{(*)}{=}\frac{1}{(1-a)^2}\int_0^\infty\frac{dt}{1+\left(\frac{1+a}{1-a}t\right)^2}=\frac{1}{(1-a)(1+a)}\int_0^\infty\frac{du}{1+u^2}=\frac{1}{(1-a)(1+a)}\frac{\pi}{2}.$$ So $$I'(a)=\frac{\pi}{2}\left(2-\frac{1-a}{1+a}\right)\Rightarrow I(a)=\frac{\pi}{2}\left(3a-2\ln\left(a+1\right)\right).$$  It looks too easy, is there any crucial lack?  $(*)$ — we have to check $a=1$ here by hand and actually consider $[0,1), (1,\infty)$ but result on these two intervals may differ only by constant - it may be important but in my opinion not crucial for this proof.


I am writing a small Bash script to do some automatic commands. In particular, I would like to save the current directory path in a variable called my pwd and then use mypwd to change directory.  I have tried the following lines with no success:  mypwd=${PWD} cd mypwd/other/ cd $mypwd/other/   How can I perform this operation in Bash?

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 want to check whether a user contains a certain public group. I have tried the following select statement  [SELECT id, Name FROM Group where RelatedId=: userInfo.getUserRoleId() and DeveloperName  = *`<public group name>`* Limit 1]   But this does not return any record even though I have assigned the user into the public group.

I am trying to find out all the public groups related to an user and display it on a vf page. Is this doable?  Step 1:  from Groupmember I get the group Id related to a user using  list<groupmember> g_m = [select id from groupmember where userorgroupid =: userid];   Step 2: I query all the group info   This gives me only a subset of groups of type ="Regular". How do I access all the Public Groups related to a user.  I also want to display the groups that the user is related to as part of nesting (ie) if user A is related to public group A and public group A is nested within Public group B the user becomes part of Public group B to which I want visibility into .  Any help would be greatly appreciated.


Good Day ma'am/sir,  I need help, and am not locating the right type of help. I just got my mother a new PC with Ubuntu on it, after initial setup and updates, all was operational...upgraded to 14:04 (newer one available) (and I have the disc that came with PC it is for Ubuntu 13:04, I believe) So the problem; I know the passwords, we set them up to work for her, the problem is in the User Accounts part, her profile (the only one set up) was switched from administrator to standard user, and now for everything and anything it will ask for administrator privilege and the password does not do anything, just spits back the password bar. I tried changing the password, I just can not get her account back to Administrator. If any help is able, it would make the world of a difference. Thanks for your time, Good Day,  Semper Fidelis  Lt. Woods

I clean-installed Ubuntu 11.10 today, and then installed VirtualBox.  This required me to add myself to the vboxusers group, and since 11.10 seems to no longer have a graphical app to add users to a group, I ran the following command:  sudo usermod -G vboxusers stephane   This is a problem.  I now see what I should have run instead is:  sudo usermod -aG vboxusers stephane   The end result is I'm no longer in the groups I should be in.  Including whatever group is required to run "sudo".  When I run any command as sudo now, I get the following:  $ sudo ls [sudo] password for stephane:  stephane is not in the sudoers file.  This incident will be reported.   Is there a way to fix this, or do I need to re-install from scratch again?


I was just wondering if we have any proof at all whether the universe is finite or not. I have heard that it is indeed expanding - which could mean that it is possibly finite... is this true? or what is anyone's opinion?

I thought the universe was finite, but then I read this:    And they seem to assume it is infinite. So which is it?