I can't do anything with apt-get because there are a stupid package that blocks it from working. This is what happens:  $ sudo apt-get upgrade Reading package lists... Done Building dependency tree        Reading state information... Done You might want to run 'apt-get -f install' to correct these. The following packages have unmet dependencies:  gimp-help-sv : Depends: gimp-help-common (= 1:2.8-0precise8~ppa) but 1:2.8-0precise16~ppa is installed E: Unmet dependencies. Try using -f.   Ok, I guess I run apt-get -f install then.  $ sudo apt-get -f install Reading package lists... Done Building dependency tree        Reading state information... Done Correcting dependencies... Done The following package was automatically installed and is no longer required:   icedtea-netx-common Use 'apt-get autoremove' to remove them. The following extra packages will be installed:   gimp-help-sv The following packages will be upgraded:   gimp-help-sv 1 upgraded, 0 newly installed, 0 to remove and 27 not upgraded. Need to get 0 B/29.6 MB of archives. After this operation, 0 B of additional disk space will be used. Do you want to continue [Y/n]?  (Reading database ... 803609 files and directories currently installed.) Preparing to replace gimp-help-sv 1:2.8-0precise8~ppa (using .../gimp-help-sv_1%3a2.8-0precise16~ppa_all.deb) ... Unpacking replacement gimp-help-sv ... dpkg: error processing /var/cache/apt/archives/gimp-help-sv_1%3a2.8-0precise16~ppa_all.deb (--unpack):  unable to create `/usr/share/gimp/2.0/help/sv/gimp-tool-crop.html.dpkg-new' (while processing `./usr/share/gimp/2.0/help/sv/gimp-tool-crop.html'): No space left on device No apport report written because the error message indicates a disk full error                                                                               dpkg-deb: error: subprocess paste was killed by signal (Broken pipe) Errors were encountered while processing:  /var/cache/apt/archives/gimp-help-sv_1%3a2.8-0precise16~ppa_all.deb E: Sub-process /usr/bin/dpkg returned an error code (1)   Ok. But it can't be that I've ran out of space?  $ df -H Filesystem      Size  Used Avail Use% Mounted on /dev/sda2        15G   11G  3.1G  79% / udev            2.1G  4.1k  2.1G   1% /dev tmpfs           828M  1.1M  827M   1% /run none            5.3M     0  5.3M   0% /run/lock none            2.1G  316k  2.1G   1% /run/shm /dev/sda5       125G  103G   16G  88% /home   This is what happens whatever I am trying to do. How can I get rid of those stupid messages?

Encountered an error while updating through Synaptic Manager. Subsequent updates gave the error at the bottom of the output. I'm a noob so any help is appreciated.  al@al:~$ sudo apt-get -f upgrade Reading package lists... Done Building dependency tree        Reading state information... Done Correcting dependencies... Done The following NEW packages will be installed:   libjack-jackd2-0:i386 The following packages have been kept back:   linux-headers-generic skype 0 upgraded, 1 newly installed, 0 to remove and 2 not upgraded. Need to get 0 B/202 kB of archives. After this operation, 493 kB of additional disk space will be used. Do you want to continue [Y/n]? y (Reading database ... 310056 files and directories currently installed.) Unpacking libjack-jackd2-0:i386 (from .../libjack-jackd2-0_1.9.8~dfsg.2-1precise1_i386.deb) ... dpkg: error processing /var/cache/apt/archives/libjack-jackd2-0_1.9.8~dfsg.2-1precise1_i386.deb (--unpack):  './usr/share/doc/libjack-jackd2-0/buildinfo.gz' is different from the same file on the system dpkg-deb: error: subprocess paste was killed by signal (Broken pipe) Errors were encountered while processing:  /var/cache/apt/archives/libjack-jackd2-0_1.9.8~dfsg.2-1precise1_i386.deb E: Sub-process /usr/bin/dpkg returned an error code (1)


So I had a beautiful system running real nice up until I wanted to set up an old webcam last night. I did sudo apt-get update and got this:  Fetched 1,475 B in 3min 25s (7 B/s) Reading package lists... Done W: The repository 'http://security.ubuntu.com/ubuntu yakkety-security Release' does not have a Release file. N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use. N: See apt-secure(8) manpage for repository creation and user configuration details. W: The repository 'http://ca.archive.ubuntu.com/ubuntu yakkety Release' does not have a Release file. N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use. N: See apt-secure(8) manpage for repository creation and user configuration details. W: GPG error: http://download.opensuse.org/repositories/home:/jgeboski/xUbuntu_16.10  Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 12C6ADA61C85BB5E W: The repository 'http://download.opensuse.org/repositories/home:/jgeboski/xUbuntu_16.10  Release' is not signed. N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use. N: See apt-secure(8) manpage for repository creation and user configuration details. W: The repository 'http://ca.archive.ubuntu.com/ubuntu yakkety-updates Release' does not have a Release file. N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use. N: See apt-secure(8) manpage for repository creation and user configuration details. W: The repository 'http://ca.archive.ubuntu.com/ubuntu yakkety-backports Release' does not have a Release file. N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use. N: See apt-secure(8) manpage for repository creation and user configuration details. W: The repository 'http://ppa.launchpad.net/eugenesan/ppa/ubuntu yakkety Release' does not have a Release file. N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.   And sudo apt-get install for anything yields  E: Package 'program' has no installation candidate   I suspect that I'm having this issue because I'm using Ubuntu 16.10. If not, I'd like to know how to fix it, because I really like my system the way it is. Otherwise, I'd consider installing 16.04 or 17.10, but I'd also like to know  which one is better, and if there is a way to install without losing all my programs and stuff. Some of them were pretty frustrating to install, and I really need them.  Thanks!

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


In an online video lecture the teacher has explained how to add to PATH both on the command line and via .bashrc, and has indicated that the proper way of doing this is through .bashrc but has not adequately explained why.    My question is what is the difference between executing the following from the command line:  $ export PATH=/home/username/bin:$PATH   Or simply adding the line: export PATH=/home/username/bin:$PATH to my ~/.bashrc.

I'm wondering where a new path has to be added to the PATH environment variable. I know this can be accomplished by editing .bashrc (for example), but it's not clear how to do this.  This way:  export PATH=~/opt/bin:$PATH   or this?    export PATH=$PATH:~/opt/bin


show that if $N$ is relatively prime to 10, then there exists a multiple that consists only of 1s.  The multiple can be expressed as :  $$\frac{(10^a-1)}{9}$$  thus if $\gcd(N,3)$ is not 3, using the totient function it would be easy to find $a$ such that this is $0\bmod N$  If $\gcd(N,3)$ is 3, then we would need to find $10^a-1$ divisible by $3N$ which is also possible.  from . It is said that:  "If N is relatively prime to 10, then we may divide out all powers of 10, to obtain an integer of the form 111...1 that remains divisible by N."  which I'm not sure I follow. I would want to know what this means since the answer seems concise

I need to prove that there are infinitely many numbers  of the form $x = 111....1$ such that $31\mid x$  what I tried - I wrote x as   $\sum_0^{n-1} 10^i$  I know that $(10,31) = 1 $  now I'm stuck .. any help will be appreciated


My goal is to be able to generate random tuples consisting of 3 variables. 2 be float(x,y coordinates ) and the last one a string. Each tuple should have the format of (float, float, string). I'm pretty sure the x,y is easy but i'm unsure if its possible to generate a string as the third parameter. The string should be a random choice of within a set.  For example say I have a list of strings ["one", "two" , "three"]. I would want my generated tuple to consist of two random floats and one of the strings within that set. I was thinking something similar to this code below   [(randint(0, 180), randint(0, 180)) for _ in range(100)]   Once again just to clarify i am just trying to figure out if its possible to add one the strings from the set as my 3rd variable in my tuple

Assume I have the following list:  foo = ['a', 'b', 'c', 'd', 'e']   What is the simplest way to retrieve an item at random from this list?


I have launched some batch jobs that I didn't finish. Now I notice my queue table is almost 1 GB. Is it safe to empty it?

I have a Drupal 7 site and the queue table has over 4K records. They are primarily for the "update_fetch_tasks" queue. Is the queue table by nature a temporary place holder?   I would like to clean it out and see if it fixes some issues that I am experiencing with the update module. I've done some digging on the queue module and from what I can tell is that proper usage is to claim the queue items and when you are done with them you should delete them. So it seems odd that a core module is leaving records in the queue.   Is there any harm in removing records from the queue?


I was working on historical data looking for anomalous patterns that we would not expect to occur at random. I'd like to create a scheme to analyze data and markets to test for statistical significance and consistency over time.  Question : Are there some tools we could use to evaluate the nonrandomness of a database? What do we use usually to say that something is random or not (statistically)? Figure we work with change in some value over time.  Question : Does the Benford's law could answer in part this question?


I have a problem when run the code below in Window OS using Python 3.6 32bit.  subprocess.call(["mkdir", "-p", path_results + "it" + str(actual_iteration)])  The error is   Trackback : ......\Python36-32\lib\subprocess.py", line 997, in _execute_child startupinfo) FileNotFoundError: [WinError 2] The system cannot find the file specified.  Anyone please tell me what's wrong and help me fix it. Thank you.

What is the most elegant way to check if the directory a file is going to be written to exists, and if not, create the directory using Python? Here is what I tried:  import os  file_path = "/my/directory/filename.txt" directory = os.path.dirname(file_path)  try:     os.stat(directory) except:     os.mkdir(directory)         f = file(filename)   Somehow, I missed os.path.exists (thanks kanja, Blair, and Douglas). This is what I have now:  def ensure_dir(file_path):     directory = os.path.dirname(file_path)     if not os.path.exists(directory):         os.makedirs(directory)   Is there a flag for "open", that makes this happen automatically?


Basically, I have a lot of audio files representing the same song. However, some of them are worse quality than the original, and some are edited to where they do not match the original song anymore. What I'd like to do is programmatically compare these audio files to the original and see which ones match up with that song, regardless of quality. A direct comparison would obviously not work because the quality of the files varies.  I believe this could be done by analyzing the structure of the songs and comparing to the original, but I know nothing about audio engineering so that doesn't help me much. All the songs are of the same format (MP3). Also, I'm using Python, so if there are bindings for it, that would be fantastic; if not, something for the JVM or even a native library would be fine as well, as long as it runs on Linux and I can figure out how to use it.

How could I detect (preferably with Python) duplicate MP3 files that can be encoded with different bitrates (but they are the same song) and ID3 tags that can be incorrect?  I know I can do an  checksum of the files content but that won't work for different bitrates. And I don't know if ID3 tags have influence in generating the MD5 checksum. Should I re-encode MP3 files that have a different bitrate and then I can do the checksum? What do you recommend?


