I'm writing a systemd timer. What value should I use for WantedBy?

In various examples, I have seen all of these different choices suggested:   WantedBy=timers.target WantedBy=multi-user.target WantedBy=basic.target WantedBy=default.target WantedBy=mytimer.target (custom user-defined name)   However, in the examples I have found, no further explanation is offered.  The following pages also don't offer any explanation of WantedBy:       I want to understand one simple* method I can use when needed to write a systemd timer instead of a cron job.   * Setting up a cron job is 1 line. Systemd timers involve writing two files and running one or two systemctl commands. But that fact alone is not necessarily what makes systemd timers harder than cron in my experience -- it's the multitude of options and the (seeming) lack of clear documentation with simple examples that are fully explained.


Suggested Edits Dashboard doesn't agree with Suggested Edits view

I recall :    It was one that I knew could use a bit more spit and polish, but I didn't have the inclination or energy to edit it myself, so I skipped it.  I wander my way over to  (10K only), and look at the listing...    ...so, when did I approve this again? I skipped the question; that doesn't mean I gave my tacit approval, does it?  Seems like the dashboard needs to agree with the suggested edits view.


Strange shading on surface. Normals facing right way, no double faces, no double vertices

I can't find the solution to this one; I don't know the correct name of the problem. The shading is different on parallel faces facing the same direction.    I've tried:  - Recalculating Normals  - Removing doubles  - Tried smooth and flat shading  - Deleting and remaking faces  - Adding Edge Split modifier  Any ideas? Thanks  Edit: Link to .blend:


Why have deep neural networks risen in popularity?

Why we tend to design more deep neural network instead of shallow?


Fatal error: Uncaught mysqli_sql_exception: Incorrect integer value: '' for column `id16714481_casestudy_db`.`users`.`verified` at row 1

I don't understand why this is happening even though I have classified $verified as a boolean on my bind_param.     $sql = "INSERT INTO users (user_name, email, verified, token, password) VALUES (?, ?, ?, ?, ?)";     $stmt = $conn->prepare($sql);     $stmt->bind_param('ssbss', $username, $email, $verified, $token, $password);


How does the Earth have enough gravity to hold on to its atmosphere?

I'm looking for numbers/math that describe how earth (or any other planet) holds on to it's atmosphere.  Presumably, we would be able to determine the exact atmospheric pressure that we would expect to have on a planet of a given radius/mass/density, assuming that we start with infinite amount of atmosphere in which most of it disperses till we get into an equilibrium.


I have over 6000 records and half of them are formulas that are missing a variable so they result in #N/A on the spreadsheet, what i want to do is if the cell is #N/A then leave the cell blank, otherwise print a string like so  =IF(AR6347="#N/A","","string in here")   But this does not work with ="#N/A", is there a way to do this?


How does the Commander interact with Banishing Light or Oblivion Ring?

What happens if a commander is sent to the command zone via  and then enchantment is destroyed? Can the commander return to the battlefield from the command zone?.  I think that  would not allow that to happen.


question mark show like "????" instead persian character from php or mysql...!

excuse me...! my english is not very good! until last week i'm use "www.000webhost.com" webhost and i had no problem!!! But today I bought a new server and use old file like before... I dont know the problem is from php files or database?  Please show me the solution  this my php code      <?php      //Creating a connection     $con = mysqli_connect("___","___","___","___");      if (mysqli_connect_errno())     {        echo "Failed to connect to MySQL: " . mysqli_connect_error();     }     /*Get the id of the last visible item in the RecyclerView from the request and store it in a variable. For            the first request id will be zero.*/       $id = $_GET["id"];      $sql= "Select * from db_app where id between ($id+1) and ($id+10)";      $result = mysqli_query($con ,$sql);      while ($row = mysqli_fetch_assoc($result)) {          $array[] = $row;      }     header('Content-Type:Application/json');      echo json_encode($array);      mysqli_free_result($result);      mysqli_close($con);   ?>   this my database code      CREATE DATABASE `android_db`;  USE `android_db`;   CREATE TABLE IF NOT EXISTS `db_app` (   `id` int(15) NOT NULL AUTO_INCREMENT,   `movie_name` varchar(45) NOT NULL,   `movie_image` varchar(10000) NOT NULL,   `movie_genre` varchar(40) NOT NULL,   PRIMARY KEY (`id`) );


A friend asked me to develop a logo for his wife's hair salon. Originally I worked with just text, but she said she definitely wanted scissors as part of the logo, so I built in the the H + D (hair daun) in to the scissors but originally mirrored so that when the girls has the logo on their uniforms, the logo would then appear correctly. So we went for the normal look.  Today, however, a local business in their hometown has told them that I have stolen the logo from his site, made a few minor adjustments to make it appear as if it is a custom logo.   I had no idea the company existed until an hour ago, and I am really confused as to where the comparison has come from.  My Logo       Supposed Stolen Logo


If $F_n$ is the Fibonacci sequence, show that $F_n < \left(\frac 74\right)^n$ for $n\geq 1.$

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


Why do I have to use law of conservation of energy to solve problems regarding calculation of extension in spring length when a box attached to the lower end of the spring is released from rest (such that the spring was in it's natural length initially) and allowed to fall under gravity? I mean why can't I just simply use $x = mg/k $?


How to prove this :$\left(\cfrac{1}{2}\right)! = \cfrac {\sqrt {\pi}}{2}$?

$\left(\cfrac{1}{2}\right)! = \cfrac {\sqrt {\pi}}{2}$  I saw this in a math book. I tried to prove it but I'm unable to. Any hints or solutions would be most appreciated.


My account was banned after I asked 6 questions since early August, three of which were edited by a staff-like person. I only posted some error messages and code that is not working for the CS50 course, and I have no idea what was wrong with this. I edited some of the questions after being banned, so can I now have the ban lifted?


How do I avoid paying for an item that I was refunded for on a credit card when the payment due date is coming up?

I purchased an item which the merchant then refunded to my credit card. However, the payment due date is coming up, and my credit card has still not been credited with the refund on my credit card statement.  What can I do to avoid paying for the item that I was already refunded for?


When creating an object (prior to ES6) one could instantiate an object like so...  var Animal = function(){}   and then  var dog = new Animal();   ...  Inside the animal "class" one can add...  var Animal = function( name ){     this.constructor.prototype.name = name;  }   The question is basically, what is the difference between using the regular this in oppose to using this.constructor.prototype  var Animal = function( name ){     // what is the difference between this    this.constructor.prototype.name = name;     // and that    this.name = name;  }   I know this kind of basic, if anyone would care to explain. Thanks in advance!


how do i change the color to individual body parts?

i am following the complete beginners guide 2.8 on youtube but when he changes the color of the guys legs and hands, on mine it is all linked to the same color and i dont know how to fix it. top picture is the video and bottom is what i did. first time ever on blender


Is there any reason we shouldn't let posters self-delete closed questions immediately?

It's been brought to my attention that since the  rolled out, there's a seeming inconsistency when you want to delete your own (non-negative-scored) question   You can always delete your own, unanswered, open question, but You cannot delete your own, unanswered closed question for two days after closure   This seems illogical; if anything, others having closed a question would seem to make it a better candidate for self-deletion, not worse.  And given that one of the window's main goal is to ensure the OP has a chance to clarify or improve, I don't see much point in blocking it.  Am I missing anything obvious?  EDIT: It appears that this issue pre-dates the changes - before, the same seeming inconsistency existed for users without deletion privileges; now it exists for everyone.  Also, I stink at finding dupes.


Username not changed when question is made Community Wiki

I was recently browsing through Meta, when I came across  which was made a Community wiki. When I was looking through it, I realized that the user who had asked the question, () had changed his username from "Sonic the Masked Werehog" to "Sonic the Curiouser Hedgehog" (presumably) after the question that they asked was made Community Wiki.  Is this a bug? or a feature that was left as-is like the "feature" that usernames mentioned in comments do not change after the user has changed their name?


Identifying students' purposes and institutions' purposes

I don't necessarily consider it a hardship to teach calculus or the like to students whose preparation in prerequisites is weak, but but I am offended by the practice of making it a personal policy to treat learning the material ONLY as a price paid to get a grade to put on one's resume, rather than as the thing they're there for.   I'm wondering how to identify instances of such behavior quickly when they occur. How can one identify institutions that tolerate or encourage my position as outlined in my first paragraph above, and those that are hostile toward it?  I think the latter---where that hostility may exist---often include respectable institutions in which lots of students want to get degrees in law or business or the like.


Changing background color to transparent in GeoServer?

How to set the background color to transparent. I want use style which describe in *.sld file for all my photo with tif format. How to do that?


I was playing a round of firestarter, on the day 3, full team We did it all stealthily and burned the money.  One guy started to sawing the boxes but next thing I knew all the boxes popped open.  One of the guys claims that in mastermind there is a hidden skill that makes unlocking one box opens all the others.  Is it actually a skill or was it a glitch or something?


A polynomial $\ f(x)$ has integer coefficients such that $\ f(0)$ and $\ f(1)$ are both odd numbers. Prove that $\ f(x) = 0$ has no integer solutions.

Let there be a  polynomial $\ f(x)$. It has integer coefficients such that $\ f(0)$ and $\ f(1)$ are both odd numbers. Prove that $\ f(x) = 0$ has no integer solutions.


Which is correct? Everyone here at xyz wish you a happy holiday or  everyone here at xyz wishes you a happy holiday?


I've always wondered who vacuumed the corridors or did other cleaning/housekeeping kinds of duties in common areas of the Enterprise or other Galaxy-class/large ships. Especially in TNG, the ship has civilians providing services for the crew, such as a bartender and a barber. So is there any canon references of having a janitor or other civilians providing services like this?


I have a list of this type :  l = [{"id":"21", "region" :['2', '6', '4']}, {"id":"12", "region" :['1', '3', '8']}]   I want to sort the list on the "region" field, and that also at 2nd index. that is :  l = [{"id":"21", "region" :['2', **'6'**, '4']}, {"id":"12", "region" :['1', **'3'**, '8']}]   How do I do it ? I am aware of itemgetter. But couldn't do with that also.


Why is the gravitational force $10^{38}$ times smaller than the strong nuclear force?

Also, why is the weak interaction force $10^7$ times smaller than the strong nuclear force?


Adding tags to files in OS X: How to use, where are tags stored, and will they work on a network?

I've heard it is possible to add tags to a file's meta data in OS X, and have Spotlight search through such tags.   In a nutshell, how would one access this feature in Finder – not Spotlight (Command+Space) – but the adding of tags themselves? Where are these tags stored?  Do they go in .DS_Store (I tend to delete those!) or elsewhere in the filesystem? Does this tagging mechanism work on removable drives?  What are the requirements? Does this tagging mechanism work over a network share?  I have some Windows SMB network shares at home that I frequently store files on.  Would it work on those or is another configuration required? Aside from Spotlight, are there any command-line tools for searching through or accessing the tag data for files?   Thank you!


