Can someone tell me why there are four file permission numbers instead of three?

This question was flagged as duplicate, and I looked at the suggested question. It did not explain why there are four numbers instead of three. Like in WordPress. the folder permissions you should never set it to is 7777. What does the fourth number mean, and can someone provide a simple, lay person explanation?  I was reading an article  and it mentioned three sets of numbers ranging from 0 to 7.  Read = 4.  Write = 1.  Execute = 2.  To get read-write permissions, add 4 and 2 to get six, and to get read and execute, you add 4 and 1 to get 5. If you want write and execute, add 2 and 1 to get 3. To not set permissions, set it to 0, and to allow all permissions, set it to 7.  The article says three numbers are needed. The first number sas that you, the owner, are given permission. The second number is for the group that the account is a part of. The third number is for everyone else. For example, the number 750 indicates that I, the owner can do everything, everyone in my group can read and execute, and anyone else who is not in my group cannot access it. However, I have seen four numbers instead of three. Like 0644 which indicates someone doesn't have any permission, there is a read  and write number, and two read permissions. 7777 means that everyone regardless of who is accessing the system has access to read, write, and execute.  Finally, what's the difference between reading, writing, and executing? And why do I sometimes see RWSRWSRT in Win SCP?


I'm still using Ubuntu 19.04 because it's what was current when I installed the OS but it is no longer supported so I want to upgrade to 20.04 LTS (or even just 19.10).  This should be very simple. There are loads of tutorials on how to upgrade from from 19.10 or 18.04 to 20.04. But it seems like it's not possible from 19.04. Could this be true?  If I run sudo apt upgrade I get a bunch of 404 errors because the disco archives don't seem to exist anymore. But I ran:  $ sudo apt dist-upgrade Reading package lists... Done Building dependency tree Reading state information... Done Calculating upgrade... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.  $ sudo do-release-upgrade Checking for a new Ubuntu release Your Ubuntu release is not supported anymore. For upgrade information, please visit: http://www.ubuntu.com/releaseendoflife  Please install all available updates for your release before upgrading.   I tried  $ update-manager -c   And it told me I was no longer supported and needed updates but when I said "ok" to installing updates it gave me the exact same error.  I'm not sure what to do here. I can't update any more because I can't apt update. I guess I could manually set all my apt repos to the Eoan Ermine ones and update again. Is that what I need to do? Where do I set that?


I need to loop recursively through files in specific folders (to add them to git skip-worktree). I've made a script for that: #!/bin/bash  scan_recursively () {     echo "Doing $1"     if [ -f "$1" ]; then         echo "git update-index --skip-worktree $1" >> output.txt     else         for f in $1/*; do             scan_recursively "$f"         done     fi }  echo "" > output.txt for folder in fol1 fol2 file1.txt #fol\ 11 do     scan_recursively $folder done  And it works fine, but when I uncomment fol\ 11 it breaks into an infinite loop and in the console I see repeatedly: Doing fol/*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/*/*  With the number of /* growing until I stop the program. Same happens when a sub folder contains space in it's name


How to put a no-filled box around a paragraph

I want to emphasize a certain part of a document by putting a box around it. Any help is much appreciated.


What happens if we remove the requirement that $\langle R, + \rangle$ is abelian from the definition of a ring?

Ever since I learned the definition of a ring, I've wondered why the additive group is required to be abelian.  What happens if we allow $\langle R, + \rangle$ to be nonabelian as well as $\langle R, \cdot \rangle$?  Is this impossible?  If not, what is the this type of algebraic structure called?  Here is the definition of a ring that I am using:        $\langle R , + \rangle$ is an abelian group with identity $0$.   $\langle R , \cdot \rangle$ is associative.   $a\cdot (b + c) = a\cdot b + a \cdot c$.   $(a + b)\cdot c = a\cdot c + b \cdot c$.


I've got an input where the user is able to enter their website URL.  I can't use FILTER_VALIDATE_URL because that requires that the user types in http:// before their URL. Some users might just type www.website.com or website.com.  How can I validate a URL with the following rules:   doesn't require the user to have http://, https://, or any other form of this doesn't require the user to have www. before their link (example: just website.com) doesn't matter what domain extension is used allows links like www.website.com/username or anything alike to be used   How would this be done?


The Drupal 8 REST UI configuration page asks me to select Authentication providers for GET method; otherwise, it doesn't allow me to export the REST request.  How can I provide anonymous user to access my REST GET API without providing any auth information?


We have a totally custom theme that we have built in house, recently the WordPress updater has started saying the theme is out of date.     When I investigated this supposed update it links me to a similarly named theme in the WordPress theme directory but one that is not developed by us.    We normally update our themes manually either through the filesystem or FTP. We have never submitted our theme to the WordPress directory nor do we have a mechanism or infrastructure to allow our themes to "phone home" to check for updates.  What is going on here? How do I stop it misreporting the theme update? I really want to stop this behaviour to prevent an over eager customer trying to update the theme to this one and breaking their site.


Can I receive email or iPhone notifications for questions with my favorite tags?

Is it possible for me to get push notifications or emails (or other) when a question arises on specific tags?


Forcing fonts to be embedded in LuaLaTeX

I have compiled a huge document with LuaLaTeX - I've tried stripping it down to a MWE but cannot get the behaviour to repeat.  The issue is that the document contains un-embedded fonts, and to submit my PhD thesis to my university I need all fonts to be embedded.  I have tried doing embedding fonts after compiling in Acrobat Pro, but lots of characters break when you do this.  So I have to do it in LaTeX - but I can't work out how to solve this. I've heard rumour of editing pdftex.map in some folder like /users//library/texlive etc etc but I can't find it, and don't know what to edit.  Any help would be much appreciated.  Cheers.  EDIT: I solved the problem through a lot of trial and error and wanted to describe how here in case someone else stumbles on this question. In short, I had pdf figures generated in R that did not contain embedded fonts. I started an Adobe Acrobat trial (free) so I could use the pro features. I then saved all figures as pdf/a. This embedded the fonts without any degradation or significant alterations (I tried other methods that stopped the graphs being lossless - but this method worked a treat).   One wrinkle was a few figures for which Adobe broke when trying to save as pdf/a. For these, I used the embedFonts() function in R - embedFonts(filename, new_filename) - this took the original pdf graphs and embedded the fonts. I still had to do the conversion to pdf/a for some reason in Adobe, but the combination of steps for the problem graphs.  The combination of these two approaches allowed me to upload my thesis to the online directory. Hope this helps someone else who runs into this issue.


Try to prove a generalization of the IVT?

Here is the statement :  "Let $f: (a,b) \to \mathbb{R}$ a continuous function on $(a,b)$ with $a<b$ and $a,b \in \bar{\mathbb{R}}$. Then for all $u \in \left(\lim \limits_{x\to a} f(x), \lim \limits_{x\to b} f(x) \right)$ or $u \in \left(\lim \limits_{x\to b} f(x), \lim \limits_{x\to a} f(x) \right)$ (with $\lim \limits_{x\to a} f(x) \ne \lim \limits_{x\to b} f(x)$) there is $k \in (a,b)$ such that $f(k) = u$."  So we have three main cases :   Let $a,b \in \mathbb{R}$ with $\lim \limits_{x\to a} f(x)= \pm \infty$ and $\lim \limits_{x\to b} f(x)= \pm \infty$. Let $a=-\infty$ and $b=+\infty$ with $\lim \limits_{x\to -\infty} f(x)= c\in \mathbb{R}$ and $\lim \limits_{x\to +\infty} f(x)= d\in \mathbb{R}$. Let $a=-\infty$ and $b=+\infty$ with $\lim \limits_{x\to -\infty} f(x)= \pm \infty$ and $\lim \limits_{x\to +\infty} f(x)= \pm \infty$.   I tried to prove the first case. I want to apply the initial theorem which only works for compact interval.   WLOG, I suppose that : $\lim \limits_{x\to a} f(x)= - \infty$ and $\lim \limits_{x\to b}(x)= + \infty$  Writing the definition of limits I obtain :   $\forall A \in \mathbb{R}, \exists \eta_1>0, \forall x \in (a,b), \mid x-a\mid \le \eta_1 \Rightarrow f(x) \le A$. $\forall B \in \mathbb{R}, \exists \eta_2>0, \forall x \in (a,b), \mid x-b\mid \le \eta_2 \Rightarrow f(x) \ge B$.  Then for $k \in (a,b)$, I can chose $\eta_3 = \min\{\eta_1, \eta_2\}>0$ such as for $x\in [k-\eta_3, k+ \eta_3]$ I have $f(x) \in [B,A]$.  Does that imply that I can apply the usual theorem ?  Thanks in advance !


What is the best order to watch LotR/Hobbit franchise?

I have not watched any of the entries in the Lord of the Rings/Hobbit franchise and as per my knowledge The Hobbit's story occurs before LotR but the release order is different. So for better understanding should I go with the Hobbit trilogy first or should I go with release order?


could someone please tell me what the value of the three resistors  in circle  (R1) 1 orange,orange black,gold red,red,black,gold and the same for the third   (R2/R3)second the grey resistor   (R28)  brown,black,silver,gold,black  (R30)not sure if its pink,purple or brown , red,gold ?  the rest i have managed  to get the values   i cant seem to find hem anywhere  thanks


What is the function of "the" in these kinds of phrases? It cannot be the definite article.   Can someone analyze this? It's common and definitely standard but seems to elude any grammatical explanation.


Has SO apologized for their licensing fait accompli?

In the latest , the following was posted (emphasis mine):     Licensing         MIT licensing of code was proposed, but held back due to community naysayers.   CC-BY-SA incremented from 3.0 to 4.0. - likely in good faith.   Vast majority of community likely fine with 4.0.   Vast majority not fine with fait accompli.   Some (a very few?) thought that this happened in bad faith.         Stack Overflow:                We have apologized for the fait accompli.     We want to signal our intent to keep up with future changes to CC-BY-SA.     We will create a process and be engaged on licensing issues on Meta.     We have had hours of meetings on this, and it is a big priority.     We have no intention of moving away from creative commons or paywalling users content in any way.           Has that actually happened? Was there any place were SO made any sort of apology related to their actions in the licensing space? The original re-licensing announcement is , and there was a follow up post to it , but I don't see any apologies there, and I don't know of any other posts related to this.   For those suggesting that  question is a dupe of mine, I disagree. It was answered in one week and its possible SO did something since then. The SO leadership seems to have explicitly stated something was made, which is in direct contrast with the answer in that post.


Why second countable for definition of manifold?

What is the motivation to define a manifold to be second countable? What kind of pedagogical issues does this avoid?


How do I cut an unwanted remaining of an intersection?