This is the class where I'm getting null pointer exception Presenter.java       Display d;      interface Display     {                public List<String> getLists();                  }      public void output()     {         List<String> out = d.getLists(); // getting null pointer here         for(int i=0;i<out.size();i++)         {             System.out.println(out.get(i));                  }     }      public static void main(String[] a)     {          Presenter p = new Presenter();         p.output();     }  }   I'm implementing the interface Display in the class below, and returning the newList as below.   View.java  public class View implements Presenter.Display {      String[] a = {"London","Paris","New York"};      List<String> newList = new ArrayList<String>(Arrays.asList(a));      @Override     public List<String> getLists() {          return newList;     } }   I've looked through several examples but I'm not getting how to get the value of getLists() method in the presenter class.   What am I missing here ? Please help

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


When viewing the activity tab on my profile (.../679449/freshprinceofso?tab=activity), I noticed that some nomination comments don't adhere to the same style as the rest of the comments and appear enlarged:    This happens when using the "Request Desktop Site" option in Chrome.  App: Chrome 32.0.1700.99  OS: Android 4.4.2; Nexus 5 Build/KOT49H

In the responses tab in my profile, responses to comments on nomination posts include a working link in the page source, but because there's no title the links are empty and useless.    When listed in the inbox such posts do have a title, though in this case the link is to the post and not directly to the comment. (Actually, the links in responses end up being redirected and also go to the post and not to the comment, but they try to go to the comment.)  In Supercollider:    In Global Profile:


I've noticed a lot of people ask this question, but I just don't understand. If the number next to the name is the seasonal rank like people say, how can someone have a level of 222 or 261? Seasonal ranks only go up to 100.

Since Beyond Light I noticed that there is a number next to a Guardian's name. (Before the update, the blue box used to hold the equipped class of the player.)  When I die and am waiting for respawn, I always see that my number is 1, so I don't think it is the Season Pass level, but then again it may simply be a bug. So, what does this number mean?


I can use the "script" command to record an interactive session at the command line.  However, this includes all control characters and colour codes.  I can remove control characters (like backspace) with "col -b", but I can't find a simple way to remove the colour codes.  Note that I want to use the command line in the normal way, so don't want to disable colours there - I just want to remove them from the script output.  Also, I know can play around and try find a regexp to fix things up, but I am hoping there is a simpler (and more reliable - what if there's a code I don't know about when I develop the regexp?) solution.  To show the problem:   spl62 tmp: script Script started, file is typescript spl62 lepl: ls add-licence.sed  build-example.sh  commit-test         push-docs.sh add-licence.sh   build.sh          delete-licence.sed  setup.py asn              build-test.sh     delete-licence.sh   src build-doc.sh     clean             doc-src             test.ini spl62 lepl: exit Script done, file is typescript spl62 tmp: cat -v typescript Script started on Thu 09 Jun 2011 09:47:27 AM CLT spl62 lepl: ls^M ^[[0m^[[00madd-licence.sed^[[0m  ^[[00;32mbuild-example.sh^[[0m  ^[[00mcommit-test^[[0m         ^[[00;32mpush-docs.sh^[[0m^M ^[[00;32madd-licence.sh^[[0m   ^[[00;32mbuild.sh^[[0m          ^[[00mdelete-licence.sed^[[0m  ^[[00msetup.py^[[0m^M ^[[01;34masn^[[0m              ^[[00;32mbuild-test.sh^[[0m     ^[[00;32mdelete-licence.sh^[[0m   ^[[01;34msrc^[[0m^M ^[[00;32mbuild-doc.sh^[[0m     ^[[00;32mclean^[[0m             ^[[01;34mdoc-src^[[0m             ^[[00mtest.ini^[[0m^M spl62 lepl: exit^M  Script done on Thu 09 Jun 2011 09:47:29 AM CLT spl62 tmp: col -b < typescript  Script started on Thu 09 Jun 2011 09:47:27 AM CLT spl62 lepl: ls 0m00madd-licence.sed0m  00;32mbuild-example.sh0m  00mcommit-test0m         00;32mpush-docs.sh0m 00;32madd-licence.sh0m   00;32mbuild.sh0m          00mdelete-licence.sed0m  00msetup.py0m 01;34masn0m              00;32mbuild-test.sh0m     00;32mdelete-licence.sh0m   01;34msrc0m 00;32mbuild-doc.sh0m     00;32mclean0m             01;34mdoc-src0m             00mtest.ini0m spl62 lepl: exit  Script done on Thu 09 Jun 2011 09:47:29 AM CLT


I made some greenest pixel composites in GEE and they looked odd--like a river showing up in a town. I found that a granule from 2015 is not georeferenced accurately...then I found another from the same date.      Is there a process for reporting this sort of thing?

I'm downloading Sentinel-2 tiles from  but they dont seem to be 100 % aligned. Right image is band 08 Sentinel-2 added to ArcGis Desktop (i have done nothing more than adding the 08.jp2 to the map), left esri basemap photo. The offset in Sentinel is about 35-40 meters. How do i correct them?    . Level-1C, Sentinel-2:   SOLUTION:  From HDunn's answer i did this:  Using a road vector layer i added five point pairs and calculated difference in x and y coordinates. The mean differences i used as xvalue and y value in Shift tool. Result:


As there a possible way to make a multi-colors PSD/AI/Image to be only two colors

I don't know how to call this but how to make a monochrome like the one on bottom. The exclusion (white), but originally it doesn't overlap.


I Airdrop tons of mp4 video files to my phone, but for some reason, I have one video file that fails to AirDrop. I examined the Get Info window of each one that worked and of the one that didn't. Same approximate size, same file type, etc. Anyone know how to solve this? Edit: This happened when I exported from Premiere. Found  that had lots of ideas.

Editing videos in Premiere, sometimes a certain video fails to Airdrop to an iPhone. I examined the Get Info window of each video that worked and of the one that didn't. Same approximate size, same file type, same codex etc. Looked at the settings in Premiere seem similar. Anyone know how to solve this? Found this  and tried a bunch of the suggestions. Tried converting it to .mov in Quicktime failed. Tried saving it as 4k in Quicktime failed. Tried importing it to Photos (works) then Airdropping it. Failed. Tried trimming it in Quicktime. Failed. Tried uploading it to Dropbox then downloading it to Photos on the iPhone. Failed.


I am reading a pdf which I guess it's written in LaTex, so all I need to know is that which package is this to refer figures and bib items?

In GKP's Concrete Mathematics, there is a useful and interesting feature I would like to see in more books. The bibliography entries include:   a - the page numbers where the book or article is cited in the document. b - a few lines of review of the cited work.   It is a kind of mix between bibliography, index and review.  Are there stable LaTeX packages/BibTeX styles to do (a) and (b) ?  EDIT: I wrote (b) initially as "comments about the work cited". It could be understood as "gathering comments made in the book about the work and reproducing them in the bibliography".  This is not what I meant but this could be something useful for others.


I want to try to put a rectangle on my screen by using JPanel and JFrame. But I get the java.lang.NullPointerException and I don't know why. My code:  Class to create a rectangle:  package com.game.main;  import java.awt.Color; import java.awt.Graphics;  import javax.swing.JPanel;  public class Rect extends JPanel {  Graphics a;  public Rect(){           a.drawRect(100, 100, 200, 250);     a.setColor(Color.RED);     a.fillRect(100, 100, 200, 250);          } }   Class to create a JPanel:  package com.game.main;  import javax.swing.JPanel;  public class Inside extends JPanel {      public Inside(){         JPanel content = new JPanel();         Rect rect = new Rect();         content.add(rect);     } }   Class to create a JFrame:  package com.game.main;  import javax.swing.JFrame; import javax.swing.JPanel;  public class Window extends Main{      public static final int Width = 1020, Height = 860;      public Window(JPanel content){         JFrame frame = new JFrame("The Game");         frame.setContentPane(content);         frame.setSize(Width, Height);         frame.setVisible(true);         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);         frame.setLocation(100, 100);     }  }   Class to put everything together:  package com.game.main;  public class Main {      public static void main(String[] args) {         Inside inside = new Inside();         Window window = new Window(inside);     }  }   I am also not very familiar with the Graphics class, so a little bit of explanation would be wonderful.  Thank you


I need to compile my project to iOS version, but I don't have a Mac so I can't download Xcode and iOS sdk. Any ideas??

Is there any way to tinker with the iPhone SDK on a Windows machine? Are there plans for an iPhone SDK version for Windows?  The only other way I can think of doing this is to run a Mac VM image on a VMWare server running on Windows, although I'm not too sure how legal this is.


I really need a new datatype in my application, which will only store numbers from -10 to 10. Is there a way to create a datatype with specific values, which will raise an error if the value is invalid? I used:  typedef int digit;   The thing that happens is a new datatype which is actually int is created. I also tried this:  typedef int{-10 > int value < 10} digit;   but it raised this:  exit status 1 main.cpp:3:12: error: expected unqualified-id before '{' token typedef int{-10 > int value < 10} digit;            ^ main.cpp:3:35: error: 'digit' does not name a type; did you mean 'div_t'? typedef int{-10 > int value < 10} digit;                                     ^~~~~                                   div_t

Suppose I have a LimitedValue class which holds a value, and is parameterized on int types 'min' and 'max'.  You'd use it as a container for holding values which can only be in a certain range.  You could use it such:  LimitedValue< float, 0, 360 > someAngle( 45.0 ); someTrigFunction( someAngle );   so that 'someTrigFunction' knows that it is guaranteed to be supplied a valid input (The constructor would throw an exception if the parameter is invalid).  Copy-construction and assignment are limited to exactly equal types, though.  I'd like to be able to do:  LimitedValue< float, 0, 90 > smallAngle( 45.0 ); LimitedValue< float, 0, 360 > anyAngle( smallAngle );   and have that operation checked at compile-time, so this next example gives an error:  LimitedValue< float, -90, 0 > negativeAngle( -45.0 ); LimitedValue< float, 0, 360 > postiveAngle( negativeAngle ); // ERROR!   Is this possible?  Is there some practical way of doing this, or any examples out there which approach this?


This is in regards to something objective that I am writing about unhealthy familial dynamics and how someone can move on in healthy ways. This is for a course I am taking.  What is a single-word to describe a family member who refuses to apologize or admit when they're wrong, especially when they've hurt or betrayed their family members? These slights could be trivial - hurt feelings, moderate - abuse/neglect, or extreme - criminal/exploitative.  Here are a few examples of each:   Trivial - A mother in her 60s hurts the feelings of her 40 year old daughter by calling her cute and/or adorable. Not only does the mother fail to notice that her daughter is hurt, but dismisses other people when she's told that her daughter was clearly hurt and that it's considered inappropriate to refer to someone in that age group as being cute or adorable. The mother immediately dismisses what is being said by stating that she didn't do anything wrong. When asked if anyone ever refered to her as being cute and/or adorable at 40 years old, she responds with no, but refuses to make any distinction. Moderate - A father continually calls his daughter fat. She develops issues in regards to her self-image and it has a negative effect on her overall mental health. She falls behind at school. When others attempt to intervene, the father refuses to hold himself accountable or responsible and continues calling his daughter fat, even when he's aware of the consequences. Child Protective Services are brought in and the girl is removed from the home. Extreme - A son uses his parents social security numbers to take out many large loans without their knowledge. He defaults on all of the loans, leaving his parents in millions of dollars in debt. He refuses to go forward and admit to the banks/federal agencies that he used his parents social security numbers without their consent, letting his parents take the fall.   I hope for objective answers.