Show that $E[u(X_1)\mid\sum^n_{i=1}X_i=z]=\Phi \left( \frac{\sqrt n(c-z/n)}{\sqrt{n-1}} \right)$

Let $X_1, ..., X_n$ be a random sample from the $N(\mu,1)$ distribution. First show that $$E \left[ u(X_1)\, \Big|\, \sum^n_{i=1}X_i=z \right] = \Phi \left( \frac{\sqrt n(c-z/n)}{\sqrt{n-1}} \right)\,,$$ where $u(x)=1$ if $x\leq c$ and $0$ otherwise, and $\Phi(x)=P(Z\leq x)$ where $Z$ is $N(0,1)$ distributed. Then secondly determine the MVUE for $\Phi(c-\mu)$ and compare with the MLE of $\Phi(c-\mu)$ for large $n$.   Please could someone point me in the right direction on this question? I'm not sure where to start on the first part. There is a hint in the question that integration by substitution might help, but I can't even see where integration comes into it. Are there any similar questions out there that you could point me to?  For the second part, I know that a MVUE must attain the Cramer Rao lower bound, but because it's a follow on question from the first part I'm pretty stuck on this as well.   Please could you help get me going or explain to me the process that I need to follow. I'm not looking for someone to tell me the answer - just give me a push to help me get going!  (It may not be relevant, but this question is just a bit from a much bigger question. I've already successfully shown that the MLE of $\mu$ is just the sample mean).


Let $ {a_k}$ be an unbounded,strictly increasing  sequence of  positive real numbers and $x_k=\dfrac{a_{k+1}-a_k}{a_{k+1}}$. Prove that $\sum_{k=m}^n x_k>1-\dfrac{a_m}{a_n}\forall n\geq m $ and $\sum_{k=1}^\infty x_k$ diverges to $+\infty.$  What I thought: $\sum_{k=m}^n x_k=\sum_{k=m}^n(1-\dfrac{a_k}{a_{k+1}})$  As $0<\dfrac{a_k}{a_{k+1}}<1$,taking $\dfrac{a_k}{a_{k+1}}=1-\dfrac{1}{k}$ for each $m\leq k \leq n$.  But i cant carry it more .Please help me.


C# Regular Expressions with \Uxxxxxxxx characters in the pattern

Regex.IsMatch( "foo", "[\U00010000-\U0010FFFF]" )    Throws: System.ArgumentException: parsing "[-]" - [x-y] range in reverse order.  Looking at the hex values for \U00010000 and \U0010FFF I get: 0xd800 0xdc00 for the  first character and 0xdbff 0xdfff for the second.  So I guess I have really have one problem. Why are the Unicode characters formed with \U split into two chars in the string?


When we push on a wall, why isn't there any work done?

I have seen  on the site, but that was kind of different in its essence — it was aimed at asking the solution of a particular problem, while I am having trouble conceptualizing the idea of Work. Here's my understanding —  If I push a wall, it doesn't move. There is no displacement; but I DO lose some energy — a force will be applied. The wall does not move because the force that is applied is not sufficient to overcome the 'adhesive' or 'structural' forces there are at the edges of the wall and keep the wall joined to the house. Had they (and friction) not been there, the wall would have moved (though slightly). Does it not then follow that I am indeed doing work on the wall, but it simply doesn't move because other forces are doing work on it too, and my work is not enough to overcome them? It would then be reasonable to say that no net work is being done on the wall, but I see everyone saying that I, for myself, will not be doing any work at all because I will not be displacing the wall, in such a scenario.  What's wrong with my understanding?


Anyone: ("they" or "he/she") why is it sometimes plural?

Possible Duplicate:    Plural versus singular:  Anyone can learn to dance if they want to. Anyone can learn to dance if he or she wants to.  Resources online tell me that anyone is a singular indefinite pronoun. Then why is it sometimes acceptable to use the plural 'they' with 'anyone' in some cases? Does it substitute and replace 'he/she'? note: this previous posts also says anyone is [singular]:


Why do I need to use "Android File Transfer" to transfer files from my mac?

I'm curious as to why I need to download and use 'Android File Transfer' so that I can transfer files from my mac to my nexus 5. I assumed because they had a similar file structure that viewing files on one from the other wouldn't have been an issue.


How to add photo over another photo in html

how can I add picture over another picture like this:   Here is my HTML code:

Начало За нас Промоции Контакти

Веднъж хапни, за цял живот се пристрасти!

   and CSS code:  .container-fluid {      height: 470px;     background-image:linear-gradient(to bottom, black, black, transparent 70px, transparent 330px, black, black 500px),url("images.jpg");     background-size: 100% 100%;   }


I am aware flash is EOL. However, I need it for . according to  however trying to use flash results in "Right Click to enable Adobe Flash". when I do that it does nothing.  Edit: I have chromium Version 73.0.3683.103 (Official Build) Built on Ubuntu , running on Ubuntu 19.04 (64-bit) and  says Yes Flash 32.0.0 is installed in this browser  Edit 2: about:components does not have flash recognized.  in chrome it looks like   something about the sandbox broke it. --no-sandbox "fixed it"


Accidentally deleted the Downloads folder, a windows "Special Folder", how to restore?

I deleted the Downloads folder in my Windows 7 home directory (which I had moved and renamed to incoming)  I was able to restore the folder from a backup, this restores the contents as well as Desktop.ini (hidden) that gives it the right folder icon within the home directory.  However, right clicking does not show the "Location" tab, indicating that Windows doesn't recognize it as the special downloads folder. By Location tab I mean the tab that allows moving the location of the folder (try this on My Pictures, etc.). Until I see this restored I assumed Windows isn't aware that this is in fact my Downloads folder.  How to fix this?


side effect of caption package with custom counter

--- update ---  Any comments, is this a bug in the caption package or do have have to protect \refstepcounter somehow?  --- \update ---  I have the following MWE:  \documentclass{book}  \usepackage{xparse} %\usepackage{caption}  \newcounter{mycounter} % make a counter \setcounter{mycounter}{0} % init the counter  \NewDocumentCommand \mymark {} {% \refstepcounter{mycounter}% \textsuperscript{\themycounter}}  \begin{document} % one\mymark  \begin{figure} \caption{two\mymark} \label{lab:1} \end{figure}%  three\mymark  \end{document}   without caption package it produces    but if I add the package    Why is the numbering incorrect?


How to generate random numbers from 1-99 range in Objective-C?

This is my code for generating random numbers from 1-99, but it's only generating same set of numbers (15 numbers) every time. I'm storing those numbers in an NSArray and getting output in NSLog properly. It's ok, but I want different set of random numbers with no repeated number whenever I call this random method. Can any one help me please?   -(void) randoms {      myset=[[NSArray alloc]init];     int D[20];     BOOL flag;     for (int i=0; i<15; i++)     {         int randum= random()%100;         flag= true;         int size= (sizeof D);          for (int x=0; x<size; x++)         {             if (randum == D[x])             {                 i--;                 flag= false;                 break;             }         }          if (flag) D[i]=randum;      }     for (int j=0; j<15; j++)         {         myset=[myset arrayByAddingObject:[NSNumber numberWithInt:D[j]]];         }      NSLog(@"first set..%@",myset.description); }


Google is showing only one result of Stack Overflow (per query) for the last 2 days?

I typically use Google to search answers for my questions on Stack Overflow. Sorry to state that Stack search is not as powerful as Google and hence I typically rely on Google.  For that last 2 days, Google is showing only 1-2 result from Stack Overflow, where earlier it would show around 8-10 results. Changing queries in Google also gives the same result. Sometimes, more frustratingly, it shows 2 results, both of which are the same!  What has happened here? Is it some sort of strategy from Google to prevent traffic flow to Stack Exchange?  Anyone else facing this or is it only me? It is driving me nuts and hence this is my first question on this particular forum; please correct me if this is not the correct place to post this.    Here is another case where two results are exactly identical:


Relation between codimension and generic point

I don't know how to solve the following exercise, which is stated in Vakil's The Rising Sea: Foundations of Algebraic Geometry:     11.1.I. EXERCISE. Show that if $Y$ is an irreducible closed subset of a scheme $X$, and   $\eta$ is the generic point of $Y$, then the codimension of $Y$ is the dimension of the local ring $\mathscr{O}_{X,\eta}$.   The result is general, so I want to prove directly by definition but failed. I've also thought about proving by affine case, but I don't know the relation of codimensions if reduced to affine case.  Can anyone give me a solution?


Field status need to select dynamically from child to parent object

RE: Here Opportunity and section are in master detail relationship.  Section status is a picklist field in section object with values are'1-won','2-In-market','3-Won/Mandated','4-Issued Commitments','5-Pipeline','6-Proposal Pending Risk Appr','7-Proposal Early Stage' Requirement scenarios    Opty got too many sections  Need to show in opty record with section status picklist value(i.e, based on priority) eg: from section records descending order value need to pick from section status and update in opty. suppose that record gets deleted then next descending order value need to be update in opty. For this I created a statusupdate custom field in Opty.   help me for coding logic like querying and update functionality.  for this just give idea like how to map with opty and section and querying and update functionality.. –


How did Kirito bring back Yui when she was deleted by Cardinal SAO? I honestly don't understand this.


Continuously copy all file changes from one folder to another on change (Windows)

I'm working on a massive Java web application which is kept under centralized version control, but the source files are used to build and run the actual server, which then copies all the files I work on into a random temporary directory while it's running.  My problem is that I need to either rebuild this huge application to see any changes to my files, or keep track of all my changes and copy over the files I've changed back to their source location before committing them back to source control.  My question is: is there a command line script I can run that will monitor any changes in the source folder and automatically copy changed files across to temporary folder X?  The idea is to remove the human point of failure in having to manually mitigate the two-locations problem.