I have intersected a cylinder with another. I have removed the faces the way I wanted and everything worked. Now I am trying to remove the layer of the 135 ° cylinder that intersects with the other cylinder. Below are the images:  and


Using strlen() with Array Integers or Float

Is there a way, I can use of strlen() to find the length of the arrays, instead of specifying in the loop. First Code: Working With x < 4 Which is the size of the array of temps[4].  #include <stdio.h> #include <string.h>  int main(){     float temps[4] = {72.5, 73.4, 74.7, 75.2};     int x;     printf("Local Temperatures\n");     for(x = 1; x < 4; x++){         printf("Station %d: %.1f\n",x,temps[x]);     } }   My Second Code, Not Working, But Looking At What, I Am Trying To achieve with strlen() to find the size of the array.:  #include <stdio.h> #include <string.h>  int main(){     float temps[4] = {72.5, 73.4, 74.7, 75.2};     int x;     float size;     size = temps;     printf("Local Temperatures\n");     for(x = 1; x < strlen(size); x++){         printf("Station %d: %.1f\n",x,size[x]);     } }


Do card abilities that grant mana stack?

For example, if I have a creature card that says      Creatures you control have "{T}: Add one mana of any color to your mana pool."   and I have two of these creatures out, do they stack so I can tap a creature to get two mana?


Finding centrelines from polygons in QGIS?

I was wondering if there is a way to create centre lines from polygons in QGIS? I have a polygon layer, but ideally need the centrelines as a separate file.


I overstayed in the USA about 20 years ago and I worked. Can apply for a new visa?

I got my B2 visa 20 years ago and I overstayed for about four years and I worked illegally.  I have a plan to go on a business trip to Las Vegas. I'm not sure what to say to the official if I'm asked if I worked back then. I paid taxes to the IRS and had an SSN, It was not legal to work but I used that number then.  Never got a ticket or trouble there.


I am trying to get the distinct values from below code .But I find no luck to move further.  Can any one let me know what's wrong in my below code. Because I am trying to group the information to get distinct values.

  Title Values	  Month Values

          <select id="drbprogrames" class="select">         <option selected="selected">Select</option>         </select>     	         <select id="drbmonths" class="select">      <option selected="selected">Select</option> </select>


if fn converges uniformly to f then f is continuous

I have put my question here  because this is already anwered.


Using the chain rule to finding the second order partial derivative

$z=f(x,y)$ where $x=r\cos\theta $ and $y=r\sin\theta$. Find $ \frac{\partial z}{\partial x}$ and $ \frac{\partial^2 z}{\partial x^2}$   I'm having big troubles with using chain rule, in particularly the second derivative. Spent 2 hours on this already. What I have...  $ \frac{\partial z}{\partial x}=\frac{\partial r}{\partial x}\frac{\partial z}{\partial r}+\frac{\partial z}{\partial θ}\frac{\partial θ}{\partial x}$. So I'm guessing that $\frac{\partial z}{\partial r}$ and $\frac{\partial z}{\partial θ}$ are unkown? And I will need to use them to differentiate again. Any help is really welcome. This is simply only part of a bigger question.   Full Problem:


I've been using Ubuntu 12.04 and accidentally deleted a folder using Shift+Del.  Does anyone have any idea how to recover the folder?


When will other sites follow Stack Overflow Portuguese

The first site using internationalization, , is now online for over 7 months.   What are the plans for other sites like this waiting to be launched at ? Will this be happening soon?


Definition of moments and the different approaches to compute them

I was wondering about the way we refer to the term "moments". In statistics and probability the first moments is the mean $$E[X^1] $$ The second moments is the variance: $$E[(X-E[X])^2]$$ I notice that there's a difference in which we define moments. In the first case the $k'$th moment is $E(X^k)$ and the second case it is $E[(X-E[X])^k]$. Why is there a difference? In Common scientific language when people refer to the third moment is it then $E[(X-E[X])^3]$ or $E[X^3]$


Why are all of my footnotes hyperlinked to the titlepage?

Problem  I have various footnotes, which are hyperlinked from the text to the bottom of their respective pages. When I click on the hyperlinks (in the main text), they always take me to the first page of my document. I also have footnotebackref which puts a hyperlink at the footnote to take the reader back to the main body of text and these links for fine.   Edited MWE  After a lot of deletion, I have managed to reduce the document to the following lines. One might say that I have found the problem, since the removal of \usepackage[hang, flushmargin]{footmisc} stops the problem, but I would still like to have non-indented footnotes.  \documentclass{article}  \usepackage[usenames,dvipsnames]{color} \usepackage[colorlinks=true]{hyperref}  \usepackage[hang, flushmargin]{footmisc}         %Problem line. \usepackage{footnotebackref}  \begin{document} \tableofcontents             \newpage                 \section{Section} This is some text\footnote{This is a footnote.}. \end{document}


How to determine all the possible 3 layer combinations out of many files

I have a list of 21 grayscale images. I want to determine and save all the possible 3 layer combinations out of these 21 images. Can anyone a suggest a way in python?


Why do I need to set up Secure Boot password for Ubuntu to install drivers?  I installed it with secure boot unchecked, so I don't know if I have those drivers? Firefox seems to tear when scrolling so I think there are some old default linux graphics drivers.  If I set it up, do I need to enter this password every time GRUB loads?  Or is it similar to Windows' BitLocker, only asks for key if somethings changed (f.i. there's connected new USB drive)  Don't know if it matters I dual boot Windows 10 + Ubuntu 19.04


Is every single earth part of ALL NEW ALL DIFFERENT Marvel?

I know for a fact earth 616 and earth 1610 are in the All-New All-Different Marvel, but are there any other universes?


I set up an account at BlueHost and my unfinished site is now live at columbiablooms.org.  My understanding is that when I make modifications, such as enhancements, that changes are made not only to the file structure, but also the database meaning that from this point forward I need to make all my changes and content additions to this live site. Also, I want to be very careful to backup both the file structure and the database before I make changes in case I mess things up.  At this point my Acquia Dev Desktop is not very useful since there appears to be no way to merge what I've done on my local machine with what's live out there on the web.


How to generate/view PDF using Lightning Components?

I need to view/generate PDF in Lightning component. How can I achieve that?  Do I have to user VF page with "renderAs" attribute inside Lightning Component? Or is there any other way to achieve this?


I can't find anywhere to get quarried stone to build my house on the hearthfire expansion so I would like to know lots of places to get it.


I am trying to write a program where i want to create a file using the id given by the user but is the file already exists then i want my program not to overwrite it but show some message like already exists. how can i do that.  #include<stdio.h> #include<stdlib.h> struct student_info{     char fName[10],lName[10],depart[10],student_id[10];     long borrowed_books[5];  };  int main(){    struct student_info student;    FILE *fpt;    printf("enter your id:\n");    scanf("%s",student.student_id);    printf("enter your first name:\n");    scanf("%s",student.fName);    printf("enter your last name:\n");    scanf("%s",student.lName);    printf("enter your department:\n");    scanf("%s",student.depart);     fpt=fopen(student.student_id,"w");   fclose(fpt); }


After finishing The Cayo Perico Heist, how long will it be set in hard mode?

After I finished The Cayo Perico Heist, I tried setting up another heist in the Kosatka, and got this message :  The setup cost for The Cayo Perico Heist is $25000. Setting up now will set the heist to Hard Mode. Do you wish to proceed?  It seems that there is a cooldown period before the heist reverts to normal mode from hard mode. How long will it take before it reverts to normal mode? Also, does the cooldown timer run even if you're logged out of GTA Online? E.g., if I quit GTA Online just after finishing the heist, the next time I log back in, will I have to wait for the cooldown period to finish before it reverts to normal mode?


covering map with finite fibres and preimage of a compact set

Let $f:X\to Y$ be a covering map (covering maps are surjective) , Y be compact set. And suppose that $f^{-1}(y) $ is finite for each $y\in Y$. Prove that $X$ is also compact.  I think that this problem does not need the hyphotesis of covering map , I think that only is necessary that $f$ is an open map (covering maps are open maps)  Well I dunno how to start this problem :/  If I consider an open covering $ X = \bigcup U_a $ , then $f(X)=Y = f(\bigcup U_a) = \bigcup f(U_a) $   I don't know if it's convenient to consider a finite subcovering of $Y$ at this moment, or I need some tricky argument ... Please help me )=


Is there a more typographically-satisfying bigints package?

I found the bigints package but as its documentation shows, the symbol is simply scaled up in size which leads to a much thicker stroke:   Is there a package that deals with this properly, or failing that, can someone sketch out how I could achieve the correct result, maybe with some TikZ wizardry? I only want the basic integral sign, not oint or anything else.


Create a link to a folder on the left panel of Nautilus file manager?

I would like to create a link to some new folder that I have in my home. The left panel shows docs, images downloads etc. But I would like to add my other folders that I created myself like university etc,  It use to be as simple as drag and drop the folder on the panel, but it doens't work anymore. How can I create a link?  The image is to show what panel I'm talking about:


How to release keyboard and mouse from grab by a hung unkillable app?

Suppose I have an X application, which grabs keyboard and mouse as its normal mode of operation (e.g. QEMU), but which, due to a bug somewhere, hangs really hard (e.g. gets stuck in Disk sleep). Normally I'd kill an app using kill(1) from a remote terminal, but if the app is in Disk sleep mode, it can't really be killed. I could kill this app's connection to X server by the xkill utility, but this time I can't do this because mouse is grabbed, so xkill will fail to run.  So, how do I release my keyboard and mouse from grab by an X client, if I'm willing to sacrifice this client, but am unable to kill it by the OS means?


How do I grep for lines containing either of two words, but not both?

I'm trying to use grep to show only lines containing either of the two words, if only one of them appears in the line, but not if they are in the same line.  So far I've tried  grep pattern1 | grep pattern2 | ... but didn't get the result I expected.


What happens to my data if I cancel my iCloud Storage subscription?

I have a plan of $0.99/month. Now I want to cancel my subscription.  I have 30GB of iCloud Data. I don't know what happen with all my data in iCloud. Will I still be able to get access, or it will be deleted once I cancel my subscription?


Include revision history in inline editing

If the user have reputation higher than 2K they are given the inline editor when editing questions and answers. However, the revisions are not shown in inline editing.  Inline editing for user with Rep > 2K :        Standard editing for user with Rep < 2K :        I think inline editing for 2K+ users should have the revision feature. Is it really necessary to remove the revisions option for 2K users? Because normally on Stack Overflow features and privileges increase with reputation, but this looks like an opposite case here.  It is very useful if 2K+ users also have the revision history when editing inline.


How to clear a collection before an object is deleted

I am new to Java Programming and Hashmaps and I have a problem that I need help with.  I have a Hashmap that stores a collection of objects:  HashMap<String, Shape> turtleShapes = new HashMap<String, Shape>();   I am trying to ensure the turtles shape collection is cleared before the Turtle object is deleted.   How do I go about this?