When speaking with someone recently I was continuously taken aback by how he could not concede even the slightest detail in my argument (which was not unreasonable), and it happened another time previously. Both times had to do with me pointing out 'error' in his action.  He very much exhibits that 'I cannot be wrong' attitude.  I first thought to call this arrogance or pride but he is not overbearing like arrogance demands and he does not show excessive self esteem that pride demands.  What is a word that can accurately describe this attitude?


The probability that two friends will be able to meet each other between 9:00am and 12:00 noon, not waiting for each other for more than 15 minutes is?

I recently read a math problem and, having not yet taken anything beyond calculus 1, was curious about how to solve it correctly.   Problem:  Calculate the probability of two people meeting at the same location between 1 and 2 p.m. Assume both people show and person 1 will wait 15 minutes for person 2.     Doesn't this probability increase as the time frame shrinks?  For example, Isn't there a much smaller chance the pair will meet if person 1 arrives at 1:00 vs arrives at 1:45 (the probability of meeting becomes 1).  Is this somewhat easily answered using basic statistics?  Just curious if my thought process is accurate or way wrong.


Apache cannot fully determine domain name when I tried restarting after install.  I get this error;  $ sudo /etc/init.d/apache2 restart Restarting web server config apache2 apache2: Could not reliably determine the server's fully qualified domain name, using 127.0.1.1 for ServerName.   Why am I seeing 127.0.1.1? I have tried saving ServerName localhost into my /etc/init.d/apache2 but it keeps redirecting me to Google search page every time I type phpmyadmin.  Will appreciate any expert help.

When I restart my Apache server using the command  sudo /etc/init.d/apache2 restart   I get the following error:  Restarting web server apache2 apache2: Could not reliably determine the server's fully qualified domain name, using 127.0.1.1 for ServerName ... waiting apache2: Could not reliably determine the server's fully qualified domain name, using 127.0.1.1 for ServerName   Is the server using 127.0.1.1 instead of 127.0.0.1? What causes this error?


I've just found out that you can @comment to the author of a successful edit to your post. That's excellent.  From time to time I will reject an edit and would like to thank the editor, but let them know why their suggestions were rejected.  While @comment for accepted edits doesn't autocomplete and so it looks like it won't reach the editor, but it will. What is the behavior for the authors of the following?   pending edits rejected edits

How do the comment replies (aka "pinging users") work?  Who can I send an @reply to? How do I respond to a specific user when entering my comment? Will they be notified? What do people mean when they talk about "pinging" another user?  Related:


As the title says, why doesnt the iris get destroyed?

I may just not remember this, but doesn't the Stargate horizon destroy everything in its way when the gate is activated? How then, can the Stargate's Iris stay in tact?


I would like to prevent my program from sending stdout and stderr to any terminals, files or devices. For this, I have three command crossing my mind, but I cannot distinguish their differences. Could you please explain the meaning of each of them to me please.  # ./run > /dev/null # ./run > /dev/null 1>&2 # ./run > /dev/null 2>&1

I'm reading an example bash shell script: #!/bin/bash  # This script makes a backup of my home directory.  cd /home  # This creates the archive tar cf /var/tmp/home_franky.tar franky > /dev/null 2>&1  # First remove the old bzip2 file.  Redirect errors because this generates some if the archive # does not exist.  Then create a new compressed file. rm /var/tmp/home_franky.tar.bz2 2> /dev/null bzip2 /var/tmp/home_franky.tar  # Copy the file to another host - we have ssh keys for making this work without intervention. scp /var/tmp/home_franky.tar.bz2 bordeaux:/opt/backup/franky > /dev/null 2>&1  # Create a timestamp in a logfile. date >> /home/franky/log/home_backup.log echo backup succeeded >> /home/franky/log/home_backup.log  I'm trying to understand the use of /dev/null 2>&1 here. At first, I thought this script uses /dev/null in order to gracefully ignore errors, without causing the script to crash (kind of like try catch exception handling in programming languages). Because I don't see how using tar to compress a directory into a tar file could possibly cause any type of errors.


Given ($X$, $Y$) whose MGF is defined as:  $$M_{XY}(s, t)=E[e^{sX+tY}]$$  Find $M_{XY}(s, t)$ when $X$ and $Y$ are two jointly normal random variables with $E[X]=\mu_X$, $E[Y]=\mu_Y$, $var(X)=\sigma^2_X$, $var(Y)=\sigma^2_Y$, and $\rho(X, Y) = \rho$?  I am so confused about this question. Every method I try seems to land in a dead end. So far I have tried using the Law of Unconscious Statistician as well as noting that $sX + tY$ follows Normal distribution but the integral always seems impossible to solve. Any help would be appreciated. Thanks  EDIT1  After checking some posts and doing more research I have conducted the following and would like to know if it is a valid method:  Since $(X, Y)$ is jointly normal, we can write:  $$ (X, Y) = (\mu_X, \mu_Y) + \Sigma^{1/2}(Z_1, Z_2) $$  Where $\Sigma^{1/2}=\begin{bmatrix}\sigma_X & \sigma_{XY}/\sigma_X\\ 0 & (\sigma_Y^2-\sigma_{XY}/\sigma_X^2)^{1/2} \end{bmatrix}$ (Obtained this matrix through Cholesky Decomposition)  Evaluating the above expression gives us:  $$\begin{bmatrix}X \\ Y\end{bmatrix} = \begin{bmatrix}\mu_X + \sigma_X Z_1 + (\sigma_{XY} / \sigma_{X} Z_2) \\ \mu_Y + (\sigma_Y^2 - \sigma_{XY}^2\sigma_X^{-2})^{1/2} \end{bmatrix}$$  Since now X and Y have been decomposed into functions of two independent normal random variables, we can simply multiplying the corresponding MGF of these functions. Is this argument correct? If not could you please tell me which assumption I am making is mistaken. Thank You

Show that $(X_1,X_2)$ has a bivariate normal distribution with means $\mu_1, \mu_2$, variances $\sigma _1^2 $ and $\sigma _2^2$, and correlation coefficient $\rho $ if and only if every linear combination $t_1X_1+t_2X_2$ has a univariate normal distribution with mean $t_1\mu_1+t_2\mu_2$, and variances  $t_1^2\sigma _1^2+t_2^2\sigma _2^2+2t_1t_2\rho \sigma_{12}$ where $t_1, t_2$ are non zero constants  My work:  Joint mgf of $X_1 $and $X_2=e^{[t_1\mu_1+t_2\mu_2+\frac{1}{2}(t_1^2\sigma _1^2+t_2^2\sigma _2^2+2\rho \sigma_1 \sigma_1t_1t_2 )]} $  I am confused here to find the proper grouping to get the forward result.  For the backward result, I know I have to find the m.g.f. of $t_1X + t_2Y$, for any $t_1 $and $t_2$ real,and plug in the $E(t_1X + t_2Y)$ and $Var(t_1X + t_2Y)$.  I am struggling to get the correct backward result.  Second part:   Let $Y_i=X_i/\sigma_i, i=1,2$ Show that $Var(Y_1-Y_2)=2(1-\rho)$  I have found, $Var(Y_1)=\sigma_1, Var(Y_2)=\sigma_2$ since $X_1/\sigma_1=\sigma _1$  How can I prove that $Var(Y_1-Y_2)=2(1-\rho)$? Thank you so much for your help!


I just want to know if a 24v 2.2A output power adaptor can be use on a 24v 0.75mA unit? I have not tried it because I'm afraid that it might harm the unit due to a huge difference in Ampere..  I would really appreciate if someone can answer me this..  Thank you so much..

Power supplies are available in a wide range of voltage and current ratings.  If I have a device that has specific voltage and current ratings, how do those relate to the power ratings I need to specify?  What if I don't know the device's specs, but am replacing a previous power supply with particular ratings?  Is it OK to go lower voltage, or should it always be higher?  What about current?  I don't want a 10 A supply to damage my 1 A device.


Let's say we have the following (but actually on a much larger scale):  ABCDEF GHIJKL MNOPQR   Is there a way to rotate it to read as the following:  FLR DKQ DJP CIO BHN AGM   I wouldn't know where to start on account of it being Monday morning. Thanks,  JJ

Inspired by , say you have a 4x4 two dimensional array, write a function that rotates it 90 degrees. Raymond links to a solution in pseudo code, but I'd like to see some real world stuff.  [1][2][3][4] [5][6][7][8] [9][0][1][2] [3][4][5][6]   Becomes:  [3][9][5][1] [4][0][6][2] [5][1][7][3] [6][2][8][4]   Update: Nick's answer is the most straightforward, but is there a way to do it better than n^2? What if the matrix was 10000x10000?


In the following statement, which one is grammatically correct?     XYZ caterers is on to something big   OR     XYZ caterers are on to something big   I thought that it should be 'are' as caterers is plural. But it has been suggested that I might be wrong. What do you think?

Which one of these two statements is correct?     Our staff do ...      Our staff does ...   And is staffs ever correct?


Yesterday I was playing on one of my Minecraft worlds. After a few minutes, my PC froze and nothing on the screen would move. After about 40 minutes, my screen was  completely frozen and I decided to force my PC to shut down. When I started Minecraft again, my world had disappeared off the list. I then went on the "%appdata%" files, under ".minecraft" and "saves," and saw my world in the list! How can I get the world file shown in that folder to appear in the list of worlds in the game?

I was playing on my main world when my laptop ran out of power.  I found a charger and woke it up, but Minecraft had crashed.  Now, it doesn't appear in the world selection screen!  I have verified that it still exists in the Minecraft folder, and the directory contents look to be in order.  Does Minecraft save an internal flag somewhere when it crashes hard?  If so, how do I reset it?


For E.g. Do not allow search results to display for Accounts records

I want to be able to restrict access to some of the objects from the global search.  Is this possible?


I've updated and searched for libzeroc-ice3.7, but it isn't found. I'm not sure why. Looking on  it seems it should be listed for my server.

How do you use terminal to enable Universe source? Or any those 4 from Software Sources: Main, Universe, Restricted, Multiverse Main is on by default and Restricted is on if durring Ubuntu installation i tick Enable Restricted Formats. Answer with line where version checked so it auto detects it. Like command I know for partner but that goes to Other Software tab sudo add-apt-repository "deb http://archive.canonical.com/ $(lsb_release -sc) partner"


What do you call someone who doesn't know their worth or is under-performing their potential?

