Missing DB table blocking uninstall of custom module

Simple problem PITA to fix.  I created a module with a custom entity and some other stuff. But there was an error during installation and the DB table did not get created.  Attempting to uninstall gives an error because it can't find the table to delete it.   [ERROR] SQLSTATE[42S02]: Base table or view not found: 1146   Table 'xxxxx.zzzzz' doesn't exist:  SELECT base_table.id AS id, base_table.id AS base_table_id                          FROM {zzzzz} base_table LIMIT 1 OFFSET 0; Array()   So I'm stuck - I've fixed the problem but can't uninstall the module to reinstall it.  How can I persuade the uninstall to work?  I have considered faking the table it's asking for, but is it going to expect the field tables to be there as well?  What I really need is for it to be less picky about the tables being missing.


When solving for the value, we know that $e^{\pi i}=-1$ . I am confused as to what is the right answer when you evaluate this.I am getting two possible answers: $e^{3\pi i/2}$ = $(e^{\pi i})^{3/2}$ so this could be $(\sqrt{-1})^3=i^3=-i$ or it could be $\sqrt{(-1)^3}=\sqrt{-1}=i$. Which one is the correct answer, and where am I going wrong? Thanks.


bash-like last command in history using up-down arrow keys in zsh

In bash, we can use the up and down arrow keys to get the last or nth previous command in history.  Can we do this in zsh?


Javascript confirm() method. How to put separate action on 'cancel' and 'ok' button

I have a JSP page where I have put a JS code for confirm() method. I am calling this from the form "onsubmit". The dialog box has 2 buttons "OK' and 'cancel'. On clicking "OK" the form should be submitted which is happening but on click of 'cancel' button I need to redirect the page to some other page. Below is the JS code.  function showDialog() {     if(confirm("Press OK to confirm")) {      console.log("Clicked OK, confirmation.");} else { console.log("Clicked Cancel, confirmation.");         }  Below is the form tag where I am calling JS function:  <form:form  name="login" id="login" action="<%=loginPass%>" method="POST" autocomplete="off" onsubmit= "showDialog()">


Prove that $\lim\limits_{n\to\infty}\frac{2^n}{n!}=0,n\in \mathbb{N}$

If we know that $\frac{2^n}{n!}>0$ for every $n\in \mathbb{N}$ and $$\frac{2^n}{n!}=\frac{2}{1}\frac{2}{2}...\frac{2}{n}$$ how to bound this sequence above?


iOS app keeps showing red popup in notification tray until you go to main web site

I'm using the SE iOS app version 1.3.0.  This morning I woke up and checked the app.  It showed a red popup with "3" in the notification tray.  One was a comment so I went to it.  That should have cleared the "3" from the tray, but I noticed that whenever I closed the app and went back into it, the notification tray kept showing "3".  Even after I force closed the app and relaunched it, it still showed "3" in the notification tray.  Finally I went to SE on a desktop PC and clicked on the notification tray there.  Then I went back to the iOS app and the notification tray finally didn't show "3" anymore.


I need to disable SSL browsing completely in Chrome.  If not completely, at least disable  and force  to load, FOR EXAMPLE (FB is just an example - i understand that TODAY it does not permit non-secure browsing).


How to read a text file in Java Eclipse?

I am a very novice programmer trying to read a text file in Java Eclipse.     Here is my code:    package readFromfile;  import java.io.File; import java.io.FileNotFoundException; import java.util.Scanner;  public class justDo {   public static void main(String[] args) throws FileNotFoundException {      System.out.println(System.getProperty("user.dir"));     File file = new File(System.getProperty("user.dir") +   "/src/report.txt");         Scanner hemp = new Scanner(file);       System.out.println(hemp);      } }      Instead of reading a text file and displaying the file's contents in the console I get this:    C:\Users\Vanessa\eclipse-workspace\readFromfile java.util.Scanner[delimiters=\p{javaWhitespace}+][position=0][match  valid=false][need input=false][source closed=false][skipped=false][group  separator=\,][decimal separator=\.][positive prefix=][negative prefix=\Q-  \E][positive suffix=][negative suffix=][NaN string=\QNaN\E][infinity  string=\Q?\E]   Can someone please explain why I am getting this and explain how to properly read a text file in Java Eclipse? Please help. Thank you all so much in advance.


How do you set the default font for a new text object?

Whenever I add a text object it always defaults to Bfont. How do I change that? I have not seen any settings in the user preferences. (However there is a setting to change the UI font.)


Sort list of dictionaries by date in Python 3.4

I have a list of dictionaries like this but with many more dictionaries:  x = [{"duration":datetime.time(5,30),"date":datetime.date(2016,02,13)},{"duration":datetime.time(3,30),"date":datetime.date(2016,02,11)},{"duration":datetime.time(2,0),"date":datetime.date(2016,02,16)}]   Is there a way to sort this list in ascending order of date using Python keywords such as sorted and lambda without making a custom sorting function? I have been looking at the sorted  and the use of lambda in the optional key argument.


What does "hash" mean here, where does it come from- meaning to discuss, work out, iron out something- especially the details of something- until an agreement is reached.   Examples (taken from various dictionaries)   The department was hashing out the new syllabus.   I need to hash this matter over with you.    I'll call my mother to hash out to details of the Christmas dinner.    They met during the day to hash out  the campaign's reaction to the controversy.  The detectives hashed out their theories about who committed the murder.  They've spent quite a bit of time hashing over the problem.     We need to sit down and hash things out.


Can't install Ubuntu, no suitable graphics mode found

I have downloaded Ubuntu 14.04.2, put it onto a flashdrive, booted from the drive and I am greeted with:  No suitable graphics mode found. Booting in blind mode.   Needless to say, I can't install. Booting the "Try Ubuntu" option just yields a black screen. Booting the "Install" option yields a maximized window title bar which is empty and the rest of the screen is another color and empty as well.  Tried so far: replacing the quiet splash with vga=772 (same result) and xforcevesa (doesn't boot through) nor 771 (800x600x256 colors), 788 (800x600x16bit), 789 (800x600x24bit) 869 (1152x720x256)   The hardware of the PC is all right, Itt's a monitor, not a TV and I have Windows installed right now and had video output before installing any graphics drivers.  The problem started in Ubuntu when changing a GeForce 570 to a 780 GTX.  I've tried  but there is no alternate installer for 14.04


Need help with Dual boot Win 8.1 & Ubuntu 14.04 on HP Envy j112 tx Notebook

I bought a new HP notebook with pre-installed Win 8.1. I am trying to dual boot it with Ubuntu 14.04. I have followed the usual steps, and installed Ubuntu on my system. However, when I boot the system it goes to Win 8 and does not dual boot.  I was able to access ubuntu in the legacy mode, but had to manually intervene the boot process. To change the legacy mode I ran boot-repair, as advised on the forum here, with the recommended settings. This is the before and after bootinfo.       Now, when I try to boot into Ubuntu from the HDD it goes into grub rescue mode with the error '/boot/grub/ i386-pc/normal.mod not found.  Which I suppose is bound to happen since grub-pc was replaced to grub-efi in the  boot repair.  The problem is that even after the boot repair the system boots into OS manager which by default boots Win 8. I read here    that HP notebooks might be hard-coded to boot only Win 8. Since I am new to linux I'm unable to figure out what to do next and how to work around this problem. Any help would be much appreciated. Thank you.


how to fix "sudo: apt-repository: command not found" in Deepin distro

what I want to achieve is to install Firefox beta channel to update the current version so after running this command  sudo apt-repository ppa:mozillateam/firefox-next   I got this error  sudo: apt-repository: command not found   I've searched a lot to fix this, I found to fix this is to install   sudo apt-get install python-software-properties   which is printing the following  Reading package lists... Done Building dependency tree        Reading state information... Done python-software-properties is already the newest version (0.96.9debian1). 0 upgraded, 0 newly installed, 0 to remove and 1 not upgraded.   and I've tried what is mentioned in this  and nothing worked. I can't find any solution for this.


Expression for a choice which isn't really one

What would be a nice short expression to describe a choice which isn't really one, in that all of its possible outcomes are ultimately equivalent despite being presented as different?  My first thought was "false choice", but this turns out to have a different meaning, and my next idea was "empty choice" which doesn't seem to exist. Does anyone know of such an expression?


Is there a general formula for solving 4th degree equations (quartic)?

There is a general formula for solving quadratic equations, namely the Quadratic Formula:  $$ x = \frac{ -b \pm \sqrt{ b^2 - 4ac } }{ 2a } $$  For third degree equations of the form $ax^3+bx^2+cx+d=0$, there is a set of three equations: one for each root. Is there a general formula for solving equations of the following form? $$ ax^4 + bx^3 + cx^2 + dx + e = 0 $$ How about for higher degrees? If not, why not?


I'm writing a Java app to generate tries for Latex using TikZ.  I'm struggling to typeset a  to follow example below:    Could someone provide me with an example how to properly nest children nodes and corresponding labels.  What I got now is:  \begin{tikzpicture} \node [circle] {}     child{ node [circle] {} edge from parent node[above left] {$B$} }     child{ node [circle] {} edge from parent node[above left] {$F$}             child [circle] {}         };  \end{tikzpicture}   But edge labels won't match to the right edges.


Do Stack Exchange sites have any features to make them friendly to people with disabilities?

Some people, for example those with dyslexia, will be challenged in accessing most websites, however, if web pages are designed to include them they can make valuable contributions. For example Steve Jobs, Leonardo da Vinci and Nikola Tesla were dyslexic, and Stephen Hawking has .  In addition to dyslexic people, we also have to factor in elderly people, autistic people, and the blind. They could be facing various difficulties that we need to be sensitive to, such as overstimulation, navigation difficulties, and visual impediments.  How is Stack Exchange working to make their platform more disability friendly?


Ajax takes 10x as long as it should/could

I have just hit my first serious issue with WordPress and for someone that enjoys Ajax this is a biggy.  I have an Ajax request that is taking 1.5 seconds to complete while using the Ajax API.   If I take the same exact code and run it with a custom script(no WordPress) the Ajax request takes merely 150 milliseconds. This is not an exaggeration  If you look at the very first comment of  and the conversation that follows you will see that this slowness is caused by the fact that on your request, all of WP is loaded...  I am hoping that there is a solution out there that will make it possible to make Ajax requests while not loading all of WordPress.   What are your experiences with speeding up Ajax requests with WordPress?


File permissions changed but group user can't write in them

I have done the follow:   chown'd it to a group chmod 775 usermod   this is the status of the permission drwxrwxr-x  3 root www-data 4096 Mar 22 23:11 html  The groups my user is in ubuntu : ubuntu adm dialout cdrom floppy sudo audio dip www-data video plugdev netdev lxd  But if I do touch test it just gives me a permission denied. Am I missing something.  As for a little background, I'm running a Ubuntu server on AWS. I'm also trying to give my apache user writing permission in the html folder.