Lightning Inter-Component Communication Patterns: how to pass efficiently pass down data from parent to dynamically created child?

I know two ways of pass data from parent to child in the case of a static created child components: passing attribute values from parent to child and exposing child methods to parent.   The latter method can be easily used even with dinamically generated child components since the only thing needed is to give to each child a different aura:id.   I have troubles implementing the first method instead. I don't know how to pass an aura attribute to a dynamically generated child component but only how to pass a value. This means that I'm not able to change its value later.  Is it possible to pass an aura attribute to a dynamically generated child component? How?    Some references on the two ways of passing down data from parent to static generated child taken from a  on Salesforce Developer Blog.  Attributes  parent.cmp  <aura:component>    <aura:attribute name="parentAttribute" type="String"/>     <c:childComponent childAttribute="{!v.parentAttribute}"/> </aura:component>   child.cmp  <aura:component>    <aura:attribute name="childAttribute" type="String"/>  </aura:component>   Of course, a handler in the child component could be used to detach a change of childAttribute.  child.cmp (new version)  <aura:component>    <aura:attribute name="childAttribute" type="String"/>     <aura:handler name="change" value="{!v.childAttribute}" action="{!c.onChildAttributeChange}"/> </aura:component>   childController (new version)  ({     onChildAttributeChange : function (component, event, helper) {         console.log("Old value: " + event.getParam("oldValue"));         console.log("Current value: " + event.getParam("value"));     } })   Methods  child.cmp  <aura:component>     <aura:method name="myMethod" action="{!c.executeMyMethod}">          <aura:attribute name="param1" type="String"/>          <aura:attribute name="param2" type="String"/>      </aura:method> </aura:component>   childController.js  ({     executeMyMethod : function (component, event, helper) {         var params = event.getParam('arguments');         console.log('Param 1: '+ params.param1);         console.log('Param 2: '+ params.param2);     } })   parent.cmp  <aura:component>     <aura:attribute name="parentAttribute1" type="String" default="A"/>     <aura:attribute name="parentAttribute2" type="String" default="B"/>      <c:childComponent aura:id="child"/>      <lightning:button label="Call child method" onclick="{! c.onCallChildMethod }" /> </aura:component>   parentController.js  ({     onCallChildMethod : function(component, event, helper) {         var attribute1 = component.get('v.parentAttribute1');         var attribute2 = component.get('v.parentAttribute2');         var childComponent = component.find('child');         childComponent.myMethod(attribute1, attribute2);     } })


How does time of exposure relate to aperture?

I was trying to derive the relation between the aperture and time of exposure. I'm taking two apertures f/2 and f/4. From the formula     A α 1/√t   I got,    f/2 α 1/√t1    -> A   and    f/4 α 1/√t2    -> B   Doing A/B, I got the result    t2 = 4t1 (I am taking the approximation out)   or    t1=(1/4)t2   Am I doing this right? If so,for the first lens with twice the aperture of the second lens, will the same amount of light will enter the first lens in just a quarter of the time it takes for the second?


How can I prevent my computer from waking up accidentally?

When I put my computer into sleep mode, it will wake up while I'm away from it. There's nothing near the computer that could move the mouse or accidentally press a button and I have no idea what might be causing it.  I tried checking what woke it, apparently LASTWAKE only tells me that it has been in sleep mode, not what woke it up.    I also couldn't find anything in my Power Options regarding Sleep that seems off. Poking around in the Event Viewer I notice the following:   The Power-Troubleshooter event at the top notes the following:     The system has returned from a low power state.      Sleep Time: 2012-10-27T11:31:53.408927000Z    Wake Time: 2012-10-27T12:25:51.887029300Z      Wake Source: Unknown   So does anyone have an idea to find out what might be causing it and how I can prevent my computer from randomly waking up?


Story about encounter with hostile aliens

This is a short story I read in the late 80s or early 90s in an anthology or collection.  Here are the plot points I remember:   A human spaceship encounters a ship with hostile aliens (HA). There may be friendly aliens (FA) on board the human spaceship A human (or perhaps FA) telepath scans the HA and finds they are hostile and bent on conquest of other races The captain and crew decide on a bluff: pretend they are from a large federation of many species, one so big the HA will become discouraged and drop their plans of conquest They invite one or more HA on their ship To pretend that there are many (more) races in their federation, they do things like put a fake control panel in the ships aquarium and claiming the fish in them are one of the races in their federation The HA can't conceive of multiple races cooperating and are convinced there must be some race on top controlling it all. If not, they can just be conquered one at a time This goes on for a little while until, seeing their plan isn't working (via their telepath) the humans change their plan so that when      the ship's cat (so far unseen by the HA) walks in the room, one of the humans loudly calls "The CAT!" causing everyone to stand rigidly at attention while the cat walks around more or less ignoring everyone and everything the way cats do. Having seen the "top dog" and the rigid discipline and fear he instills in everyone else, the aliens "realize" the humans are deluded into thinking all races are equal members in their 'federation", the cats are really in control of a huge empire, and they should not be messed around with.


How to "grep" for line length in a given range?

NOTE: This question is the complement of this Q&A:     I need to get only the lines from a textfile (a wordlist, separated with newline) that has a length range of minimum or equal than 3 characters, but not longer or equal than 10.   Example:   INPUT:   egyezményét megkíván ki alma kevesen meghatározó   OUTPUT:   megkíván alma kevesen   Question: How can I do this in bash?


Is it right that Ubuntu 20.04 arm pi4 sources are http?

I am using Ubuntu 20.04 on my raspberry pi 4. As I tried to upgrade, I noticed that the sources are only http. Are they the official right ones? Can someone please share the proper sources? Why doesn't it use https? Is it not official? It seems to be very unsafe to me. Here are the sources used on my pi currently: deb http://ports.ubuntu.com/ubuntu-ports focal main restricted                                                                                deb http://ports.ubuntu.com/ubuntu-ports focal-updates main restricted deb http://ports.ubuntu.com/ubuntu-ports focal universe deb http://ports.ubuntu.com/ubuntu-ports focal-updates universe deb http://ports.ubuntu.com/ubuntu-ports focal multiverse deb http://ports.ubuntu.com/ubuntu-ports focal-updates multiverse deb http://ports.ubuntu.com/ubuntu-ports focal-backports main restricted universe multiverse  deb http://ports.ubuntu.com/ubuntu-ports focal-security main restricted  As also as focal-security universe and focal-security multiverse and src. (Cant be posted, due to reputation, sorry. ) Thank you!


Is there a way to call process builder from Apex?

With the roll out of sub-processes, it seems like there would be a way to call a process builder from apex, but I'm not finding anything in the documentation.  Does anyone know if you can call a process builder from apex?


How to deal with a Chaotic Evil player character as a player

I am taking part in a campaign supposed to be a normal hero adventure. One of our players, who is a first timer to DnD and never really claimed an alignment at the start of the campaign, has pretty much become a Chaotic evil character: stealing from absolutely anyone, attacking people unprovoked, refusing to help at all even when the story revolves around us helping others out.  When we started our campaign this character didn't have any alignment listed at all.  The chaotic evil actions surprised every single one of us including the DM, whom did say that we were supposed to be the heroes of this campaign. He's even been trying to show her that her constant theft isn't profitable giving her a few measly copper but her behavior hasn't changed at all.  A lot of us have been trying to talk her out of her actions but she continues to persist.     Since I am not the DM I'm not really able to take matters into my own hands but I am worried that this character will have a devastating effect on the campaign, especially when I see the other players' frustrated reactions to her actions such as stealing in plain sight from NPCs we're currently talking to.    We've even had our giant fighter try and grapple her just so she wouldn't murder the guy we were currently talking to for no reason. Besides telling the DM about my frustrations is there anything I could do in game, in character to try and deal with this potentially destructive player and show her that her chaotic evil personality is becoming frustrating to the rest of the group?


Singular vs plural: the effect of conjunctions

Consider:   Please check that the username and password is correct. Please check that the username and password are correct.   If I had to break the statement into its parts:   Please check that the username is correct. Please check that the password is correct.   I feel that username and password can be seen as a single noun and therefore the correct form is is. Based on  answer, I'm confused: the number of the verb is determined by the number of the verb's subject. Is username the subject or object?  Can someone please advise?    This question was marked as a duplicate but the duplicate tagged isn't quite related. Rather, based on @user2370114 response, this  is a better match. Furthermore, it doesn't address my concern about the subject vs object distinction (as answered by @RegDwigнt♦).  To summarize:   If you are speaking of multiple things, and even if both were singular, the copula (verb of being) would still be plural. Both username and password are the subject. Interestingly, in my use here, are felt more natural :)     So can I rather ask: is there ever a time when items can be seen as a single subject and therefore take the singular form of the verb?


GNOME has grey bar on top and bottom after upgrade from 17.04 to 17.10, how do I fix it to how it's supposed to look?

This is how my desktop looks after the update, the top bar turning grey and the addition of the bottom bar happened after the update.    From my searching of screenshots this does not appear to be how it is supposed to be. Is there any way to fix it?


This is a question from the free Harvard online abstract algebra .  I'm posting my solutions here to get some feedback on them.  For a fuller explanation, see  post.  This problem is from assignment $5$.     Prove directly that distinct cosets do not overlap.   Let $H$ be a subgroup of $G$ and let $a$, $b$, and $c$ be elements of $G$ such that $b\not\in aH$ and $c$ is in both $aH$ and $bH$.  Then there are elements $h$ and $h^\prime$ in $H$ such that $c=ah$ and $c=bh^\prime$.  So $ah=bh^\prime$ and $b=ahh^{\prime -1}$.  But $hh^{\prime -1}\in H$ so $b\in aH$.  This contradicts our original assumption. Therefore, there can be no element in more than one distinct coset.  Again, I welcome any critique of my reasoning and/or my style as well as alternative solutions to the problem.  Thanks.


A single word meaning deep love of reading

Not bibliophile, or really anything "biblio-" because that means a love of books, which might mean a collector or someone who loves the books themselves, but not necessarily their content.  Also, not words like bookworm, because they refer to the person who loves reading, whereas I'd like a word that describes the act or state of loving to read.


Difficult logic question with conditional statements

[click here for image of question][1]      [1]:       The question states: in this problem we will only consider (real- valued) function with domain $\mathbb{R}$ (real numbers). We define two new concepts. Let $f$ and $g$ be two functions;         we say $f$ is a rival of $g$ if $∃x∈ \mathbb{R}, s.t. ∀y∈ \mathbb{R}, x< y \text{ then } |f(x)-g(x)|<|f(y)-g(y)|$   we say $f$ is a frenemy of $g$ if   $∀x∈ \mathbb{R}, ∃y∈ \mathbb{R}, s.t. x< y \text{ AND } |f(x)-g(x)|<|f(y)-g(y)|$         a) Is the claim “ if $f$ and $g$ are any two functions and $f$ is a rival of $g$ then $f$ is a frenemy of $g$” true or false? If it’s true, prove it, if it’s false then show it with a counter example.   Can someone please show me how to solve for the first question a)? For the the two concepts defined, do I have to first find out if they are true or false before finding if the claims are correct? Is it technically saying that there’s a real number smaller than all other real numbers(y)?