One who has potential, but never gives the effort to show it.   What would be the best word or words that match this description?


I have used many decoupling capacitors in circuits and have seen them in many textbooks, but they never give an explanation about why they picked a certain size of capacitor.  Everyone seems to have a "rule" about the size that they picked up along the way.  But is there an actual formula that dictates what size of decoupling capacitor to use?  If not, are there some mathematics and physics that I could be pointed to to develop something more rigorous than a rule of thumb?  Many people have said that the size is not always critical, but I imagine there is a point at which changing the size would cause the circuit to fail or at least degrade.  I would like to know what this critical point is, determining the bare minimum case, etc.

Lots of chips nowadays require smoothing capacitors between VCC and GND for proper function. Given that my projects run at all sorts of different voltage and current levels, I was wondering if anyone had any rules of thumb for a) how many and b) what size capacitors should be used to ensure that power supply ripple doesn't affect my circuits?


(a)Assume D is bounded and f is uniformly continuous on D. Prove that f(D) bounded. (b)Give an example of a bounded set D and continuous g : D → R such that g(D) is unbounded.  I don't know how to prove bounded function. Please give me some hints. Thank you so much!!!

I am trying to prove the following:  If $A\subset\mathbb R$ is bounded and $\,f:A\to \mathbb R\,$ is uniformly continuous, then $f[A]$ is bounded.  Could you check my proof?  Let $A \subseteq [-K,K]\subseteq \mathbb R$. Let $\varepsilon = 1$. If $f$ is uniformly continuous there is $\delta$ wuth $|x-y| <\delta$ imply that $|f(x)-f(y)|<1$ for all $x,y\in A$. Let $a \in A$. Then because $A$ is bounded there is a finite number of balls $B(a_n,\delta)$ that cover $A$. Let the number be $N$. Then $f(a)-N \le f(x) \le f(a) + N$ for all $x\in A$.


How can I evaluate $$\sum_{n=1}^\infty\frac{2n}{3^{n+1}}$$? I know the answer thanks to , but I'm more concerned with how I can derive that answer. It cites tests to prove that it is convergent, but my class has never learned these before. So I feel that there must be a simpler method.  In general, how can I evaluate $$\sum_{n=0}^\infty (n+1)x^n?$$


I have a template class with separate declaration and implementation:  // template.hpp template <typename T> class Foo {   T _data;   void func(); };  // template.cpp #include "template.hpp"  template <typename T> void Foo<T>::func() {   // Do something on _data }   those template files will be compiled into a library, and in another cpp file I link the library and instantiate the template class as follows:  // my.cpp #include "template.hpp"  struct MyData {   // Some data here };  class Bar {   Foo<MyData> foo; };   I get linker error when compiling my.cpp file. Is there any way to avoid the linker error by just modifying the template.hpp and template.cpp?   I don't want to move the template implementation into the header file and I can't move the MyData into template.hpp.

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


I am still confused about how to use the word everyone.  I have this sentence on a test:         Everyone wants to do their  part.   Everyone wants to do   his  part.   Everyone wants to do  our part.      I think the answer is version with their.

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


I love regexp but I find it rather confusing why there is no "match all" special character? For example, if I wanted to select a HTML tag and its contents, I would do re = "<tag>([\s\S]*)</tag>"  You see, [\s\S] is a workaround to solve the absence of a match-all special character. Is there a reason why a match-all is missing from the spec? I know about . but it's not that pretty either: re = "<tag>([.\n]*)</tag>"

For example, this regex  (.*)<FooBar>   will match:  abcde<FooBar>   But how do I get it to match across multiple lines?  abcde fghij<FooBar>


I've always been fascinated with low poly art styles. Throughout many years I tried to teach myself pixel art, but when low poly art was introduced to me during a time when I was looking for inspiration on a new project it was just fascinating. Here is an example of what I'd like to attempt:  Does anyone have any good resources or tutorials I can follow? The tools I have at my disposal include:  Access to University Photoshop through virtual desktop  Pixelmator I am looking for tutorials centered on 3D low-poly art that can be exported in order to view on the web as a 2D image. Here is another example from Google's Cubeslam game. I'm not quite sure what process their team approaches to make the art,

I've been interested in creating Geometric Polygonal art illustrations, i.e. making polygons and shapes with different color shading represent a face, or an object, see  set of .  How are they achieved? Is there some script for Illustrator which alters the image adding the shapes according to the colors or shades? How would I transform a normal image of Marilyn Monroe for example, to a polygonal illustration of her?


I need help with removing the subsection name from the header. My LaTeX file names both subsection (to the left) and section (to the right) at the header, I only want the section name to be in the header. For example, looking at the picture below, I want to remove "2.1 Background" but keep the "2 Global Climate Change". A picture of my latex code is illustrated below. Thanks in advance!

how to display current section title in header insted of chapter title?  I'm using book and fancychap   MWE  \documentclass [11pt,oneside,final]{book} \usepackage[nohints]{minitoc} \usepackage[round]{natbib} \usepackage{longtable} \usepackage[font={footnotesize,it}]{caption} \usepackage{bookman}  \usepackage[T1]{fontenc}  \usepackage{setspace} \doublespacing %\onehalfspacing \usepackage{multirow} \usepackage[left=35mm,top=30mm,right=30mm,bottom=30mm]{geometry} \pagenumbering{Roman} \usepackage[small,compact]{titlesec} \usepackage[Lenny]{fncychap} \usepackage{arabtex} \usepackage{cp1256} \setcode{cp1256} \usepackage{float} \usepackage[final]{graphicx} \usepackage{epstopdf} \usepackage{array}  \setarab \raggedbottom \begin{document} \chapter{introduction} \thispagestyle{empty}  \section{one} bla bla bla bla bla  \section{two} bla bla bla bla   \end{document}


I have to calculate the angle of complex summations like  (exp(1i*0)+exp(1i*2*pi/3)+exp(1i*-2*pi/3))   which is equal to  (exp(1i*0)+exp(1i*2*pi/3)+exp(1i*4*pi/3))   but the results are different! because of the precision of exp matlab function.  ans =     4.4409e-16   ans =    -2.2204e-16 + 2.2204e-16i   the angle of the first one is zero but the second one result $3\pi/4$ which is wrong!

I am writing a program where I need to delete duplicate points stored in a matrix. The problem is that when it comes to check whether those points are in the matrix, MATLAB can't recognize them in the matrix although they exist.  In the following code, intersections function gets the intersection points:  [points(:,1), points(:,2)] = intersections(...     obj.modifiedVGVertices(1,:), obj.modifiedVGVertices(2,:), ...     [vertex1(1) vertex2(1)], [vertex1(2) vertex2(2)]);   The result:  >> points points =    12.0000   15.0000    33.0000   24.0000    33.0000   24.0000  >> vertex1 vertex1 =     12     15  >> vertex2     vertex2 =     33     24   Two points (vertex1 and vertex2) should be eliminated from the result. It should be done by the below commands:  points = points((points(:,1) ~= vertex1(1)) | (points(:,2) ~= vertex1(2)), :); points = points((points(:,1) ~= vertex2(1)) | (points(:,2) ~= vertex2(2)), :);   After doing that, we have this unexpected outcome:  >> points points =    33.0000   24.0000   The outcome should be an empty matrix. As you can see, the first (or second?) pair of [33.0000 24.0000] has been eliminated, but not the second one.  Then I checked these two expressions:  >> points(1) ~= vertex2(1) ans =      0 >> points(2) ~= vertex2(2) ans =      1   % <-- It means 24.0000 is not equal to 24.0000?   What is the problem?    More surprisingly, I made a new script that has only these commands:  points = [12.0000   15.0000           33.0000   24.0000           33.0000   24.0000];  vertex1 = [12 ;  15]; vertex2 = [33 ;  24];  points = points((points(:,1) ~= vertex1(1)) | (points(:,2) ~= vertex1(2)), :); points = points((points(:,1) ~= vertex2(1)) | (points(:,2) ~= vertex2(2)), :);   The result as expected:  >> points points =      Empty matrix: 0-by-2


How can I apply a limited palette to a photo, while still keeping the value variations within the original image?

How would I convert a photograph or pattern to use only colors from a palette I give it? Is this possible in Photoshop? I think Pic2Color used to do something like this but it's offline...


I am currently doing a coding challenge at codesignal, challenge name is  commonCharacterCount, I have kind of made the logic below , but after troubleshooting for some time I can see the if statement is not running at all, I am not sure what the reason behind as both the typesS1Array[x]and  S2Array[i] are of String. Any hint on this please , what I am missing here. int commonCharacterCount(String s1, String s2) {          String[] S1Array= s1.split("");     String[] S2Array= s2.split("");          int count=0;       for(int x=0;x<S1Array.length;x++){           // S2ArrayCopy is to check if the S2Array's array element is already been checked using 1 and 0, if 1 then count will not be updated as already checked             int[] S2ArrayCopy= new int[S2Array.length ] ;             Arrays.fill(S2ArrayCopy,0);           for(int i=0;i<S2Array.length;i++){                                                                     if(S1Array[x] == S2Array[i] && S2ArrayCopy[i] != 1 ){                                                  count++;                                 S2ArrayCopy[i]=1;                                  break;             }                                                }                       }

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?


As the title says, what is exactly what is being tested before deciding to use a non-parametric alternative  test (as Kruskal-Wallis for ANOVA, or Mann-Whitney's U for student's t)?  Most sources are not specific on this issue, being content with just referring to the "normality of the data" (e.g. ). This leaves us with two options, either the normality of the residuals or the normality of the response variable, and looking online both arguments are used.  For "data normality" as "response normality" we have other sources (e.g. , and ). For example, in the Biostatistics Handbook by John McDonald which on his  section refers to the , which gives a sequence of examples of normality testing on histograms and distributions of different response variables:     Parametric tests assume that your data fit the normal distribution. If your measurement variable is not normally distributed, you may be increasing your chance of a false positive result if you analyze the data with a test that assumes normality.   Also stating that residuals come as a second option:     If there are not enough observations in each group to check normality, you may want to examine the residuals (each observation minus the mean of its group).   On the other hand, for "residual normality",  is on board with it:     Since it is a non-parametric method, the Kruskal–Wallis test does not assume a normal distribution of the residuals, unlike the analogous one-way analysis of variance.   As well as other answers on this website ()  I am inclined to think it is residual normality what matters, but I am actually curious on why it seems to be such a common error—that actually makes its way into academic contexts, handbooks and "general knowledge"—and if there's some weight or sense into the "response variable normality" position.

I've got a weird question. Assume that you have a small sample where the dependent variable that you're going to analyze with a simple linear model is highly left skewed. Thus you assume that $u$ is not normally distributed, because this would result in normally distributed $y$. But when you compute the QQ-Normal plot there is evidence, that the residuals are normally distributed. Thus anyone can assume that the error term is normally distributed, although $y$ is not. So what does it mean, when the error term seems to be normally distributed, but $y$ does not?