Georeferencing/rectifying multiple images of different shapes and sizes at once using ArcGIS for Desktop?

A couple of weeks ago I georeferenced a set of 7 scanned maps (.tiffs). Although the scans all have different shapes and sizes, the outline of all the maps on there is the same, and after having georeferenced them, the maps align quite nicely.   Today I found out that the southern area should be referenced differently. The same mistake has been made for all images: the northern part is allright for all maps, but the southern boundary of my maps should be shifted upwards a bit. I don't want to do the tedious job of aligning all tiffs by hand again.    Does anybody know if there is a way to rectify them all at once? Can I relate the tiffs in some way?


Iam a severe beginner, so please bear with me ...   I un-installed playonlinux from my machine*. Now, whenever running sudo apt-get update, the system still prints these warnings:     W: GPG error:  precise InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 73F0D6E88E3D6C3A      W: The repository ' precise InRelease' is not signed.      N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.   When I look at sources.list, it does not contain any reference to playonlinux that I can identify. I also ran apt-key update. When I try to purge playonlinux, it says that Package 'playonlinux' is not installed.   How can I fix this? Thanks!  *I am running Elementary OS 0.4.1. (Built on "Ubuntu 16.04.2 LTS").


Recently, I read on the reddit sentence: "Grinned from ear to ear when I heard it". I would like to ask why there is no subject at the beginning of "I". Is this something acceptable, is it normal for colloquial language? I understand the sentence, but the subject is missing, in my opinion.


Newton's third law states that every force has an equal and opposite reaction. But this doesn't seem like the case in the following scenario:  For example, a person punches a wall and the wall breaks.  The wall wasn't able to withstand the force, nor provide equal force in opposite direction to stop the punch.  If the force was indeed equal, wouldn't the punch not break the wall? I.e., like punching concrete, you'll just hurt your hand. Doesn't this mean Newton's third law is wrong in these cases?


I just updated from Ubuntu 10.10 to 11.04 and have an issue regarding the screen resolution. I have Intel integrated gfx chip and my monitor supports resolutions larger than 1024x768. (in 10.10 I've been using 1280x1024) But as soon as I upgraded, I'm stuck with 1024x768 resolution and seems I can't change it.  running xrandr In terminal yields the following results,   Screen 0: minimum 320 x 200, current 1024 x 768, maximum 4096 x 4096 LVDS1 connected 1024x768+0+0 (normal left inverted right x axis y axis) 0mm x 0mm    1280x800       58.1 +    1024x768       60.0*     800x600        60.3     56.2      640x480        59.9   VGA1 connected 1024x768+0+0 (normal left inverted right x axis y axis) 344mm x 194mm    1366x768       59.9 +    1360x768       60.0      1024x768       75.1     72.0     70.1     60.0*     832x624        74.6      800x600        72.2     75.0     60.3     56.2      640x480        72.8     75.0     66.7     60.0      720x400        70.1     1280x1024_60.00 (0xce)  109.0MHz         h: width  1280 start 1368 end 1496 total 1712 skew    0 clock   63.7KHz         v: height 1024 start 1027 end 1034 total 1063           clock   59.9Hz   What maybe the problem? Is it a bug? What kind of steps I should take in order to get a higher resolution? (changing xorg.conf maybe?) Any insight is highly appreciated. Thanks in advance.   UPDATE    Screenshot after running xrandr --addmode VGA1 1360x768  As you can see, side bar is not completely visible and Ubuntu logo at the task bar is missing. Also when you open an application, the Task bar of the application (where it should go to the top panel) is missing as well..


Why would I choose Libav over FFmpeg, or is there even a difference?

From what I've seen it looks to me like Libav's avconv is thought to become a successor of ffmpeg — is that correct?   If that's true, why is that so? What exactly is libav doing better and why would I want to choose it over ffmpeg?   I came to this "issue" while installing Ubuntu 12.04.1 LTS in a VM and when I've installed ffmpeg it came up with a message telling mit ffmpeg is deprecated and I first thought "wtf?".  If I use avconvWill I be able to migrate my scripts depending on ffmpeg more or less easy to libav? I'm mostly using it for writing meta data and doing audio conversion (wav, flac, vorbis, mp3, aac).


Ubuntu 14.04 32bit.iso will not load, at all, from KINGSTON usb

My computer doesn't seem to be capable of using this on a USB stick. Am I missing something here? I've followed all instructions i can find for using a USB drive but my computer will not load the .iso file at all. Am I supposed to convert it or what?


Prove a assertion concerning Lebesgue space

Let $f_n \in L^1$ such that $f_n\rightrightarrows f$. Then I want to conclude that If $\mu(X)<\infty,$ then $f\in L^1$ and $\int f_n\to\int f$, so I want to make use of the Dominated convergence theorem, the thing is that I don't know which would be my dominating function.  I was trying to figure out if the measure could play that role, but after thinking a little bit I have realize that the measure doesn't have to be bigger than the absolute value of the functions of the sequence.  Another thing I was thinking of, is to apply Fatou's lemma, but I can't ensure that my functions are positive.  So, Can someone help me to prove this theorem please ?  Thanks a lot in advance :).    NOTE: I think this theorem is taken from Folland's Real analysis, modern techniques, and their aplications 2nd Edition :), This is to have all the definitions so we can talk the same language as in the book (this is, same notation and theorems or machinery)


Can frictional force accelerate (speed up) a body?

I think since $F=ma$ thus the frictional force can produce acceleration in a body in some cases, is my view correct?please suggest some example then. If not then where i went wrong?


Why does this regex match too much? (Doesn't stop at slash)

This code outputs the $captured array, but $captured[1] contains bar/this rather than my expected bar. What's missing in my regex to stop from returning more than bar?  <?php      $pattern = '/foo/:any/';     $subject = '/foo/bar/this/that';      $pattern = str_replace(':any', '(.+)', $pattern);     $pattern = str_replace(':num', '([0-9]+)', $pattern);     $pattern = str_replace(':alpha', '([A-Za-z]+)', $pattern);      echo '<pre>';      $pattern = '#^' . $pattern . '#';     preg_match($pattern, $subject, $captured);      print_r($captured);     echo '</pre>';


Immediately after posting  I saw this error message:    I hit cancel and went back to the home for Meta Stack Exchange and saw my question. However, I was unable to see it for maybe 4 or 5 minutes (seeing that error every time).  It eventually started working but it was obviously fairly surprising to have this happen. Also, I believe I have seen this in the past but didn't have the foresight to take a screenshot or commit the exact error message to memory.  My device is a Droid MAXX with Android 4.4.4.  Edit: somewhat ironically, as I posted this the following happened:    I attempted retrying multiple times to no avail, found the question again, and continued to see the same error for maybe a minute or two, trying periodically.


What's $-\frac{1}{27}$ in the p-adic ring $\Bbb Z_2$?

What's $-\frac{1}{27}$ in $\Bbb Z_2$?  I was naively thinking take the repeating string of the standard binary representation of $3^{-n}$, put it to the left of the point and you get $-3^{-n}$ in $\Bbb Z_2$.  Hey presto, it works for $-\frac13$ and $-\frac19$ so why not?  But if I take $x=\overline{000010010111101101}_2$ I can see that $x+512x=-1$, so I get $-\frac1{513}$ in $\Bbb Z_2$.  It is at least a multiple of $\frac13$, but not the one I was expecting.  In general it would seem we get $\dfrac{-1}{2^{3^{n-1}}+1}$ by my naive method, which coincides for the two first cases - because $3$ and $9$ are one away from $2$ and $8$.  I should mention $3^{-n}$ have the peculiar property that one half of the repeating binary string is the inverse of the other.  This problem arose while I was trying to prove that fact - feel free to prove that if you're minded to do so!  How do I correctly calculate an arbitrary rational number such as $-3^{-n}$?


It is well known that the following three definitions of a normal subgroup are equivalent:  $gNg^{-1}\supseteq N$ for all $g\in G$  $gNg^{-1}\subseteq N$ for all $g\in G$  $gNg^{-1} =N$ for all $g\in G$  However this equality comes from the fact both $g$ and $g^{-1}$ satisfy the requirements.  Can we have a subgroup $H$ such that $gHg^{-1}\subsetneq H$? clearly such a subgroup must be both of finite order and non-normal, which is one of the reasons I can't find a counterexample.  It can also be proven without much difficulty if such a $G,H, g$ existed then $g^{-1}$ would satisfy $g^{-1}Hg\supsetneq H$  Thank you kindly  Regards.


How can I export a 3D character, including its animation?

I'm new to Blender. I want to insert character animation in a live-action video. I downloaded a simple rigged 3D figure, and created a keyframe animation. Now, what I'd like to do is to export that short animation sequence, so I can insert it into my motion-tracked video. Now, how can I export then import that animated figure coughing, and then insert it into the video and duplicate it? EDIT: Problem solved. I KNEW this was a simple fix.. All I needed to do was to save the file, then go into the file (that I wanted to IMPORT the animation into), then use "append" to import the object from that Blender file. It kept the animation and model intact, and now I have the little dude coughing on my 3D tracked video! huzzah.


I've downloaded and installed Android Studio and also added the path to my .bashrc  export PATH="~/android-studio/bin/:$PATH"   What I'm looking at now is that one command which will launch android studio from anywhere in the Ubuntu file system. For example if I type subl or atom anywhere it opens up the respective editor. Can something like that be done here?


He helps terraform Mars, and then regrets it

I saw a story on TV when I was a child (in the 80s) that involved a man working from earth to transform the climate of Mars. Then, later, he travels to the surface of Mars, and discovers the corpses of Martian life forms everywhere, which I remember as being made of a lot of squidgy tubes, like octopi or kelp (not humanoid at any rate). He's filled with heartbreak and regret.  I'm pretty sure this isn't from one of the adaptations of The Martian Chronicles.


How can I get QGIS Print Composer to print OSM map at desired zoom level?

Like the title suggests, I'm trying to print a map that uses OSM Stamen data from the OpenLayers plugin.  My map looks like this in QGIS:   And like this in the Print Composer:   But when I export the map to an image, it appears to be at a smaller zoom level.   Is there any way to actually make the map look like I'm desiring? I came across  thread, but it didn't lead me anywhere productive.


Interpretation of betas when there are multiple categorical variables

I understand the concept that $\hat\beta_0$ is the mean for when the categorical variable is equal to 0 (or is the reference group), giving the end interpretation that the regression coefficient is the difference in mean of the two categories. Even with >2 categories I would assume each $\hat\beta$ explains the difference between that category's mean and the reference.  But, what if more variables are brought into the multivariable model?  Now what does the intercept mean given that it doesn't make sense for it to be the mean for the reference of two categorical variables?  An example would be if gender (M(ref)/F) and race (white(ref)/black) were both in a model.  Is the $\hat\beta_0$ the mean for only white males?  How does one interpret any other possibilities?  As a separate note: do contrast statements serve as a way to method for investigating effect modification?  Or just to see the effect ($\hat\beta$) at different levels?