Ubuntu 18.04 Server unable to see Windows 10 OS as dual boot

My machine config:     Threadripper 1950x 16-core  +  Gigabyte X399 aorus 7      32GB DDR4      Samsung NVME 960 512GB      UEFI mode with GPT partition scheme   Windows 10 Pro + Ubuntu Server 18.04 LTS  I previously had Windows 10 + Ubuntu 16.04 Server as dual boot and I never had any problems.  What I did so far:  1) I Installed Windows 10 x64 Pro (1803) on my machine - no problems  2) I tried to install Ubtunu 18.04 Server as dual boot but it did not detect existing windows OS. Tried multiple boots but no luck so finally installed Ubuntu causing windows wiped out  3) Then I installed Windows 10 (as dual boot) without disturbing Ubuntu partitions. No problems  4) Now only windows 10 boots so I followed  and fixed the issue but now Only Ubuntu boots  5) Then I followed   but it STILL does NOT detect Windows 10 OS but I can mount the windows  partition on Ubuntu. os-prober also sees the Windows OS but grub doesn't! Please see below and advise, Many thanks!  root@ubuntu18:~# mkdir -p /media/windows root@ubuntu18:~#  fdisk -l /dev/nvme0n1 Disk /dev/nvme0n1: 465.8 GiB, 500107862016 bytes, 976773168 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: gpt Disk identifier: 01BADB0F-4C8E-4332-BA18-822F08CE451B Device             Start       End   Sectors   Size Type /dev/nvme0n1p1      2048   1050623   1048576   512M EFI System /dev/nvme0n1p2   1050624 361760767 360710144   172G Linux filesystem /dev/nvme0n1p3 361760768 370149375   8388608     4G Linux swap /dev/nvme0n1p4 370149376 370182143     32768    16M Microsoft reserved /dev/nvme0n1p5 370182144 976773119 606590976 289.3G Microsoft basic data root@ubuntu18:~# root@ubuntu18:~# mount -t ntfs-3g /dev/nvme0n1p5 /media/windows/ root@ubuntu18:~# os-prober /dev/nvme0n1p1@/EFI/Microsoft/Boot/bootmgfw.efi:Windows Boot Manager:Windows:efi root@ubuntu18:~# update-grub Generating grub configuration file ... Warning: Setting GRUB_TIMEOUT to a non-zero value when GRUB_HIDDEN_TIMEOUT is set is no longer supported. Found linux image: /boot/vmlinuz-4.15.0-20-generic Found initrd image: /boot/initrd.img-4.15.0-20-generic Adding boot menu entry for EFI firmware configuration done root@ubuntu18:~# df -h Filesystem      Size  Used Avail Use% Mounted on udev             16G     0   16G   0% /dev tmpfs           3.2G  1.6M  3.2G   1% /run /dev/nvme0n1p2  169G  1.7G  158G   2% / tmpfs            16G     0   16G   0% /dev/shm tmpfs           5.0M     0  5.0M   0% /run/lock tmpfs            16G     0   16G   0% /sys/fs/cgroup /dev/loop0       87M   87M     0 100% /snap/core/4486 /dev/nvme0n1p1  511M   29M  483M   6% /boot/efi tmpfs           3.2G     0  3.2G   0% /run/user/0 /dev/nvme0n1p5  290G  187G  104G  65% /media/windows   but no luck, Please advise.


Question about coding rarity and non-MonoBehaviour referencing

I have a non-MonoBehaviour script called Item which contains two classes.  public class Item {     public string itemName;     //public string itemRarity;      public Item(string newItemName)     {         itemName = newItemName;     } }   and  public class ItemRandomizer {     List<Item> itemContainer = new List<Item>();      public void AddItem(Item item, int amount)     {         for (int i = 0; i < amount; i++)         {             itemContainer.Add(item);         }     }      public Item GetRandomItem()     {         int index = Random.Range(0, itemContainer.Count);          // want to return item combined with rarity         return itemContainer[index];     }   I want GetRandomItem to not only return a random item "type", e.g., gloves, contained in the itemContainer list, but also combine it with a rarity (common, rare, legendary) and return that if possible.   How can I code this functionality in a flexible way so that two base items with the same drop chance can have varying drop chances when it comes to their rare versions? Swords and axes have the same drop chance, but a rare sword might be rarer than a rare axe. I'd like to maintain that kind of flexibility.  Also, if I make public string itemRarity a property of the Item class, but I want to set the rarity tier in GetRandomItem() in the ItemRandomizer class, how should I do that? Thus far, I've almost exclusively used MonoBehaviour classes so any pointers are appreciated.


How to setup pulsaudio to stream to other pc?

I have two identical machines running ubuntu 15.04. I want to stream audio from one machine to the other.  I have followed this thread to setup my client and server.   The problem is that the server is not discovered and doesnt show up in sound settings.  Suggestions?


How can Print Preview be called from Javascript?

I have a page that is supposed to launch the Print Preview page onload.  I found this:  var OLECMDID = 7; /* OLECMDID values: * 6 - print * 7 - print preview * 1 - open window * 4 - Save As */ var PROMPT = 1; // 2 DONTPROMPTUSER var WebBrowser = '<OBJECT ID="WebBrowser1" WIDTH=0 HEIGHT=0 CLASSID="CLSID:8856F961-340A-11D0-A96B-00C04FD705A2"></OBJECT>'; document.body.insertAdjacentHTML('beforeEnd', WebBrowser); WebBrowser1.ExecWB(OLECMDID, PROMPT); WebBrowser1.outerHTML = "";   But...   it does not work in FireFox. it's kind of ugly.   Is there a better way for IE or a way that works for FireFox?


"Host key verification failed" error when transfering files using SCP command

When I am trying to transfer files using SCP command I'm getting this error (Removed my IP and RSA key):  @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY! Someone could be eavesdropping on you right now (man-in-the-middle attack)! It is also possible that the RSA host key has just been changed. The fingerprint for the RSA key sent by the remote host is ------------------------(RSA key) Please contact your system administrator. Add correct host key in /home/users/myaccount/.ssh/known_hosts to get rid of this message. Offending key in /home/users/myaccount/.ssh/known_hosts:4 RSA host key for 'my IP' has changed and you have requested strict checking. Host key verification failed. lost connection   I am using newly installed Ubuntu 12.04 and I can connect to this server using ssh. Any help?


why are my hair strands coming from the bottom of my donut and not the top

why are these hair strands coming from the bottom and not at the top of the icing


C#: Difference between ' += anEvent' and ' += new EventHandler(anEvent)'

Take the below code:  private void anEvent(object sender, EventArgs e) {     //some code }     What is the difference between the following ?  [object].[event] += anEvent;  //and  [object].[event] += new EventHandler(anEvent);   [UPDATE]  Apparently, there is no difference between the two...the former is just syntactic sugar of the latter.


electric chewing gum prank circuit diagram

I'm new to electronics. I'm trying to find out how this works out of curiosity.  Does anyone have a circuit diagram for the circuit? Is the current safe for such a prank? Internal picture:   EDIT: Merged  Help here would be greatly appreciated: This question has been asked several times on this site and elsewhere, and it seems as if the posters became satisfied with inaccurate answers. How on earth do the electric shock prank pens/bubble gum work? I have no intention of shocking anybody or recreating this circuit, I am simply baffled by how it operates. I have verified that all purported explanations readily available online are inaccurate or incomplete. The above image shows the only two components in the circuit. I do not know for a fact what the white component is, but I have to assume it is a high value capacitor.  The above image is a literal layout of the circuit. The 50k load is the user's hand. Both switches are closed upon pressing the button. The switch is before the capacitor. This is based on closely observing the circuit and is 100% accurate unless someone can prove otherwise. I tested this with varying capacitance and inductance values and was unable to induce a significant current in the load for more than dozens of miliseconds. When testing I moved the virtual switches from the ground to the positive wire. When I move the switch after the capacitor I can have a long lasting current through the load, but the voltage/current are very low. Edit: It is beginning to appear as if the white piece (Shown as cap above) is an active component/IC. There may not even be a capacitor in this circuit. What I know:  The device behaves as follows: When the pen is held and the button is pressed a mildly painful electric shock is felt. After about 3 seconds, the pain gradually decreases until it is not longer felt. Upon releasing and pressing again the full shock is felt once again, even if only released for the slightest moment. The button and grip are the electrodes. It uses 4 1.5V button cells in series (with high internal resistance) The shrink wrapped component is a tightly wound step up transformer. The   secondary uses extremely thin wire. It apparently is an autotransformer, as it has three leads and is wrapped around one ferrite column.  What I think I know:  I measured the frequency on the primary with a primitive oscilloscope. It was equal to a couple hundred hz, which is reasonable considering the pain of the shock. If the frequency is ~200hz, the capacitor (if the white component is a cap) would have to be over 100uF non polarized. This may be possible as I have discovered high capacitance low voltage smd caps. The primary inductance would have to be several mH. The turn ratio would (I believe) have to be at least 1:90. This surprised me because I read that most autotransformrs have a low ratio. I then encountered higher ratio custom ones (which is more reasonable if varying wire gauges are used).  What I want to know:  What the white component is. Is it merely a capacitor? Does it serve other functions? How on earth does this circuit work. It seems so simple and then again I can't explain or emulate its behavior accurately in a simulator...  Help will be greatly appreciated, as this has kept me occupied for a long time.


Why do we use AC for long distance transmission?

Why do we use AC (Alternating Current) for long distance transmission of electrical power?  I know that AC is such a current that changes polarity (magnitude and direction) and has fixed poles.


After installing Phyton3.6 , Terminal won't see it. Why?

After installing Phyton 3.6 , I can't get Terminal to find it . I am trying to learn Phyton and very new at this. Please help with details instructions. Thanks  This is what I get:  Last login: Fri Dec 22 08:24:04 on console Carmens-MacBook-Pro:~ Clp$ phyton -bash: phyton: command not found Carmens-MacBook-Pro:~ Clp$ phyton3 --version -bash: phyton3: command not found Carmens-MacBook-Pro:~ Clp$


If we disbelieve $H_0$, why quote a p value calculated assuming $H_0$ was true?

Hypothesis testing seeks to reject a null hypothesis ($H_0$) on the basis of an assumption made about the sample following a certain distribution. This assumption is conditional on $H_0$ being true. So what is the flaw with the following reasoning?     If I reject $H_0$ in favor of the alternative hypothesis ($H_1$), I   must then assume that (1) $H_1$ is true, and (2) that at the   same time the variable under examination follows the distribution   used to reject $H_0$. Since we also stated that the assumed   distribution is conditional on $H_0$ being true, it appears that $H_0$   has got to be true in order to justify the assumption made about the   distribution. Logically, it would therefore seem that both $H_0$ and   $H_1$ have to be true, which is a paradox, because they are mutually   exclusive!


Ideally I'm trying to put together a PHP script that I can query from any web browser and it returns the country of the IP address that accessed the PHP script.  Is this possible or is there a better solution?


Difference in physical meaning between $\vec{D}$ and $\vec{E}$

I understand that $\vec{D}=\varepsilon_0 \vec{E} + \vec{P}$, but, physically, what is the difference between these two vector quantities? What is their physical meaning?


Strange annoying 1px line when I save a PDF from InDesign

I am creating a PDF file from InDesign and sometimes(90% of the times) when I export my work from InDesign into a PDF file a strange annoying 1px line appears(view immage) at the edge of the document... Did you ever had this problem? Why does it appear ?


Please show hats in the Android app (aka android app hates hats)

I don't hate hats. Proof:    Yet, the Android app isn't showing them:    Saw  asking for hats in the Android app, and , also saying essentially "it's not worth it".  Fine.  Except, the iFolks got their hats on this year:    That's religion-based discrimination (totally! don't deny it!) and I demand nothing but fairness.  All apps should be born equal.