Word meaning you are describing something as if to a child

Looking for a word that describes the feeling of being told something in an overly simplified manner that feels offensive.


Is it OK to delete a question that didn't get much activity and post it again?  I've actually seen a user do this and gotten answer on third attempt.


What does comma operator in C do when we return an integer with two values?

I was actually returning a float value when I typed , instead of . but it did not give me any error. Then I tried running the below code.  #include<stdio.h> #include<conio.h> int getValue(); int main() {     int a = getValue();     printf("%d", a);     return 0; }  int getValue() {     return 2, 3; }   Now the output is 3, that is it returned the second value. This happened two years ago and was searching for the proper answer since then.  Studying  I came to know that it returns the second value after evaluating, but what does it do with the first one?  I studied the logic of the stack(how the values are pushed and pop internally) but I don't think this have anything to do with it.  Does it processes the two values or do something else?


Combinatorics Question Involving Arranging Letters in INTELLIGENT with Restriction

How many ways are there to arrange the letters in INTELLIGENT with at least two consecutive pairs of identical letters?  I know that we would use the inclusion exclusion principle here and that there are $\dfrac{11!}{2!2!2!2!2!1!}$ ways to arrange the word with no restrictions.   My first guess would be to assign two pairs of identical letters as a single block which we could choose two pairs from five possible pairs to get the pairs themselves. Then these pairs could be arranged in such a block in two ways. Then we would have to figure the number of ways to arrange this block in the entire word. I'm just confused where to go from here...


How to identify the tables needs to de-fragmented by doing a VACCUMM Full or ReIndex (for indexes) Is there any query to find the free space in between the tuples to find the right candidates to perform the VACCUUM FULL


Can I put \fbox along the diagonal so that they touch each other?

I am creating a block-diagonal matrix and want to use boxes along the diagonal but the boxes don't touch each other, so it looks funny.  What's a workaround for this?  Here's my code:  \documentclass{article} \usepackage{amsmath} \begin{document} \[   \begin{bmatrix}            \fbox{$B_1$} & 0 & 0  \\      0 & \fbox{$B_2$} & 0 \\      0 & 0 & \fbox{$B_3$} \\    \end{bmatrix} \] \end{document}   something like the matrix in the middle ...of this answer (but without the red and color filling)    Thanks,


Can you identify each character and spacecraft in this Star Trek TNG 30th anniversary poster?

Can you identify every character and spacecraft in ? Please mention the episode(s) if you can.  The poster is for the 30th anniversary of . (First aired on September 28, 1987.)    I got many of them (along with episodes), but there are plenty I don't recognize. A few occur more than once. (e.g. - Jean Luc Picard and Tasha Yar)


"All posts" incorrect displayed on graph on analytics page

I have access only to SOru analytics (), so can provide gif only from here.        Все сообщения = all posts. Вопросы = questions. Ответы = answers.  I guess it should be: All posts = answers + questions. But right now All posts == questions.  Exported CSV also has incorrect values.


What causes blue and red gradient/shade around black spots in photos?

Right now I'm trying to improve the sharpness of my photos, and for that I've checking if my D7000 has some autofocus issues. Therefore I tested my  and my . I figured that the autofocus for both lenses is correct, so I probably have to learn to use it in a better way.  While testing I started to read a little more (eg. ) about the  and I've learned of the sweet point of each lens. But even with optimized condition I encounter a blue and red gradient in the black square of my test photo.  What do you call this gradient and what is it the result of?    Example details of shot with of my 35mm prime; the only after-work I did is to crop and to set the exposure of the images (same style for each photo):    ISO 400 1/60 f/1.8:  ISO 400 1/60 f/5:   ISO 400 1/60 f/8:     You can see the  blue and red gradient or shade I'm trying to learn about even better when you zoom in:   ISO 400 1/60 f/8:


Where's my error? Probability three of a kind, three dice rolled once

Classic and simple problem: Three indistinguishable dice (6-sided) are rolled at the same time. What's the probability that we have rolled three of a kind?  Now I know that the answer is $\frac{1}{36}$, as explained for example in a thread on this site .  But when I think about it from the following way, I get another solution. Where's my error?  Order does not count, so the space of possible outcomes is $\Omega = \{(x_1 \leq x_2 \leq x_3)\ \lvert\ x_i \in \{1, \cdots, 6\} \}$ with $\lvert\Omega\rvert = \binom{6+3-1}{3} = 56$. The set of outcomes we want is $\{(1,1,1),\cdots(6,6,6)\}$ with cardinality 6. So the probability of rolling three of a kind is $\frac{6}{56}$.    Can you point me to my thinking error? Thanks in advance!


Instant e-mail notifications of answers to questions

I'd like to have Instant notifications by email of answers to my questions.  Can this be implemented?


I've a laptop which dual boots Windows 10 and Ubuntu (16.10). I'm based in India and the time that I see is 5.30 hours ahead. i.e. 5.30PM when the local time is 12.00PM I've tried to set the Hw clock with   sudo hwclock --localtime   This is what I see  sudo hwclock -r 2017-03-04 17:30:43.420286+5:30   Timezone     cat /etc/timezone     Asia/Kolkata  Raw output  sudo hwclock --debug hwclock from util-linux 2.28.2 Using the /dev interface to the clock. Assuming hardware clock is kept in UTC time. Waiting for clock tick... ...got clock tick Time read from Hardware Clock: 2017/03/04 12:44:07 Hw clock time : 2017/03/04 12:44:07 = 1488631447 seconds since 1969 Time since last adjustment is 1488631447 seconds Calculated Hardware Clock drift is 0.000000 seconds 2017-03-04 18:14:06.075863+5:30   In the Time Applet I've set it to get time automatically and that still reutrns this time.  Any help is much appreciated   EDIT: This is the solution  In terminal:  gksu gedit /etc/default/rcS   You may need to install gksu. In which case:  sudo apt-get install gksu   else ensure the file says:  UTC=no   Save and exit  Boot to Windows. Set correct time with the time applet. Boot to Ubuntu.  The correct time should be up


Using Zorn's Lemma to prove existence of a function

Using Zorn's Lemma, I want to prove that for any two sets $A,B$ either there is an injective function $f:A\to B$ or there is an injective function $g:B\to A$. Any ideas on how to approach this proof?


If you use sudo su - or sudo -s you will get the full root certification  "likewise a root user ".  Is this user an official user or is it from canonical?  ~$ sudo su - [sudo] password for username:  root@lp:~# id uid=0(root) gid=0(root) groups=0(root) root@lp:~# pwd /root root@lp:~#


How to export your Ocean Modifier Mesh and Animation to Unity? | Blender v2.80.72

/*Edited: For Blender 2.7 Users I found a detailed  with pictures. */  I want to build an VR-Scene in Unity with a little Island and and ocean around.   For the ocean I am quite happy with the ocean modifier and made already an looping animation with the water.    But I simply cannot find a solution to export the mesh + animations to Unity. I keyframed the time and scale and found the problem, that these can't update when I apply the modifier. To my understanding blender needs to apply the modifier when exporting, so I can even get the shape of Ocean.  [  I tried and failed with  explanation.  Could somebody please give me an more beginner friendly explanation?  Here is my blendfile:


Affinity Designer v Adobe Illustrator for creating an svg icon library

I am looking at exporting SVG images using Adobe Illustrator 2020 for putting together my own custom icon library to use in a web page. This is a simple set of 2 artboards.  With a minus icon outline and a minus icon filled.  Exporting When I export these using File->Export->Export for Screens... I can select some SVG options.  This then generates the following files: minus.svg <svg id="Layer_1" data-name="Layer 1" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 128 128">   <defs>     <style>.cls-1{fill:red;}</style>   </defs>   <rect id="minus-filled" class="cls-1" y="46" width="128" height="32" rx="4.16"/> </svg>  minus-outline.svg <svg id="Layer_1" data-name="Layer 1" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 128 128">   <defs>     <style>.cls-1{fill:none;stroke:red;stroke-miterlimit:10;stroke-width:4px;}</style>   </defs>   <rect id="minus-outline" class="cls-1" x="2" y="48.5" width="124" height="31" rx="4.16"/> </svg>  When I copy paste the svg directly to a web page and view it, then I see 2 outlined rectangles.  preview.html <!DOCTYPE html> <html lang="en">  <head>     <meta charset="UTF-8">     <meta name="viewport" content="width=device-width, initial-scale=1.0">     <title>Document</title>      <style>         svg {             height: 128px;             width: 128px;         }      </style> </head>  <body>     <svg id="Layer_1" data-name="Layer 1" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 128 128">         <defs>             <style>                 .cls-1 {                     fill: red;                 }             </style>         </defs>         <rect id="minus-filled" class="cls-1" y="46" width="128" height="32" rx="4.16" />     </svg>      <svg id="Layer_1" data-name="Layer 1" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 128 128">         <defs>             <style>                 .cls-1 {                     fill: none;                     stroke: red;                     stroke-miterlimit: 10;                     stroke-width: 4px;                 }             </style>         </defs>         <rect id="minus-outline" class="cls-1" x="2" y="48.5" width="124" height="31" rx="4.16" />     </svg> </body>  </html>  This can be corrected by adjusting the internal css (defs/styles), ala cls-1, in one of the svgs so the css classes do not clash. How To... Is it possible to get AI to generate the SVGs so I can get more control over these styles? Ideally I would want to get Adobe Illustrator to output different css classes depending on whether its outline of filled, something like: minus.svg <svg id="Layer_1" data-name="Layer 1" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 128 128">   <rect id="minus-filled" class="icon-filled" y="46" width="128" height="32" rx="4.16"/> </svg>  minus-outline.svg <svg id="Layer_1" data-name="Layer 1" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 128 128">   <rect id="minus-outline" class="icon-outline" x="2" y="48.5" width="124" height="31" rx="4.16"/> </svg>  Then control the css colours in my own (global) css using: .icon-filled {   fill: red; }  .icon-outline {   fill: none;   stroke: red; }  Without using the IDs.


How many objects are available for garbage collection?

class Cardboard{     Short story = 200;     Cardboard go(Cardboard cb){         cb = null;         return cb;     }      public static void main(String args[]){         Cardboard c1 = new Cardboard();         Cardboard c2 = new Cardboard();         Cardboard c3 = c1.go(c2);         c1 = null;           } }   After go() is executed c2 should be pointing towards null, as implied by the method.This reference of c2 is passed to c3 variable, which again is pointing to null only thus c2's object must be available for garbage collection.


