Thank you in advance for your assistance.  I recently purchased a new laptop for use with Ubuntu 14.04 (Dell Inspiron i3542-8334BK), and am pleased to report that almost everything works out of the box.  The one exception is the touchpad. Ubuntu does not recognize it as a touchpad, but rather as a mouse. Note that Windows 7 (default installation on my laptop) DOES recognize the touchpad and has full support. Curiously enough, Debian Wheezy also supports my touchpad (running kernel version 3.2).   The largest problems with this are as follows:   No scrolling The sensitivity of tap-to-click is outrageous. I normally disable tap-to-click due to general sensitivity problems in Trusty but here I can barely type a sentence without the touchpad accidentally clicking somewhere I don't want it to.   The relevant output from  xinput list  is:   Virtual core pointer                     id=2    [master pointer  (3)] ⎜   ↳ Virtual core XTEST pointer                id=4    [slave  pointer  (2)] ⎜   ↳ DLL0651:00 06CB:2985                      id=11   [slave  pointer  (2)]   DLL0651:00 06CB:2985 is, of course the touchpad.  Thanks!  UPDATE: The previous Linux Kernel version did not provide support for my touchpad. A kernel update that happened today offered full hardware support.

I just got my laptop in the mail and I installed Ubuntu 14.04 LTS. It all went smooth until it booted up and I noticed my touch pad doesn’t work at all. It works perfectly on Windows and when I use a wireless mouse it works as well.  Here's my xinput:  ⎡ Virtual core pointer                          id=2    [master pointer  (3)]   ⎜   ↳ Virtual core XTEST pointer                    id=4    [slave  pointer  (2)]   ⎜   ↳ 2.4GHz RF  KEYBOARD  AND  MOUSE               id=11   [slave  pointer  (2)]   ⎜   ↳ DLL06AB:00 06CB:78F1                          id=13   [slave  pointer  (2)]   ⎜   ↳ SynPS/2 Synaptics TouchPad                    id=15   [slave  pointer  (2)]   ⎣ Virtual core keyboard                         id=3    [master keyboard (2)]       ↳ Virtual core XTEST keyboard                   id=5    [slave  keyboard (3)]       ↳ Power Button                                  id=6    [slave  keyboard (3)]       ↳ Video Bus                                     id=7    [slave  keyboard (3)]       ↳ Power Button                                  id=8    [slave  keyboard (3)]       ↳ Sleep Button                                  id=9    [slave  keyboard (3)]       ↳ 2.4GHz RF  KEYBOARD  AND  MOUSE               id=10   [slave  keyboard (3)]       ↳ Integrated_Webcam_HD                          id=12   [slave  keyboard (3)]       ↳ AT Translated Set 2 keyboard                  id=14   [slave  keyboard (3)]       ↳ Dell WMI hotkeys                              id=16   [slave  keyboard (3)]     I would love to have my track pad working and I've done some googling and browsing of this site and nothing I've tried has worked. Any input would be great. Let me know if there’s any other information that can help remedy this. I'm pretty new to Linux. Thank you very much.  Edit: I've updated the kernel to 3.19 and checked my Additional Drivers which had nothing for me. Neither of which worked.


In the following sentence: "It came into existence on or by 30 September." What does "by 30 September" mean?

I have read the Rules of a competition. The text of the Rules include a sentence as follows:     As per stated in the Rules the entrants will be notified by May 30th 2010.   Does the sentence above mean that May 30th is included in the term of notification or not?


I need to speed up PC System Time by adding a random number of seconds for each (for example) 200 milliseconds. I tried to solve this problem by looking at  thread.  using System; using System.Runtime.InteropServices; using System.Threading;  namespace TimeSpeedUp {     struct SystemTime     {         public ushort Year;         public ushort Month;         public ushort DayOfWeek;         public ushort Day;         public ushort Hour;         public ushort Minute;         public ushort Second;         public ushort Millisecond;     }     class Program     {         [DllImport("kernel32.dll", EntryPoint = "GetSystemTime", SetLastError = true)]         public extern static void Win32GetSystemTime(ref SystemTime sysTime);          [DllImport("kernel32.dll", EntryPoint = "SetSystemTime", SetLastError = true)]         public extern static bool Win32SetSystemTime(ref SystemTime sysTime);         public static Random Random = new Random();          static void Main(string[] args)         {             Timer timer = new Timer(SetTime);             timer.Change(0, 200);             while (true)             {                 ConsoleKeyInfo keyInfo = Console.ReadKey(true);                 if (keyInfo.Key == ConsoleKey.Escape)                 {                     break;                 }             }         }          public static void SetTime(object obj)         {             // Current time             SystemTime currentTime = new SystemTime();             Win32GetSystemTime(ref currentTime);             // Set system date and time             SystemTime updatedTime = new SystemTime();             updatedTime.Year = (ushort)currentTime.Year;             updatedTime.Month = (ushort)currentTime.Month;             updatedTime.Day = (ushort)currentTime.Day;             updatedTime.Hour = (ushort)currentTime.Hour;             updatedTime.Minute = (ushort)currentTime.Minute;             updatedTime.Second = (ushort)(currentTime.Second + Random.Next(1, 3));             // Call the unmanaged function that sets the new date and time instantly             Win32SetSystemTime(ref updatedTime);         }     } }

How can I change the local system's date & time programmatically with C#?


I'm making a custom map and I needed some help from you guys! I'm trying to use the /testfor command in 1.9 and here's what I've tried:  /testfor @a[-47,10,-37,1]  /testfor @p[-47,10,-37,0]  /testfor @p[-47,10,-37]  /testfor @p[x=-47,y=10,z=-37,r=1]   Any suggestions? Thanks in advance! :)

If I do:  /testfor @p[x=,y=,z=,r=]   It says:     The entity UUID is in an invalid format.