Front suspension or full suspension mountain bike

I'm considering buying a mountain bike and have narrowed it down to two models (make and model aren't important for this question).  One model is a full suspension bike (front and back), the other is front suspension only.    What are the advantages/disadvantages to going with a full suspension vs front suspension? (I'd prefer answers from people with experience riding both types of bikes.)  EDIT  To answer some of the questions looking for more detail...  The 2 bikes are roughly in the same price range, around $1000 USD (the full suspension is slightly more money), and my plans are to ride it primarily in some single track trails that are in the area.  There will be a lot of hills and rocks and such.  I doubt there will be any on-road riding involved.


How to change apple ID while it has been disabled for security reasons

I just bought apple iPhone 4s from my friend but it throw an error "This Apple ID has been disabled for security reasons" is it possible that i change apple ID during this state? Or  is there any other way to change it?


What is the difference between range and xrange functions in Python 2.X?

Apparently xrange is faster but I have no idea why it's faster (and no proof besides the anecdotal so far that it is faster) or what besides that is different about  for i in range(0, 20): for i in xrange(0, 20):


Why is __init__() always called after __new__()?

I'm just trying to streamline one of my classes and have introduced some functionality in the same style as the .  However, I'm a bit confused as to why __init__ is always called after __new__. I wasn't expecting this. Can anyone tell me why this is happening and how I can implement this functionality otherwise? (Apart from putting the implementation into the __new__ which feels quite hacky.)  Here's an example:  class A(object):     _dict = dict()      def __new__(cls):         if 'key' in A._dict:             print "EXISTS"             return A._dict['key']         else:             print "NEW"             return super(A, cls).__new__(cls)      def __init__(self):         print "INIT"         A._dict['key'] = self         print ""  a1 = A() a2 = A() a3 = A()   Outputs:  NEW INIT  EXISTS INIT  EXISTS INIT   Why?


Does scandisk/CHKDSK produce a log file when running before login?

I scheduled and ran CHKDSK after restart, but it took a long time, so I left it to run all night. In the morning, it had finished and the computer had logged in, but I had no way of knowing if it found bad sectors or anything.  Is there a log file I can look at?  This is what CHKDSK looks like when running before login:


I am using a formula where I have to use $\boldsumbol l$. However on the slide, it looks like the letter capital I. How can I have a nice curvy version to denote vector l?


What `chkdsk` verifies and what it does not verify?

What kind of problems  can identify? Are there any disk problems that chkdsk cannot identify and will mark a malfunctioning storage device as a healthy one? Are there cases when I would need to use other tools to check disks for logical or physical errors?


Confusion in Definition of separable polynomials

Definition -1: Any polynomial $f(x)\in F[x]$ is called separable if all the irreducible factors of $f(x)$ are separable. Definition -1 is from 'Pearson' publication Modern Algebra and Definition-2 is from 'Dummit and Foote'. Definition -2: A polynomial is said to be separable over $F$ if it has no multiple roots( i.e., all its roots are distinct). According to Definition -1 $f(x)=(x-2)^3(x^2-2)$ over $\Bbb{Q}$ is separable. But this example contradicts the Definition -2. Am I wrong some where? Or the definition of book is wrong. Any help will be appreciated. Thanks!


Is there any way to distribute spacing equally in every object?    Is there any option to do? I want 2MM spacing in every geometrical shape.  Thanks in advance.


Book recommendation for ordinary differential equations

This question has been posted before, but I need book with specific qualifications. I do not need books for engineers, book that is centered around calculations and stuff. I need to find a book that is theoretical, proves the statements and has good presentation of the theoretical structure. I have had the book by Tenenbaum, I did not like it. I would be very very thankful if someone shared their knowledge with us about this matter.


How to run a console through SSH client and keep it open?

I have a node application in development in a ubuntu server through SSH connection, I'm using bitvise ssh client, and running node server.js through its GUI terminal.  But then when I exit the ssh client, the server terminal is closed remotely, how can I keep it open? I'm not sure if the question is related to this specific client or to SSH in general.


What is the difference between ls and l?

I accidentally typed l instead of ls today and found that the command still printed a list of the files in my current directory. Trying l --help brings up the help file for ls suggesting that l is just an alias of ls.  Howver, each file was suffixed by a *. Why is this and what does it mean?  In case it makes a difference, this is when running the latest stable version of Ubuntu.


How to build a Mixed Effects Logistic regression Model?

I am new to data analysis and now working on a Mixed Effects Logistic Regression Model.  Currently, I have the following data frame (model_data):  Road Id Vehicle_id  entry_time           exit_time          1        1        2017-01-31 00:00:00  2017-01-31 00:00:00 last_veh_time  vehicle_type     status 300            4 wheel          0    Likewise, I have the information (nearly a million rows) of all the vehicles entering a place and exiting the same place.  Status can be either $1$ or $0$ for all of these.  last_veh_time is the last vehicle passed the same place before how much time.    I want to know the probability of a getting status $0$ for a vehicle based on the entry_time and last_veh_time. To do this, I created the model:   model = glmer(status ~last_veh_time + (1 |link ),               data=model_data, REML=FALSE)   Is this the right approach?  Any help is appreciated.


Why is jumping into water from high altitude fatal?

If I jump from an airplane straight positioned upright into the ocean, why is it the same as jumping straight on the ground?  Water is a liquid as opposed to the ground, so I would expect that by plunging straight in the water, I would enter it aerodynamically and then be slowed in the water.


Diffuse $5$ points on a sphere. Prove there is a closed half-sphere that has at least $4$ points on it.


Open-source the project code before or after publication?

I recently completed a part of my project and communicated a paper to a conference. Let's call the paper's title as "project x: for this and that". Now, I wish to open-source project x to facilitate reproducible research and to have more (at least some) people use it (and cite it!).   Are there any specific drawbacks or risks involved in open-sourcing project x on, say, Github or Sourceforge? Do note here that I would still be improving on project x, and possibly sending the extended version to a journal (my area of work being Computer Science).  I understand that if a conference/journal requires double-blind review and my project is searchable on the Internet, I am revealing my identity to the reviewers. This is bad, right?  Are there any other cons I should be considering? And are there any pros of open-sourcing before a making it into a publication?


Show any matrix $A_{n\times n}$ can be written as sum of two nonsingular matrices

A nonsingular matrix is one which is invertible, and hence the determinant is not equal to $0$. So at first I thought about having $\det(A_{1})+\det(A_{2})=\det(A_{1}+A_{2})$ and then the resulting sum being a invertible matrix, but this is not generally the case.  Then I thought about eigenvalues, as the determinant is the product of the eigenvalues and that using that I could showing that the spectrum of the sum is equal to the sum of the spectrums.   Is that a better way?


Could someone please advise me on the below.  This method only currently returns false, except for when I send fixed to it.  if I pass it rand or flood it still returns false. I would normally pass rand30 or 10flood for example.   I have printed to screen and I cant see any issues. Maybe I am missing something.  Please could you advise me on this?  public boolean validateTrtype(String trType){                     if(trType=="fixed")                         return true;                     else if(!(trType=="fixed")){                     String trName = trType.substring(0, Math.min(trType.length(), 4));                     String trName1 = trType.substring(Math.max(0, trType.length() - 5));                     String[] trTypeSplit = trType.split("(rand)|(floo)");                     i = trTypeSplit[0];                     System.out.println(i);                     j = trTypeSplit[1];                     System.out.println(j);                     this.str = trName;                     this.str1 = trName1;                     System.out.println(str);                     System.out.println(str1);                     }                     if((str=="rand") && (isInt(j)==true) && !(Integer.parseInt(j)<0)){                         return true;                     }                     if((str1=="flood") && (isInt(i)==true) && !(Integer.parseInt(i)<0)){                         return true;                     }                     else                     return false;                  }


Great-circle lines in Equirectangular projection

Just to check that I'm on the right track:  Are all great-circles on the sphere and in equirectangular projection (i.e. latitude, longitude pairs) either:   meridians (i.e. going pole to pole) of the form tan latitude = sin360(longitude + rotation) * amplitude + offset   (with additional restrictions on the offset/amplitude combinations -- obviously, all great circle paths with an amplitude of 0 also have offset 0 - the equator).  Or are there great-circle paths that do not fit into this scheme (again, only in a longitude-latitude coordinate system, not on other map projections).  Note: I added the tan above after posting the question, in a reaction to whubers excellent reply. It turns out that offset then always is 0.


Physics are not simulated past a certain frame?

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


GCD of polynomials over a field and its extension

Let $E$ be an extension of a field $F$.   Let $f(x),g(x)\in F[x]$ with $d(x)$ their GCD in $F[x]$.   Claim: $d(x)$ is GCD of $f(x)$ and $g(x)$ in $E[x]$.  Proof. Case 1. $d(x)=1$. Thus $f(x),g(x)$ are coprime in $F[x]$, and so we can write  $$1=a(x)f(x) + b(x)g(x)$$ for some $a(x),b(x)\in F[x]$, and since this expression is valid in $E[x]$ too, so $f(x)$ and $g(x)$ are coprime in $E[x]$.   Case 2. Suppose $d(x)$ is not unit in $F[x]$.   Then $f(x)/d(x)$ and $g(x)/d(x)$ are polynomials in $F[x]$ with GCD $1$, so their GCD is $1$ in $E[x]$. Hence $d(x)$ is GCD of $f(x)$ and $g(x)$ in $E[x]$.   Q. Is the assertion and proof correct?


I have an email system that I am making in a WordPress plugin to send the emails with this code:  include(PLUGIN_DIR.'config/class_phpmailer.php');  $email = new PHPMailer();  $email->From      = get_option('admin_email'); $email->FromName  = 'my name'; $email->Subject   = $subject; $email->Body      = $body;  foreach($emails as $mail) {     if(is_email($mail)) {         $email->addAddress($mail);     } } if($name) {     $att = PLUGIN_DIR.'uploads/'.date('Ymd').'_'.$name;     $email->AddAttachment($att); }  // check if email is sent or not if(!$email->Send()) {     echo "Message was not sent <br />PHPMailer Error: " . $email->ErrorInfo; } else {     echo "Message has been sent";     $_POST = array(); }   This works great. Tested it online and sends to all the tested emails.  Can I make it like this? I mean, with phpmailer class not native to WP. Is this wrong? Is it best to use native WP phpmailer? If so, how can I do it?  Thanks in advance.