Is my proof below correct? What specific property of rationals did I exploit in my proof? It looks like the property I exploited is the following: Given any positive rational, I can always write it as sum of arbitrary number of positive rationals, whereas given any positive integer I cannot write it as a sum of arbitrary number of positive integers. Has it got to do with the fact that $\mathbb{Q}$ is a field?       Problem Prove that the additive groups $\mathbb{Z}$ and $\mathbb{Q}$ are not isomorphic.   Solution Let there exist an isomorphism between $\mathbb{Z}$ and $\mathbb{Q}$. Now consider the element $1_{\mathbb{Q}}$. We then have $\phi(1_{\mathbb{Q}}) = z \in \mathbb{Z}$. Since $\phi$ has to be a bijection, $z$ cannot be zero, since $\phi(0) = 0$.  Now consider the element $\left(\dfrac1{z+1}\right)_{\mathbb{Q}}$. We now have $$z = \phi(1_{\mathbb{Q}}) = \phi\left(\underbrace{\left(\dfrac1{z+1}\right)_{\mathbb{Q}} + \left(\dfrac1{z+1}\right)_{\mathbb{Q}} + \cdots + \left(\dfrac1{z+1}\right)_{\mathbb{Q}}}_{z+1 \text{ times }} \right) = (z+1) \phi\left(\left(\dfrac1{z+1}\right)_{\mathbb{Q}}\right)$$ However, there is no element in $y \in \mathbb{Z}$ such that $(z+1)y = z$.    First update  Actually I realize that I complicated it unnecessarily. Instead, we can do like this. Since $\phi$ is an isomorphism, we have $\phi(q_{\mathbb{Q}}) = 1_{\mathbb{Z}}$ for some $q \in Q$. However, $$\phi(q) = \phi(q/2+q/2) = 2\phi(q/2)$$ And there is no $y \in Z$, such that $2y=1$. Hence, $\phi(q/2)$ remains unmapped.    Thanks


Is the following the correct way to get the number of bytes in a file? Are there more straightforward ways, perhaps directly from the FILE* object? size_t num_bytes(FILE *fp) {     fseek(fp, 0, SEEK_END);     return (size_t) ftell(fp); }  Additionally, why does ftell return a long int and not a size_t object? I find it a bit difficult to figure out which "size-ish" functions return size_t and which don't. Is there a good way to remember that? Or is the reason that ftell isn't size_t because it uses -1L as the "fail value" ?


How to run a script when install a rpm package?

I try to build rpm package. I follow .   I want to run a script (bash or python) when run command as "rpm -Uvh mytest-1.0-1.el6.noarch.rpm" .   Could run a script when install a rpm package? How?


What Ubuntu should I install in this PCr?

Well I have this old laptop, I bought it in 2009. It is an Acer 5720  INTEL CORE 2 DUO T7300 2.00 GHZ 2GB RAM Hard Drive: 150GB Hard Disk Drive MOBILE INTEL 965 Express Chipset Family  I tested Ubuntu 15.10 by the Live CD; It ran good, but I want to know if other "flavour" could run better than Ubuntu, or maybe an older version . Thanks


I am building a simple message app, at the moment I would like to view the users image next to their text. I am trying to get the users image from the firebase database. However, whenever I try to getValue() of the an image the app crashes. If I choose to replace imageURI with an image link, then I see it works with that link.  08-27 23:14:02.392 4817-4817/com.myproj.blogapp E/UncaughtException: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String java.lang.Object.toString()' on a null object reference                                                                          at com.myproj.blogapp.MessageAdapter$1.onDataChange(MessageAdapter.java:79)                                                                          at com.google.android.gms.internal.to.zza(Unknown Source)                                                                          at com.google.android.gms.internal.vj.zzHX(Unknown Source)                                                                          at com.google.android.gms.internal.vp.run(Unknown Source)                                                                          at android.os.Handler.handleCallback(Handler.java:739)                                                                          at android.os.Handler.dispatchMessage(Handler.java:95)                                                                          at android.os.Looper.loop(Looper.java:145)                                                                          at android.app.ActivityThread.main(ActivityThread.java:5938)                                                                          at java.lang.reflect.Method.invoke(Native Method)                                                                          at java.lang.reflect.Method.invoke(Method.java:372)                                                                          at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1400)     @Override public void onBindViewHolder(final MessageViewHolder viewHolder, final int index) {      final Message c = messagesList.get(index);      final String sender = c.getFrom();     databaseReference = FirebaseDatabase.getInstance().getReference().child("Users").child(sender);     databaseReference.addValueEventListener(new ValueEventListener() {          @Override         public void onDataChange(DataSnapshot dataSnapshot) {               imageUrl = dataSnapshot.child("image").getValue().toString(); //error on this line             viewHolder.setUserimage(context,imageUrl);               String name = dataSnapshot.child("name").getValue().toString();             viewHolder.displayName.setText(name);          }         @Override         public void onCancelled(DatabaseError databaseError) {         }      });      viewHolder.messageText.setText(c.getMessage());     viewHolder.time.setText(EpochtimeToDateAndTimeString(c.getTime())); }


Confusion on how to solve this question about sequences.

Write down the first five values of each of the following recursive sequences: $$ s_0 = 2, \quad   s_n = s_{n−1}^2 + s_{n−2}^2 + \cdots + s_0^2 $$ for all integers $n \geq 1$.  Approach: Say for $s_1= s_0^2 + s_1^2 + s_0^2$ which means $s_0^2 + s_0^2$ since $s_1$ isn't greater or equal to $1$.   So is the answer $8$ or just $s_0^2$ which will be $4$? I am confused by this part $[\ldots + s_0^2]$.


I am confused by expressions like $\mathbb{R}/\mathbb{Z}$, especially if I see something of the sort $SL(2,\mathbb{R})/SO(2,\mathbb{R})$. I don't know what to make of it. I understand what a quotient of a group for an equivalence looks like, but I can't get my head around expressions like above.   Is a quotient like this always a group and what do elements in the set $SL(2,\mathbb{R})/SO(2,\mathbb{R})$ look like?


Skyrim mannequin duplication fix not working?

I have the mannequin duplication glitch on 4 of my mannequins at my manor and have been trying to fix it for days. I’ve been trying to follow these steps I found other people use but it doesn’t work for me? Every time I leave my house the loading screen is only black with fog. I’m not sure how to get a loading screen that has pictures and I am desperate.     1) Put 2 of each item that you have been duping into the mannequin's inventory, nothing else. Also, make sure you don't have any more than 4 of each in your own inventory.      2) Leave and re-enter, making sure that when you leave the house, the loading screen shows an image instead of just a black, smoky screen. This ensures that the house (im)properly reloads.      3) Activate the mannequin, and remove one of each item from it's inventory. Without exiting the menu, go to your items and put each one back. WARNING: If you have 6 or more items in your own inventory at this time, it will ask you how many you want to place, and this will cause failure. This is why you can't have more than 4 to begin with.      4) Leave and re-enter, again, making sure that the loading screen shows an image when you leave. NOTE: This is why I like the Riften house, as it's easy to remember which door you went through last, and you can just use the other one.      5) Activate the mannequin, and remove all the items from it's inventory, leaving it naked.      6) Leave and re-enter one last time. Again, be sure it reloads the right way. When you go to your mannequin it should still be naked, and will have stopped duping items.


Zero score answers ranked before positive voted ones

I just realized that answers that have 0 scores are ordered before other answers that have one or more votes. Is this a new feature to promote new answers or a bug?  Examples        Pictures


Don't suggest a tag that I've added a synonym of

I have already added the tag , but it is also suggesting I add the tag :    Could it grey it out, or hide it, if I have already added a synonym please?  Also, can there be a space between suggested tags: and the tag, like this:     suggested tags:    not what it is now:     suggested tags:


When is it better to collect money from a node instead of transferring it?

Most of the time, I earn more gold transferring with a merchants to my nodes than when I'm collecting.   In which situation you can get more gold from collecting VS transferring it ?


Space opera featuring gladiatorial combat with an enhanced main character

I’m looking for a book I last read in the late 1970s to early 1980s. The main character was a young male humanoid whose skeleton had been enhanced with titanium to increase its lightness and strength. I think this character ended up leading some sort of battle against a rival faction or planet.


Pointing to a node with calculated name, why do I get to the east, not to the center?

It seems like I'm doing something wrong when using foreach variables to indicate node numbers. The two foreach loops are anchoring the paths to the east of each node. Why does this happen?    \documentclass{article}  \usepackage{tikz} \usetikzlibrary{backgrounds,fit,patterns,decorations.pathreplacing,calc}  \makeatletter \tikzset{   labelnode/.style={draw=none, fill=none, black},   latentnode/.style={draw, minimum width=5mm, shape=circle, ultra thick, black},   dagconn/.style={arrows=->, black, thick}, } \makeatother  \begin{document} \begin{tikzpicture}[scale=1]  \pgfmathsetmacro{\colgap}{1.6}  \pgfmathsetmacro{\rowgap}{1.3}   \node[labelnode] (x1) at (\colgap*0,\rowgap*1) {$X_1$};  \node[labelnode] (x2) at (\colgap*1,\rowgap*1) {$X_2$};  \node[labelnode] (x3) at (\colgap*2,\rowgap*1) {$X_3$};   \node[latentnode,blue] (x4) at (\colgap*0,\rowgap*0) {$X_4$};  \node[latentnode,red] (x5) at (\colgap*1,\rowgap*0) {$X_5$};  \node[labelnode] (x6) at (\colgap*2,\rowgap*0) {$X_6$};   \foreach \c in {1,...,2} {    \foreach \r in {1,...,2} {      \pgfmathsetmacro{\st}{(((\r-1)*3)+\c)}      \pgfmathsetmacro{\en}{\st+1}      \draw[dagconn] ([xshift=0.2cm]x\st) to ([xshift=-0.9cm]x\en);    }  }   \foreach \c in {1,...,3} {    \foreach \r in {1,...,1} {      \pgfmathsetmacro{\st}{((\r-1)*3)+\c}      \pgfmathsetmacro{\en}{\st+3}      \draw[dagconn] (x\st) to (x\en);    }  } \end{tikzpicture} \end{document}


Strange behavior of $\lim_{x\to0}\frac{\sin\left(x\sin\left(\frac1x\right)\right)}{x\sin\left(\frac1x\right)}$

Alright, scratch everything below the line. Let me present one cohesive question not marred by repeated edits.  The limit $\lim_{x\to a}f(x)=L$ exists iff for every $\epsilon>0$ there is a $\delta>0$ such that $|f(x)-L|<\epsilon$ when $0<|x-a|<\delta$.  Thus, $\lim_{x\to0}\sin\left(\frac1x\right)$ does not exist because, being that it oscillates infinitely near $0$, there is no $\epsilon,\delta$.  On the other hand, with the limit$$\lim_{x\to0}\frac{\sin\left(x\sin\left(\frac1x\right)\right)}{x\sin\left(\frac1x\right)}\\\lim_{x\to0}x\sin\left(\frac1x\right)=0\\y=x\sin\left(\frac1x\right)\\\lim_{y\to0}\frac{\sin y}{y}=1\\\lim_{x\to0}\frac{\sin\left(x\sin\left(\frac1x\right)\right)}{x\sin\left(\frac1x\right)}=1$$  this proof can be shown. However, since $\sin\left(\frac1x\right)$ oscillates infinitely, by the same definition of limit we used to show the above, the limit does not exist. How do I resolve this discrepancy?