As I know, exponential function is strictly monotonic increasing function. So it means that for $x,y \in \mathbb{R}$, if $e^x=e^y$ then $x=y$. But how about exponential matrix? If I have two matrices $X,Y$ satisfy $e^X=e^Y$, does that mean $X=Y$?

Let $G\subseteq GL_n(\mathbb R)$ and let $\mathfrak g$ denote its Lie algebra.  Let $e: \mathfrak g \to G$ be the map $X \mapsto e^X$.     Does there exist an example of $G$ and $\mathfrak g$ such that $e$ is   not injective?   Of course I think the answer is no, there is no such example because $e: \mathbb R \to \mathbb R$ is injective.      What about $G\subseteq GL_n(\mathbb C)$?   Since the map is the same I again think there should not exist such an example.


Today while installing a 12v LED strip on my windows with the power adapter plugged but the LED turned off, I noticed the led that I pushed down against the wall got turned on partially. It wasn't right. My finger shouldn't have enough resistance to turn on those led with 12v. Right away, I tested the DC adapter output line with a 90-1000vac surveyor and found out that the 12vdc line from the DC adapter carries a high voltage AC. When testing with a meter, it measures about  12vdc, and unstable AC range from 38-0Vac. ( properly higher AC voltage, since my meter may not be fast enough.)  1, Is it safe to use this power adapter? ( It powers up the LED strip fine. I have also found a 5V usb charger that carries a HIGH voltage AC before, of which I discarded right away.)  2, What is the cause of this HIGH voltage AC? ( Is it because it's not isolated? or it's not filtered properly at the output end? I can't open the case, as it's sealed completely with no screws. )

I'hv seen every 2 pin SMPS AC to DC adapters shows a little high voltage respective to the ground on the out put, on both + and GND wires(or more if more wires present).  This voltage is high enough to light small neon bulbs or a line tester, but very low current, barely could be felt. This voltage vanishes if I connect the output to ground somehow, e.g. touch it while standing on floor bare foot.  As the size of the adapter increases, the AC voltage and current increases. When laptop adapters are powered from a ungrounded AC outlet, they gives reasonable shock from the 19V DC(or whatever else) output.  Perhaps this is the reason why many 3 pronged laptop adapter carries a warning CONNECT ONLY TO GROUNDED OUTLET Connecting to a grounded outlet magically vanishes the high voltage.  I am aware about the EMI filtering capacitor connected between high voltage and low voltage ground, I tried to solve this by removing them, but this trick is not working.   Why and how this mysterious AC voltage is created ?  Is it harmful to sensitive electronics components ? Is there any way to solve this without grounding the DC output side ?


I am trying to understand what is a constructor and could you tell me why I am still able to run the program without error?  As you can see I am not doing it correctly but it still works!! why?? and when I tried to put LL=(object name ) after my class DELL it is not working? but when I retrieved the LL it works why??? If I am not clear do not hesitate to tell me and I am sorry in advance for this mess  #include <iostream> #include <string> using namespace std;   class DELL{ public:     DELL(){         cout <<" bla bl bla\n";     }     void setname(string x){         name = x; }          string getname()         {             return name;} private: string name;   };  int main(){      DELL (); // Variant 1     DELL LL(); // Variant 2     return 0;  }

Is there any good reason that an empty set of round brackets (parentheses) isn't valid for calling the default constructor in C++?  MyObject  object;  // ok - default ctor MyObject  object(blah); // ok  MyObject  object();  // error   I seem to type "()" automatically everytime. Is there a good reason this isn't allowed?


On , I exchanged some comments with someone going by the name "user6292850 and continued that discussion .  Later, I returned to see that the comments were now attributed to a user named "" in the comments section, but NOT in the continuation in chat (and ). Does it make sense to have the names change in chat as well, if it's being changed in the comments? Alternatively, does it make sense to not change the names in either place, to be consistent with both chat and other commenters' references?

There are answers or  which refer to answers by another user's username without providing a link to them, if the user's name has changed there is no way to know which answer is being referred.  Possible improvements:   Ease other answers linking via Markdown (say, ^answerid:123^, or whatever syntax makes sense) Keeping a name trail Others?   I don't know how pervasive this problem is, it is probably very small and doesn't even deserve any action.


Sorry for the broken english  hallo i have this small problem with my duelshock 4 controller  it wont connect with my ps4 i tried to reset and it still doesn't work  the licht doesn't blink if you push the ps4 button.  i tried to use it on my pc it works a little bit but it loses connection every 6 seconds   I don`t know if a part is broken because this controller is 3 years old

I was playing my PS4 two days ago and then packed it up with two controllers that were both connected to this PS4.   I got to where I was going, set everything up and now the controllers won't connect. They show pulsing orange when they plug in, but when I hit the PS Button to connect, it blinks white 1-2 times and goes back to orange.   I have tried resetting them both.  Can anyone help?


$type_of_poker = "hold'em no limit"; $sql = "INSERT INTO hands (type_of_poker) VALUES ('$type_of_poker')";   Im trying to put hold'em no limit into a SQL database but it won't let me use ' i cant upload holdem no limit for a long list resones that have to do  with the rest of my code.

If user input is inserted without modification into an SQL query, then the application becomes vulnerable to , like in the following example:  $unsafe_variable = $_POST['user_input'];   mysql_query("INSERT INTO `table` (`column`) VALUES ('$unsafe_variable')");   That's because the user can input something like value'); DROP TABLE table;--, and the query becomes:  INSERT INTO `table` (`column`) VALUES('value'); DROP TABLE table;--')   What can be done to prevent this from happening?