Deciding whether $2^{\sqrt2}$ is irrational/transcendental

Is $2^\sqrt{2}$ irrational? Is it transcendental?


Global sections of a tensor product of vector bundles on a smooth manifold

This question is similar to      and    except that I am concerned with smooth manifolds. If $M$ is a smooth manifold and $V$ and $W$ are (smooth, real) vector bundles on $M$, are there reasonable conditions that ensure that the map $\Gamma(M,V)\otimes_{\mathscr{O}_M(M)}\Gamma(M,W)\rightarrow\Gamma(M,V\otimes W)$ is an isomorphism? Equivalently, are there any reasonable conditions under which taking global sections of finite locally free $\mathscr{O}_M$-modules commutes with tensor product?  I don't really know much smooth manifold theory, and my intuition is mostly derived from algebraic geometry, where the analogous question, as is indicated in the questions I linked to, is not a simple one, even for invertible sheaves. I'd always assumed the situation for smooth manifolds would be the same, but I was just looking at the Wikipedia page on vector-valued differential forms, and it seems (unless I'm misunderstanding which is certainly possible) to claim there that for $V$ an arbitrary vector bundle and $W$ the $p$-th exterior power of the cotangent bundle, $p\geq 1$, the answer to my question is "yes," with the justification being that "$\Gamma(M,-)$ is a monoidal functor." Looking at the definition of a monoidal functor, it seems to me that all this implies is that there is a map from the tensor product of the global sections to the global sections of the tensor product (which is clear from the definitions) and not that this map is an isomorphism.


The JFrame doesn't receive external var updates

I am new to java.I created a JFrame class in netbeans, then i did  public class Tela extends javax.swing.JFrame{ ... public Tela(){ Status st;    lblCarism.setText("Carisma: "+st.getCarism());              } }   Then I have the Class Jogo:  public class Jogo{     static Status st;  public static void main(String[] args){     int[] vida = {12,12};     st = new Status("Diegolo","todos","Libertado","espirito",vida,8,4,2,2,8,0,7,5,20,13,16,0,40,1,0);     Tela.start(); }   }  And The class Status  public class Status {  String nome; String Sex; String Classe; String Raca; int[] Vida = new int[2]; int forca; int vel; int pontoVel; int percep; int furt; int impac; int mira; int intel; int carism; int defCort; int defPerf; int defMag; int Xp; int lvl; int ouro; int poder;  public Status(String nom, String Sex, String Classe, String Raca, int vida[], int forca, int vel, int percep, int furt, int impac, int mira, int intel, int carism, int defCort, int defPerf, int defMag, int poder, int Xp, int lvl, int ouro) {      pontoVel = (int) vel / 10;     this.nome = nom;     this.Sex = Sex;     this.Classe = Classe;     this.Raca = Raca;     for (int i = 0; i <= 1;i++) {         this.Vida[i] = vida[i];     }     this.forca = forca;     this.vel = vel;     this.percep = percep;     this.furt = furt;     this.impac = impac;     this.mira = mira;     this.intel = intel;     this.carism = carism;     this.defCort = defCort;     this.defMag = defMag;     this.defPerf = defPerf;     this.Xp = Xp;     this.lvl = lvl;     this.ouro = ouro;     this.poder = poder; } //getters and setters }   The Problem is, when i compile the code, it returns a Null exception because of the  lblCarism.setText("Carisma: "+st.getCarism());   line, but I ititialized the Carism already.Is there a way to tell the Jframe class that i updated the Carisma?(I didn't find anything about it on internet)  Edit:Even if i try         lblCarism.setText("Carisma: "+Jogo.st.getCarism()); it returns Null Exception, and this question isn't a duplicate.I'm asking about swing and not about Null Exceptions.


In an attempt to learn more about Ubuntu and its packages, I want to remove all non-essential packages, so I can install what I need, when I need them and know what they do.  I'm using the commands dpkg --clear-selections and apt-get dselect-upgrade for this. I also slightly modify the selection by setting apt libstdc++6 (due to apt) install-info (due to grep) to install again (somehow dpkg thinks they are not essential, but apt-get complains).  Is this ok, or is this bad? If it's ok, what do I do with the large list of packages with "deinstall" status in dpkg?  An additional note, I'm doing this on a VPS template so I have no control over the initially installed packages.


What is the meaning of this construction in the following sentence heard in ?     DA's office is pursuing this as a capital case, which means that come   sentencing it will be up to the jury to decide [his] punishment...   Is this a short version of when it comes to or a separate instance of to come usage with the same meaning? That is when the sentencing time comes...


Which derivation of drift velocity is correct?

In the derivation of drift velocity I have seen two variations and want to know which one's correct.   $s=ut+\frac{at^2}{2}$ Assume that the drift velocity of any electron in any conductor is : $$\vec{v_d}=\frac{\vec{l}}{t}$$ Due to the electric field the acceleration of electrons in any conductor is: $$a=\frac{-e\vec{E}}{m}$$ Now the distance travelled by an electron after a long time (initial thermal velocity = 0) $$l=\frac{at^2}{2}\implies \frac{-e\vec{E}t^2}{2m}$$ the time between the collisions is $\tau$ $\therefore$ $$l=\frac{-e\vec{E}\tau^2}{2m}$$ thus the velocity is $$\vec{v_d}=\frac{-e\vec{E}\tau}{2m}$$ In another proof I saw the author using $v=u+at \implies v_d=\frac{-e\vec{E}\tau}{m}$   My question is which of the the two equations of motion can be used in the proof? Can they be used at all.


How can I universally change the following keybindings to something that is faster?    Option+Arrow (move 1 word) Option+[delete] (delete 1 word) Command+c (copy) Command+v (paste)  Command+x (cut) Command+z (undo)   Contorting my pinky to press the command key is too slow  OS version:  MacOS Sierra 10.12.6  I have tried swapping keys. Swapping keys messed up other shortcuts. I have also looked for keymapping software.


What are these dark green spots inside raw eggs?

I bought a tray of eggs recently. They aren't old, I have them in the fridge, and the date stamped on the egg says they are good for another month.  In two eggs that I cracked open today, there were dark green spots inside the shell (looked like mold maybe?), and floating around the egg white.   Any idea what that is? Is it a sign that the whole tray may be contaminated with something??  I only noticed the green on the shell after I mixed one of the eggs into a bread dough, and now I need to know if I should throw the dough out or not (it's a huge batch of dough).


Further Understanding of Wash Sale Rules

First let's make sure I understand a Wash Sale:  Let's say I invest in 100 shares of ABC stock for $100 and after a week sell the 100 shares of ABC for $70, I've lost $30 which I can deduct from my taxable income come tax time. However, if I reinvest into ABC for ANY amount within 30 days of exiting ABC for a loss there is a wash sale which means I can no longer claim the original $30 loss as a loss.  Considering that is all correct, here is my theoretical scenario:  Let's say I buy 100 shares of ABC at $1 a share and at the end of the day I sell all 100 shares of ABC at $0.70 (30% loss). On the following day I buy 100 shares of ABC at $0.70 a share and sell at the end of the day when ABC is at $1 a share (30% gain). Let's theorize that this loss / gain cycle repeats consecutively for 8 additional days so at the end I have the following:   Lost $30 dollars every other day starting with day 1 and felt -$150 over the 10 day span. Gained $30 dollars every other day starting with day 2 and felt +$150 over the 10 day span.   Per wash sale rules I cannot claim ANY wash sale loss because on the last day I invested in ABC and made a profit.  Knowing I cannot claim any losses, my question is: Do I have to pay taxes on all of the gains? That is, will I still have to pay taxes on $150 dollars even though I only ended up gaining a net total of $0 from the time I started?  Here is a visual example of my scenario:  Day:      | 1    2    3    4    5    6    7    8    9    10 Loss:     | -$30      -$30      -$30      -$30      -$30    Gain:     |      +$30      +$30      +$30      +$30      +$30  Felt Loss | -$30      -$60      -$90      -$120     -$150 Felt Gain |      +$30      +$60      +$90      +$120     +$150 Net Gain  | -$30 $0   -$30 $0   -$30 $0   -$30 $0   -$30 $0


How can I avoid colored light reflections?

so I'm sorta new to Blender and stumbled upon a problem which is probably easy to fix. So I realized that the color of the ground gets reflected onto other surfaces during the render, as seen on this picture:     How can I prevent the green color from appearing on other things than the ground?


Convert Object to ObjectArray but the Array should have the Type of the Object

I've a function wich Converts a Object to a Object Array.  I know I can do this  new [] {obj}   but then the Array is of Type object[]. I want that the Array is of the Type of whatever obj.GetType() returns!  Is this possible in a performant way?


How to get "people reached" info from Users Table?

How can I get "people reached" data from the Users table for Stack Overflow?  I didn't find any fields related to the people reached state in the Users table/schema.  Is it possible to get that data from the Users table or using User_id?  Here is my query:  SELECT     Id,     Reputation FROM     Users WHERE     Location like '%Tamilnadu%' ORDER BY     Reputation DESC;


No Add Friend Button but many mutual friends?

An old friend and I have 18 mutual Facebook friends. Until a month ago, I could have sent him a friend request, as the button to add friend was there.   Then all of a sudden, the "add friend" button is gone, although there is still a button to send message. I am not blocked from his page, I just can't add as a friend.   How is it possible that the Add Friend option has mysteriously disappeared when we have so many mutual friends on Facebook and the only privacy settings for "who can send you friend requests" are "everyone" and "friends of friends"?   I should add: 3 months ago I sent him a friend request, which he declined at the time, but after that the "add friend" button was still there. I never sent another request. The add friend button has been there all along until, like I said, it just strangely disappeared like literally overnight!


Why isn't this a valid sleeping location in Terraria?

My house is right next to the dungeon and is also underground by a couple of blocks. There are 6 blocks in between the floor and ceiling, and in between the two walls are 10 blocks. There also are 2 torches, a work bench, and a chair.  For some reason it's not a valid sleeping area though.  Help?


How to fix QGIS error "Entry Point could not be located"?

Today, after returning from vacations, I started my QGIS 1.7 and got this terrible message:    Help, anyone?


Identify this 80's movie about a force-field shaped like a bubble

I have this vague memory from when I was a kid of a movie that involved a few kids and one of them, somehow, creates a force-field in the shape of a bubble.  My memory is faint but I seem to remember they controlled the bubble with an Apple IIc computer (lol) and they could fly in space, around the world, etc.  I cannot remember anyone who actually stared in the movie and none of my searches are finding anything.  Thanks.


Is it ethical for an instructor to use their own textbook in an undergraduate course?

Students in an undergraduate course often have no choice of a textbook for the subject and are expected to buy the book recommended by the instructor. The expectations can be advisory or mandatory. Given the degree of control that an instructor has over their undergraduate students, especially freshmen and sophomores, is it ethical to use a textbook authored by the instructor in an undergraduate course? Does such requirement not constitute a conflict of interest?  P.S. I understand that practically this is done times and again, but I would like to sense the general feelings.