I've got a huge list of date-times like this as strings:  Jun 1 2005  1:33PM Aug 28 1999 12:00AM   I'm going to be shoving these back into proper datetime fields in a database so I need to magic them into real datetime objects.   This is going through Django's ORM so I can't use SQL to do the conversion on insert.


This question comes from this  debate at SuperUser Forum. I have asked it here too because:     It appears not to be only a technical question, but a language question too. Most of the answers in the referred thread until now seem to me most like "Everybody says 32 bit, so it must be correct" kind, instead of reason and logic based.   The question is: as long as a computer that works with, say, 64 bit(s) uses more bit(s) for computing than a computer that works with, say, 32 bit(s), should we say ... ?   32 bit operating system 32 bits operating system   What if we change "operating system" by "graphics card", "motherboard", or "version of the program"?

Why are year, pound and mile in the singular form in the phrases below?   five-year-old children  20 pound note 10 mile run   Is that because they're acting as adjectives, which are always invariable in English?  Is it incorrect to say...   five-years-old children? 20 pounds note? 10 miles run?


I asked a question that seemed like a good one at the time, but it was put on hold by a mod because it was too vague. Which was actually a fair point; I could not replicate the issue in a clean solution as well, and the subject was vague, so I opted to delete it.   Now I know that asking too many junk questions can get you banned from asking questions, but how much does asking a question like that affect your standing when you choose to delete the question?  P.S. No rep changes occurred, because the question was neither up- nor downvoted; it is not a question regarding rep, but more of the background calculation that can get you banned from asking questions.

A self-deleted post is often not a low-quality post and may simply be a mistake noticed by the user, unlike moderator- or community-deleted posts which may indicate serious problems that the user may not recognize or may have intentionally posted.  Should they carry less weight in the question ban algorithm?


The prince was promised a seat on the small council. At the end of season 5, I thought he was on the boat with them. But in season 6, it turns out he stayed in Dorne. Why did he stay in Dorne when his fiancé was on the boat and he was given a seat on the small council?

In the final episode of Game of Thrones season five, Ellaria and Doran Martell with her daughters, the King of Dorne were seeing off Myrcella, Trystane, Jaime and Bronn who were leaving for Kings Landing.   The last season left off at the sequence where Myrcella falls, and then Ellaria is shown bleeding from her nose, due to the poison she used to kill her.   Now in the season 6 premiere, we see Jaime arriving in Kings Landing (it is right now almost sun down). The show then takes us to Dorne, Ellaria with one of her daughter is in the same clothes as they were in last season. So it is the same day from the final season, only that it just got brighter instead of darker. They get the message about Myrcella, then Doran is killed. Next Trystane is killed (who is seen painting the stone that is put on the eyes of the dead, so he must be in Kings Landing for Myrcella's funeral) but suddenly Obara Sand appears.   What's going on? It makes no sense, the first sequence shows Jaime in Kings Landing, the next show Ellaria and Doran talking and it seems like they have just returned from the port.


I was trying to install kde in my ubuntu 15.10.  I used the following command  sudo apt-get install kubuntu-desktop   I encountered these two errors--  The following packages have unmet dependencies:  kde-telepathy-minimal :                 Depends: kde-config-telepathy-accounts (>= 15.04.0)                          but it is not going to be installed.   Now whenever I try to use apt-get it shows this error continuously.  I am unable to even remove the half installed kubuntu-desktop.

$ apt-get install -f -o 'Dpkg::Options::=--force-confmiss --force-all --force-confnew --overwrite-conffiles' --reinstall at-spi2-core Reading package lists... Done Building dependency tree        Reading state information... Done You might want to run 'apt-get -f install' to correct these: The following packages have unmet dependencies:  kde-workspace-bin : Depends: qdbus but it is not going to be installed  libqt4-dbus : Depends: qdbus (= 4:4.8.5+git192-g085f851+dfsg-2ubuntu4) but it is not going to be installed E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution).   I don't quite understand "but it is not going to be installed". Why doesn't it install it then?  apt-get -f install does not help, it does nothing:  $ apt-get install -f Reading package lists... Done Building dependency tree        Reading state information... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.


I am trying to design an environment that has one forest with an empty root, a user domain and multiple domains for different groups that have firewalls between the domains.  I want to have a central user database but segmentation at the IP level for each group of folks.    For the first group the forest would look like this    I will be adding other groups' domains after this first one is working.  Assume there is a firewall between each domain and they are segmented with a subnet for each group's domain.  Here is the initial firewall design    I am trying to allow a user on the Application server to enumerate the users and group objects in the users domain.   Here is the problem.    My users can log in no problem if I don't allow any connectivity between the app server and the User DCs but they cannot enumerate users and groups.    Other the other hand If I allow TCP 389 (LDAP) and TCP 88 (Kerberos) I can enumerate the users and groups but interactive logins are really slow and the app server is looking for 135 (EPmapper) to be open during profile load.    As a test I opened 135 and then the EPmapper passed a random high for the netlogon port which of course the app server then tries to hit.    So what do you think is best course of action?    I cannot open all random highs, that is silly.   I can make the netlogon port static on all my DCs and then open only that port.  Any other ideas?

I want to run DFS replication between a couple of servers. It's my understanding that the servers need to be part of a domain for this. Being able to give people a username and password that works on all servers would be useful too, so I can lock up the admin password.  All machines will be running Windows 2008R2 and they will all be running Windows Firewall, so I need to be able to allow the other machines to connect to this server, but lock out everyone else.   So my question is: what ports do I need to allow the machines to connect to the Domain Controller over?


Just the other day I got a push notification message that asked if I wanted to upload certain photos I took at a certain place to Google Maps for that place.  It kind of shocked me since I never remember allowing Google Maps access to my photos (must have tapped too quick sometime I guess) and I wonder if they have been uploading my photos like other applications upload your contacts as soon as you allow them access?  They could have analyzed it locally since there's geo information in my images but still the push notification came when I wasn't engaged with the app so that means it came from a server.  I wonder if my images are now in Google's cloud and linked to my account or it was just a suggestion made by analyzing my local data.

Yesterday I've visited a restaurant. The restaurant had a beautiful garden and colorful plants. So I took several pictures there. Today, Google Maps sent me a notification and offered me to share those pictures as I've taken for that restaurant.  How does Google Maps know that I've taken pictures there? Does the app regularly check(while the app is running) my pictures and their location without my knowledge? If so, then Google Maps can also upload those pictures to somewhere without even asking me? So if I allow access to my photos for an app, does that mean the app can access my photos without showing a "BROWSE" or something like that and upload to somewhere? I though iOS API needs photos to be picked by user to be shared by an app. Otherwise any app that has proper access permissions can access to all of my photos and then may upload all of them to cloud, whithout my knowledge, right?  Edit: Ok, I'm having hard time to explain myself. I know if Google Maps has access permissions to photos, then it can access photos. That's not the issue here. The problem is that: My phone is locked and sitting on the table. Then I get a notification from Google Maps, asking to share the photos I've taken yesterday at the restaurant I've visited! Not only that, when I click the notification, Google Maps opens up with a view with already selected photos which all taken at the specified location. This is only possible if I opened the Google Maps app, after taking photos, which I did for getting back to home. The problem is, when I open the Google Maps or any other app that has access permission to photos, does this mean all those app can access all of my photos, any time(if app is running in foreground)? I thought apps need to call some iOS APIs to show me the thumbnails, then only the photos I've checked will be delivered to app. That is, I thought apps can only access the photos I've picked from the thumbnail view and the thumbnail view is mandatory and handled by iOS, just like passcode and touchID(apps can't read users' fingerprint or passcode, it's all handled by iOS).


Here $K$ is identified as $\{1\}\times K$. I think because $G/K$ does not depend on $H$, it is natural to say that $G/K$ and $H$ is isomorphic.

I'm trying to understand what the relation is between the direct product and the quotient group.   If we let $H$ be a normal subgroup of a group $G$, then it is not too difficult to show that the set of all cosets of $H$ in $G$ forms a quotient group $G/H$: \begin{equation} G/H = \{ g H \mid g \in G \} \end{equation}  On the other hand, the Cartesian product of two groups $G$ and $H$ is defined as: \begin{equation} G \times H = \{ (g,h) \mid g \in G \text{ and } h \in H \} \end{equation} where $(g,h)$ denotes the set of ordered pairs. The direct product operation on this set is defined as: \begin{equation} (g_1,h_1)(g_2,h_2) = (g_1g_2,h_1h_2) \in G \times H \end{equation} and it is easy to see that the direct product forms a group.  Is the following statement true: \begin{equation} K = G \times H \implies G \simeq K / (\{e_G \} \times H) \end{equation} If so, under what conditions is it true? And how can we see it is true (or false)?  Edit 26/03:  Up to this point, I believe I have found a method (see below) of showing the isomorphism relation. I would be really grateful if someone could tell me whether this proof is correct or not.  Let us identity the elements of $h \in H$ with element of $K$ by setting $h \equiv (e_G,h)$. The elements of $K/H$ are as usual defined by: \begin{equation} K/H = \{ (g,h) H \mid g \in G \text{ and } h \in H \} \end{equation} Since $h_1H=H$ for some $h_1 \in H$, we have: \begin{equation} (g,h)H = (g',h')H \iff g=g' \text{ and } h' = h h_1 \tag{1} \end{equation} and so without loss of generality we can write every element of $K/H$ in the form $(g,e_H)H$. Now, let the map: \begin{equation} f : G \to K/H \end{equation} be defined by: \begin{equation} f(g) = (g,e_H) H \tag{2} \end{equation} The map is one-to-one. This can be seen by equation $(1)$, because if: \begin{equation} f(g) = f(g') \end{equation} then: \begin{equation} (g,e_H) H = (g',e_H) H \implies g=g' \end{equation} Furthermore, the map is trivially onto: \begin{equation} \forall (g,h) H \in K/H \; \exists \; g \in G \; , \; f(g)=(g,h) H \end{equation} and thus the map is bijective. Finally, the map is also a homomorphism, because: \begin{equation} f(gg') = (gg',e_H) H = (g,e_H)(g',e_H) H = (g,e_H)(g',e_H) HH = (g,e_H) H (g',e_H) H = f(g) f(g') \end{equation} and so $f$ is a isomorphism. Thus, by definition of equation $(2)$, we have shown that $G  \simeq K/H$.  Any input is much appreciated.


I am writing my senior design report and I am creating it using Overleaf-LaTeX. My issue is that I can't get the underscore to look like this I am using underscores to manually do this, with no avail since Overleaf will not add more than one space between underscores. This is my first time using LaTeX, I apologize if this is extremely easy.