Well this is kind of an elementary question, but here it goes:  Consider the following code:  listA = ['a','b','c'] listB = listA listB.pop(0) print listB print listA   The output comes as:  ['b','c'] ['b','c']   However, shouldn't the output be:  ['b','c'] ['a','b','c']   What exactly is happening here? And how could I get the expected output? Thanks in advance :)


I have a Raspberry Pi, and I'd like to use it as a DNS server on my LAN.  I'd like it to work like the following:  The Raspberry Pi is a DNS server, but not a fancy one. When it receives a request, if it doesn't have the result cached, it looks it up from another DNS server, and caches it for future.  I've looked at a few solutions, but they're all fiendishly complex, as if I'm setting up some kind of uber DNS solution for an enterprise.  All I want is to speed up repeated DNS requests to make web browsing faster.  Oh, OS is Debian Squeeze.


How can the centripetal force lead to objects flying apart?

I don't understand how the centripetal force, which always points to the center of our circular motion can cause this scenario:  We have a big stone which spins very fast, so fast that a part breaks down, because of the centrifugal force (this is at least how my text books describes it).   My problem: the centrifugal force does not really exist (we only use it in accelerated frames of reference, so the newton laws still work there), so if we're in a laboratory frame of reference, which force would "pull" that piece of the stone to the outside of the circle, when we only have the centripetal force (as mentioned pointing to the center of the circular motion...)?   (Please don't try to explain it in an accelerated frame of reference, because there I understand it, but I don't understand it in a laboratory frame of reference)


Downloading email messages as text files (multiple accounts) from command line

I would like to use some tool from command line, to check and download mail, from different providers (gmail, hotmail, yahoo...) periodically and automatically, and save them as text files, preferably a text file for each email. I don't want my previous emails, so it shoud be possible to specify not to download previous emails, but only new ones since this solution is set up. I have been looking for such a thing and found fetchmail, but it saves all the messages in a single mbox file. What do you suggest? Thanks  EDIT: This is not a duplicate of the question suggested, since I am not going to send any email from this computer. It will not even have a keyboard or mouse connected. My question is about downloading all my emails individually as plain text file ("readable"), and stored in txt format.


Idempotent of closure and other properties

I have to prove:   $\mbox{ClCl}A = \mbox{Cl}A$ $\mbox{diamCl}A = \mbox{diam}A$ If $G$ is open set then for any $A$ we have $ \mbox{Cl}(G \cap A) = \mbox{Cl}(G \cap \mbox{Cl}A)$   My attempt:   $\mbox{Cl}A \subseteq \mbox{ClCl}A$ is quite easy by fact that $A \subseteq \mbox{Cl}A $. But I don't have idea how can I prove that $ \mbox{ClCl}A  \subseteq \mbox{Cl}A$   But the point 2. and 3. is for me too difficult. Could you give me some hints? Thanks in advance!


How to show multiple links (comma separated) in one cell of Lightning Datatable

Is it possible to add multiple links to a single Lightning Datatable cell. For example, as in the screenshot.    24 and 25 are different references that point to different records of the same object.  Now I use this code to display one link:  {label: 'Use Case', fieldName: 'Cases',  type: 'url', typeAttributes: {  label: { fieldName: 'CaseName' }, target: '_self' }, sortable: true }


I am trying to read from a URL but my program constantly gives me this error:  java.io.IOException: Server returned HTTP response code: 403 for URL: https://www.google.com/search?q=weather+in+seattle&oq=weather+in+sea&aqs=chrome.0.0l3j69i57j0l2.4686j0j4&sourceid=chrome&ie=UTF-8 at java.base/sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1913) at java.base/sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1509) at java.base/sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:245) at java.base/java.net.URL.openStream(URL.java:1117) at Main.main(Main.java:17)      Exception in thread "main" java.lang.NullPointerException       at Main.main(Main.java:25)   What must I do to fix this?


I have about two hundred bibtex references in my document. Sometimes I am browsing the references section and find something that I want to use again. Let's say there is an item like the following:  [45] Smith, John. Whatever paper, 2013   The problem is then which ID should I use in order to add another reference to the same paper? There are two ways to include such reference again:   Search for "Whatever paper" in the bibtex file and see that the ID is "smith2013.blablabla". Search for [45] on the generated PDF file, then find a text like "according to Smith [45]", then go to the TEX file and find "according to Smith \cite{smith2013.blablabla}".   This is obviously time consuming. It would be much better to see those IDs on the exported references:  [45] [smith2013.blablabla] Smith, John. Whatever paper, 2013   I only want to see this while I am writing the document, so it should be easy to remove those IDs when I generate the final version.


I really need some help regarding rendering a night scene. When i tick the denoising option. My render become ugly where there is a black dirt on the image. As in the image below.   And if i untick the denoising option. There will be a lot of noise in the scene.   How should i really render this kind of scene. Hope anyone can help me. And sorry for my bad english.


What provides the centrifugal force for planets orbiting a star?

this is a question I had when I was a kid. I'm a bit ashamed because I think I am missing out on something very obvious since I have the same question despite almost being an engineer now!  From Newtonian physics, I understand how although the gravitational force pulls the planet towards a star, and the planet 'falls' towards the star, due the angular momentum, it also moves laterally. In case of a planetary orbit, this is just enough to keep it moving around it in an elliptical orbit. (With speed and radius being such that angular momentum and energy is conserved)  But let's consider a single planet and star system where the planet moves around the star in a circular path for simplicity. If gravitational force provides centripetal force, what can account for the centrifugal force?  I have a feeling it is related to some inaccurate view I have, of centrifugal force. The  and  talk about two concepts: fictitious and reactive centrifugal force. But it would be safe to assume the star(EDIT: sorry, I meant to choose a frame of reference such that the centripetal force on the planet has to be cancelled by a centrifugal force on the planet in the direction: star to planet) as a stationary frame of reference for the purpose of this question, right? Which means that it is not a fictitious force, right? Or is it not considered a centrifugal force if you take the star as the reference frame?


A post that doesn't exist is shown on the "Top network posts" section on this user profile on English Language & Usage Stack Exchange

A post that doesn't exist is shown on the "Top network posts" section on this . The title is called "6", and the URL of the post leads to this .


Movie about teenagers who get abducted by aliens after they enter a house

There's this sci-fi movie I'm trying to find. I'm sure it's post 2010. Here's what I remember:  Group of teenagers enter a house and lose consciousness. They awake somewhere that looks Earth-like. One of them appears to have like a mechanical hand that has been surgically attached to his arm. This gives him super strength. They try to escape the facility they're being held in. Somewhere during the movie (possibly at the end), they break out and discover they're in space on some sort of spaceship.  On Google, I tried several combinations with "teenagers", "alien", "abduction", but for the life of me I can't find it.


Finite-dimensional Inner product space, if $A^{2}x=0 \Rightarrow Ax=0$

Let $X$ be a finite inner product space and $A:X\rightarrow X$ a linear   transformation. If $A$ is self-adijoint and if $A^{2}x=0$ then $Ax=0$.


How can we find factorials in decimal form?

I've heard of factorials such as $5!$ and $3!$, which work like this: $5!=5\times4\times3\times2\times1=120$ and $3!=3\times2\times1=6$.  At least this is what we get.  Also, surprisingly, $0!=1$, but how can we figure out values for factorials in decimal form such as $(2.5)!$ and $(3.34)!$?  Maybe we should use gamma for part of it?  What else?  I also know that we can draw graphs for factorials.  I just want to know how to find values for factorials in decimal form?


Ubuntu VPS CPUs sometimes go wild with a process I don't recognize

My VPS sometimes goes wild because of     /tmp/.X17-unix/.rsync/c/lib/64/tsm --library-path   /tmp/.X17-unix/.rsync/c/lib/64/ /tmp/.X17-unix/.rsync/c/tsm64 -t 302   -f 1 -s 8 -S 8 -p 0 -d 1   Any idea what it is and what does it do? And more important, how can I make sure it dosn't kill my VPS? Thanks  edit: after killing the pid and restarting the VPS, I'm now seeing 3 pids that kills my CPU with just "./cron" in the command.   I tried cd-ing into .X17-unix to see what's in there but it says the folder does not exist.  After killing the ./cron pid, it is quiet but I guess it will return at some point. The user is root so I can't kill this user, please help.


There are times where I want, say, a superscript $t$ to the left of another letter to denote, say, the transpose of a matrix. Or, I might want to decorate a letter on the left with a prime, $'$, because the right side is busy being decorated by another letter. Right now I use, $\left.^t M\right.$ and $\left.'E^r\right.$ which is inadequate because it introduces white spaces. How do I deal with this?


I know it is probably silly question but I did not found the answer. I use ubuntu 16.04 and the terminal colors are just black and white even if using ls ll etc. The .bashrc file doesn't contain any content about the terminal colors for some reason. How can I set the terminal colors to match those in 18.04 version? (green usr name blue current path colored folders files etc.)  I tried to change some things on the preferences menu but it didn't help to solve the issue.


Can't activate Windows 10 Pro with license linked to Microsoft account or product key

I'm trying to activate a new Windows installation using the digital license that's associated with my Microsoft account. On the old (activated) pc, I can go to the activation setting and see the "Windows is activated with a digital license tied to your Microsoft account" message.  On the new PC, if I log in with the same Microsoft account, Windows is not activated. I get the message that a valid product key has not been found (0xC004F213).  Using the trouble shooter, I get the message that Windows cannot be activated on this device. I then click "I recently changed the hardware for this device."  I then get a dialog showing me the device with the old motherboard. If I click "Activate", I get a simple "Windows cannot be activated" message.  If I go back to settings and try to change the product key, and enter the old pc's product key, I get an error that says the key is invalid (0x80041023).  I'm kind of at a loss now. How do I get this working?  Windows 10 Pro x64 was installed on both devices using the same USB drive.


Out of mere idle curiosity, what is the state of internationalizing the Stack Exchange engine and community creation process?  Specifically:   A fully localizable UI A crowdsourcing interface to get things translated (assuming that's the road that's going to be taken for translation - it would make little sense not to, though?) Guidelines for building non-English communities and applying the SE culture to those sites (well, or not)   The last time I asked this on the old Stack Exchange 1.0 Meta some time last year, this was planned, but not yet being implemented.