The function $f: (0,1) \to \mathbb R $ defined by $f(x) := 1/x$ is not uniformly continuous, but it is continuous. Proof: given $\epsilon > 0$, then for $\epsilon > \mid 1/x - 1/y \mid$ to hold we must have   $\epsilon > \mid 1/x - 1/y \mid = \frac{\mid y-x \mid }{\mid  xy \mid } = \frac{\mid y-x\mid }{xy}$  $\mid x -y \mid < xy\epsilon$  Therefore to satisfy the definition of uniform continuity we would have to have $\delta \leq xy\epsilon$ for all $x, y$ in (0,1). but that would mean that $\delta \leq 0$ Therefore there is no single $\delta >0$  I don't understand $\delta \leq 0$  part... why it is less than or equal to 0 ?


I have written a method which I will call in a Trigger.While trying to save this code as Apex class, I am getting the error " Error: Compile Error: Loop variable must be of type SObject at line 7 column 13"   My code goes as below ,appreciate any help, thanks  public class LeadBefore {     public static void UpdateChapterEmailAddress (){          set<Id> JDRFLocationId = new set<Id>();         List<Lead> vLstLead = new List<Lead>();           for(Lead vLead:trigger.new)         {             if(vLead.JDRF_Location__c != null)             {                 JDRFLocationId.add(vLead.JDRF_Location__c);                 vLstLead.add(vLead);             }         }         Map<Id, JDRF_Location__c> vMapIdJDRFLocat = new Map<Id, JDRF_Location__c>([Select Id, Name, General_Email_Address__c from JDRF_Location__c where Id In: JDRFLocationId]);         for(Lead vLead: vLstLead)         {             if(vMapIdJDRFLocat.containsKey(vLead.JDRF_Location__c))             {                 vLead.Chapter_Email_Address__c = vMapIdJDRFLocat.get(vLead.JDRF_Location__c).General_Email_Address__c;             }         }     } }


Should it be /about_us or /about-us?  From usability point of view, I personally think /about-us is much better for end-user yet Google and most other websites (and javascript frameworks) use underscore naming pattern. Is it just matter of style? Are there any compatibility issues with dashes?


"When people do make changes" - which tense is this?

Which tense are sentences like:   "When people do make changes good things happen" "Even if monkeys can play an important role, their actions can pose risk to the general public"


I have a problem with second normal form (2NF) and I have been unable to solve it by using Google. It is making me crazy because I am a teacher and I don't want to teach wrong stuff to my students.   Let's have a table with 5 fields.  Gradings = {StudentName, SubjectCode, SubjectName, #Exam, Grade}  Dependencies are this way:  StudentName, SubjectCode, #Exam -> Grade  SubjectCode -> SubjectName  SubjectName -> SubjectCode  Therefore, candidate key 1 is {StudentName, SubjectCode, #Exam} and candidate key 2 is {StudentName, SubjectName, #Exam}.   Prime attributes are {StudentName, SubjectCode, SubjectName, #Exam} and non-prime attributes is Grade  According to the definition of second normal form, a non-prime attribute cannot depend on a part of a candidate key. The only non-prime attribute (Grade) does not depend on a part of a candidate key so this table seems in 2NF .  The problem is that I think something is amiss (and I could be wrong). I think subjects should have their own table.   Gradings = {StudentName, Subject Code, #Exam, Grade}  Subjects = {Subject Code, SubjectName}  But 2NF does not produce this. 3NF is about dependencies between non-prime attributes so it does not produce this either. But it seems to me that this is the right outcome, because it has no redundancy.  I guess if non-prime attribute was defined as "attribute that is not a candidate key", 2NF would produce the desired result. But I have checked this again and again and non-prime attribute is defined as "attribute that does not BELONG to a candidate key".  What am I doing wrong?


Fourier transform of $e^{-\frac{1}{2}x^2}$

Fourier transform of   $$e^{-\frac{1}{2}x^2}$$   I know to use the Fourier transform direct formula however I keep getting an algebraic mess. so if someone could help me out with detailed steps that would be very much appreciated!


What will happen to the entropy in a universe made out of antimatter?

The second law of thermodynamics states that;     The total entropy of an isolated system can only increase over time or it can remain constant in ideal cases where the system is in a steady state (equilibrium) or undergoing a reversible process. The increase in entropy accounts for the irreversibility of natural processes, and the asymmetry between future and past.   So if there was a universe made up of antimatter will the entropy of that universe increase or decrease?   Because according to my research;     The Feynman–Stueckelberg interpretation states that antimatter and antiparticles are regular particles traveling backward in time.   Will the entropy of a universe made up of antimatter increase or decrease? Or is there any possibility that there can be a universe made up of antimatter because the entropy always increases by time? And what will happen to such a universe assuming that the entropy decreases? (because antimatter travel backward in time)


How is the precise value of pi calculated?

We often see the value of pi(irrational) with large no of digits behind the decimal place. How is such precise value of pi calculated?


Basic question on second covariant derivative

I am having a question on the wikipedia article   Using the notation therein I don't get why $(\nabla_{u}\nabla_{v}w )^a=u^c\nabla_{c}v^b\nabla_{b}w^a$.  It is clear that $(\nabla_{u}\nabla_{v}w )^a=(u^c\nabla_{c}v^b\nabla_{b}w)^a$.  What do I miss?


Is it a good or a bad practice to use R packages from CRAN for research? I'm talking about the common packages like: simple models for regression, estimation, econometrics. Most of them use function that can be written easily on your own.  My yes arguments:   Time to focus on the main part of the research The community is a good quality control R offers a lot of modern methods Some models are too complicated to write them on your own   My con arguments:   Not every package of R has been created in an academic environment There could be bugs that influence the outcome and I do not know it Most models can be written in a short time period from scratch   How can we use open source without risking failures in the outcome? Are there certain quality indicators for packages in general and for R?


I just featured a question on meta...and I'm not a moderator

In a strange twist of events, I got this error that said that my edits couldn't be submitted because I needed the moderator tag . I'm not a moderator, so I just decided to humor the system.  And now there's this random old FAQ that's featured on SFF meta as a result (). It's even showing up in the sidebar:    Here is a screenshot of , which don't show me adding the tag, but I did:        I'm not sure why this happened, but I will note that it's a community wiki  question and the previous revisions were all done by an ex-moderator whose account is now deleted.  I can't add any red tags here on MSE though.


How can a non-operator player run this command by clicking on a clickable tellraw text?

I have used an online  to create a /tellraw command which uses clickable events to run /scoreboard commands (adds @p to a team), so I can use it on my Realms server.  The problem was, when non-operator players (they don't have cheats enabled) clicked the text, they didn't have the permission to use the command that would run when clicked. I have tried /execute to fix it, but then i realized that /execute is also a "cheat".  How can I fix this without having to give someone the ability to "cheat"?


I came across some lightning tags that are still in beta, ex: lightning:input (Beta) lightning:tabset (Beta) etc  Not sure for how long they were in beta, is it advisable to use them for building UI and deploy to production?


I don't like google chrome group tab option. Previously it appeared once, but following simple instructions I managed to disable it. So before I done this:  chrome://flags/ search for "Tab Grid Layout" and disable it. search for "tab group" and disable 3 more things. Then restart, twice.  Recently, the group tabs reappear again, and I cannot get rid of them. I want the old fashion tabs. I have disabled "Tab Grid Layout", no help. I have searched for "tab group", but previous 3 things are not appearing any more. Thank you!


My Cycles and eevee Render is all white, what should i do?

enter image description here this is my evevee render


A sci fi anthology had a short story about a time traveler who invented a machine that may have caused a catastrophic event by its use.  The traveler from the future showed up to the front porch of his earlier self to warn his earlier self of the impending doom.  The world on the horizon behind the future self was being consumed.  The earlier self asked the future self just how far into the future he had come with his time machine.  "About five minutes..."  the man on the porch said, "Not far enough."


Where should I ask question about programming details?

I have a questions about how to start developing (programming) something, what tools should I use to this project, what should I know for this purpose itc. and I don't know where I should post them. Can someone help?


Is the first white walker also the Night King?

We have seen the first white walker, created by the the children of the forest.      We also see a white walker who was supposed to be the Night King several times.      Based on their faces, can they be the same person? I know the best canon explanation for the Night King is him being the 13th Lord Commander of the Night's Watch, however, this can easily be a red herring.  Any canon evidence, supporting/disproving the first white walker being the Night King is also welcome. Although the images are from the series, book explanations are also welcome.  EDIT: Actually my question is very different and focused compared to the differences between books and show. It is already somewhat answered, both characters played by the same person.


There exists a minimal uncountable well ordered set.

There exists a well-ordered set $A$ having a largest element $\Omega$ such that the section $S_\Omega$ of $A$  by $\Omega$ is uncountable but every other section is countable.  Can anyone make me understand this theorem?  I can not understand what Mukres has tried to say  in his Topology's Book.. I can  not visualize what Mukresh has said in the proof.  I can not understand why we always get an element $\Omega$ such that the section less than $\Omega$ is countable. What ensures the availability of $\Omega$ in a uncountable well ordered set?  Can anyone make me understand with proper example?  Thank you in Advance.


How to get all posts (in chunks) via XML-RPC?

I would like to retrieve all posts of a blog via the XML-RPC API of Wordpress.  There are the methods of blogger.getRecentPosts and metaWeblog.getRecentPosts which - given a sufficiently high value as number of posts (or -1) in theory should return all posts.  However, this does not work for very large blogs or very weak servers that cannot hold the whole blog in memory. In that case, these functions will not return anything at best or throw an error into the response XML.  A solution would be to retrieve smaller chunks of, e.g. 50, posts at a time and put it all together on the receiving side. For this to work one would need to specify an offset for the posts to get. I was not able to find a way to specify such an offset in the documented API.  Is there any way to make this work, either by specifying an offset or by using other than the methods mentioned above?  I'm not looking for a description on how to write a plugin or modify Wordpress itself in any way. I can do that, sure, but I'm talking about authorized retrieval of data of arbitrary Wordpress blogs.  Edit: I've opened a trac ticket at Wordpress with a suggestion for solution:


Where should I ask this question? Work tools and work managment tools for a volunteer activism group?

We have about 15 people with more joining in. We'll have our overview group & several subprojects. We need tools to coordinate ourselves. Where do I ask about tool ideas? I've looked around and PM and alternatives to Basecamp seem to cost per user. We can afford to pay a flat year fee but that's all. Need: Chatting at top level, that shows up in member's email and stays on the tool. Chatting for each project, separate from the top level. Ideally, subtopic conversations within each project. File storage or area to put links to google docs & spreadsheets. List of members Search ability to search emails, search for a member's info. Pleasant, pretty easy to use interface. Most members aren't overly tech sophisticated. I've looked through the stack applications and found project management, but it was about how to, not tools to. I've looked through meta questions, but haven't seen any the seem related.