Any alternate thing in JavaScript to make a file upload control ?    actually the problem was, i am creating file upload control dynamically using htmlwriter, and when i use request.form[fileuplodctrl].tostring() , i am getting only the file name not path...   can any one suggest me any other ways to get full file path :)


How to make a terracotta block with specific placing properties

I am trying to create a custom map where colored terracotta can only be placed on other terracotta blocks of the same color, but I don't know the command.


I would like to know how to malloc (and hen realloc) an array of a structure.  Here is my structure :   typedef struct tag {     char *key;     char *val; } tag;   I use this structure in another structure :   typedef struct node {     int id;     double lat;     double lon;     int visible;      tag *tab; } node;   I define a node *n, then:  n->tab = (tag*)malloc(sizeof(tag) * 5);   but I have an error of malloc corruption.  void remplisTag(xmlNodePtr cur, node *n) {     xmlNodePtr fils;     n->tab = malloc(sizeof(*n->tab) * 5);     if (n->tab == NULL) {         error(E_ERROR_MALLOC);     }     printf("apres malloc\n");     int taille = 5;     int ind = 0;     xmlAttrPtr attr1, attr2;     xmlChar *key;     xmlChar *value;     fils = cur->xmlChildrenNode;     fils = fils->next;     while (xmlStrcmp(fils->name, (const xmlChar*)"text") != 0) {         if (xmlStrcmp(fils->name, (const xmlChar*)"tag") == 0) {             if (ind == taille - 1) {                 n->tab = realloc(n->tab, sizeof(tag) * (taille + 5));                 taille = taille + 5;             } else {                 taille = taille;             }             /* searching for key */             attr1 = xmlHasProp(fils, (const xmlChar*)"k");             if (attr1 == NULL) {                 error(E_KEY);             } else {                 key = xmlGetProp(fils, (const xmlChar*)"k");                 if (key == NULL) {                     error(E_KEY_V);                 }                 /* searching for value */                 attr2 = xmlHasProp(fils, (const xmlChar*)"v");                 if (attr2 == NULL) {                     error(E_VALUE);                  }                 value = xmlGetProp(fils, (const xmlChar*)"v");                 if (value == NULL) {                     error(E_VALUE_V);                 }                 tag t;                 t.key = malloc(sizeof((char*)key));                 strcpy(t.key, (char*)key);                 strcpy(t.val, (char*)value);                 t.val = malloc(sizeof((char*)value));                 n->tab[ind++] = t;             }         }         fils = fils->next;     }     free(n->tab); }   In main:   node *n = malloc(sizeof(node)); xmlNodePtr cur;   in a while loop:  remplisTag(cur, n);


What are Windows 8 "spellchecking preferences"?

I added another language to my Windows 8 machine.  In the language options, there is a set of radio buttons titled "Spellchecking Preferences" with the following options:   Full Partial Mixed Mixed Authoritative   My US-English default language does not have this option.  I cannot find what the choices here mean in any documentation.  What do these options do and why do they only show up for some languages?


Which is correct, "you and I" or "you and me"?

When the phrase is used as an object, why so many native speakers are saying "you and I" instead of "you and me"? I'm not a native speaker but I thought "you and me" is correct. Not sure if this falls into the same category, but "Just between you and me" sounds more natural than "Just between you and I".


Let $m$ be the mass of a rocket in free space (including fuel) at the time $t$. Now suppose that the rocket ejects a mass $\Delta m$ during the interval $\Delta t$ with velocity $v_e$ relative to the rocket.   I was told that the correct ansatz is as follows:  $$ mv = (m - \Delta m) \cdot (v + \Delta v) + \Delta m \cdot (v + \Delta v - v_e). $$  If you work this out, it reduces to:  $$ m \Delta v - \Delta m v_e = 0. $$  However some books start with the equation  $$ mv = (m - \Delta m) \cdot (v + \Delta v) + \Delta m \cdot (v - v_e) $$  which reduces to   $$ m \Delta v - \Delta m v_e - \Delta m \Delta v = 0. $$  Then you need to "neglect" the higher order term $\Delta m \Delta v$ to get the correct result.   Is there any good conceptual reason why the first ansatz is the more correct one?  However if you use $\tilde m = m(t+ \Delta t)$ in the derivation, you get the correct result without the need of neglecting higher order terms in the line of the second derivation:  $$ (\tilde m + \Delta m) \cdot v = \tilde m (v + \Delta v) + \Delta m (v - v_e) $$  so why is the following equation the conceptually wrong ansatz:  $$ (\tilde m + \Delta m) \cdot v = \tilde m (v + \Delta v) + \Delta m (v + \Delta v - v_e)? $$


here Is Code there any way to get Index of the object from the list by calling a method in the list.  for example something like this:  class A{     String a="";     String b=""; }  List<A> alist= new ArrayList();  for (A a : alist) {     a.getIndexInList(); }


Where to start dissecting this racing track?

I quite new to blender; i wand to make the following kind of track for a racing game i am working on. I am overwhelmed by the many things to stard; for this case is it better to start with the road or with the landscape ? I was thinking to use spline and extrude the road to be able to adapt the road; is it the proper way of doing it ? For the landscape i should start with a plane that i subdivide a lot but then how to get this random moving vertices ? Thanks !


I tried to install:  Ubuntu 20.04 Xubuntu 20.04 Kubuntu 20.04  But, post install on execute sudo apt-get update, I received the message "Hash Sum mismatch" What is the problem? I tried:  apt clean apt-get clean rm -rf /var/lib/apt/lists/*


I am trying to build a client-server Program in which the server sends the image to client and client displays the received image in JFrame. I am converting Image on the server-side to ImageIcon object and sending it to the client via ObjecOutputStream. But it fails and gives me failed to load image contents error on server-side, it happens while the ObjectOutputStream.writeObject() method is called.  Server-side code  import java.io.*; import java.net.*; import javax.swing.*;  public class ImageServer{    private static ServerSocket serverSocket;   private static final int PORT = 1234;    public static void main(String[] args){         System.out.println("Opening port…\n");        try{          serverSocket = new ServerSocket(PORT);        }        catch(IOException ioEx){          System.out.println("Unable to attach to port!");          System.exit(1);        }        while(true){              try{                Socket connection = serverSocket.accept();                 ObjectOutputStream outStream =new ObjectOutputStream(                                               connection.getOutputStream());                ImageIcon icon=new ImageIcon("//Give image path//");                System.out.println(icon.getImageLoadStatus());// To check if image is loded correctly or not.                 outStream.writeObject(icon);                 outStream.flush();              }             catch(IOException ioEx){                 ioEx.printStackTrace();             }       }  } }   Just give the path for an image file, for testing purposes.  Client-side code  import java.io.*; import java.net.*; import java.awt.*;  import java.awt.event.*; import javax.swing.*;  public class ImageClient extends JFrame{     private InetAddress host;     private final int PORT = 1234;     private ImageIcon image;      public static void main(String[] args){           ImageClient pictureFrame = new ImageClient();          pictureFrame.setSize(340,315);          pictureFrame.setVisible(true);          pictureFrame.setDefaultCloseOperation(EXIT_ON_CLOSE);       }     public ImageClient(){         try{            host = InetAddress.getLocalHost();         }         catch(UnknownHostException uhEx){              System.out.println("Host ID not found!");             System.exit(1);         }          try{             Socket connection = new Socket(host,PORT);              ObjectInputStream inStream =new ObjectInputStream(                                            connection.getInputStream());              image = (ImageIcon)inStream.readObject();              connection.close();         }         catch(IOException ioEx){               ioEx.printStackTrace();         }         catch(ClassNotFoundException cnfEx){               cnfEx.printStackTrace();         }          repaint();   }    public void paint(Graphics g){        image.paintIcon(this,g,0,0);    } }   Error generated on Server-side  java.io.IOException: failed to load image contents      at javax.swing.ImageIcon.writeObject(Unknown Source)      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)      at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)      at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)      at java.lang.reflect.Method.invoke(Unknown Source)      at java.io.ObjectStreamClass.invokeWriteObject(Unknown Source)      at java.io.ObjectOutputStream.writeSerialData(Unknown Source)      at java.io.ObjectOutputStream.writeOrdinaryObject(Unknown Source)      at java.io.ObjectOutputStream.writeObject0(Unknown Source)      at java.io.ObjectOutputStream.writeObject(Unknown Source)      at ImageServer.main(ImageServer.java:27)   This is a code excerpt from the following book:


Prove central binomial coefficient upper bound

I am trying to prove that $\binom{2n}{n} < \frac{4^n}{\sqrt{2n}}$. I tried induction, but with no effect (all I can get to is $(2n+1)(2n+2) < 4\sqrt{n(n+1)}$ which is false)


I have been tasked with one insecure form, one secure form. For my insecure form, I have the PHP statement  $sql = "INSERT INTO Name(Name) VALUES ('$firstname')";   Here the user input is obviously taken directly from the from and saved as $firstname. Now, I am having trouble actually injecting SQL into this form. Could someone point me in the right direction? I've tried dropping the table but I either get a SQL error or the injection actually is inserted.  EDIT: This is different from the question that is apparently a duplicate, as I know HOW to make it secure, what I'm trying to do is inject my already insecure code. The example in the duplicate question did not work for me and gave a syntax error.


How can I remove the title of my list of figures? I am able to do it for the table of contents but not for the list of tables or figures.


Why don't the two forces balance each other In Newton 3rd law?

Why don't the two forces of action and reaction balance each other ?  I imagine that although they are opposite forces, they have different points of application. Is this true?


Want to render animation nodes text animation on sheepit

I have a blender animation where I have used the trim text feature of the animation nodes add-on of blender. However, when I upload it to the render farm, those parts don't render out. I've been told, on blender stack exchange, that it's because the render farm does not have the animation nodes add-on installed. I would however appreciate it if someone suggested a workaround to this.


numbers on a credit card expiry date year form

What is the best display to have for the years on a credit card expiry date field for payment. Should you have the whole year 2013, 2014, or is it better to have it displayed the same as on the credit card itself, 13, 14, etc.  Also how many years should you have? Amazon seems to go 16 years, but do some credit cards really have that long an expiry date?


The commonly available spreadsheet function PERCENTILE / PERCENTILE.INC is described as giving the alpha quantile of a sample.  The 95th Percentile is described as the value below which 95% of the samples fall - [Wikipedia] - please correct it if wrong.   This is commonly employed in "95th Percentile Billing" for services, which claims to "ignore sporadic usage spikes" - and is offered as a fairer (and cheaper) alternative to paying for a fixed level, but companies employ different methods of calculating it - some use p, and some 1-p. 1) Which is technically correct? p or 1-p?   Say I have a series of usage samples indicating transactions per minute of:  A1. 20 A2. 20 A3. 20 A4. 100 A5. 20   It's clear that 80% of the samples are 20 or below, ignoring the spike of 100. The function PERCENTILE(A1:A5,1-0.8)=20, which is what the lay customer would expect, whereas PERCENTILE(A1:A5,0.8)=36, which seems to not ignore this usage spike.    Also, consider the example:   A1. 20 A2. 20 A3. 100 A4. 100 A5. 20   PERCENTILE(A1:A5,0.8)=100 and PERCENTILE(A1:A5,0.95)=100 - which seems to clearly be the "upper 5%" while PERCENTILE(A1:A5,0.2)=20 seems more intuitively correct, and PERCENTILE(A1:A5,0.05)=15 defeating intuition as its lower than any value in the range.   2) How can I explain this lower value, to people who do not have a mathematical background - including myself?  3)  Is either p or 1-p a technically correct value for p being the "lowest 95 percentile"? 4) Is there a formula that would most accurately average the lower 95% of samples? What is it called?  This could easily be a $1 000 000 / year question.