I wrote a review of the movie Detroit  and in the section What irked me about the film, I started in the following fashion: -  No doubt, Detroit is an engrossing flick, its greatest problem lied in the fact that it runs much longer than it should have.  A friend of mine pointed out that it should be lay instead of lied. I'm confused as to which form is correct and why? Thanks in advance for your help.


Querying and modifying TEXINPUTS from inside a latex file?

If I have images, or files that I \input or \include, I know I can use:  TEXINPUTS=/path/to/extra/dir pdflatex myfile.tex   ... to allow Latex to find files not present in subdirectories in the current directory.   But, I'd rather not use TEXINPUTS as an environment variable on the command line - I'd prefer if there was something like a \texinputs macro that I could read or append to from inside Latex, so I could write my file as:  \edef\texinputs{\texinputs:/path/to/extra/dir} \documentclass{...   ... and then just run pdflatex myfile.tex on the command line (and have everything work as expected).  Is there a way to do this in Latex (that is, from inside a .tex file being processed by Latex)? (I'm aware that I could write a shell script, but then I have an additional file to think of; I'm also aware I could use something like arara (?) for this, but let's say I don't have the time at the moment to acquaint myself with a new tool).


Regression residuals and their properties

The question is very basic. Which properties do we want to see in the residuals of a regression and why? To be more specific I mean the empirical residuals not the theoretical.


Partition recovery for NTFS partition with corrupted MFT

The affected SSD is removed from a laptop with 4 partitions to be used in an external enclosure, one primary partition (C:) cannot be found in Windows, but could be read in Ubuntu. After I was trying to fix it with TestDisk in Windows, now it cannot be found or read in Ubuntu as well. I don't know what I did with TestDisk but the MFT was corrupted per Chkdsk and could not be repaired.  I used active@ partition recovery demo edition and made a raw image of that partition on another HDD. The superscan on the original disk found that C: partition in a bad status with missing $MFT, $MFTMirror and other attributes but the superscan on the raw image found that C: partition in an excellent status with all the files that I can preview in binary form.   The C: drive is about 100G, Im tempted to purchase the full version of active@ partition recovery (btw, if you know a better alternative please let me know) to recover the partition from the raw image , but should I do it in place or on another HDD? And there are several things not that clear to me:   Does what has happened suggest there are physical damages on my original SSD? Should I stop working on it now to prevent further loss? the other three partition, two seem pretty normal, one is called "system reserved". I don't know if MBR should be on this partition  or the corrupted C:? I did managed to write booting information on both this partition and the C: with TestDisk that completely corrupted it. I'm still confused where should the MBR be. If it's on C: can the active@ partition recovery recover it? The active@partition recovery found loads of volumes (can post a screenshot later), except for the good C: that I can recognize and plan to recover, I don't know what to do with the rests. Some are with FAT boot sector which I wonder why, and named "EFIxxxx" , and loads are simply with bad sectors.


How to control two separate circuits with one switch?

I have two separate circuits with different types of diodes. One circuit draws 3,5V and the other draws 9V. How can I wire this up so that one switch can turn both circuits on or off? As far as I understand I can do this with a relay. What kind of relay would I use?  This is NOT a duplicate of former question    ...as some of the people here seem to believe.


A better way to say "to engage in double standard"

As is, it sounds a bit awkward to me.  Let me try to incorporate what I am after into a sentence. Just as Bush once said "If this were a dictatorship, it'd be a heck of a lot easier, just so long as I'm the dictator.", I would like to write something along these lines: "Double standard does not bother me for as long as I am the one engaging in/doing it".  It does not quite roll off the tongue. Hopefully there is a better way.


What force provide tangential velocity change in whirling block problem?

In whirling block problem as given below, I understand that Tension force is acting as central force in its motion so its angular momentum is conserved.  With time r will decrease if system is left isolated, and since angular momentum is conserved as r decreases its tangential velocity will increase. I want to know what force provides this change in tangential velocity of object.  I searched about this and found whats below but could not understand the tangential equation.


I am a Canadian with dual citizenship that left Canada without using my Canadian passport

I have dual passports, Canadian and Japanese. The last names on the passport are different, one being my Mom’s maiden name and the other my Dad’s.   I booked a flight to Japan from Canada using my Japanese passport which is in my Moms maiden name. I carried both passports but I did not have an opportunity to present my Canadian passport when I left Canada.   When booking the ticket, I entered my Japanese passport number and from what I’ve read on this forum the airline then notifies immigration that I have left the country. But as I never entered Canada using the Japanese passport in the first place does this cause any problems?  How should I book a flight back to Canada?  Any response is greatly appreciated!


Run 32bit applications on Windows 10 64 Bit

I've got a Windows 10 Computer (home edition), which has 4GB of Ram and an i5 processor. I need to run an old 32 bit accounting programme. The vendor said it won't release a 64 bit version (although a 64bit version exists, it's missing key features from the older version).  The programme installs fine, but when I click on the programme icon, it says the programme won't work on a 64 bit system.   What options do I have?    I've done a fair bit of research, but it seems to run up dead ends.   1) WoW64     Apparently, this is supposed to let you run 32 bits on 64 bit Windows. However, I am not sure how to install it. I think it's for web servers only. However,  says it can work on Windows 7, but doesn't explain how to set it up (or if it will work on Windows 10).  2) XP mode     A 32bit Windows XP emulator. However, it seems to be for Windows 7 only. Also according to this , you need Windows Professional.   3) Virtual Box Machine    Let's you emulate Windows. Seems overkill for my purposes. Plus I would need to buy a 32 bit Windows license. I think it would run slowly with 4GB of Ram.  4) Partition drive into 32bit and 64 bit versions Apparently, you can use the free tool  to split the drive into two and then install separate 32bit and 64 bit versions.   Again, seems overkill and it looks like I would need buy a 32 bit Windows 10 license.   Are these my only options?     Images  Installation    First run (From the error message I guess it's a 16-bit program)   Clicking on programme


I've installed Ubuntu 12.04 (near windows 7) on my laptop(Dell studio xps 1640 with Ati Radeon HD 3670) and everything is working fine, but when I want to shutdown my computer it freezes!  I don't know what to do after that, then I have to use power button to power off the computer and it's not good at all. I don't know what's the problem and I don't know how to figure this out.  I installed the graphic card driver (12.6 version) from ATI website and it fixed my problem with playing videos but I think after that this shutdown problem appears!  Would you tell me what's the problem and how can I fix it?


Argument principle on fourth-order equation

How many roots of the equation $z^4+8z^3+3z^2+8z+3=0$ lie in the right half plane?  The hint is to apply the . I am not sure how that will go. I can take $f(z)=z^4+8z^3+3z^2+8z+3$, so that for any closed curve $C$, $$\int_C\frac{f'(z)}{f(z)}dz=2\pi i(N-P)$$ where $N$ and $P$ denote respectively the number of zeros and poles of $f(z)$ inside the contour $C$. But here we are looking at the right half plane. I can't see how to apply the result from the argument principle.


Is there anyway to report undeleted accounts that are requesting deletion?

For example  has "please delete me" in user description and has been inactive for a while. Is there a way to remind an admin the owner of the account desires the account to be deleted?


Good afternoon,  The square root of $-1$, AKA $i$, seemed a crazy number allowing  contradictions as $1=-1$ by the usual rules of the real numbers. However, it proved to be useful and non-self-contradicting, after removing identities like $\sqrt{ab}=\sqrt a\sqrt b$.  Could dividing by $0$ be subject to removing stuff like $a\times\frac1a= 1$?  A way I can think of defining this is to have $\varepsilon=\frac10$. Remeber it may be that $\varepsilon\neq\varepsilon^2$, we don't know whether $\left(\frac ab\right)^n=\frac{a^n}{b^n}$, and other things alike; so they can't disprove anything.  This seems fun! What about defining a set $\mathbb E$ of numbers of form $a + b\varepsilon$? There would be interesting results as $(a+b\varepsilon)\times0 =b$.  Are these rules self consistent? Can such a number exist? If not, what rules can we change to make it exist? If yes, what can we find about it? How can it help us?   If there is no utter way of dividing by zero without getting a contradiction no matter the rules used, how can that be proven?


how to sort database records stored in array

i have stored the records from database in a array. Now i want to sort the array based on the price index and than print the result according.  Can any one help me with this?  Code i tried ..  <?php include('db.php');  $query = mysql_query("SELECT * FROM user");  $array = array();  while($row = mysql_fetch_assoc($query)) {   $array[] = $row;   $price[]=$row['price']; }  echo "<pre>"; print_r($array);   Output..  Array (     [0] => Array         (             [id] => 1             [name] => abc             [email] => abc@gmail.com             [contact] => 27488887             [price] => 12AED         )      [1] => Array         (             [id] => 2             [name] => siddharth             [email] => dgsfgsjkf@gmail.cm             [contact] => 7878787             [price] => 10AED         )      [2] => Array         (             [id] => 3             [name] => abc             [email] => def@gmail.com             [contact] => 4554545             [price] => 2AED         )      [3] => Array         (             [id] => 4             [name] => xyz             [email] => test@gmail.com             [contact] => 878778             [price] => 1AED         )      [4] => Array         (             [id] => 5             [name] => dandas             [email] => sdskagdsa             [contact] => 24221             [price] => 200AED         )      [5] => Array         (             [id] => 6             [name] => ass             [email] => asas             [contact] => 78787             [price] => 3AED         )  )   Now i want to sort the array obtained as output by price and then display the records..


I have a trigger on the Custom Object that calls a class. That class makes an HTTP GET request to a Web Service.  However I get the following error:  Callout from triggers are currently not supported.  How can I get data to an external Web Service using Apex code?  However i can use @future method but it can only be support void and this method cannot return results, i need to be able to send data to external ervice and receive acknowlegements from it.


A village has about $1$ million residents. Suppose each resident has a jar with $100$ coins in it.Two jars are considered to be “equivalent” if they have the same number of 10c, 20c, 50c, $\$$1 and $\$$2 coins in them. How many different (i.e. nonequivalent) jars of coins exist? Is it theoretically possible that every person in this village has a different jar of coins?  I understood that if we have $k_1$ 10 coins in the jar where $k_1$ is between $0$ and $100$ inclusive, then there are $100-k_1$ coins of other denominations in the jar. Likewise, we also have $k_2$ 20c coins in the jar where $k_2$ is between $0$ and $100$ inclusive, so the combined number of 50c, $\$$1, and $\$$2 coins in the jar is $100-k_1-k_2$. And we always have some $k_1, k_2, k_3, k_4, k_5$, let's say, so that the sum of those $k$'s is $100$.  I got stuck since I don't know how to 'compare' the number of coins in jars for different residents.