Can somebody help me, i need to replace HTML content of element inside DOM using jQuery ajax. The EventListener, from which i call this replacement is tied to one of the inner elements inside html that is about to be replaced, so i need to register new eventListener after replacement and i need to do it after 2 consecutive ajax requests. Does such code breaks anything? 1.It seems to work, but i do not know, is this event listener lives until all async code is run inside it? 2.Is creating another EventListener recursively is ok and doesn't interrupt current one? 3.Also, i'm new to javascript and jquery, how to properly call function from inside object "c" in my case and from inside  jquery.delegate callback at the same time? is it ok to do like i did? Like "c.ajaxHtml();" const c = {     // ...     onPaymentToShipping: function() {         $(document).delegate('#guest-shipping-address-body input[type=\'checkbox\']', 'click', function() {             if(this.name == "shipping") {                 if(this.checked){                     c.ajaxPaymentToShipping();                     const hideCrap = document.querySelector('.collapsible');                     if(hideCrap){                         hideCrap.style.display = 'none';                     }                 }                 else{                     (async function() {                         //saves data via jQuery ajax                         await c.ajaxPaymentToShipping();                          // uses stored data via jQuery ajax, creates new html template and replaces html, where current EventListener is tied to one of inner elements                         await c.ajaxHtml();                          // edit stuff in new html elements using ajax, nothing important, can be run asyncronously                         c.onCountryChange();                           // call same function (recursively once?) to register same eventListener, but for newly created element.                         c.onPaymentToShipping();                      })();                 }             }          });     },     // other stuff...     // ...     // ... }

I have a bit of code where I am looping through all the select boxes on a page and binding a .hover event to them to do a bit of twiddling with their width on mouse on/off.  This happens on page ready and works just fine.  The problem I have is that any select boxes I add via Ajax or DOM after the initial loop won't have the event bound.  I have found this plugin (), but before I add another 5k to my pages with a plugin, I want to see if anyone knows a way to do this, either with jQuery directly or by another option.


I computed the gcd of the 2 polynomials in the ideal and their gcd is equal to 1 ,using euclid algorithm.  I want to know if the ideal in the title is a principal ideal and why ?   I know a principal ideal is the ideal generated by only one element.So $\langle  x^2,x+1 \rangle = \langle 1 \rangle$ but if that was a principal ideal then any ideal generated by 2 or more ideals would be principal because he could be generated by $1$ or some gcd of those polynomials. I think the same for non polynomial rings .. since the gcd can be 1 or any number , any ideal can be generated by one element so any ideal would be principal.What am I missing ?

I tried the following $$I = \langle X^2,X+1\rangle =\langle X^2,X+1,X^2+2(X+1)\rangle =\langle X^2,X+1,(X+1)^2+1 \rangle$$  Yet no matter how I arrange it, I cannot obtain $1$. Can someone help me out?


I am using the email validation as mentioned below :  private static final String EMAIL_PATTERN = "^[_A-Za-z0-9-\\+]+(\\.[_A-Za-z0-9-]+)*@[A-Za-  z0-9-]+(\\.[A-Za-z0-9]+)*(\\.[A-Za-z]{2,})$";   in this pattern i need (hypen, apostrophe, underscore, period) to be included.  For example - pqr.m.o'abc@xyz.com  Please suggest

Over the years I have slowly developed a  that validates MOST email addresses correctly, assuming they don't use an IP address as the server part.  I use it in several PHP programs, and it works most of the time.  However, from time to time I get contacted by someone that is having trouble with a site that uses it, and I end up having to make some adjustment (most recently I realized that I wasn't allowing 4-character TLDs).  What is the best regular expression you have or have seen for validating emails?  I've seen several solutions that use functions that use several shorter expressions, but I'd rather have one long complex expression in a simple function instead of several short expression in a more complex function.


What does the  user do?  In particular, the description says that one of the things that it does is     Randomly poke old unanswered questions every hour so they get some attention   What does that mean?

I see the  on the user page.  It seems to edit posts sometimes.  What is it? And why has it downvoted over 1800 times? See also:


My understanding is that I should only use a comma before "but" if it precedes an independent clause.  What if I want a "pause comma" before "but" and it does not precede an independent clause?  Example:  One day, Ted thought he saw another boy dancing, but it was just the reflection of himself.

I was once told by an English professor that a comma should never be used before but in a sentence. For years, I have followed her advice but sometimes I just feel like it just needs to be there. On the other hand, my brain also tells me that the word but is, in a sense, performing the same function as a comma in the sentence.    Does anyone know if there is a rule for this?


I've written a short python script for use in QGIS (currently using 2.8.1) to set the CRS for all loaded layers to OSGB 1936 / BNG. The script correctly sets the CRS but I have to manually scroll in/out to refresh the screen after running it - not a big issue though slightly annoying and possibly easy to fix!  I've tried using the code snippet below to refresh but I still have to manually scroll in/out.  qgis.utils.iface.mapCanvas().refresh()   Is there a line of code to force a full refresh/re-render of all loaded data?