How do I solve this infinitely nested radical?

$\sqrt{1+2\sqrt{1+3\sqrt{1+4\sqrt{1+...}}}}$  Apparently, the answer is 3.


I've seen so many questions about using sudo without a password, but my question is, does sudo need a password?   I've read on some sites that sudo allow us to execute a command with privilege of root user without password. But whenever I try to execute chmod with sudo it requires a password, not of the root account but the password I use to log into Ubuntu.  Are passwords for root and system administrator different?


My spellchecker insists on replacing "furthest" with "farthest". I was under the impression that farthest is strictly speaking in terms of distance, whereas furthest is more abstract.   gives the following example:     The further [quantity] you walk, the farther [distance] you get.   What gives?


How do you stop Windows from asking "How do you want to open this file?" when Process.Start fails?

Consider the following code, which simply starts a process from VB.NET:  Public Shared Sub ShellandWait(ProcessPath As String, Optional Arguments As String = "")      'Starts a process/program and waits for it to finish before execution continues.      Using objProcess As New System.Diagnostics.Process          objProcess.StartInfo.FileName = ProcessPath         objProcess.StartInfo.Arguments = Arguments         objProcess.StartInfo.WindowStyle = ProcessWindowStyle.Normal         objProcess.StartInfo.ErrorDialog = False          objProcess.Start()          'Wait until the process passes back an exit code          objProcess.WaitForExit()          'Free resources associated with this process         objProcess.Close()      End Using  End Sub   If we pass in a file name for ProcessPath, say "C:\test.xml", but no program is associated with the .xml extension, Windows 10 will pop up a box asking "How do you want to open this file?"  Is there anyway to prevent Windows from opening this popup?  I'd like this scenario to be handled in code instead of Windows interjecting itself.   EDIT:  I don't want to find the program associated with the extension.  In the majority of cases where Process.Start fails, there will be no program available to handle the file type (I just used xml as an example).  My code currently warns the user that the appropriate application is not found, but the popup from Windows also shows, which I find confusing.  I just want to disable the popup from showing, if possible.


PCA scores in my own implementation have different sign from the ones computed in R

I am trying to implement PCA (NIPALS method) using Excel. The problem is that my results are not exactly matching with the results of R. There is only a difference in sign: if my scores are positive, then scores using R are negative.   I don't know what is going on. What to do?


I'm currently generating some presentations with beamer for students of my course. Some like to print the material, so I created a handout. Some students prefer to have 2,3,4,6 etc. pages per sheet of A4 paper. How can I go about to automatize the following code, so that it outputs 4 different files in 1x2,1x3,2x2,2x3 format?  I'd like to avoid having to compile it again everytime for the different formats.  \documentclass[a4paper]{article} \usepackage{pdfpages}  \begin{document} \includepdf[pages=1-last,nup=1x2,landscape=false,frame=true,             noautoscale=false,scale=1,delta=0mm 5mm]{Pres7Chap13-Handout.pdf} \end{document}


Intransitive verbs with preposition in passive sentences

The words listen, shout, etc. are intransitive verbs, but why are they used in passive sentences with preposition to, at, etc.?  e.g:     she was never listened to.   I don’t like to be shouted at.                                                  When intransitive verbs are used with preposition, are they considered as transitive verbs?


Proof: Well defined multiplication in groups

Can anyone please show me how to prove this?  Define for sH ∈ G/H and tH ∈ G/H the multiplication:  (sH)(tH) = (st)H  Show that this is well-defined.  How do I prove this? Also, I'm unsure of what I have to show as a part of this proof as I don't really understand what is meant by "well-defined" in this context? Can anyone please help me out?  Thanks


I am beginning to study probability and I found the following problem:  What is the probability of to get a number twice after two throwings?  The answer was that since we have six distinct results in a fair die every possible result has $1/6$ of probability of happen and since that the result is:  $$ P(\text{rolling the same number twice in a row on a fair die} ) = (1/6)(1/6).$$  I understand till the part of the probabilities, I know that since every event is independent of the other we are applying the multiplication rule, However I would like to go more deep in the analysis and not to take this as a strict rule, I would like to understand why we had to multiply the numbers, I mean why not to sum them or divide?, I need to understand why the rule of multiplication works, I would like to receive a empirical or formal explanation of this result in order to understand more, thanks for the support.  I would like to state that my question is different since I know that if I have the scenario of only one die, thrown out in two different times my result is correct but I don't understand why we have to multiply the probabilities I know that we are using the multiplication rule but why it works? what is the reason to multiply the numbers I mean why not to divide it or to sum it, I would like to go more deep in the analysis.


Does windows have any decent sampling (eg. non-instrumenting) profilers available?  Preferably something akin to Shark on MacOS, although i am willing to accept that i am going to have to pay for such a profiler on windows.  I've tried the profiler in VS Team Suite and was not overly impressed, and was wondering if there were any other good ones.  [Edit: Erk, i forgot to say this is for C/C++, rather than .NET -- sorry for any confusion]


How to clean my soldering iron tip or how to determine that it's beyond repair?

First, I've read though questions  and  and was unable to solve my problem. I have recently (as in less then a month ago) obtained  with  tip.  From the start I had problems wetting the tip. I tried everything but solder just wouldn't flow over the whole tip. I later found information in one of manufacturer's catalogs that I should wrap solder with flux around the tip and then turn on the iron. After few tries, I managed to get a big part of the tip wet (and it was working great), but one small part wouldn't wet.  After some soldering I decided to try to get whole tip wet and obtained  tip refresher. After using it according to the manual, the whole tip was covered in black substance which should be easily removable, but it isn't.  Now about half of the tip is contaminated and about half seems to be working (I managed to clean the working part).  My question is: Is there any other way to clean the tip? Two things from questions I linked I didn't use were dedicated tip cleaning mesh (couldn't find a source of them in my country) and flux outside the wire (because I don't have any at the moment) and how to decide when a tip is dead and needs replacing?  Also, how do the tip refreshers feel (I'm assuming that they are more or less all alike)? I often find them described as paste, while the one I got is solid (but melts when in contact with hot tip).


What is going on with the JavaScript room?

Seriously, almost all of the flags I get are in the JavaScript room. . In case you are tired, it leads to the "Ask a question" screen. I don't care about these silly flags, really. But I wondered if there is something we can do to make the flags more pertinent and save them for when things really are obscene. If I am right and the majority of flags come from a certain place (and assuming most are dismissed) should this chat be closed?  Of course they could go to another chat and similar things happen. I'm not sure how to know what users or how often they are flagging but it seems to be like "the chat room who cried wolf". If nothing else, I would like to bring attention to those who are flagging there. If the chat is that bad then make it a gallery or stop visiting it.  Edit  OK, I don't really think the chat should be closed. This was a poorly-formed question from the beginning, because that wasn't my main point of the post. It was more to get a discussion about why it seems, at least to me, that most of the flags (at least lately) appear to come from there and if there is anything to be done about it.


Floated 48% div needs a full line of text to keep it's size?

The template to rebuild my website works great except for the 2 divs in the center which are floated left & right. They seem to need at least a full line of text in each one to stay open.  If not the navigation on the left seems to go off screen to the left. The left & right divs are fixed widths.  The 2 center ones are floated I believe properly & cleared. Each 48% width.  Is there a way to keep them fully expanded for pages that do not have a line that covers the full width. I know my screen is 1920px's wide & they are getting wider.  I have been researching this for days & always seem to end up at this site.  The only thing I can think of is to put say 16 - 100px wide spacer gif's side by side in each center 48% div. That just isn't right.  Is there a way to keep the div's full width?  Full page sample. If either of the 2 full lines in the 2 center div's are shortened the left nav goes further left.


How to remove obsolete packages after failed release upgrade via do-release-upgrade on Ubuntu?

Sometimes, when I upgrade a system via do-release-upgrade, the update process fails and the script tells me to finish the process manually via dpkg --configure -a. This is a not serious problem - after manually solving the dependencies problem and the finishing upgrade process all works well.  But the do-release-upgrade script has a cleanup process after finishing the upgrade:  Remove obsolete packages?   XXX packages are going to be removed.   Continue [yN]  Details [d]y   which removes some obsolete packages from old version of system.  Seems that this process doesn't execute when the automatic upgrade fails and I finish upgrade manually, so obsolete packages from old version remain installed in the system.  How I can run the "Remove obsolete packages" process manually after finishing the upgrade by hand?


Does the sum of a convex function and monotonically increasing function (not necessarily convex) yield a convex function?


Does Euler's Formula prove all imaginary numbers equal $0$?

Euler's formula is  $$ e^{i \theta } = \cos \theta + i \sin \theta $$  If we take $\theta$ to be $2 \pi$ we get  $$e^{2i \pi} = \cos (2 \pi ) + i \sin (2 \pi ) $$  Which simplifies to  $$e^{2i \pi} = 1$$  But we also know   $$e^0 = 1$$  Therefore, can we not say  $$e^0 = e^{2i \pi}$$  and thus,  $$0 = 2i \pi$$  Which leads to being a big problem for all imaginary numbers.  Example with $25i$:  $$\begin{align} 25i &= \frac{25 (2 \pi) i}{2 \pi} \\ 25i &= \frac{25 * 0}{2 \pi} \\ 25i &= 0 \\ \end{align}$$


Another (perhaps humorous) term for "The Gold Standard"

Gold Standard as in:     an example against which others of the same type are compared   -    Any other humorous ways to refer to this?  Something like "the holy mother"...


Convergence of $\sum_{n=2}^{\infty} \frac{1}{(\log 1)^p+(\log 2)^p+\cdots +(\log n)^p}$

Consider the series  $$\sum_{n=2}^{\infty} \frac{1}{(\log 1)^p+(\log 2)^p+\cdots +(\log n)^p}$$  where $p>0$.  For what $p$, the series converges?  This question appears in the Tier 1 Analysis exam (2014/08) of Indiana University Bloomington. And I modify it a little to make it look more tight...


Is King Joffrey not actually Robert's Son?