Why is df -h size, util and dispo not corresponding to each other

When I'm using the command "df -h" I'm having the following output :   Filesystem                 Size   Used  Avail Use% Mounted on /dev/mapper/fedora-root    20G    9,4G  8,8G  52% / devtmpfs                  1,9G       0  1,9G   0% /dev tmpfs                     1,9G    1,2M  1,9G   1% /dev/shm tmpfs                     1,9G    1,0M  1,9G   1% /run tmpfs                     1,9G       0  1,9G   0% /sys/fs/cgroup tmpfs                     1,9G    108K  1,9G   1% /tmp /dev/sda1                 477M    129M  319M  29% /boot /dev/mapper/fedora-home   916G    279G  591G  33% /home   Or it says my root is of 20G with 9.4 used and 8.8 still available it's 2G that disappeared. I know a very similar question as been answered here  and I'm just wondering if the reason could be the same here since I'm using LVM.  If not is there any way to reclaim that space that disappeared because for home there is an amazing 46G that disappeared.


Pointwise convergence on a complete metric space

Let $ f_n :X \rightarrow R $ be sequence of continuous function on complete metric space $(X,d)$, which convergence pointwisely to $ f: X\rightarrow R  $ mean that $ f_n(x)\rightarrow f(x)$ $ \forall_x \in X$      I have to prove that $\forall \epsilon$  $\exists n$ $\exists V\neq\emptyset$, $ V \subset X$ , so that $|f(x)- f_m(x)|<\epsilon $ for $x\in V$, $m>n$ and $V$ - an open set.    Fortunately I managed to do it using some inequalities and triangle inequality, but I also have to prove that the assumption of the complete metric space is necessary here. I have a hint that I should set $Q$ in a series, use $(Q,d_e)$ as a space then set a base $B_1,B_2 ...$  in $Q$ and finally define continuous function $f_n : Q\rightarrow\{0,1\}$ that $f_n(q_i)=0$ and $f_n ^{-1}(1) \cap B_i \neq\emptyset$ for $i\le n$.     Honestly I just don't know how to start so every piece of advice will be helpful.


I’m trying to scrap prices from various e-commerce site. However the IMPOrtxml function is not working  For instance,


I have dual American/French citizenship. I'm retired and live in France. My passports are both valid.  I will soon make a round-trip to the US and don't know which passport I have to show to police, customs.  I suppose that leaving France and entering the US I will show my US passport, but on my trip back to France, do I show my French passport - without or with an ESTA?  If it's without, police/customs might ask me how I entered the US without an ESTA.


QGIS Select By Location geometric predicates explanations?

Im trying to test if a polygon either a) touches or b) is only semi-contained by another polygon. The first is self-explanatory i guess, but the second could be many of the different predicates offered in QGIS.  I was therefore wondering if there are any more indepth explanations of the geometric predicates used in QGIS' select by location. (the only slightly basic explanation is  which doesn't give any real clue as to what the terms cover)


I am going to implement regex to catch url in strin. To do so, I have wrote regex expression but it only captures sub-part of expected input not all. How can I fix it so that it can catch all of the expected input and mark them as url?  expected input  ftp://joe:password@ftp.filetransferprotocal.com http://www.google.com/search?q=good+url+regex&rls=com.microsoft:*&ie=UTF-8&oe=UTF-8&startIndex=&startPage=1 https://some-url.com?query=&name=joe?filter=.#some_anchor www.some-url.com?query=&name=joe?filter=.#some_anchor www.some-url.edu?query=&name=joe?filter=.#some_anchor www.some-url.gov?query=&name=joe?filter=.#some_anchor www.some-url.co.uk?query=&name=joe?filter=.#some_anchor www.some-url.xxx?query=&name=joe?filter=.#some_anchor ww2.some-url.com?query=&name=joe?filter=.#some_anchor http://en.wikipedia.org/wiki/Björn_Andrésen   my code is \(?\bhttp://[-A-Za-z0-9+&@#/%?=~_()|!:,.;]*[-A-Za-z0-9+&@#/%=~_()|]


Multiplication cancellation property by Peano axioms

I am trying to prove cancellation property of multiplication of natural numbers, $xy=xz$ implies $y=z$, with Peano axioms and arithmetic but not using or defining order on natural numbers. It can be done for addition. But for proving multiplication cancellation property one uses order. Why is that so?


How can I use covariant return types with smart pointers?

I have code like this:  class RetInterface {...}  class Ret1: public RetInterface {...}  class AInterface {   public:      virtual boost::shared_ptr<RetInterface> get_r() const = 0;      ... };  class A1: public AInterface {   public:      boost::shared_ptr<Ret1> get_r() const {...}      ... };   This code does not compile.  In visual studio it raises     C2555: overriding virtual function return type differs and is not   covariant   If I do not use boost::shared_ptr but return raw pointers, the code compiles (I understand this is due to  in C++). I can see the problem is because boost::shared_ptr of Ret1 is not derived from boost::shared_ptr of RetInterface. But I want to return boost::shared_ptr of Ret1 for use in other classes, else I must cast the returned value after the return.      Am I doing something wrong?  If not, why is the language like this - it should be extensible to handle conversion between smart pointers in this scenario? Is there a desirable workaround?


Parallel execution does not increase performance

I would like to parallelize finding minimal element and its index in array. My idea was to split my array into smaller parts and to process them separately, then I just choose the least element (because I get minimal elements for each part of array). The code below works just fine, but I'm confused with execution time. Sometimes parallel implementation runs even longer than single-threaded. I have two threads on my system. What's wrong with my code? package lab4; import java.util.ArrayList; import java.util.List; import java.util.concurrent.*;  public class Main {     public static class MyPair {                  public Double val;         public Integer pos;                  public MyPair(Double v1, Integer v2) {                      this.val= v1;             this.pos= v2;          }      }          public final static int ARR_LEN=100000000;          static double get_random(double a, double b)     {         return ThreadLocalRandom.current().nextDouble(a, b+1);     }      static void minElem(double[] mas) throws InterruptedException, ExecutionException     {      int n=Runtime.getRuntime().availableProcessors();      ExecutorService executor = Executors.newFixedThreadPool(n);      int step=ARR_LEN/n;      List<Future<MyPair>> tasks = new ArrayList<>();      for(int thread=0; thread<n; thread++)      {         int a=thread*step;         int b=a+step;         tasks.add(executor.submit(new Callable<MyPair>() {                 public MyPair call() {                     int local_min_index=-1;                     double local_min_value=Double.MAX_VALUE;                     for(int i=a; i<b;i++)                         {                         System.out.println(Thread.currentThread().getId());                             if(mas[i]<local_min_value) {                                 local_min_value=mas[i];                                 local_min_index=i;                             }                          }                     return new MyPair(local_min_value, local_min_index);                 }              }));      }      MyPair res=new MyPair(Double.MAX_VALUE, -1);      for(Future<MyPair> task: tasks)             {                 MyPair temp=task.get();                 if(temp.val<res.val) res=temp;             }      System.out.println("multi-thread min-value: "+res.val);      System.out.println("multi-thread index: "+res.pos);      return;     }          static void minElem_single(double[] mas)     {      double min_value=Double.MAX_VALUE;      int min_index=-1;      for(int i=0; i<ARR_LEN; i++)         {             if(mas[i]<min_value) {                 min_value=mas[i];                 min_index=i;             }         }      System.out.println("single-thread min-value: "+min_value);      System.out.println("single-thread index: "+min_index);      return ;     }          public static void main(String[] args) {         // TODO Auto-generated method stub         double[] mas = new double[ARR_LEN];         double n1=0,n2=0,n3=0;          for(int i=0; i<ARR_LEN; i++)             {                 mas[i]=get_random(-776.998, 509.667);             }          try {              n1=System.currentTimeMillis();             minElem(mas);             n2=System.currentTimeMillis();           } catch (InterruptedException e) {             // TODO Auto-generated catch block             e.printStackTrace();         } catch (ExecutionException e) {             // TODO Auto-generated catch block             e.printStackTrace();         }               minElem_single(mas);          n3=System.currentTimeMillis();          System.out.println("multi-threaded time is: "+(n2-n1));          System.out.println("single-threaded time is: "+(n3-n2));         return;     }  }


$\sum|a_n|^2<\infty$ and $\sum a_n<\infty$ implies $\sum\log(1+a_n)$ converges

Note that all elements are complex numbers. Suppose we know $$\sum_{n=1}^\infty|a_n|^2\quad\text{and}\quad\sum_{n=1}^\infty a_n$$converge. How can we conclude $\sum_{n=1}^\infty\log(1+a_n)$ converges? This is an effort to prove that $$\prod_{n=1}^\infty(1+a_n)$$converges.  If I knew that $\sum a_n$ was absolutely convergent, then I think I'd be able to use the power series expansion of $\log(1+a_n)$ and interchange summations. However, I don't think this is the intended method of solution. Will someone help me with this homework problem?  Update: Other work I've done so far:  Disregarding finitely many terms if necessary, we can assume $|a_n|<\frac{1}{2}$ for all $n$. Thus, we know $0\leq|a_n-\log(1+a_n)|<|a_n|^2$, so by comparison, we know $\sum_{n=1}^\infty |a_n-\log(1+a_n)|$ converges. Since it is absolutely convergent, it is convergent, so now we have $$\sum_{n=1}^\infty a_n-\sum_{n=1}^\infty\left( a_n-\log(1+a_n)\right)=\sum_{n=1}^\infty\log(1+a_n),$$therefore the series is convergent. Is this correct?


What is regressive about a regression line?

I know what a regression line is.    What I'm curious about is the use of the word "regression".  What's regressive about a regression line?   The etymology of  is      early 15c., from Latin regressionem (nominative regressio) "a going back, a return," noun of action from past participle stem of regredi).   So, how is a regression line a "going back, a return"?


Print acronym + full name in brackets at the first occurence of \ac{XYZ}

I am using the acronym package and have the following problem: In my document, I always want to use \ac{...} for my acronyms, so I don't have to care about whether I already mentioned the full name of the acronym or not. \ac{...}'s default behavior is that it prints the full name and the acronym in brackets when the acronym is mentioned the first time (Example: \ac{HTML} is printed as "HyperText Markup Language (HTML)"). The next time I use it, only the acronym gets printed.  This is okay in most cases. But for some acronyms, like "HTML", it would be better to have the acronym first and the full name in brackets, like "HTML (HyperText Markup Language)". I can achieve this if I write \acs{HTML} (\acl{HTML}), but then I can't use \ac{HTML}, because the next time it will print the full version + acronym in brackets again ;)  Is there any way to reverse the full name and the acronym at the first time \ac{} is used (or is there an alternative command to achieve this)?  I know that it seems to be possible with the glossaries package (see ) but the solution provided there is applied to all acronyms, not only to some of them. Also I would like to keep the acronym package if possible.