MySQL Syntax error from INSERT INTO email address

I'm having trouble inserting an email address into a MySQL database.  I'm getting the dreaded 1064 error like so..  Error creating new user You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '@email.com, password, 20)' at line 1 -- 1064  So I'm guessing I need to escape the @ in the email variable?  But nothing i do seems to please Maria.  Generating the query in PHPMyAdmin was no help either. Any advice gratefully accepted.  // update SQL     $sql2 = "INSERT INTO members (username, email, password, balance) VALUES ($new_player, $new_email, $new_password, 20)";     if ($db->query($sql2) == TRUE) {             echo "** New User Created **
";                 } else {                 echo "Error creating new user " . $db->error." -- ". $db->errno ."
";     }


I just deployed a Ruby on Rails one click app to an Ubuntu server. I was curious where I go in to edit the home page of the app. The domain is "gitship.com". When I look throughout the server, I can't find the index.html or something like this to edit the home page and background image from the "Yay you're on rails" screen with the earth background.


Matrix is conjugate to its own transpose

Mariano mentioned somewhere that everyone should prove once in their life that every matrix is conjugate to its transpose.  I spent quite a bit of time on it now, and still could not prove it. At the risk of devaluing myself, might I ask someone else to show me a proof?


Curved space-time VS change of coordinates in Minkowski space

I'm looking for a rather intuitive explanation (or some references) of the difference between the metric of a curved space-time and the metric of non-inertial frames.  Consider an inertial reference frame (RF) with coordinates $\bar x^\mu$, in flat spacetime $\eta_{\mu \nu}$ (Minkowski metric).   If I have well understood, on one hand, I can go to an accelerated RF by change of coordinates $x^\mu(\bar x)$. The metric is given by: $$\tag{1}g_{\mu \nu}(x) = \frac{\partial \bar x^{\alpha}}{\partial x^{\mu}} \frac{\partial \bar x^{\beta}}{\partial x^{\nu}} \eta_{\alpha \beta}$$ On the other hand, I know that a curved space-time with metric $q_{\mu \nu}$ cannot be transformed to Minkowski $\eta_{\mu \nu}$ by coordinate transformation. In other words there does NOT exist any coordinate $x^\mu(\bar x)$ such that (in the whole coordinate patch): $$\tag{2}q_{\mu \nu}(x) = \frac{\partial \bar x^{\alpha}}{\partial x^{\mu}} \frac{\partial \bar x^{\beta}}{\partial x^{\nu}} \eta_{\alpha \beta}\qquad \leftarrow \text{(does not exists in curved space)}$$   So far, everything is more or less ok... But my question is:    What is the difference between $q_{\mu \nu}$ and $g_{\mu \nu}$? I mean, in both cases a particle would "feel" some fictitious forces (in which I include the weight force due to the equivalence principle).  What physical situation can $q_{\mu \nu}$ describe and $g_{\mu \nu}$ cannot?   I additionally know that by change of coordinates $q_{\mu \nu}$ is locally Minkowski. But still, I can't see clearly the difference.


I came across the following problem that says:  Let $f$ be an analytic function defined on $\mathbb{D}=\{z\in\mathbb{C}:|z|<1\}$ such that the range of $f$ is contained in the set $\mathbb{C}\setminus (-\infty,0]$. Then  $f$ is necessarily a constant function. there exists an analytic function $g$ on $\mathbb{D}$ such that $g(x)$ is a square root of $f(z)$ for each $z\in\mathbb{D}$. there exists an analytic function $g$ on $\mathbb{D}$ such that $\operatorname{Re}g(z)\geq 0$ and $g(z)$ is a square root of $f(z)$ for each $z\in\mathbb{D}$. there exists an analytic function $g$ on $\mathbb{D}$ such that $\operatorname{Re}g(z)\leq 0$ and $g(z)$ is a square root of $f(z)$ for each $z\in\mathbb{D}$.   I have to determine which options are correct. Can someone help in the right direction? Thanks in advance for your time.


Big cache_form slows Drupal website and the whole server

I have a custom form in my site. After couple of months a big issue appears.   Not only that the table cache_form has become huge, but also if I empty that table and disable my custom form, the cache_form keeps increasing over and over, so my website and whole server becomes very slow.   Some spambots are killing my server and I've already tried "Bad behavior" module, but there aren't any positive results. Also my custom form has a Honeypot protection, so I receive very few spams from there, but the bots keep slowing everything.   Can anyone post some advice, anything will be useful?


By assigning the date to awk, I can get current date as following in yyyy-mm-dd:  awk -F, -v date="20$(date +%y-%m-%d)" '{print date}'   Output:  2019-02-17   Is there a way to add number of days to current date, let's say 7, so the output would be:   2019-02-24   Noting that using a method like below isn't providing the required output:  awk -F, -v date="20$(date +%y-%m-%d +7 days)" '{print date}'   Solution  is not providing same date format


I mounted a Windows share to my Ubuntu 11.10 system via adding the following line to the /etc/fstab:  //serveraddr/sharedfolder /mnt/foldername/ smbfs credentials=/home/myname/.smbpasswd 0 0  using the .  But there's a problem with the permissions. The owner of the mount folder is root. I can not create any folders or files in the mounted point is I don't become the root. Even I can not change the ownership to my default user via   sudo chown -R myname .  I googled and saw that it might stem from the fact that Windows file formats (fat32/ntfs) can not save ownership. But when I connect to the same location via samba as   smb://serveraddr/sharedfolder  by providing my credentials, I have the privileges to write without being the root.  How can I make it to let me write to the mounted folder?


Is There A Canon Reason Why Yoda could Identify Darth Bane

In the final season of Star Wars The Clone Wars, at one point, Yoda ventures to the Sith world of Moraband. There he encounters an ancient Sith ghost, whom he is able to identify as Darth Bane. I know this question has already been asked, , but the answer was strictly from Legends. Is there a canon reason why Yoda knows who Darth Bane was?


sufficient condition vs necessary condition

First sentence:     If you live in Los Angeles, then you live in California   Second sentence:     If you don't live in California, then you don't live in Los Angeles.   I am not sure, but I would like to say that the first sentence is NOT a sufficient condition because it is necessary you must live in Los Angeles to live in California.  Is it correct that the first sentence is NOT a sufficient condition, and the second sentence IS a necessary condition?


Add ability to increase font size for android app

I have a hard time reading questions and answer on Stack Exchange sites sometimes. I hate having to bring my phone or laptop very close to my face to read things sometimes. I would love if there was an option to increase the font size in the app. Can this please be done?


I'm having issues with the boolean in my if statements

I'm writing a program to test my knowledge of certain Japanese letters. Basically I want the program to output a random letter such as あ and then I type my answer a into the scanner, and if my answer is correct, it will output "Correct" and otherwise "Wrong".  I'm honestly not sure what I'm doing wrong in my program. It all seems logical to me yet my console keeps outputting "Wrong" when my answers are clearly correct:  public class Gojuon {     public static void main(String[] args) {         List<String> list = new ArrayList<String>();         list.add("あ");         list.add("い");         list.add("う");         list.add("え");         list.add("お");          for(int i = 0; i < 3; i++) {             String gojuonLetter = list.get(new Random().nextInt(list.size()));             System.out.println(gojuonLetter);             Scanner scanner = new Scanner(System.in);             System.out.println("Type Romaji:");             String answer = scanner.nextLine();              if(gojuonLetter == "あ" && answer == "a") {                 System.out.println("Correct");             } else if(gojuonLetter == "い" && answer == "i") {                 System.out.println("Correct");             } else if(gojuonLetter == "う" && answer == "u") {                 System.out.println("Correct");             } else if(gojuonLetter == "え" && answer == "e") {                 System.out.println("Correct");             } else if(gojuonLetter == "お" && answer == "o") {                 System.out.println("Correct");             } else {                 System.out.println("Wrong");             }         }     } }


website is Not showing Arabic language in menu list

i am facing a problem from last 3 days on wards,     problem is in my menu item  list is not showing in Arabic but content inside website is showing in Arabic what will be the issue........please solve this  http://image-dent.com/arabic/index.php


Movie about a girl looking for her kidnapped brother

I've seen this live action movie as a child in late 1980s or early 1990s on a black & white TV in Hungary with Hungarian voices (probably dubbed). It has stayed with me a long time now, but I still haven't figured out what it was. I remember a number of details, but I'm not sure I remember everything right.  The story starts in a Christmas festival. A brother (around 6) and sister (around 10) have a look around and end up in Santa's trailer. He tells them a nursery rhyme (that actually rhymes in Hungarian): "Close your eyes and open your mouths, I'll give you some candy." They do as instructed.  When the sister opens her eyes she got no candy and also her brother and the guy dressed as Santa are gone. She's alone.  She goes looking for the brother. It takes years and she has many adventures. One I recall is a visit to a village that turns out to be built on the back of a huge dragon. (Maybe drilling a well disturbs the dragon's slumber.)  She ages. At some point an inventor joins her on the quest to find her brother. The inventor helps her get to her destination, a castle in a forest. At the end he builds a Leonardo da Vinci-style flying machine to get past some obstacle (orcs?). The inventor perishes though and his book of inventions with him.  She makes it to the castle though. Her brother lives there as the prince. He does not quite remember her and seems a bit cold. But then he starts sketching a flying machine, just like the inventor did! I'm not sure exactly what that means, but yay!


Vertical table lines are discontinuous with booktabs


How do I ask questions on Stack Exchange sites and don't get downvoted?

I can get why I am getting downvotes when I ask question about JavaScript - I don't have experience and should learn language instead of doing stuff with it.  I can't get why I am getting upvotes on some not-so-popular exchange sites like neo4j for a similar stupid question. But it lets me not get banned from the Stack Overflow site and keep asking questions.  And I certainly can't get why I am getting downvotes on an iPhone forum when I asked about similarity between a battery in an iPhone and a Tesla car.  I am not going to give links to my question, because I kind of feel I will get even more downvotes and will get banned. The only thing I want to know - how to not get downvotes?