How to  automatically reloaded raster layer if source is changed? (The path is the same but inside source file are changes)  I use:   qgis.utils.iface.mapCanvas().refresh()   but layer not refresh.  # # #  The maps are repainting but there are still the same image (source file is changed on disc)  I use:    layers = qgis.utils.iface.legendInterface().layers()   for layer in layers:       layer.triggerRepaint()


[root@host]# ls -lad /etc/ecm/zookeeper-conf lrwxrwxrwx 1 root root 29 May 11 19:51 /etc/ecm/zookeeper-conf -> /etc/ecm/zookeeper-conf/3.4.6   I have a smylink from /etc/ecm/zookeeper-conf point to /etc/ecm/zookeeper-conf/3.4.6 But /etc/ecm/zookeeper-conf/3.4.6 doesn't exist.   So, when I run ln -s /etc/ecm/zookeeper-conf-3.4.6 /etc/ecm/zookeeper-conf, I get ln: failed to access '/etc/ecm/zookeeper-conf': Too many levels of symbolic links   1.How to build a smylink forcibly with ln?  2.How to decide whether a bad symlink is exist with python? If you run os.path.exists(bad-link), you will get False

If I call os.stat() on a broken symlink, python throws an OSError exception. This makes it useful for finding them. However, there are a few other reasons that os.stat() might throw a similar exception. Is there a more precise way of detecting broken symlinks with Python under Linux?


How do I calculate  of Lie group and Lie algebra? I would be thankful if anyone can give good example or general formula on calculating adjoint of any Lie group

Given the Lie algebra, what is the systematic way to construct the matrix representation of the generators of the desired dimension? I ask this question here because it is the physicists for whom representation of groups is more important than mathematicians.   Let us, for example, take $SU(2)$ for concreteness. Starting from the generic parametrization of a $3\times 3$ unitary matrix $U$ with $\det U=1$, and using the formula of generators $$J^i=-i\Big(\frac{\partial U}{\partial \theta_i}\Big)_{\{\theta_i=0\}}$$ one can find the $3\times 3$ matrix representation of the generators.  However, I'm looking for something else.    Given the Lie algebra $[J^i, J^j]=i\epsilon^{ijk}J^k$, is there a way that one can explicitly construct (not by guess or trial) the $3\times 3$ representations of $\{J^i\}$? Will the same procedure apply to solve other Lie algebras appearing in physics such as that of $SO(3,1)$ (or $SL(2,\mathbb{C})$)?


While roaming in meta stackoverflow I came across an user named .  I checked one of his best answer   where I found his username as Al Everett.  on clicking, it redirects to his profile named as Krampus.  Here is a couple of screenshots     I guess it happended because it is a migrated question whereas I don't see it in other questions.

On a whim the other day, I changed my meta name from Lord Torgamus to Popular Demand.  I just noticed that the old name has "stuck" to the author tag of ; everywhere else on meta, my new name displays as expected.  Is this a feature?  Is it a bug?  Mostly I'm just curious, as I can't think of a strong reason in favor of keeping this behavior or a strong reason for changing it.  A question somewhat like this has been raised before as , but the previous poster implied that the issue had something to do with migration, which my situation shows is not the case.


sorry if this is very basic, but I've been going around in circles for a while. I'm new to PHP, but none of the documentation seems to help, and none of the previous questions on here quite explain it.  I'm trying to create a simple form that takes user input and creates a record in a database, but the code I have does not seem to recognise the variables provided. When I use strings instead, the insert operation completes, so I know it's not a problem with the connection.  I don't get any error messages - the page refreshes as though nothing had happened.  <form action="" method="post">     <input type="text" name="new_word" id="word" required="required"/>     <input type="text" name="book_ref" id="book" required="required"/>     <input type="text" name="page_range" id="page" required="required"/>     <input type="submit" value="Submit" name="submit"/> </form> <?php if(isset($_POST["submit"])){     $servername = "localhost";     $username = "user";     $password = "pass";     $dbname = "database";     $conn = new mysqli($servername, $username, $password, $dbname);     if ($conn->connect_error) {         die("Connection failed: " . $conn->connect_error);     }     $stmt = $conn->prepare("INSERT INTO `words` (`Word`, `Book ID`, `Page`)  VALUES (?,?,?)");     $stmt->bind_param(1, $word);     $stmt->bind_param(2, $book);     $stmt->bind_param(3, $page);     $word = $_POST["new_word"];     $book = $_POST["book_ref"];     $page = $_POST["page_range"];     $stmt->execute();     $conn->close(); } ?>

If user input is inserted without modification into an SQL query, then the application becomes vulnerable to , like in the following example:  $unsafe_variable = $_POST['user_input'];   mysql_query("INSERT INTO `table` (`column`) VALUES ('$unsafe_variable')");   That's because the user can input something like value'); DROP TABLE table;--, and the query becomes:  INSERT INTO `table` (`column`) VALUES('value'); DROP TABLE table;--')   What can be done to prevent this from happening?


I have a schengen visa for single entrance. My itinerary shows that My first entry country will be Italy.  At the same time, on my visa there is no country restriction written.   My plans have changed a little after issuing visa and I will travel to my destination through Barcelona with connection of 4 hrs. So technically it turns out that my first entry will be to Spain.   I would like to know if this will cause any issues? Is it ok or not?

In case, if I get a multiple-entry Schengen visa in one of the embassies in Ukraine, Kyiv - should my first trip be to the country which issued the visa?  Any there any requirements of this sort? Does this condition vary depending on embassy which issued the visa?  What are the possible consequences on not visiting that country first? Does it somehow depend on country where the embassy is (i.e. non-Schengen and not EU members)?


I was just looking at the implementation of , when I stumbled across this snippet:  root = []  # root of the circular doubly linked list root[:] = [root, root, None, None]  # initialize by pointing to self   I am familiar with circular and doubly linked lists. I am also aware that new_list = my_list[:] creates a copy of my_list. When looking for slice assignments or other implementations of circular doubly linked lists, I could not find any further information on this specific syntax.  Questions:   What is going on in this situation. Is there a different syntax to achieve the same result? Is there a different common use case for some_list[:] = some_iterable (without the self reference)?