Joffrey came across as a bit of a little **** in Seasons 1 and 2, but in Season 3 (especially the end of The Climb) we see that he is utterly, utterly insane.  Could the source of this madness be that he is actually be born of incest between Jaime and Cersei? How could anyone know?


I am working on a unix-like file system and I need to take in commands from the command line. Some commands are one argument like mkfs, ls, etc. But some are two commands like mkdir foo, rmfile hello. My question is, how can I parse the string to take in a command (cmd), but also take in a second argument (next)? Here is my code so far: (I have not included the functions for the sake of space)  int main(int argc, char *argv[]){      string cmd;     string next;       while (1){         cout << "Russ_John_Shell> ";         cin >> cmd;            //Checks to see whether the string has a file/directory name after the command         if (next == ""){             //mkfs command             if (cmd == "mkfs"){                 makeFS();             }             //exit command             else if (cmd == "exit"){                 exitShell();             }              //ls command             else if (cmd == "ls"){                 listDir();             }             //command not recognized at all             else {                 printf("Command not recognized.\n");             }          }         else{              //mkdir command             if (cmd == "mkdir"){                 makeDir(next);             }             //rmdir command             else if (cmd == "rmdie"){                 remDir(cmd);             }             //cd command             else if (cmd == "cd"){                 changeDir(next);             }             //stat command             else if (cmd == "stat"){                 status(next);             }             //mkfile command             else if (cmd == "mkfile"){                 makeFile(next);             }             //rmfile command             else if (cmd == "rmfile"){                 remFile(next);             }             //command not recognized at all             else {                 printf("Command not recognized.\n");             }         }     } }   Thanks in advance for any help!


Is the magnetic field calculated by Ampere's Law only because of the currents crossing the loop?

In Ampere's Law,      $$\oint \vec B \cdot \mathrm d \vec l = \mu I$$      the current outside the curve is not included on the right hand side   of the equation.*   Does it mean that the magnetic field 'B' calculated by using Ampere's Law, gives the contribution of only the currents crossing the area bounded by the curve?


Sooner or later, a user may see that his answers are getting a lot of up-votes, then he gets a large negative reputation change labelled "voting corrected". This is because a user has voted on the answers in a short period of time, and then the system detects it and deletes the votes. Obviously, this is to protect the site from scripts, sock puppetry, or from people sorting answers by author, not content.  I have heard that you should avoid "five votes in a row", but how exactly is unusual voting behaviour detected? Is the exact algorithm classified?


Truth in advertising; Fargo claims of being a true story

Isn't it against the law to blatantly lie to the viewing public?  If the TV series  is not true then why do they say it is?


Is $\int\limits_{0}^{\pi}x\cdot f(\sin x)dx=\pi \cdot \int\limits_{0}^{\pi/2} f(\sin x)dx$?

How can I prove that for all continuous $f$ $$\int\limits_{0}^{\pi}x\cdot f(\sin x)dx$$ $$=\pi  \int\limits_{0}^{\pi/2}f(\sin x)dx$$


What is the canonical way to redefine the \emph command

Question says it all. What is the best way to redefine the \emph command to be bold font and upright?


I need to start reading Lucifer comics, but I am having trouble figuring out where to start

Do I read the Sandman stuff, or do I jump right into the main comics? Because I really want to maintain continuity, what's the right sequence to ensure that I get every bit of the story?


Is there a particular reason the elves die off so fast? After the first war against Sauron, I recall the elves being decimated, to the point that they're almost useless army-wise in the trilogy. But I'm guessing men suffered equal or greater losses as well.  Anyways, other races just seem much more capable of repopulating, while is seems like there are incredibly few (if any?) elven children. Considering the fact that elves are immortal, wouldn't their population be the fastest to grow? Also the seem to be perpetually 40 years old, so aren't they eternally fertile as well? Why don't they have more kids and build bigger societies?


Can a wizard who studied to be an Animagus have the possibility to choose in which animal he will be transformed?

And what will define in which animal a wizard will be transformed? is it due to his apparence or moral quality?


When I do   \documentclass{article} \usepackage{stmaryrd}  \begin{document}  $\varbigcirc$ test \par \phantom{$\varbigcirc$} test  \end{document}   I get    which is not what I would expect. I would expect that the two "test" are left aligned and that the interline space is not as large.  How to fix this issue?


Generating tuple from a list of items in Python

I;m trying to generate a tuple list from a larger list. how do I do it in pythonic way?  c = ['A1','B1','C1','A2','B2','C2']   Output required is something like this:  c = [('A1','A2'),('B1','B2'),('C1','C2')]   I tried to iterate through the list and put a regex to match for mattern and then added that to a tuple but that doesn;t look convincing for me.. Any better way to handle this?


How to add Object to array in javascript

I have this code like this:  $scope.role.object_access_right = {contact:1,group:1,image:1,text:1,email_template:1,email:1,channel:1,campaign:1,invoice:1,user:1,account:1,tenant:1,}   I have empty array here,  $scope.access = [];   How can I push the key to empty array to have result ?   $scope.access = [contact,group,text ...]


How to copy on Ubuntu 18.04 with HP deskjet F4210 all-in-one printer?

I managed to be able to make a scan with my HP Deskjet F4210 All-in-One printer and Ubuntu 18.04 thanks to this article:  I followed this advice:  2 Blockquote +50 I had been using HP Deskjet 4535 MFP Scanning feature within Ubuntu 16.04. However after installing 18.04, it didn't worked, as mentioned by Tanama. (While I had fresh installed 18.04, my home directory was same as one I had used for 16.04.) I verified that "hplip" package was installed during 18.04 stock installation, and tried simple-scan, sane-utils, hp-setup, hp-probe and so on. None of those attempts worked. Even Gimp -> Create -> xscanimage didn't helped. Finally, following worked for me. I installed hplip-gui package after going through this URL:  Blockquote Run Dash -> HPLIP Toolbox (HP Device Manager) and configured my device. I had used manual mode to detect device by explicitly providing static IP address I have assigned to my Wireless MFP. After that, use Actions tab within HP Device Manager, and select "Scan". It starts "simple-scan".   Thank you for this! I have been working on this for more than a year to make it work. I can also print, but I haven't found out yet how to make a copy. I do have HP Device manager now. The printscreen shows the menu I can see when I open HP Device manager, and it shows the last installation details of the command 'hp-setup'. Could anyone advice me how to be able to make a copy? Thanks a lot!


I found this javascript regex to validate the different format the US phone numbers can be written. But it has problem: it fails to match the second rule in this group:     The first group of three digits, know as area code start with a number   2–9, followed by 0–8, and then any third digit.   It accepts 9 whereas it should only accept numbers from (0-8). This regex show it all:   /^(1[- .]?)?(\([2-9]\d{2}\)[. -]?|[2-9]\d{2}[. -]?)[2-9]\d{2}[- .]?\d{4}$/gm


I write in my preable the following code:  \usepackage[a4paper, inner=1.5cm, outer=3cm, top=2cm, bottom=3cm, bindingoffset=1cm]{geometry} \usepackage[onehalfspacing]{setspace} \renewcommand{\figurename}{Grapheme} \renewcommand{\listfigurename}{List of Graphemes} \renewcommand{\tablename}{Tables} \renewcommand{\listtablename}{List of Tables}  \begin{document} \tableofcontents \listoffigures \listoftables \chapter{Introduction}   but when I scroll to the List of Graphemes in my PDF it still says List of Figures.  Why is this happening?  I want it to be saying "List of Graphemes"  I'm using Kile 2.1 in Linux mint.


I am unable to see anything on the screen while using any version of Ubuntu

Every time i install Ubuntu either 12.10 or any version of Linux mint it install well but i cannot be able to see anything on the screen on when i use a DESKTOP screen by connecting on a VGA that time i see from a different screen.


I need to know the meaning of the higher order derivatives of a polynomial.   Let make an example. Assume we have a polynomial of degree n. Then $$ f(x)=a_0+a_1x+a_2x^2+\ldots+a_nx^n $$  We know that the first derivative means the slope of the polynomial (in a certain point, x) and also we know that the second derivative means the curvature of the polynomial (again at the certain point). So, I need to know if other derivatives have any meaning for us.


I'd like to give /dev/root more space on my CentOS 7.4 system.  # df -h Filesystem      Size  Used Avail Use% Mounted on /dev/root        20G   18G  302M  99% / devtmpfs        7.8G     0  7.8G   0% /dev tmpfs           7.8G   28K  7.8G   1% /dev/shm tmpfs           7.8G  826M  7.0G  11% /run tmpfs           7.8G     0  7.8G   0% /sys/fs/cgroup /dev/sda2       1.8T  2.7G  1.7T   1% /home tmpfs           1.6G     0  1.6G   0% /run/user/0   As you can see I have more than enough space mounted to /home.  # /sbin/fdisk -l Disk /dev/sda: 2000.4 GB, 2000398934016 bytes, 3907029168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disk label type: dos Disk identifier: 0xf2e91416     Device Boot      Start         End      Blocks   Id  System /dev/sda1   *        4096    40962047    20478976   83  Linux /dev/sda2        40962048  3905974271  1932506112   83  Linux /dev/sda3      3905974272  3907020799      523264   82  Linux swap / Solaris   How can I add 500 GB to /dev/root ?  Is this possible without going into rescue mode?  If not which commands do I need to do it in a Debian based rescue environment?  Edit: Ended up reinstalling with better partitioning.


I am currently using python concurrent.futures to add threading to my function. I want to kill all threads and continue down the program (or exit out if there is nothing else to do) if 1 thread of the pool matches a condition. All other threads in the pool should stop (either abruptly or gracefully) import concurrent.futures import random   def randomizer(number):     print("Randomized: "+str(number+random.randrange(0,10)))      if some_case:         allthreads.kill()   # This is obviously non working code  if __name__ == '__main__':      numbers=[5,4,3,2,1,0]      with concurrent.futures.ThreadPoolExecutor() as executor:         executor.map(randomizer, numbers)


I can not run following command with sudo to change a sysfs paramete:  $ sudo echo 300 > /sys/block/md0/md/stripe_cache_size bash: /sys/block/md0/md/stripe_cache_size: Permission denied   However, it works with out sudo when I change to the root user:  $ sudo su [root] [ /home/arh ]    #  echo 300 > /sys/block/md0/md/stripe_cache_size [root] [ /home/arh ]    # cat /sys/block/md0/md/stripe_cache_size 300   Here is the file permissions:  $ ls -l  /sys/block/md0/md/stripe_cache_size  -rw-r--r-- 1 root root 4096 Feb  2 08:50 /sys/block/md0/md/stripe_cache_size   Does it make sense to you ?  Note that I have changes /etc/sudoers file with visudo to make sudo commands password-less.