I'm trying to create a signature and date line in a document.  I need the date line to always be in the same spot on the page no matter what name is under the signature line, such as:  ----------------------   ---------------------- Representative           Date  ----------------------   ---------------------- Program Manager          Date   Here is the code I currently have:  \makebox[2.5in]{\hrulefill} \hspace {1.0in}\makebox[2.5in]{\hrulefill} \\ User Representative \makebox[2.5in][r]{Date} \\  \vspace{.2in} \makebox[2.5in]{\hrulefill} \hspace {1.0in}\makebox[2.5in]{\hrulefill} \\ Program Manager \makebox[2.5in][r]{Date} \   I want to be able to change the names, such as change Program Manager to Joe Foo and have the word 'Date' stay in the exact place.  Any help would be greatly appreciated.  I'm still a newbie at TeX so please forgive my ignorance.


In S06E05 () of Game of Thrones, what happened to Hodor while Brandon was having a vision with the Three Eyed Raven?   How did Hodor get mad or abnormal in the first place?

In early an early episode of season 6 of Game of Thrones, "Home", through his magic Greensight ability, Bran sees a vision of Winterfell in the past. , then named Wylis (Walder in the books) that could speak. Do the books, or series, explain any way why this changed, why Wylis became Hodor and stopped speaking? Hodor.


Suppose that $f : [a, b] \to \mathbb{R}$ is continuous and that $f([a, b]) \subset [a, b]$. Prove that there exists a point $c \in [a, b]$ satisfying $f(c) = c$.   (If either $f(a) = a$ or $f(b) = b$ there is nothing left to show, so you might as well assume that $f(a) = a$ and $f(b) = b$. Since $f$ takes its values in $[a, b]$ this is the same as assuming that $f(a) > a$ and $f(b) < b$.)  So far, I have:  Pf. Assume $f(a)>a$ and $f(b)< b$.  Let $x, y \in [a,b]$ such that $f(a)=x$ and $f(b)=y$ which means $f[a,b]=[x,y]$. Notice $[x,y]\subset [a, b]$. Since f is continuous on $[x,y]$, there exists some $c \in [a,b]$ such that $x$ is less than or equal to $c$ is less than or equal to $y$...  This is where I am stuck because I don't think I can just assume by Intermediate Value Theorem that some $f(c)=c$?

Question: Let $a, b \in \mathbb{R}$ with $a < b$ and let $f: [a,b] \rightarrow [a,b]$ continuous. Show: $f$ has a fixed point, that is, there is an $x \in [a,b]$ with $f(x)=x$.  I suppose this has to do with the basic definition of continuity. The definition I am using is that $f$ is continuous at $a$ if $\displaystyle \lim_{x \to a} f(x)$ exists and if $\displaystyle \lim_{x \to a} f(x) = f(a)$. I must not be understanding it, since I am not sure how to begin showing this... Should I be trying to show that $x$ is both greater than or equal to and less than or equal to $\displaystyle \lim_{x \to a} f(x)$ ?


This is a common example physics teachers use. As far as I know, it never actually holds true.   There are point masses: A(light, eg. feather), B(heavy, eg. hammer) and, C(eg. the Earth). They are all stationary relative to each other and there are no forces acting on them other than that of gravity's up until the impact. A and B are an equal distance away from C. At no point do any of them occupy the same point in spacetime.   In all possible configurations, B will always be closer to the barycenter of the system and thus impact C first.  Additionally, if there are two, two body experiments; one with A-C and, one with B-C, B will still impact sooner. While C exerts an equal gravitational force on both A and B, B exerts a stronger force on C than A does.

The common understanding is that, setting air resistance aside, all objects dropped to Earth fall at the same rate. This is often demonstrated through the thought experiment of cutting a large object in half. The halves clearly can't then fall more slowly just by being sliced in two.  However, I believe the answer is that when two objects fall together, attached or not, they do "fall" faster than an object of less mass alone does. This is because not only does the Earth accelerate the objects toward itself but the objects also accelerate the Earth toward themselves. Considering the formula: $$ F_{\text{g}} = \frac{G m_1 m_2}{d^2} $$  Given $F = ma$ thus $a = F/m$, we note that the mass of the small object doesn't seem to matter as when calculating acceleration the force is divided by the $m$ term, its mass. However, this overlooks that the force is actually applied to both objects, not just to the smaller one. The acceleration on the second, larger object is found by dividing $F$, in turn, by the larger object's mass. The two objects' acceleration vectors are exactly opposite, so closing acceleration is the sum of the two:  $$ a_{\text{closing}} = \frac{F}{m_1} + \frac{F}{m_2} $$  Since the Earth is extremely massive compared to everyday objects, the acceleration imparted on the object by the Earth will radically dominate the equation. As the Earth is $\sim 5.972 \times {10}^{24} \, \mathrm{kg} ,$ a falling object of $5.972 \, \mathrm{kg}$ (just over 13 pounds) would accelerate the Earth about $\frac{1}{{10}^{24}}$ as much, which is one part in a trillion trillion.  Of course in everyday situations, we can for all practical purposes treat objects as falling at the same rate because of this negligible difference—which our instruments probably couldn't even detect. But I'm hoping not for a discussion of practicality or what's measurable or observable, but what we think is actually happening.  Am I right or wrong?  What really clinched this for me was considering dropping a small Moon-massed object close to the Earth and a small Earth-massed object close to the Moon. This made me realize that falling isn't one object moving toward some fixed frame of reference, but that the Earth is just another object, and thus "falling" consists of multiple objects mutually attracting in space.


How would one reasonable differentiate the integral of the form $\int_{f(x)}^{g(x)} h(x) dx$, provided $h$ is continuous? Does this even make reasonable sense? The main point is that the integrand is also a function of $x$.


I used the commands at the end of this article to try installing the restricted extras the article recommends.    sudo apt-get install ubuntu-restricted-extras  When I input this command in the terminal, I receive the following error message:  E: Could not get lock /var/lib/dpkg/lock - open (11: Resource temporarily unavailable) E: Unable to lock the administration directory (/var/lib/dpkg/), is another process using it? rick@rick-XPS-L521X:~$ sudo apt-get install ubuntu-restricted-extras E: Could not get lock /var/lib/dpkg/lock - open (11: Resource temporarily unavailable) E: Unable to lock the administration directory (/var/lib/dpkg/), is another process using it? rick@rick-XPS-L521X:~$ sudo apt-get install libavformat-extra-53 libavcodec-extra-53 E: Could not get lock /var/lib/dpkg/lock - open (11: Resource temporarily unavailable) E: Unable to lock the administration directory (/var/lib/dpkg/), is another process using it? rick@rick-XPS-L521X:~$ sudo apt-get install ubuntu-restricted-extras [sudo] password for rick:  E: Could not get lock /var/lib/dpkg/lock - open (11: Resource temporarily unavailable) E: Unable to lock the administration directory (/var/lib/dpkg/), is another process using it?   The first time I tried installing the restricted extras, the terminal brought me to a legal approval page which ended with no way to agree or not agree to the terms.  So I exited and tried to install again but then received the error message.  How do I fix this?

I get this error when trying to use apt-get:  E: Could not get lock /var/lib/dpkg/lock - open (11 Resource temporarily unavailable) E: Unable to lock the administration directory (/var/lib/dpkg/) is another process using it?     How can I fix this?


I have two student loans I would like to pay off:  A: $6000 - 6.5%  B: $3000 - 6.5%  I am receiving a tax refund of a bit over $3000.  I am not sure whether to pay off B in one fell swoop to get it out of the way, or to halve the principal of A, reducing the total interest I pay over time.  I also have two additional loans of similar principal and half the interest rate for each.  I am not sure how, if at all, they factor into this decision.  Thank you.

My Situation:   About $36k USD in graduate student loans.  There are 4 different federal loans in play, each with a fixed rate of 6.8%.   $12k w/ ~$1.2k in unpaid interest  $10k w/ ~$1k in unpaid interest  $8k w/ no unpaid interest (all principal) $6k w/ no unpaid interest (all principal)  All loans are in repayment. Some loans are subsidized, some are not. This no longer matters now that they're all in repayment though, right?     Is there a most cost efficient way to pay these loans off?  Should the interest be ignored for now on the ones that have $1k in unpaid interest for the time being, because payments to the other two loans will will go directly to principal (minus the monthly compounded interest of course)?  On the surface, I would assume that since they're all the same interest rate, it doesn't really matter, but I'm not sure how the accrued interest would factor in. I'm not interested in psychological wins like debt snowballing. I'm looking for the route that will have me paying the least.


Thanks for your support in these days of facing problems with tabular environment.   I'm not able to understand the way table format works.   I'd like to have a type S in the second column of my tabular environment but it doesn't work with subfloat, any ideas?  \documentclass[12pt,a4paper,oneside,openright]{book} \usepackage{adjustbox} \usepackage{array} \usepackage{dcolumn} \usepackage{amsmath,amssymb}  \usepackage{amsthm} \usepackage{booktabs}  \usepackage{caption}  \usepackage{multirow} \usepackage{siunitx}  \usepackage{tabularx} \usepackage{ltablex} \usepackage{makecell} \usepackage{subfig} \begin{document} \begin{figure} \centering \subfloat[Recovery rate medio per tipo di collateral]{\footnotesize \begin{tabular}{lp{2cm}}         \toprule         Tipo di Collateral & Media Recovery Rate (\%) \\         \toprule         No collateral      & 66.80 \\         Third party plus one other & 88.13 \\         Two guarantees & 84.67 \\         Commercial Building & 86.22 \\         Other Financial Asset & 61.52 \\         Other Real Estate & 85.76 \\         Other Vehicles & 59.83 \\         Residential Building & 92.48 \\         Securities & 78.70 \\         Third Party Guarantee & 75.30 \\         \bottomrule     \end{tabular}     \label{RRpercollateral:fig:a}               } \subfloat[Box plot RR per tipo di collateral]{\includegraphics[width=0.55\textwidth, height=0.45\textwidth]{help2.pdf} }\\ \caption{Recovery Rate per tipo di collateral} \label{RRpercollateral_all} \end{figure} \end{document}

I'm finishing my Msc. Thesis and I'm facing the last problems with some tabular, I'm not able to align this one.  \documentclass[12pt,a4paper,oneside,openright]{book} \usepackage{adjustbox} \usepackage{array} \usepackage{dcolumn} \usepackage{amsmath,amssymb}    \usepackage{amsthm} \usepackage{booktabs}  \usepackage{caption}   \usepackage{multirow} \usepackage{siunitx}  \usepackage{tabularx} \usepackage{ltablex} \usepackage{makecell}  \begin{document} \begin{table} \centering \caption{Analisi variabile tasso di interesse\label{tab:stat:tasso}} \begin{tabular}{p{3cm}p{3cm}} \toprule Data di segnalazione & \makecell[ccc]{\% \\ Tasso di interesse\\ medio} \\ \toprule 2014h1 & 3.59\\ 2014h2 & 3.44 \\ 2015h1 & 3.37 \\ 2015h2 & 3.82 \\ 2016h1 & 3.68 \\ \bottomrule Media & 3.58 \\ \end{tabular}% \end{table}% \end{document}


What is the most concise way to resolve a hostname to a local IP address in Arch Linux?