I'm creating a Python3 program that generates SVG images with random circles that I need for a personal project. Right now the program works perfectly, but I'd like to fine-tune some parameters to produce the best results possible. My idea is to have a display window that shows the intermediate result and an interactive shell to change some of the values that generate the position of the circles, without having to create thousands of different images and compare them. When I finish I can simply save the result. And here comes the problem: I don't really know how to achieve this result. I first thought of using Matplotlib, which is usually perfect for these kind of tasks, but it doesn't seem to be able to read SVG files. I also thought of drawing circles directly into a plot, but some of them have to be blurred (Gaussian blur filter in the SVG file), and Matplotlib doesn't seem to be able to blur shapes. Finally I looked for something else able to display either an SVG file or directly the text the program produces to generate the SVG file, but with no luck. Edit: I just tried CairoSVG to convert the SVG file to PNG. It works, but it doesn't support Gaussian blur, so it's a suboptimal solution. I can accept a solution that involves converting the SVG file to PNG or some other format, but I'd like it to support at least Gaussian blur, otherwise I can simply draw every circle with Matplotlib. Thanks in advance for the help!


Remove all files/directories except for one file

I have a directory containing a large number of files. I want to delete all files except for file.txt . How do I do this?  There are too many files to remove the unwanted ones individually and their names are too diverse to use * to remove them all except this one file.  Someone suggested using   rm !(file.txt)   But it doesn't work. It returns:  Badly placed ()'s    My OS is Scientific Linux 6.  Any ideas?


How can I make ls show information about the directory specified only, not info about its sub-files or folder contents?

Say I have folder "foo" residing, the home directory. I want to get some info of it, owner, group, permissions, etc...  I then do this to try to get the information:  cd ~ ls -l foo   Of course it now lists the info of the contents of "foo"  Then I could do something like this  cd ~ dir=foo ls -l $foo/.. | awk 'BEGIN { dir="'$foo'" } { if($9 == dir) { print $0 }  }'   But isn't there an easier way to do this?


Find the number $b$ such that the line $y = b$ divides the region bounded by the curves $y = x^2$  and $y = 4$ into two regions with equal area.  I could find the area of this region but i have no clue how to split it parallel to the $x$ axis perfectly... this is too abstract for me...  I found the whole area and got $\dfrac{32}{3}$... I tried plugging that back into the definite integral but that definitely wasn't right...


Prove functions defined by sup and inf are continuous

Suppose $f$ is continuous on $[a,b]$. Show that the functions defined by $m(x)=\inf\{f(y):y\in[a,x]\}$ and $M(x)=\sup\{f(y):y\in[a,x]\}$ are well defined and are also continuous on $[a,b]$  I have already managed to prove that they are well defined, since $f$ is continuous on $[a,b]$ so it is bounded. Therefore for every $x\in[a,b]$, the set $\{f(y):y\in[a,x]\}$ has a supremum and an infimum. To prove that they are continuous on $[a,b]$, I've taken an arbitrary sequence $\{x_n\}$ contained in $[a,b]$ converging to some number $c\in[a,b]$ and am attempting to show that $m(x_n)\rightarrow m(c)$ and $M(x_n)\rightarrow M(c)$, but I'm not quite sure how. Any help would be appreciated, thanks!


Given that the rationals are countable and the denseness of $\mathbb{Q}$ in $\mathbb{R}$ how can $\mathbb{R}$ be uncountable?

So I was walking on some subset of a spherical metric, when I came across an idea that I haven't yet been able to disprove or shake. It goes as follows:  Let the rational numbers be countable an lie dense in the real numbers. Then the irrational numbers must also lay dense in the reals.  Proof: Suppose $x,y$ real numbers and $x\neq y$, assume without loss of generality that $x<y$. Then there exists a rational number $q$ such that $x+\pi<q<y+\pi$, so $x<q-\pi<y$, which is irrational. $\blacksquare$   Take any arbitrary 2 elements $x,y$ from the irrational numbers. Then because the denseness of the rationals, there lies a rational $c$ inbetween. Take any arbitrary 2 elements $p,q$ from the rational numbers. Then because of the denseness of the irrationals, there lies a rational $c$ inbetween.   On a first glance, this would suggest that the cardinality of the irrationals is equal to the cardinality of the rationals. This is obviously not true. The question is, why not? For this I have been unable to find a rigorous argument that does not use the fact that the reals are uncountable.  PS: I'm aware of:  . This question does however not have any satisfactory answers because they are all either built on intuition (This question specifically looks at rigorous ways to prove this.) or use the uncountability of the reals (I already know this proof. I'm looking for an alternative.)


Flux of electric field through a closed surface with no charge inside?

I'm reading the Feynman lectures on electromagnetism and in Vol II, Chapter 1.4  he talks about the flux of the electric field and says that flux of $E$ through and closed surface is equal to the net charge inside divided by $\epsilon_0$.     If there are no charges inside the surface, even though there are   charges nearby outside the surface, the average normal component of $E$   is zero, so there is no net flux through the surface   I cannot see why the net flux is zero here. Say we have a closed unit sphere at the origin with no charge inside it and at the point $(2, 0, 0)$ we have some charge $q$.   Well doesn't this charge then define the electric field $E$ for the system and it will flow into the unit sphere on the right hand side, and out of the unit sphere on the left hand side? Furthermore, as the strength of the electric field decreases with distance from $q$ won't we have more flux going into the right hand side which is closer to the charge $q$, and less flux leaving through the left hand side as it is further away - and hence we should have a non-zero flux?   Can someone please explain what I am misinterpreting here?


I have a Meizu M8 phone running android with Termux. I had set up ssh access to Termux over WiFi, but I want to be able to do that over USB because of possibly lower latency and higher speed. If I connect the phone to my macbook using USB, I can use adb to get shell or transfer files, so I think ssh over USB is possible. How can I achieve this?


Install Ubuntu with current setup and apps to OS-free PC

I have Ubuntu installed, with some small apps and scripts running on it. I need to deploy this current setup to other PCs.  Until now whenever I needed this setup I just installed it manually to other PCs.  Is there any way I could make an image or a clone or something of this PC and just deploy it? Something like a clean install but with the scripts and apps added there


Over a commutative ring, $AB = I_n$ and $BA = I_m$ implies that $m = n$.

If $R$ is a commutative ring, and $A \in M_{n \times m}(R)$, $B \in M_{m \times n}(R)$ with the property that $AB = I_n$ and $BA = I_m$, prove that $n = m$.  I’m aware of a proof involving traces in the case that $R$ is a field of characteristic zero, but cannot think of / know of a proof for this more general case.


How to prove that if $f^3 = f$, $f$ is diagonalizable?

Prove that     Let $V$ be a finite dim. vector space over a field of characteristic zero, and $f: V \to V$ be a linear   map.Then if $$f^3 = f,$$ then $f$ is diagonalizable.   Since $f$ is zero of the polynomial $$p(x) = x^3 - x$$ the minimal polynomial $m_f$ should divide $p$, hence $m_f$ can be the following polynomials only: $$m(x) = (x-1) \\ = x \\ = x+ 1 \\ =x^2 - x \\ = x^2 + x \\ = x^2 - 1 \\ =x(x-1)(x+1) $$  But, I couldn't show that if $m$ is either of the followings $ x^2 + x $ & $ x^2 - 1  $ & $ x(x-1)(x+1) $, it should be diagonalizable. So for these 3 cases how can we prove that $f$ should be diagonalizable ?


How can I send someone the most recent version of one branch of my git repo without version control history?

I'm trying to send someone a copy of the current state of one branch on my Git repository. He doesn't have access to the repository itself and doesn't need version control history. I would also like to send the file over email, so including excessive history will cause the file size to be too large. I could manually clone that branch myself with --depth=1 in a new folder, then compress that folder and send it, but that seems like a roundabout way to accomplish what could be done with git-bundle. However, if I do git bundle create repo.bundle -1 HEAD, which according to  should bundle only the 1 most recent commit, I get a 590 B file and an error when I try to clone from the bundle to test it: error: Repository lacks these prerequisite commits: error: 123456...             # example SHA, HEAD~1 fatal: bad object 789101...  # example SHA, HEAD fatal: remote did not send all necessary objects  How can I get only the most recent version of the branch from my local repository?


wheres the settings box in lower left corner?

when I create a sapling or geometry, I noticed on the tutorials I watch a settings dialog appears where you can change vertex, branches of a tree, etc, how do I get that box? -thanks. -Steve.


I've tried to solve the limit $$    \lim_{n \to \infty} \binom{2n}{n}$$ but I'm not sure.  $    \lim_{n \to \infty} \binom{2n}{n} =     \lim_{n \to \infty} \frac{(2n)!}{n! n!} $  Now I have put $\frac{(2n)!}{n! n!} \sim \frac{(2n)^{2n}}{n^n n^n } =\frac{(2n)^{2n}}{n^{2n} }= (\frac{2n}{n})^{2n}=2^{2n} \rightarrow +\infty$  Is it right?


How to execute a function on Console closing in C#

I have a simple C# Console Application and I want to execute a function when the user is closing the Console Application. So I need an event probably, which fires a function on pressing Ctrl + C, clicking the close button or writing something into the console to shut down. I tried every single code snippet on Stackoverflow and other pages but none of them worked on all cases. One solution worked for everything during debugging the Application in Visual Studio, however on running the compiled exe File in a Console Prompt, it didn't work on Ctrl + C and clicking the close button. Can anyone help me?  Here's my code in the Main class:  using System; using System.Collections.Generic; using System.IO; using System.Linq; using System.Threading;  namespace BankClient {     class Program     {         private static DB _db;         private static string _notUpdatedUsersCsvFilePath;          static void Main(string[] args)         {             BankServer server = new BankServer();             _db = new DB();             _notUpdatedUsersCsvFilePath = "not_updated_users.csv";              if (File.Exists(_notUpdatedUsersCsvFilePath))             {                 string[] lines = File.ReadAllLines(_notUpdatedUsersCsvFilePath);                  if (lines.Length > 0)                 {                     Console.WriteLine($"Es sind noch unbearbeitete Einträge von Kunden vorhanden, welche nicht in der Datenbank aktualisiert werden konnten:");                     foreach (string l in lines)                     {                         Console.WriteLine($"{l.Split(';').First().Trim()} {l.Split(';').Last().Trim()}");                     }                     Console.WriteLine();                 }             }               Console.WriteLine("Fetching DB...");             if (_db.fetchDB()) Console.WriteLine("Fetched DB successfully.");             else             {                 Console.WriteLine("An error occured whilst fetching DB!");                 Console.ReadLine();                 return;             }              Console.WriteLine();             foreach (Kunde k in _db.Kunden)             {                 Console.WriteLine($"- {k.Vorname} {k.Nachname} ({k.Id}) -> Kontostand: {k.Kontostand}");             }              Console.WriteLine();              Kunde kunde = _db.Kunden.Find(k => k.Id == 1);              if (kunde == null)             {                 Console.ReadLine();                 return;             }              kunde.Kontostand += 100;             kunde.ChangeMade = true;              Console.WriteLine($"{kunde.Vorname} {kunde.Nachname} ({kunde.Id}) -> Kontostand: {kunde.Kontostand}");              Console.ReadLine();              onClosing();         }          private static bool onClosing()         {             bool error = false;              Console.WriteLine("Stopping application...");             Console.WriteLine("Updating DB...");              Dictionary<bool, string> tmpDB = _db.saveDB();              if (tmpDB.ContainsKey(true))             {                 Console.WriteLine("Updated DB successfully.");             }             else             {                 error = true;                 Console.WriteLine(tmpDB[false]);                  foreach (Kunde k in _db.Kunden)                 {                     if (k.ErrorMessage != null)                     {                         File.AppendAllText(_notUpdatedUsersCsvFilePath, $"[{DateTime.Now}];" + $"{{id: {k.Id}, vorname: \"{k.Vorname}\", nachname: \"{k.Nachname}\", kontostand: {k.Kontostand.ToString().Replace(',', '.')}, filiale: {k.Filiale}, status: {k.Status}, errorMessage: \"{k.ErrorMessage}\"}}" + Environment.NewLine);                     }                 }             }              if (!error)             {                 Thread.Sleep(5000);                 Environment.Exit(-1);                 return true;             }              Thread.Sleep(10000);             return false;         }     } }   Best regards, Steven


Render doesent show almost anything (material or textures)

a little while ago was everything working perfectly. But now, when i have even just basic cube in the scene, then when i want to add texture or materieal, or even if i wont add any of them to the cube, when i go to Rendered viewport shading, all i see is this (just a grey cube with nothing on it, i have set the color tu blue but nothing):  And when i render it it shows just checkered cube like this:  I know its probably gonna be something dumb, but i just cant figure out what the problem is. Thanks for help.