I need a good explanation (references are a plus) on Python's slice notation.   To me, this notation needs a bit of picking up.   It looks extremely powerful, but I haven't quite got my head around it.


I installed Ubuntu from the Microsoft Store on Windows 10 Version 1803 and it appeared to install properly. Normally when it first comes up it will prompt for a username and password and then let you do whatever you want. In this case the Ubuntu window closes down immediately both after the continuation in the initial install and after trying to invoke it from the task bar. I have successfully installed it on a prior  setup of Windows 10 version 1803. What should I look for that might prevent me using Ubuntu?

Please let me know if there is a more appropriate site to post this error. I have a brand new Dell i-7 Skylake laptop, brand new Samsung Pro 960 SSD, New Windows 10 build 16299 (Fall Creators Update released yesterday) just upgraded from build 15063. I downloaded Ubuntu from Windows Store and get this error: The WSL optional component is not enabled. Please enable it and try again. See https://aka.ms/wslinstall for details. Error: 0x8007007e Press any key to continue...  I googled the recommended site and passed the hex error code with no luck. Rebooting didn't help. Any ideas?


I have problem in formatting json string in c#  I have following two lines  string formater = @"{'attachments':[{'title':'New item added','title_link':{0},'text':{1},'image_url':{2},'color':'#764FA5'}]}"; string myJson = String.Format(formater, product.Url, "text", product.ImageUrl);   I'm getting this Exception  System.FormatException: Input string was not in a correct format.   I think because of curly braces inside formatting string, how can i escape?

How can brackets be escaped in using string.Format? For example: String val = "1,2,3" String.Format(" foo {{0}}", val);  This example doesn't throw an exception, but it outputs the string foo {0}. Is there a way to escape the brackets?


I am flying with Qatar Airways, Manchester to Melbourne, via Doha in March of this year. However I would like to check in an additional bag. However the website does not display a cost per bag, but simply per kilo. Why, when other airlines only charge £65 per extra bag (British Airways) do an airline such as Qatar not offer a similar service, but charge per Kilo. I am flying in 3 months so I have no idea how many kilos exactly I would need and to just pay for an additional bag seems so much more simple. Any help would be appreciated

Can I pre-purchase more luggage allowance on Qatar Airways flights?  I am traveling with Qatar Airways from Stockholm, Sweden (ARN) to Bangkok, Thailand (BKK) and I will be carrying one additional bag beyond the carry-on and standard check-in bag.   Am I able to pre-purchase allowance for this additional bag or is it always counted as excess luggage according to the fee list on their website?  And if so are there different rules for different routes (i.e transatlantic fares or such)?


My Ubuntu version is 18.04.3 LTS. I am trying to install Node.js v12. but i can see that Version: 8.10.0~dfsg-2ubuntu0.4 can only be installed in my ubuntu . How to upgrade the version of node from 8.10.0 to 12?I tried many solutions but nothing worked for me.

How do I install the latest  on Ubuntu? I've been looking around, and I can't find anything. Is there a Ubuntu package for node.js, or do I have to compile it myself?


I need to include some SVG graphics in my latex file. The SVG files have been created with a Python program, they don't come from Inkscape (I know that there are a lot of questions answered about the connection Inkscape - SVG file - Latex, but this is not my case).  What I tried to do is, in summary:  \usepackage{svg}  \begin{figure} \includesvg{image} \end{figure}   and I also tried to set the -synctex=1 -interaction=nonstopmode --shell-escape %.tex in the Configure Texmaker section. This did not work out, producing  ! LaTex Error: File './image' not found.   How to solve it?

I'm trying to use the svg package for inserting svg images in my latex file, as suggested in other questions. But now I ran into a problem:  For example I have a image figure1.svg, if I write  \includesvg{figure1}   it will give an error says  ERROR: LaTeX Error: File `figure1.pdf_tex' not found.   But if I write  \includesvg{figure1.svg}   it will give another error says  ERROR: LaTeX Error: Unknown graphics extension: .svg.   How can I fix this problem? I'll prefer not having to convert all my svg files to pdf_tex files with some external program.    Update  My LaTeX environment is latest the TeXLive 2013 on Windows 7. A MWE code would be  \documentclass{article} \usepackage{svg}  \begin{document}  \begin{figure}[htbp]   \centering   \includesvg{figure1.svg}   \caption{svg image} \end{figure}  \end{document}


I have a Laars gas boiler that has 3 heating zones; basement, 1st floor, and 2nd floor.  I want to replace the old mercury honeywell tstats on the 1st and 2nd floor with newer honeywell RTH9580 wifi model for both. The 2nd floor is a piece of cake as the current tstat and wiring there also consists of the central cooling control.  So on the 2nd floor I have all the necessary wires for the new tstat there to work with (red, white, yellow, green, and blue).  On the 1st floor however, the current tstat only controls the heat, and there is only the 2 wires, red and white. I have a clear shot to the basement in the wall behind the 1st floor tstat, and can run new wires from there to the boiler, no problem.  My dilemma...once I get the wires there (and do I run 5 wires and just use the red, white, and blue?), how do I hook up the blue wire?  To the boiler itself?  To the wires connected to the zone valves, and which one? Or to the transformer, and how?  I've taken pictures of my entire system, can someone tell me the best method (proper preferred, not necessarily easiest) to accomplish this?   I've added some more pics to included the transformer specs and the boiler schematic                Click for larger view

I have a Laars gas boiler that has 3 heating zones. I want to replace the old mercury honeywell tstat on the 1st floor (heat only) with a newer honeywell RTH9580 wifi model. I've taken pictures of my entire system, labeled the wires in the pics to indicate the associated connections, and included the Laars wiring diagram.  There is a transformer mounted on the wall near the boiler that is wired in-line to the system (power from the panel --> into the emergency boiler switch --> into the wall transformer --> then to the boiler (low water cut off and boiler circuitry).  There is also a transformer within the boiler circuitry itself.  Can someone tell me the best method (proper preferred, not necessarily easiest) to connect the C wire?