What's the most concise way to resolve a hostname to an IP address in a Bash script? I'm using .


I found out about the fish that tells you your fortune, but I also found out there was more then one type of them.   But I wanna know is there any thing that is like this? Maybe one that doesn't crack corny jokes and weird quotes.

I just found out about the free the fish easter egg available in Ubuntu:   Press Alt + F2  Enter this:  free the fish   Are there any more easter eggs available in Ubuntu? What are they?


I am trying to create a CSV in the batch.  global void finish(Database.BatchableContext BC) {     for(ID a: temp)     {         String recordString = '"'+a+'"\n';         finalstring = finalstring + recordString;     }     Blob csvBlob = Blob.valueOf(finalstring); }   I'm able to form the CSV file, but the first record has extra characters added to the value like this:     null"001R000001dasdsadU"   I'm sure recordString has issues. How should I escape in a string?

I want to create csv files from lists and send an email attaching them, how to do that in a controller method?


I recently bought a Transformer so that I can make an ionic lifter but it has a max 30 amp output and I’m sure that is way too much for what I need plus Since I have this plugged straight into the wall I’ll definitely need an ac to dc rectifier which at most goes to about 5 amps So my question is how can I reduce the output amps so that I don’t mess up this rectifier as soon as I get it.   Btw the transformer is a 3000W YaeCCC Auto Transformer

Power supplies are available in a wide range of voltage and current ratings.  If I have a device that has specific voltage and current ratings, how do those relate to the power ratings I need to specify?  What if I don't know the device's specs, but am replacing a previous power supply with particular ratings?  Is it OK to go lower voltage, or should it always be higher?  What about current?  I don't want a 10 A supply to damage my 1 A device.


I wish to support a 900 lb motor I want to use 3 2x6x8 for a support beam will this be enough?

How much load can a board support, if it is supported only at the ends?  At the moment my specific problem is hanging a tire swing between two trees, and depending on which trees I choose they could be 10, 12, or 14 feet apart (center to center).  If I securely attach a 2x4 to the trees and hang the swing from the middle, would it be at risk of breaking from 2 children playing on it (so I'd guess around 300lbs max with them bouncing and jumping onto it)  But my bigger question is the general case: how do you calculate (or where do you look up) what kind of loads can be supported by the wood in question?  (other examples would be a 1x10 shelf with supports 24" apart, or 1/2" plywood on a 2' x 4' frame).  I'm not an engineer (well, software, but that doesn't count here), but I can do simple math (linear algebra, trig, calculus) and have a basic understanding of physics.


I've connected a graphics adapter to my Ubuntu 14.10 server. I'm using VirtualBox and need to enable access to the GPU under VM. The GPU is working on the server but not on the VM.  $ sudo lshw -C video   *-display                       description: VGA compatible controller        product: NVIDIA Corporation        vendor: NVIDIA Corporation        physical id: 0        bus info: pci@0000:84:00.0        version: a1        width: 64 bits        clock: 33MHz        capabilities: pm msi pciexpress vga_controller bus_master cap_list rom        configuration: driver=nvidia latency=0        resources: irq:151 memory:fa000000-faffffff memory:f0000000-f7ffffff memory:f8000000-f9ffffff ioport:f000(size=128) memory:fb000000-fb07ffff   I've installed the Guest Additions according the following explanation:   In addition, I went over     When I tried cat /proc/driver/nvidia/version according to the previous link, nothing happened. nvidia folder doesn't exist  Here is the error I get when I try to access the GPU from the VM:  modprobe: ERROR: could not insert 'nvidia_340': No such device Error using gpuArray No supported GPU device was found on this computer. To learn more about supported GPU devices, see www.mathworks.com/gpudevice. Error in main (line 2)  parallel:gpu:device:NoCUDADevice   Please advise.

I recently bought a new laptop with following configuration   CPU: Intel i5 2450 RAM: 8 GB DDR3 GPU: NVIDIA GeForce GTX 520 1GB   I've setup a virtual machine using VirtualBox with Windows 7 as guest. I want to use my (host's) graphics card in it but the virtual machine is only showing 128 MB of video memory.  I am using Bumblebee and start the virtual machine using   $ optirun VBoxManage startvm "Windows 7"   Please suggest me how should I use my graphics card for 3D acceleration in virtual machine.


Our Silverlight app contains a third-party control, which contains some ScrollBars (among other things). In order to troubleshoot a problem, I want to be able to stop in the debugger whenever the third-party control modifies the Minimum or Maximum properties of any of its scrollbars. Then I'll be able to look at the stack trace and learn more about what's going on.  If I was interested in the ScrollBars' Value property, that would all be easy -- ScrollBar has a ValueChanged event, so I could just add some throwaway code that hooks that event on the ScrollBar, set a breakpoint inside my event handler, and debug away. But there are no corresponding CLR events for MinimumChanged or MaximumChanged, so it won't be that simple.  I ran across a blog post that talks about , but unfortunately,  doesn't exist in Silverlight.  How can I get to the point where I can set a breakpoint that fires whenever the ScrollBar's Minimum and Maximum properties change?

In a Silverlight application I'm trying to find out when a property on a usercontrol has changed. I'm interested in one particular DependencyProperty, but unfortunately the control itself doesn't implement INotifyPropertyChanged.  Is there any other way of determining if the value has changed?


I need to do basically what is done   SELECT t.id, t.key FROM (     SELECT id, key, ROW_NUMBER() OVER (ORDER BY key) AS rownum     FROM datatable ) AS t WHERE t.rownum % n = 0    ORDER BY t.key   but using Linq to Entities. I just can't figure out how. A method ROW_NUMBER is not known and using an index in the where clause gives me an error.  Query.Where((s, i) => i % n == 0);   Edit: more precisely  Query.Select((s, i) => new { index = i, data = s } ).Where(s => s.index % n == 0).Select(s => s.data)   The only solutions that worked for me so far is to temporarily run the SQL (toList) and filter it afterwards. This however slows down my server significantly.

Say I have a list of all Projects, and that I group them by Category like this:  var projectsByCat = from p in Projects                     group p by p.Category into g                     orderby g.Count() descending                     select new { Category = g.Key, Projects = g };   Now I want to display this as a list in a web page, where first I create the left side div, secondly the right side div. I am ordering by number of Projects in each Category to show the Categories with the most Projects on top - thus I would like to split projectsByCat in two - if I put all the "odd numbered" Categories on the left and the "even numbered" categories on the right, I think I will get a reasonably sane view.  So I thought I could do this to get the odd and even members of projectsByCat:  var oddCategories = projectsByCat.Where((cat, index) => index % 2 != 0);  var evenCategories = projectsByCat.Where((cat, index) => index % 2 == 0);   And it compiles - however, when I run it, I get an exception such as this:     Unsupported overload used for query operator 'Where'.   And I thought I was safe since it compiled in the first place.. ;)  Is there an elegant way to do this? And also, is there an elegant explanation for why my creative use of Where() won't work?  Thanks in advance!


I have a generic function:  T GetVal<T>()             where T : class;  I also have a function which gets a Type and based on it should return the type specified: func(Type type) { var classType = ? // get the class type from type to use it in the next line    return GetVal<classType>() }  Is it possible?

What's the best way to call a generic method when the type parameter isn't known at compile time, but instead is obtained dynamically at runtime?  Consider the following sample code - inside the Example() method, what's the most concise way to invoke GenericMethod<T>() using the Type stored in the myType variable?  public class Sample {     public void Example(string typeName)     {         Type myType = FindType(typeName);          // What goes here to call GenericMethod<T>()?         GenericMethod<myType>(); // This doesn't work          // What changes to call StaticMethod<T>()?         Sample.StaticMethod<myType>(); // This also doesn't work     }      public void GenericMethod<T>()     {         // ...     }      public static void StaticMethod<T>()     {         //...     } }


After some studies I've found LEDs having 3 colors RGB (Red, Green and Blue), I was very interested in this topic so this question is up. The Diagram will tell the colors in LEDs.   > Red, Green and Blue color in LEDs      Why only RGB is needed?      Why can't any other color be replaced?      Why MCY Cannot be used?

In  the question emerged, where the LEDs with 5 or more dies of different colours are. (Kudos to Brian Drummond) The background is as follows:  RGB LEDs are very popular for creating colourful lighting effects. In fact, due to the three receptor types in the human eye virtually every possible colour we can perceive can be produced with a red, a green and a blue LED although the LEDs can produce only a very delimited section of the visible spectrum. With three colours it is even possible, provided a perfect mixture ratio, to produce a light perceived as a pure white. The human vision cannot recognise different light sources if they excite the three colour sensing cones in the eye at the same levels. This effect is called metamerism.  However the human can very well perceive the quality of light sources when light is being reflected by coloured surfaces or objects. Because the reflection of light on coloured surfaces is effectively a multiplication of the light spectrum with the remission spectrum of pigments. The remitted spectrum differs vastly for different sources of white light.  To cut a long story short: White light from RGB-LEDs is a mess. If you try to use it for general illumination purposes, colours of artwork are reduced to a greyish mélange and human skin looks like beeing afloat in a quarry pond for a week.  White LED having a blue chip and a conversion layer produce considerably better light for illumination but can't be tuned to produce light with different colour temperatures let alone pure colours.  While there are some LEDs with a white chip and three colour chips in one housing, those usually tend not to address a better colour rendering but to have a higher luminous flux at white light.   So the question with some additional words is:   Why are there no multichip LEDs (5 or more chips) for the production of light with higher colour rendering?


I have no idea how to start this problem. I am assuming that the Mean Value Theorem is needed in the proof but I am not exactly sure how to apply it to the given polynomial. Any hints/help would be appreciated.   If  $ \frac{a_n}{n+1} +  \frac{a_{n-1}}{n} + \cdot \cdot \cdot + \frac{a_1}{2} + a_0 = 0 $,  prove that the polynomial equation  $ a_n x^n + a_{n-1}x^{n-1} + \cdot \cdot \cdot + a_1x + a_0 = 0$  has a solution in $(0,1)$.

Knowing that $$ \frac{a_0}{1} + \frac{a_1}{2} + \frac{a_2}{3} +\cdots + \frac{a_n}{n+1} =0$$ Prove that  $$ a_0 + a_1x + a_2x^2 + \cdots + a_nx^n = 0$$ has at least one real solution.  I suspect that it's proven with the intermediate value theorem. But can't find two numbers that satisfy it.