Linear independence in Jordan Normal Basis

I am trying to understand how do we form a Jordan Normal Basis and more specifically why the chains are linearly independent. I saw some relevant question, but still, I can't figure that out.  We start with a highest order eigenvector and form its Jordan chain. Then, if we haven't had yet a basis, we take another eigenvector of highest possible order and form its Jordan chain and we continue like this. Why will two jordan chains we obtain be linearly independent?  Thanks in advance  edit:In this , he says:   The other method is to first determine the lengths of the chains (there are formulas you can use to find them). If the longest chains have length kk, then you find linearly independent vectors in $(T−\lambda I)^{k−1}$ that are not in $(T−\lambda I)^{k−2}$. Then you apply $(T−\lambda I)$ to them, and if necessary find linearly independent vectors from the ones you have so far that are in $(T−\lambda I)^{k−2}$ but not in $(T−\lambda I)^{k−3}$. You continue this way, always selecting linearly independent vectors, until you are down to finding enough linearly independent vectors in $(T−\lambda I)$ besides the ones you already have; you will be guaranteed they are linearly independent because at each stage we are always selecting vectors that are linearly independent.  My question is actually, how do we know that after applying $(T−\lambda I)$ to the vectors we already have selected, we get a linearly independent set of vectors?


Proof by induction of Bernoulli's inequality $ (1+x)^n \ge 1+nx$

I am working on getting the hang of proofs by induction, and I was hoping the community could give me feedback on how to format a proof of this nature:  Let $x > -1$ and $n$ be a positive integer. Prove Bernoulli's inequality: $$ (1+x)^n \ge 1+nx$$  Proof:   Base Case: For $n=1$, $1+x = 1+x$ so the inequality holds.  Induction Assumption: Assume that for some integer $k\ge1$, $(1+x)^k \ge 1+kx$.   Inductive Step: We must show that $(1+x)^{k+1} \ge 1+(k+1)x$  Proof of Inductive Step:  $$\begin{align*} (1+x)^k &\ge 1+kx \\ (1+x)(1+x)^k &\ge (1+x)(1+kx)\\ (1+x)^{k+1} &\ge  1 + (k+1)x + kx^2 \\  1 + (k+1)x + kx^2 &> 1+(k+1)x \quad (kx^2 >0) \\ \Rightarrow (1+x)^{k+1} &\ge 1 + (k+1)x \qquad \qquad \qquad \square \end{align*}$$


multiple /tellraw reactions from same command

I'm trying to make something and I want a /tellraw to activate and when the player clicks on it multiple things happen. What I mean is when they click on the text like 5 /setblock commands activate. I can't figure out how do do this. I have tried just putting multiple clickEvents in but it does not work. Is this even possible?  I'm playing Minecraft 1.7.10.


How are Python's Built In Dictionaries Implemented?

Does anyone know how the built in dictionary type for python is implemented?  My understanding is that it is some sort of hash table, but I haven't been able to find any sort of definitive answer.


Bug of tiny text interface when computer starts

All of a sudden, when the computer started, the log in screen was strange and the text almost unreadable so small it was. I typed the password and all the system text remained very tiny and unreadable. I went to universal access in configs and changed to large text, the problem was solved, but soon after came back. I have to keep going to config to change to "enable large text" and when the problem comes back "disable large text". I am looking for a more definitive solution for this strange system interface problem.


What specific bad things happen when gedit is used with sudo?

I read  explaining that "sometimes" root can own something at /home/$USER directory.  Can anyone give an example how to prove it. Just give a test case when something really bad happens, when I run  sudo gedit /etc/rc.local   edit file and save.  I got many downvotes  out and comments flooded in saying that it is a crime to run gedit with sudo.  Can anyone give a real example?  I clearly explained why this question is not a duplicate. There is no answer specific to gedit to the linked question.  And it is important to explain why widely used sudo gedit is bad, or not really, etc.


Calculating latitude and longitude fields using PostGIS?

I have a shape in PostGIS that has 2,658,061 records (points).   I need to create a field that is called "Latitude" and another that is called "longitude" and calculate a position in WGS84 (SRID: 4326).  How do I do this in PostGIS?


Example of topological spaces with continuous bijections that are not homotopy equivalent

In one of the books on algebraic topology (I don't remember exactly which one) there was an exercise to build an example of two topological spaces having two continuous bijections between them which are not homotopy equivalent. To be honest, this exercise confuses me a little because, as I understand, each pair of homeomorphic spaces is homotopy equivalent by construction. On the other hand, the existence of bijective continuous mapping between spaces automatically provides their homeomorphism (correct me if I'm wrong). Thus, in this logic, if we have two continuous bijections between topological spaces this will inevitably lead to the homotopy equivalence between them. I guess, however, that there is a simple counterexample related to the discrete topologies which breaks such a reasoning (see, for example, this: ), but I have certain difficulties in discovering it. Is there any suggestion?


apt-get update fails with " Clearsigned file isn't valid, got 'NOSPLIT'"

I am having this issue with a brand new Ubuntu 16.04.2 Virtual Machine.  apt-get updates fails with this error  $ sudo apt-get update -o Debug::Acquire::http=1 -o Debug::pkgAcquire::Auth=true -o Debug::Hashs=trueenter  0% [Connecting to archive.ubuntu.com]GET /ubuntu/dists/xenial/InRelease HTTP/1.1 Host: archive.ubuntu.com Cache-Control: max-age=0 Accept: text/* User-Agent: Debian APT-HTTP/1.3 (1.2.19)   Answer for: http://archive.ubuntu.com/ubuntu/dists/xenial/InRelease HTTP/1.1 200 OK Content-Type: text/html; charset="utf-8" Content-Length: 2832 Connection: Close  Get:1 http://archive.ubuntu.com/ubuntu xenial InRelease [2,832 B] 0% [1 InRelease 2,832 B/2,832 B 100%]201 URI Done: http://archive.ubuntu.com/ubuntu/dists/xenial/InRelease ReceivedHash:         - SHA512:9a57e33cddb5b821ee529e7e4e39d1039f260b1b3ceee28902b7e595dfcb95280f87f45a88f433b452657f725c6a61ee06e1d2ff12db8aac7a60e61286377232         - SHA256:1c54e2c305d7254cc3c3fb5cc5651064094e7cbff00e8f4a4e1932536864f240         - SHA1:eebbd844edee49449c7bdf6c1dc6243a85970544         - MD5Sum:c0fdedc4ecc16c0bce32d264006d74e2         - Checksum-FileSize:2832 ExpectedHash:  Err:1 http://archive.ubuntu.com/ubuntu xenial InRelease   Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?) Fetched 2,832 B in 0s (4,827 B/s) Reading package lists... Done E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial/InRelease  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?) E: Some index files failed to download. They have been ignored, or old ones used instead.   I have verified that   DNS is working correctly Tried Google DNS servers in /etc/resolv.conf /etc/network/interfaces has the correct values I am able to access http://archive.ubuntu.com/ubuntu/dists/xenial/InRelease using wget -O- No firewall configured (iptable shows ALLOW for both IP4 and IP6) Tried disabling IPV6 on the server level $http_proxy is blank   Now I am completely at loss as to why am I getting Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)  What else can I try?


Passing struct pointer vs passing struct

I was recently writing a lot of programs that pass structs around functions, to avoid global variables. However, I was wondering whether passing the struct itself or its pointer is more efficient. It sounds like it should be, because pointers are (on my 64-bit GNU/Linux system) 8 bytes, while a struct full of pointers is obviously a lot more than that.  However, if I have this struct:  struct Point {     int x;     int y; }   which is 8 bytes, the same size as the pointer, is it better to pass the entire struct to a function, or to pass a pointer? I am fairly proficient with C memory allocation, so it isn't a problem to use malloc and friends when initialising pointers.  Another thought that I had was that passing structures directly could use up a lot of stack space if they are large. However simply using pointers would use up the memory, which can be freeed easily.


I have seen a question where user information isn't mentioned in the question:     When I checked if the bug reported earlier, I found:  Two reasons were mentioned there:  The account was deleted It does not exist on the current site, but it did exist on the site the question originated on when it was migrated (in the case of migrated questions).  Here, in this case, I have checked, both the user account are existing and active (if you check in detail specific user information):    Also, the question has not been migrated from anywhere. Is it a design problem?


Please can room owners and moderators be given more tools to help prevent spam from suspended users?

Over in , we've recently been experiencing a slightly disruptive form of spamming from suspended users. The user repeatedly joins and leaves the room, often multiple times a minute, meaning that the joining/leaving animation happens over and over again. This is disruptive to the users in the room trying to chat, as evidenced by ,  and  Unfortunately, one of those occurrences resulted in messages being moved to the private , meaning that they are only visible to moderators/staff These users are actively disrupting chat rooms, and often have usernames designed to catch attention, or to get users to read their profiles. However, we have basically no ability to prevent this. Kicking them would be an appropriate action to take, but . We've had moderators destroy the accounts, but this isn't a sustainable fix, and it even appears that this can be circumvented, as we believe that this has been the same user under three different accounts (all suspended or destroyed) It's already  what the appropriate course of action here is, but nothing came from it, and the advice given by Journeyman doesn't really help when users are being this disruptive. Therefore, I'm asking for some kind of ability for room owners and moderators to help prevent this kind of behaviour. The ability to kick-mute suspended users would be great, as would the ability to hide a specific user's joining/leaving animation.


Let $I, J$ be ideals of a ring $R$. Show that $I + J = \{a + b\vert a \in I, b \in J\}$ is an ideal of R.    Because $I,J$ are ideals of $R$, so $I,J$ both have $0$, thus $0+0=0\in I+J$. This shows that $I+J$ is not empty and the additive idendity.   Suppose $a_1+b_1$ and $a_2+b_2$ are in $I+J$ where $a_1,a_2\in I$, $b_1,b_2\in J$. Then $(a_1+b_1)+(a_2+b_2)=(a_1+a_2)+(b_1+b_2)$ where $a_1+a_2\in I$ and $b_1+b_2\in J$ since $I,J$ are ideals of $R$. Thus $(a_1+b_1)+(a_2+b_2)\in I+J$, so $I+J$ is closed under addition that tells $I+J$ is additive subgroup of $R$.   Since $I,J $are additive subgroups of $R$, let $a\in I$ and $b\in J$, then $\exists -a\in I$ an $\exists -b\in J$ such that $(a+b)+(-a-b)=(a-a)+(b-b)=0\in I+J$ ; therefore, $I+J$ is a additive subgroup of $R$.  Let $a+b\in I+J$ where $a\in I, b\in J$ and $r\in R$. Since $I,J$ are ideals, so $ar,ra$ are in $I$ and $br,rb$ are in $J$, thus $r(a+b)=ra+rb\in I+J$ and $(a+b)r=ar+br\in I+J$. Therefore, $I+J$ is an ideal of $R$.    Does my proof valid? If valid, is there any way to write a better proof? If not, can you tell me what I miss? Thanks


Git on Visual Studio shows files from another branch

I have done the following test on Visual Studio 2017:  1) Created new repo with master branch:    It just has a gitginore file:    2) Created Branch1 with file1:      3) Checkout master branch again, and opened 'Show folder view':      Why on earth am I seeing file1 in master branch?


is shipped out with TeX Live, but not with MiKTeX, not even with a full installation.  Do you nonetheless know a way for manual installation? MiKTeX needs to know the path of the sty files, and the Asymptote binary file needs to know the path of the asy scripts. Thought of adding the Asymptote folder to the list of registered root directories in MiKTeX, but MiKTeX complains, that this would be “Not a TDS-compliant root directory”.  There is already a similar question: .