Where should I put the comma and the quotes in such a sentence?     The comments were significantly focused on my being “engaging, patient and extremely helpful,” “very coherent and easy-to-understand,” or "clear and straight to the point".   My question is whether I can do something like this "bla," "bla" - meaning, a simple space between two quotes and the comma before the first one.  Thanks!

Possible Duplicate:             Or is it region specific? I was always taught that when ending a quotation, that punctuation remains inside of the quote.     I think he said, "we should go to the store."   Are you sure he said, "we should go to the store?"   As opposed to:     I think he said, "we should go to the store". Are you sure he said, "we should go to the store"?   This is just an arbitrary example off of the top of my head, and it's hard for me to come up with an example for the second usage because it looks completely wrong to me.   I actually got into a small argument with my girlfriend earlier this year because she uses something similar to the second example, and said that's how she was taught (which is why I ask if it's region-specific.)  Anyway, is there a correct usage for ending a quotation with punctuation?


Is there a way to retrieve the source code of every webpage in a website and save them to a single text file?  With the appropriate CRFL characters just as if the pages were retrieved individually under Internet Explorer?  I've tried Wget, but can't seem to find the right combination of options.

How can I download all pages from a website?  Any platform is fine.


I am using Ubuntu 16.04.1.  I try to install git:  sudo apt-get install git-all   I got this error:  After this operation, 0 B of additional disk space will be used. Do you want to continue? [Y/n] y Setting up runit (2.1.2-3ubuntu1) ... start: Unable to connect to Upstart: Failed to connect to socket /com/ubuntu/upstart: Connection refused dpkg: error processing package runit (--configure):  subprocess installed post-installation script returned error exit status 1 dpkg: dependency problems prevent configuration of git-daemon-run:  git-daemon-run depends on runit; however:   Package runit is not configured yet.  dpkg: error processing package git-daemon-run (--configure):  dependency problems - leaving unconfigured No apport report written because the error message indicates its a followup error from a previous failure.                           Errors were encountered while processing:  runit  git-daemon-run E: Sub-process /usr/bin/dpkg returned an error code (1)   How to fix it?

I am using 15.04.   So I'm working with git and I installed the standard version. I set up the ssh keys and was able to clone one of my repositories to the correct folder. Everything was working great and then I decided it was a good idea to install more packages. I ran sudo apt-get install git-all. I'm looking at error codes now having to deal with upstart.  start: Unable to connect to Upstart: Failed to connect to socket /com/ubuntu/upstart: Connection refused No apport report written because the error message indicates its a followup error from a previous failure. dpkg: error processing package runit (--configure):  subprocess installed post-installation script returned error exit status 1 dpkg: dependency problems prevent configuration of git-daemon-run:  git-daemon-run depends on runit; however:   Package runit is not configured yet.  dpkg: error processing package git-daemon-run (--configure):  dependency problems - leaving unconfigured Errors were encountered while processing:  runit  git-daemon-run E: Sub-process /usr/bin/dpkg returned an error code (1)   This is what happens when I even update/upgrade my system. At this point all I'm looking to do is be able to install software and update my current software. Is there any way I can potentially reverse this issue or at least correct it?   Edit: Thankfully this issue was solved only a day or two after it happened. The accepted answer worked perfectly and took care of my issue


How can i redirect on another page when an option is selected from a select element.  HTML select:  <select id='rooms' class="full-width"> <option value="1">1</option> <option value="2">2</option> <option value="3">3</option> <option value="4">4</option> </select>   What i need is to redirect users to page.php when they select the option 2, 3, 4

This page does it the way I want it to:   But I want to find a better way using jQuery, can anyone point me to a good script that uses jQuery to accomplish this?


I've got a table of URLs and I don't want any duplicate URLs. How do I check to see if a given URL is already in the table using PHP/MySQL?


The only reason i was refused visa at France embassy was " the justification of the purpose and conditions of the intended stay was not provided" this happened twice in a year for the same reasons. what can i do to overturn this decision and can i legally apply to other EU states like Spain?

Schengen refusal formulae can be difficult to understand sometimes.    When an applicant receives a refusal with "Justification for the purpose and conditions of the intended stay was not provided", what does it mean?


If $\displaystyle \sum_{n=1}^{\infty}a_n$ and $\displaystyle \sum_{n=1}^{\infty}b_n$ are both divergent series with $a_n\downarrow0$ and $b_n\downarrow0$,   [so $(a_n)$ and $(b_n)$ are decreasing sequences which converge to 0],   and if $c_n=\min\{a_n,b_n\},\;\;$ does the series $\displaystyle \sum_{n=1}^{\infty}c_n$ necessarily diverge?  (I was led to ask this question after reading this question and math110's solution to it: .)

Find examples of two series $\sum a_n$ and $\sum b_n$ both of which diverge but for which $\sum \min(a_n, b_n)$ converges. To make it more challenging, produce examples where $a_n$ and $b_n$ are positive and decreasing.  Edit: This problem is taken verbatim from Exercise 2.7.11 on page 68 of Abbott's Understanding analysis.