When deriving the solutions for the "simple" quantum mechanical hydrogen problem, one normally uses spherical coordinates $(r,\theta,\phi)$, since the problem has rotational symmetry. The solution has the form $$\psi_{lmn}(r,\theta,\phi) = R_{nl}(r)Y_{lm}(\theta,\phi)$$ where $R(r)$ describes the radial part and $Y_{lm}(\theta,\phi)$ are the spherical harmonics.   When deriving this solution, one normally aligns the problem to the $z$ coordinate and gets a representation for $Y_{lm}(\theta,\phi)$ with the angle $\theta$ measured from the $z$-axis.  One "surprising" observation is, that the spherical harmonics and therefore the solutions of the wavefunction and its absolute squared are not rotational symmetric. I. e. it has these "lumps" of high probability density when forming the absolute squared wave function.  My question is, how does this asymmetry and distinguishing the $z$-axis relate to the "image" of hydrogen? If I actually had a single hydrogen atom and would want o measure the probability density of the electron: To which axis would the wave function be aligned?

In an hydrogen-like atoms the orbitals are solutions to the Schrodinger equation suitable for the problem.  They describe the regions where an electron can be found.  So, why don't they have spherical symmetric?  As in this picture:    Why, in a certain distance from the nucleus, are there points where an electron can be found, and points where it can't?  EDIT: Is there any intuation about the symmetry breaking?


I am required to find the moment of inertia of the lever for a project in physics. This is my attempt:  Please note that we have not been taught this yet in class so i have not been taught this officially yet.   The seperate radiuses are the distance from the fulcrum to the end of each side of the lever.  $L = 1.57m$  $r_1 = .97m$  $r_2 = .6m$  $M_{total} = 2.3 kg$  $$ I = \frac{M_{total}}{L}\int_{0}^{.97} x^2 dx + \frac{M_{total}}{L} \int_{0}^{.6} x^2 dx $$  $$ I = \frac{M_{total}}{L}[\frac{.97^3+.6^3}{3}] $$  $$ I = \frac{2.3(.97^3+.6^3)}{4.71} = \frac{165347}{300000} $$  But this seems way too easy? Am i doing something wrong?

I've tried to find the moment of inertia of a cylinder rotating about an axis parallel to its base (i.e about the 'End diameter') as one can see  . But when I checked my results with different references ,I've found that it's incorrect!.I need a help to figure out where I did it wrong. since $$I=\int\limits x^2.dm$$ $$dm = \rho.dv$$ where $$dv= r.d\theta . dr .dh$$ & $$\rho=\frac{M}{\pi R^2 H}$$ $M$:cylinder total mass. $H$:total height of cylinder. $R$:the radius of the cylinder. The distance of each infinitesimal element from the axis of rotation would be : $$\sqrt{r^2+h^2}$$ Therfore, $$I= \frac{2M}{ R^2 H}\int\limits_{0}^{R} \int\limits_{0}^{H}\, r(r^2+h^2)dh\,dr$$ and this gives a result of : $$\frac{M~H^2}{3}+\frac{M~R^2}{2}$$ Which is obviously wrong since the second term should be multiplied by a factor of $1/2$.


This is the screen for creating tag synonyms (Arqade edition):    Which is source and which is target? Every time I use this tool I get confused, as either way could theoretically make sense. The language used in all other tag-synonym contexts is Master and Synonym. Please can this page be made to match this convention too?

(Split off from my answer to ...)  The whole interface for this feature is terrible! It has almost no useful information for the poor moderator.    "Source"? "Target"? No matter so many tag merge requests have come out backwards that I've seen. The poor moderator has to take a stab in the dark. Why not call one "Synonym" and the other something like "Main tag" or whatever?  When you enter valid tags it should tell you useful stuff about each tag:   Preview of wiki and/or excerpt Creation date Whether this tag already has synonyms, how many, what they are How many questions each tag is already used on How recently each tag was applied to a question How recently each tag had its tag wiki and/or excerpt edited Maybe the users who created them, use them the most, used them most recently If there were votes for adding the synonym (in either direction), show total plus number of each up and down votes Would an option to revert/undo when a tag merge was applied "backwards" make sense and fit into the interface? Are the old tag wikis for the tags which have now become mere synonyms still stored in the database somewhere? Could we add a way to import/reinstate a tag wiki from a synonym to the new main tag? Could it work even for synonyms made some time ago?   OK some of that is not strictly necessary but might help the mod and won't be hard to implement. But some of it I think is really essential.


i make stack2[0].matrix refer to stack1[0].matrix, but after i change stack2[0].matrix, the stack1[0].matrix is changed too. why is this happen? and how can i keep stack1[0].matrix value?  thank you     let Number = function(){     this.matrix = [         [1, 2, 3],         [4, 5, 6]     ] }  stack1 = []; stack2 = [];  stack1.push(new Number); stack2.push(new Number); stack2[0].matrix = stack1[0].matrix; stack2[0].matrix[0][0] = 5;  console.log(stack1[0].matrix); console.log(stack2[0].matrix);

The primitive types (number, string, etc.) are passed by value, but objects are unknown, because they can be both passed-by-value (in case we consider that a variable holding an object is in fact a reference to the object) and passed-by-reference (when we consider that the variable to the object holds the object itself).  Although it doesn't really matter at the end, I want to know what is the correct way to present the arguments passing conventions. Is there an excerpt from JavaScript specification, which defines what should be the semantics regarding this?


Is there a statistical/information theoretic interpretation of this matrix in the context where A represents observations of data (and this matrix which shows up in e.g. solving linear systems and elsewhere)? Does it have a special name used in the context where A represents "rows of data"?

For a given data matrix $A$ (with variables in columns and data points in rows), it seems like $A^TA$ plays an important role in statistics. For example, it is an important part of the analytical solution of ordinary least squares. Or, for PCA, its eigenvectors are the principal components of the data.  I understand how to calculate $A^TA$, but I was wondering if there's an intuitive interpretation of what this matrix represents, which leads to its important role?


my question is  is it possible to install openstack on rhel7 without subscribing to the Redhat network?  I'm receiving an error of a missing dependency on phython-greenlet and so far the only solution I found is subscribe o the Redhat Network  Thanks

I'm new to RHEL. Trying to install software this morning and running into road blocks. Is it required to have a subscription to download packages via yum on RHEL?  I'm coming across different sources on the net, some make it sound like yes, you need a subscription, others making it sound like no, a subscription is only required for support.  In either case I'm stuck unable to install software ATM, because the machines I'm on don't have the subscription registered. Is there a way to install RHEL software without registering a subscription? If so, how?


$f'(\sin^2x) = \cos^2x + \tan^2x,\quad$ subject to $\quad0<x<1$  Many thanks.

Find $f(x)$ that satisfies the first-order differential equation: $$f'(\sin^2x)=\cos^2x+\tan^2x\tag{for $0<x<1$}$$


I have been beating my head on a java project for a class for a bit. At the moment, the program runs and completes, but nothing as an output. It is error free and warning free, well as far as eclipse can tell.  I would feel horrible to post the code and asking someone to debug, but i don't have enough rep to go into chat and ask if anyone cares to help.  My question is, is it completely inappropriate to post a big chunk of code under those circumstances, as i suspect it is?

So, I've been spending considerable more time on SO recently than I normally have, and one thing that I've noticed is quite a few people saying stuff like "There's a Null Pointer Error in this block of code, please help me fix it", with a huge amount of code posted, and no real clue as to where the NPE is. So my question is, what can we do to accomplish 2 goals?   Help the person asking the question become a better programmer. Help them to solve their problems.


Let  $$||x||_p=\left( \displaystyle \sum_{i=1}^n|x_i|^p\right)^{\frac{1}{p}}$$ and $$||x||_M=\max\{|x_1|,|x_2|,...,|x_n|\},$$ norms in $\mathbb{R}^n$. Show that $$\lim_{p \to \infty}||x||_p=||x||_M, \ \forall x \in \mathbb{R}^n.$$

We define p-norm in this way: $\|x\|_p = \{\sum ^N_j=_1|x_j|^p\}^ {1\over p}$ We know that It change to $\|x\|_p = \max|x_j| $    when $ p \to \infty $  How can I prove this ?


What are the ways to allow comments on user profile pages in Drupal 7? There is a profile content module, which unfortunately is not available for Drupal 7.

With users being entities in D7 I assumed the user type would would have built in "comment" option. That doesn't seem to be the case. I just want to allow users to leave comments on the user profile page. Is there a simple way to doing that?


I was working on a project and I don't know how but the viewport started hiding things out of a camera range... I tried deleting the camera but it did not work.. here is how it looks like:  the archive:   EDIT: So, I think this is probably a glitch. I tried to open it with blender 2.8 and the problem just disappeared.. I cannot save it in 2.8 tho because I Still want to use it in 2.79b.

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


I have around 20 images to scan a copy of my work book. I want to make a PDF of them. But during the insertion of these files, I am getting the error "Too many unprocessed floats".   For some number of image files I am able to compile. But after some I am getting the error. How can I remove this error?

I'm trying to a large number of figures. The code is  \begin{figure} \includegraphics[scale=0.5]{m2T4.pdf} \caption{M2T, Problem Size 513} \end{figure}   I'm not able to compile, I get the error  ! LaTeX Error: Too many unprocessed floats. See the LaTeX manual or LaTeX Companion for explanation. Type H <return> for immediate help. ... l.113 \includegraphics [scale=0.5]{m2T4.pdf} You've lost some text. Try typing <return> to proceed. If that doesn't work, type X <return> to quit. ! Undefined control sequence. \@float@Hx ...ltovf \fi \global \setbox \@currbox \color@vbox \normalcolor \... l.113 \includegraphics [scale=0.5]{m2T4.pdf} The control sequence at the end of the top line of your error message was never \def'ed. If you have misspelled it (e.g., `\hobx'), type `I' and the correct spelling (e.g., `I\hbox'). Otherwise just continue, and I'll forget about whatever was undefined. ! Missing number, treated as zero. <to be read again> \vbox l.113 \includegraphics [scale=0.5]{m2T4.pdf} A number should have been here; I inserted `0'. (If you can't figure out why I needed to see a number, look up `weird error' in the index to The TeXbook.) pdfTeX warning: pdflatex (file ./m2T4.pdf): PDF inclusion: found PDF version <1 .5>, but at most version <1.4> allowed <m2T4.pdf, id=1121, 538.28104pt x 212.1526pt> File: m2T4.pdf Graphic file (type pdf) <use m2T4.pdf>


I wanted to have a simple python script to keep repeat typing certain words and send. like have an idle game and need leave it open and using skills. Is there any library can do it?

Is it possible to make it appear to a system that a key was pressed, for example I need to  make A key be pressed thousands of times, and it is much to time consuming to do it manually, I would like to write something to do it for me, and the only thing I know well enough is Python.  A better way to put it, I need to emulate a key press, I.E. not capture a key press.  More Info (as requested): I am running windows XP and need to send the keys to another application.