It is known that the closure $\overline{S}$ of a set $S$ is the union of $S$ and its boundary $\partial S$ : $\overline{S} = \partial S$ $\cup$ $S$ . I know that $\overline{S} = \partial S$ $\cup$ $\mathring{S}$ but I was wondering if we can write it with a disjoint union : $\overline{S} = \partial S$ $\sqcup$ $\mathring{S}$ since I remember that $\partial S$ $\cap$ $\mathring{S}= \emptyset$.


How does the /proc//exe symlink differ from ordinary symlinks?

If I start a process and then delete the binary of it, I can still recover it from /proc/<pid>/exe:  $ cp `which sleep` . $ ./sleep 10m & [1] 13728 $ rm sleep $ readlink /proc/13728/exe                            /tmp/sleep (deleted) $ cp /proc/13728/exe ./sleep-copy $ diff sleep-copy `which sleep` && echo not different not different $ stat /proc/13728/exe    File: ‘/proc/13728/exe’ -> ‘/tmp/sleep (deleted)’   Size: 0           Blocks: 0          IO Block: 1024   symbolic link   On the other hand, if I make a symbolic link myself, delete the target and attempt to copy:  cp: cannot stat ‘sleep’: No such file or directory   /proc is an interface to the kernel. So does this symbolic link actually point to the copy loaded in memory, but with a more useful name? How does the exe link work, exactly?


I quite often need to reset "Ethernet" connection as shown above. Currently I disable then enable it from the control panel but I wonder if I can create a script that I can simply double-click from my desktop or whatever? My preference would be a batch file simply as I'm most familiar, but I would imagine this is perhaps more suited to Powershell?


Prove or disprove that $f$ is identity function given that $f$ is continuous and $f(f(f(x)))=x$

Let $f $ be continuous on $\mathbb{R}$ satisfying $f(f(f(x)))=x$ for all $x\in \mathbb{R}$.  Prove/disprove that $f$ is an identity function. So far I have figured out that any  point $x$ such that $f(x)\neq x $ is not isolated(if it exists). i.e every neighbourhood of such a point contains other points where function is not identity. Cant proceed any further!


Prevent Mac to sleep when lid closed on Mojave / Catalina

So I saw a lots of old discussion on this topic, but I'm trying to find out an actual solution that still works on Mojave / Catalina, without the use of external monitor/keyboard/mouse/with power adapter.  When looking up Amphetamine, they claimed that you can only do it when the 4 criteria are met, and cannot overridden it.     But on the other hands, Anti Sleep provide the feature in their pro version...     So, which one gets the real deal ? Is Anti Sleep lying about it or Amphetamine (and all other caffeine app on the appStore) is out of date ?  I also heard about InsomniaX and built-in caffeine  but it's really not user friendly, and appear not to be supported anymore...


Limit of infinite loops of sin x as n tends to infinity

Show that $$lim_{n\to\infty} \text {sin sin ... sin x} = 0 $$ for all x.  Note that the n here refers to the number of sin in the expression above.


I have an XML file looking like this:  <root xmlns="myNameSpace">     <Director>         <Name>Paul</Name>     </Director>     <Company>         <Name>Sony</Name>         <Identifier>8945</Identifier>         <CreationDate>2016-01-19</CreationDate>     </Company>     <Signature xmlns="otherNS">         <!-- Some datas-->     </Signature> </Root>   I'm coding a WCF WebService in C# and I want to parse the XML file. I want to check if the balise Company exist and if it contains the Name. WHat is the best way to check if a xmlNode contains a specific children ?  Here is my code :  private String writeResponse(XmlDocument xmlRequest) {     XmlNodeList CompagnyNode = xmlRequest.GetElementsByTagName("Company", Properties.Settings.Default.nameSpaceUri);     if (CompagnyNode == null || CompagnyNode.Count <= 0)         throw new ApplicationException("writeResponse : Missing Company");       // Code below doesn't work      // This part return an empty XmlNodeList (Count = 0)     XmlNodeList test1 = xmlRequest.SelectNodes("/root/Company/Name");      // This part return an empty XmlNodeList (Count = 0)     XmlNodeList test2 = CompanyNode[0].SelectNodes("Name");      // This part return too much node     XmlNodeList test3 = xmlRequest.GetElementsByTagName("Name", Properties.Settings.Default.nameSpaceUri); }


Counterfeit NES/SNES Games-how to know if it's fake?

The other day, i plugged in a copy of Mortal Kombat 3, and the console I was using was one of the new dual consoles(nes+snes games). I got a message at the start that said something about pirated games. How can I know if I bought say Earthbound at a Vintage Stock or Ebay is going to be authentic? Some of these older games are fairly expensive.


I've created a Baidu account to submit my sitemap.xml file to Baidu Search Console. I've also verified my phone number & email address. But when I try to submit my sitemap, they want the name as Chinese characters & QQ account number.  I'm not from China, how can I submit my sitemap to Baidu?


python regex can't match,but matched in javascript with same parttern

code is here:        import re      res = re.match('bbs1','http://bbs1.people.com.cn/userInfo.do?userNick=%E8%85%BE%E9%A3%9E%E4%B8%AD%E5%9B%BD%E9%BE%99')     print(res)   It's print None,but when I change parttern to 'http',it matches; The same parttern in javascript can matched;  var url = 'http://bbs1.people.com.cn/userInfo.do?userNick=%E8%85%BE%E9%A3%9E%E4%B8%AD%E5%9B%BD%E9%BE%99' url.match(/bbs/)


Disabling windows updates for windows 10

Starting with windows 8 I have many many many hardware issues (that are not present in Windows 7). One of these issues is the fact that an initiated restart does not work. It shuts down, the bios shows up, loads, then the windows boot loader begins loading and suddenly the progress ring halts and nothing happens anymore (I have tested it for several hours). While this is not really a problem usually (If a service attempts to initiate a restart I just pull the power after saving everything) with windows 10 it became a problem. A while ago obviously a new build was released and it tried to install said build. This is done using an initiated restart. The restart happens, it hangs in the boot loader and when I reset the machine I get the usual "Your windows has been reverted to an earlier version" message. So far so good. The problem is that since then every day this happens. It randomly asks me if I want to apply the update now, I obviously dont want it to, and set it to remind me again in 8 hours. I dont know what insane person had the idea that a forced shutdown that kills every living thing on your computer was the appropriate action for something as utterly unimportant as an update but sadly after these 8 hours it does exactly that.   After loosing a several gb download and a very long compilation has been corrupted I'm now ready to do everything to stop this madness. I first tried it the nice way and checked the update settings. Windows responds witht he following:   A note here: I am the system administrator, this is a home computer and I am on the only account there is. How do I get rid of this non-sense?   Next I tried to forcefully kill the entire update service. It seems it worked for regular updates, but the preview build update is something that is not covered by that. When I go to the settings for new build installations all I am able to change is the time new builds should be installed (if available). Is there a way to completely disable that?  So to summarize: Is there a way to prevent windows from performing any action if there are updates? Or disable updates completely? Making everything manual? In the end the updates have destroyed more on my computer than they have prevented.


I am not able to run this Python file from terminal.  I have added the shebang:  #!/usr/bin/env python   at start of the file.    Am I doing something wrong? How can I run this file from terminal?  EDIT:  I guess, this might be helpful.


How to move boot and root partitions to another drive

I have two drives on my computer that have the following configuration:  Drive 1: 160GB, /home Drive 2: 40GB, /boot and /   Unfortunately, drive 2 seems to be dying, because trying to write to it is giving me errors, and checking out the SMART settings shows a sad state of affairs.  I have plenty of space on Drive 1, so what I'd like to do is move the / and /boot partitions to it, remove Drive 2 from the system, replace Drive 2 with a new drive, then reverse the process.  I imagine I need to do some updating to grub, and I need to move some things around, but I'm pretty baffled how to exactly go about this. Since this is my main computer, I want to be careful not to mess things up so I can't boot.


I have a Lenovo G510, running Windows 10 Home 32-bit, and 4 GB RAM, but on the Task manager it shows that I can use only 1.5 GB of it.  In order to speed up my computer and free ram, I've downloaded Wise Memory Optimizer, and it shows that I can use only 2.5 GB.  So, how much RAM can I really use? And if it less than 4 GB, then how can I use really 4 GB?


Prove or disprove: for any comm. ring $R $,   For three $R $-modules $M $, $N $ and $P $, $M \oplus P \simeq N \oplus P $ implies $M \simeq N $. Let $f:M\to N $ and $g:N\to M $ be two $R $-module homomorphisms such that $gf=1_M $ (where $1_M = \operatorname{id}_M$ means the identity map on $M$). Then, $N\simeq\operatorname{Im}(f)\oplus\ker(g)$.   If $R $ is a PID and the modules are f.g., 1 is true, but I have no idea on general cases.


I was thinking about giving a finishing touch to my resume by adding a border to the document in black color. I tried using \fancybox but not impressed with the output.  \documentclass[a4paper]{article}  \usepackage[a4paper,vmargin={20mm,20mm},hmargin={20mm,20mm}, includehead,%  includefoot]{geometry}  \usepackage{fancybox}  \begin{document}  \fancypage{\setlength{\fboxsep}{0pt}\fbox}{}  Document text goes here...  \end{document}   The output that I am trying to get is something similar like this.    How do  I get multiple recessed rectangle covering the whole page ?


Where can I find the ubuntu build that works on the x1 carbon gen6

according to  there is an ubuntu 16 that is certified to work with the lenovo x1 carbon gen6. Can I get it? If so where? If not, why not?  Thanks


Why does any non-zero expression raised to the power of 0 equal 1?

How would you answer? When I opened Photomath, it said any non-zero expression raised to the power of zero equals one.


I have a lot of DWG files like basemap, and water and wastewater network.  How do I import these files into my QGIS project?


Is reducing a matrix to row echelon form useful at all?

I have just started auditing Linear Algebra, and the first thing we learned was how to solve a system of linear equations by reducing it to row echelon form (or reduced row echelon form). I know how to solve a system of linear equations using determinants, and so the using row echelon form seems to be very inefficient and an easy way to make mistakes.  The lecturer seemed to indicate that this will be useful in the future for something else, but a friend who has a PhD in mathematics said it is totally useless.  Is this true? Is this technique totally useless or is there some "higher mathematics" field/ technique where row echelon form will be useful?