Recently, the  in the help center was upgraded. Although it shows nice and clear which badges were earned by me, it does not show how many badges were awarded. For instance, if I have earned two "nice question" badeges, it only shows the badge was awarded to me, but it does not show that I have earned it twice.  Is it possible to add a counter on the badges help center to show how many badges were earned?  For example:                         ^                    |                    +-- like this

When going on the "/badges" page on a StackExchange website.  All you are presented with a tick next to badges you have achieved.    In my opinion is perfect for badges that can only be achieved once, but for those you can unlock more than once, e.g. Enlightened.    Instead of just showing a tick on these types of badges, instead show a number in the green circle (or whatever design is applicable for the website).  I understand that this could cause problems if say the badge was earned #### times.  In this case it could just show a +.  Then if the number was shown on mouse-over it could say ("Earned badge 1643 times.")  Leaving the UI nice and compact.


I can't understand whats problem. I write data to mysql with php and utf-8 issues  Write in HTML form  Binəqədi r. Çiçək  qəs  Writed database Bin?q?di r. ÃƒÆ’Ã†â€™Ãƒâ€ Ã¢â‚¬â„¢ÃƒÆ’Ã‚   When I use mysqli_set_charset($conn,"utf8"); in insert and update query   Writed database Bin?q?di r. Çiç?k  q?s  Write data manually direct to database and use  mysqli_set_charset($conn,"utf8"); in select works normal.   How can I fix it? INSERT and UPDATE with UTF-8. This is my insert code  public function insert($sql) {     $conn = new mysqli(DB_HOSTNAME, DB_USERNAME, DB_PASSWORD, DB_DATABASE);     if ($conn->connect_error) {         die("Connection failed: " . $conn->connect_error);     }     mysqli_set_charset($conn,"utf8"); //  $conn->set_charset("utf8"); use same this.     if ($conn->query($sql) === TRUE) {         return 1;     } else {         return 0;     }     $conn->close(); }   NOTE: This issues on Linux and OSX. In windows work goods. How can I fix it for linux hosting?

I'm setting up a new server and want to support UTF-8 fully in my web application. I have tried this in the past on existing servers and always seem to end up having to fall back to ISO-8859-1.  Where exactly do I need to set the encoding/charsets? I'm aware that I need to configure Apache, MySQL, and PHP to do this — is there some standard checklist I can follow, or perhaps troubleshoot where the mismatches occur?  This is for a new Linux server, running MySQL 5, PHP, 5 and Apache 2.


In the past we declared classes and can change the default value of a property like this:  public class MyClass {     private string name;      public string Name     {           get{  if(name==null) return "";  }           set{  name= value; }     } }   Now we can do:  public class MyClass {     public string Name {get; set;}  }   But how to change the default value in this way? For example, if the name is null, I want to get "" instead of null?

How do you give a C# auto-property an initial value?  I either use the constructor, or revert to the old syntax.    Using the Constructor:  class Person  {     public Person()     {         Name = "Initial Name";     }     public string Name { get; set; } }   Using normal property syntax  (with an initial value)  private string name = "Initial Name"; public string Name  {     get      {         return name;     }     set     {         name = value;     } }   Is there a better way?


I have photos of a product and I would like to create a white background behind it. Like it is done in this example:  I have tried playing with levels and the brightness but that also messes up the product itself. How do i do this?

I'm a new photographer, and I'm trying to take photos of a product with a pure white background (#ffffff). I'm using a light box (something like ), so my lighting should be solid.   But I can't seem to find the right settings for a good photo. I've taken lots of photos (100+), with a lot of different settings and basically my photos are either overexposed, or the background is not white. Here are some examples:  1.    The product is great on this photo. Only the background is WAY to grey.   f/8 -- 1/2000 sec -- ISO-6400    2.    The background is pure white. But the product is overexposed.  f/8 -- 1/320 -- ISO-6400     3.   Too grey and the product is overexposed  f/22 -- 1/200 -- ISO/128000    Based on feedback, I have adjusted the exposure parameters and gotten somewhat , but that that alone doesn't solve the fundamental problem. What else do I need to do to get a pure white background without overexposing the subject?


As far as I know, the derivative of $y$ is defined as:  $$f'(x) = \lim_{h \rightarrow 0} \frac{f(x + h) - f(x)}h = \frac{dy}{dx}$$  So $\frac{dy}{dx}$ is a limit, not a fraction of real numbers. I often read expressions like:  $$dy = f'(x)dx$$  How do we go from $f'(x) = \frac{dy}{dx}$ to $dy = f'(x)dx$? Clearly not multiplying both sides for $dx$.  The  says that:  \begin{align*}   \frac{dy}{dx} &= \frac{dy}{du} \frac{du}{dx} \text{(chain rule)} \\   \frac{dy}{dx} &= \frac1{\frac{dx}{dy}} \text{(Inverse Function theorem)} \end{align*}  This can help me transforming $f'(x) = \frac{dy}{dx}$ to $\frac{dy}{du} = f'(x) \frac{dx}{du}$.  Then how can I proceed getting rid of $du$?

In the book Thomas's Calculus (11th edition) it is mentioned (Section 3.8 pg 225) that the derivative $dy/dx$ is not a ratio. Couldn't it be interpreted as a ratio, because according to the formula $dy = f'(x)dx$ we are able to plug in values for $dx$ and calculate a $dy$ (differential). Then if we rearrange we get $dy/dx$ which could be seen as a ratio.   I wonder if the author says this because $dx$ is an independent variable, and $dy$ is a dependent variable, for $dy/dx$ to be a ratio both variables need to be independent.. maybe?


What is defferent between  List<Integer> list = new LinkedList<Integer>();   and   LinkedList<Integer> list = new LinkedList<Integer>();   When to use the first one and when to use the second one?