Finding exact cause of my deleted question

I earned the  for , which has since been removed.    Searching MSO, I found one  that indicates that I should be able to find out why the question was deleted, or at least whether it was a community or moderator decision to delete.  However, the links on the deleted question's page only provide a link to a FAQ of possible reasons.  As the OP, how can I find out definitively why my question was removed (aside from finding the closing moderator)?


Biblatex multiple authors name and initials wrong order

I'm using biblatex for my report and I've run into a small problem. When I have multiple authors in my .bib file my bibliography displays the initials of the authors (after the first) in the wrong order and I get an unwanted 'and'. So what I get:  1. Klinkrad, H. and J. Doe, 2006. Space Debris: Models and Risk Analysis. Berlin: Springer.   What I want is:   1. Klinkrad, H., Doe, J. 2006. Space Debris: Models and Risk Analysis. Berlin: Springer.   I've included a MWE and my sources.bib code:  \documentclass[a4paper,10pt]{report} \usepackage[bibstyle=authoryear, citestyle=authoryear,sorting=none,backend=biber,natbib,dashed=false]{biblatex} \addbibresource{sources.bib} \NewBibliographyString{available} \usepackage[english]{babel} \DefineBibliographyStrings{english}{available = {available at},} \DefineBibliographyStrings{english}{urlseen = {[Accessed},} \DeclareFieldFormat{url}{\bibstring{available}\addcolon\space\textless\url{#1}\textgreater} \DeclareFieldFormat{urldate}{\space\bibstring{urlseen}\space#1]}  \defbibenvironment{bibliography} {\enumerate{} {\setlength{\leftmargin}{\bibhang}% \setlength{\itemindent}{-\leftmargin}% \setlength{\itemsep}{\bibitemsep}% \setlength{\parsep}{\bibparsep}}} {\endenumerate} {\item} \usepackage{xpatch} \xpatchbibmacro{date+extrayear}{%   \printtext[parens]% }{%   \setunit{\addcomma\space}%   \printtext% }{}{}  \begin{document} \nocite{*}  \printbibliography \end{document}   And my sources.bib code:  @Book{space_debris_klinkrad,   Title                    = {Space Debris: Models and Risk Analysis},   Author                   = {Klinkrad, H. and Doe, J.},   Publisher                = {Springer},   Address                  = {Berlin},   Year                     = {2006}, }   I think it is a simple change in the definition of the Author field. However, I've not been able to find the solution anywhere.  Thanks!


how to start operating system on a Samsung SSD when old hard drive was broken so had to replace

Recently went into Apple with my early 2011 MacBook Pro, was told that my hard drive was broken. So I decided to replace it myself with a Samsung 850 EVO, all went okay, but now when I turn it on all I get is a file with a question mark in it.  I couldn't upload anything to the SSD before installing as my Mac wasn't working at all and had a white screen with a spinning wheel. I had no new operating system on my Mac as I hadn't updated it in a while. A CD came with the drive but my laptop is having none of it it just turns on to a white screen with the mouse on it.  As you can see I'm not very technical so if any responses could be dulled down a bit that would be helpful!


Use $$...$$ or \[...\] to enter math mode in LaTeX?

I read on some sites that [ ... ] (with backslashes before the brackets) should be used, rather that $$...$$  what is the difference between both? If you compare the output, the result is the same.


Let , $A$ and $B$ be two orthogonal matrices with $|A|+|B|=0$. Then prove that $(A+B)$ is singular.   From the relation $|A|+|B|=0$ it is clear that $|AB|=-1$.  Also , $|A|=|B|=\pm 1$. But how I find out $|A+B|$ ?


Continuous function that reaches each value on its range exactly 2 times.

Is there a continuous function from $\mathbb{R}\to\mathbb{R}$ that reaches all of its possible values (each value in it's range) exactly $2$ times (for example, $x^2$ would be perfect if it wasn't for $0$..). Also, the same question but $3$ times.  I'm almost certain that there aren't such functions but who knows haha maybe there are a bunch...


Note: please English is not my first and here I saw people use hard words I can not understand. please consider simple words, thank you. If I bought an item 3 times at different prices. the average formula will give me the average of this.   ($5 + $10 + 15)/3 = $10  The problem is if bought different quantities each time with different prices. Does the previous average formula represent this situation?   $5 - 1200 items   $10 - 5   $15 - 20  I did this and I am not sure it is correct $5*1200 = $6000 $10*5   = $50 $15*20  = $300  I summed all the total prices $6350 then divided it into a total of items 1200+5+20 = 1225. $6350/1225 = $5.18   is this consider average and is this correct?


Why in this code i can't swap StringBuffer's?   public static void main(String[] args) {      StringBuffer a = new StringBuffer("One");      StringBuffer b = new StringBuffer("Two");      swap(a, b);      System.out.println("a is " + a + "\nb is " + b);  }  static void swap(StringBuffer a, StringBuffer b) {     a.append(" more");     b = a; }


I have a list of objects in which each object has a property called "Frequency" and I want to be able to pick the top 10 objects that have the highest frequencies.   I saw some solutions that are kind of similar to what I am looking to solve using LINQ so any help is appreciated.


Lately I've been trying both babel and polyglossia against each other to see if there are any advantages either way. But to my untrained eye there is no significant difference in regards to output between the two.  While  is giving a good overview on the status quo I'm interested in the current "trend":  Where is the future going? babel or polyglossia?


Differential Equation Question for a separation of variables problem

I'm struggling with the differential equation $yln(x)dx/dy = ((y+1)/x)^2$  Can anyone help me out?


Relationship between cosines of angles in 4 dimensions

If the cosine of the angle between the vectors $a$ and $b$ is $x$ and the cosine of the angle between the vectors $a$ and $p$ is $y$, then, if we call $z$ the cosine of the angle between the vectors $b$ and $p$, can we write $z$ in terms of $x$ and $y$?  All vectors are in $4$-dimensional Euclidean space.


Windows 8 locked because the password were lost, how can I change it without needing to reinstall it?

I installed Windows 8 on my mother's notebook, she typed a new password for her and she lost it, she can't remember what she typed and no notes about it were made(my fault), now her Windows 8 installation just keep locked on logon/password screen.   How can I change the Windows 8 password for her account, reset the password or recovery the password without needing to reinstall entire Windows 8?   Could I just create another new account on the same computer from the safe mode or something like this?  PS: No live account was related to her Windows 8 account as far no account was registered on Windows 8 Store.


Interpreting the residuals vs. fitted values plot for verifying the assumptions of a linear model

Consider the following figure from Faraway's Linear Models with R (2005, p. 59).    The first plot seems to indicate that the residuals and the fitted values are uncorrelated, as they should be in a homoscedastic linear model with normally distributed errors. Therefore, the second and third plots, which seem to indicate dependency between the residuals and the fitted values, suggest a different model.  But why does the second plot suggest, as Faraway notes, a heteroscedastic linear model, while the third plot suggest a non-linear model?  The second plot seems to indicate that the absolute value of the residuals is strongly positively correlated with the fitted values, whereas no such trend is evident in the third plot. So if it were the case that, theoretically speaking, in a heteroscedastic linear model with normally distributed errors  $$ \mbox{Cor}\left(\mathbf{e},\hat{\mathbf{y}}\right) = \left[\begin{array}{ccc}1 & \cdots & 1 \\ \vdots & \ddots & \vdots \\ 1 & \cdots & 1\end{array}\right] $$  (where the expression on the left is the variance-covariance matrix between the residuals and the fitted values) this would explain why the second and third plots agree with Faraway's interpretations.  But is this the case? If not, how else can Faraway's interpretations of the second and third plots be justified? Also, why does the third plot necessarily indicate non-linearity? Isn't it possible that it is linear, but that the errors are either not normally distributed, or else that they are normally distributed, but do not center around zero?


Can't install packages after changing to KDE on Ubuntu 16.04

After installing KDE on Ubuntu 16.04 I can't use unity anymore and when trying to download new software with apt-get I get error messages.  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 E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution).   When I try sudo apt-get -f install i get another error message.  0 upgraded, 1 newly installed, 0 to remove and 46 not upgraded. 2 not fully installed or removed. Need to get 0 B/137 kB of archives. After this operation, 825 kB of additional disk space will be used. Do you want to continue? [J/n] j (Reading database ... 445397 files and directories currently installed.) Preparing to unpack .../kde-config-telepathy-accounts_4%3a15.12.3-0ubuntu1_amd64.deb ... Unpacking kde-config-telepathy-accounts (4:15.12.3-0ubuntu1) ... dpkg: error processing archive /var/cache/apt/archives/kde-config-telepathy-accounts_4%3a15.12.3-0ubuntu1_amd64.deb (--unpack): trying to overwrite '/usr/share/accounts/services/google-im.service', which is also in package account-plugin-google 0.12+16.04.20160126-0ubuntu1 Processing triggers for libc-bin (2.23-0ubuntu7) ... Errors were encountered while processing: /var/cache/apt/archives/kde-config-telepathy-accounts_4%3a15.12.3-0ubuntu1_amd64.deb                                                                  E: Sub-process /usr/bin/dpkg returned an error code (1)    I'm pretty sure i fucked something up along the way and I read online that I will have to delete the damaged package but I don't really know how to do that without bricking my system.