I have seen this mentioned a few times and I am not clear on what it means. When and why would you do this?   I know what interfaces do, but the fact I am not clear on this makes me think I am missing out on using them correctly.   Is it just so if you were to do:  IInterface classRef = new ObjectWhatever()   You could use any class that implements IInterface? When would you need to do that? The only thing I can think of is if you have a method and you are unsure of what object will be passed except for it implementing IInterface. I cannot think how often you would need to do that.   Also, how could you write a method that takes in an object that implements an interface? Is that possible?


This is a sci-fi novel, fairly short, and I think fairly old (50s/60s, but might be earlier). The author is well-known, but possibly for other genres as well as sci-fi, and definitely anglophone. I'm fairly sure it's the first book of a trilogy. This man travels to another planet, and things are poisonous (I'm not quite sure about that). Plants have grown to enormous sizes there. The bit I remember the best is that he's rescued by another race, who go out on the water in canoes a lot, and look a bit like otters or seals. He lives in their village for quite a while and learns their language. I think a lot of their words start with "br" or similar, and their life is at quite a slow pace. There's a battle against some other creatures at one point and an elder is killed. He refers to them a lot by the name of their race. There's also a part where he travels over a mountain pass, although I can't remember why, and stops in a cave midway, where he meets a different race, who possibly gives him oxygen (although I might be making that up). I think it's very well known, but I can't get search terms close enough to find it!

I know this is going to be a long shot but my father read a book around 1965-1967 about a space explorer who goes to a planet (he believes it is Mars) where he meets two warring alien tribes. One tribe is short and fat and one tribe is tall and skinny. He also remembers part of the story where the explorer believes one alien is urinating into the water supply and contaminating it but the alien is actually purifying it. Does this sound familiar to anyone? Thank you in advance.  ETA: He says this is not the novels with John Carter in them.


I like c#'s static classes because they can't be instantiated or inherited.  They act like a namespace that can't be imported into the code file which allows for more managed organization.  It doesn't seem that VB.NET has anything truly like this.  Modules - They're static, but everything within them is available in the global application scope which just clutters everything.  MustInherit - Keeps the class from being instantiated, but can still be inherited and then instantiated.  NotInheritable - Can't be inherited, but can be instantiated.  I guess I can settle for MustInherit, but I'd really like to see the c# equivalent of a static class.

As just stated in a recent  and , you can't inherit from a static class.  How does one enforce the rules that go along with static classes inside VB.NET?  Since the framework is compatible between C# and VB it would make sense that there would be a way to mark a class static, but there doesn't seem to be a way.


How do you prove the following fact about the transpose of a product of matrices? Also can you give some intuition as to why it is so.  $(AB)^T = B^TA^T$

Given an $m\times n$-matrix $A$ and an $n\times p$-matrix $B$. Prove that $(AB)^T = B^TA^T$.   Here is my attempt:  Write the matrices $A$ and $B$ as $A = [a_{ij}]$ and $B = [b_{ij}]$, meaning that their $\left(i,j\right)$-th entries are $a_{ij}$ and $b_{ij}$, respectively.  Let $C=AB=[c_{ij}]$, where $c_{ij} = \sum_{k=1}^n a_{ik}b_{kj}$, .  We want $(AB)^T = C^T = [c_{ji}]$. That is the element in position $j,i$ is $\sum_{k=1}^n a_{ik}b_{kj}$. For instance, if $i=2, j=3$, then the element in $2,3$ of $C$ is that sum, but the element in position $3,2$ of the transpose is that sum.  I need to get the same value for the element in position $3,2$ of the right side.  The transpose matrices are $B^T=[b_{ji}], A^T=[a_{ji}]$. They are size $p \times n$ and $n \times m$. That is, they switch rows and columns.  Let $D = B^T A^T = [d_{ji}]$. I write the indices backwards because if I want the element in position $3,2$, that is, $i=2, j=3$ just like on the other side.  So I need the summation for $d_{ji}$. But I get as $d_{ji} = \sum_{k=1}^n b_{jk}a_{ki}$, which does not match.


I'm trying to generalize the problem that follows oif the number of stairs is "n", the problem is "You climb either 1 or 2 stairs at a time, at any given time. How many ways can you get up 11 stairs?"  Eventually I noticed that as I tried n = 1,2,3,4,5 the number of possible ways are 1, 2, 3, 5, 8.... which is somehow resembling the fibonacci sequence... I tried to prove using pascal triangle since it is comnected to combinatorics and fibonacci but i dunno how to start... any idea?

There is a very interesting puzzle for Fibonacci sequence:     You are climbing a stair case. It takes n steps to reach to the top. Each time you can either climb $1$ or $2$ steps. In how many distinct ways can you climb to the top?   The answer is Fibonacci sequence: $F(n) = F(n - 1) + F(n - 2)$. The explanation is that you could reach the $n$th step either from the $(n - 1)$th step or $(n - 2)$th step.  What I fail to understand is why isn't the answer $F(n) = (F(n - 1) + 1) + (F(n - 2) + 2)$. Since, after reaching $(n - 1)$th step I have to take $1$ step to reach the $n$th step and after reaching $(n - 2)$th step I have to take another $2$ steps to reach the $n$th step.  I know I might be ignoring some very stupid detail but it's better to ask and be called a fool once than to remain a fool forever.


Currently, moderators cannot see quickly exactly which privileges a user who has flagged actually has. As described in  by animuson,     when reviewing flags, we   don't see your reputation. Without opening your profile, we have   absolutely no idea what privileges you actually possess.   In the linked question this has lead a moderator to advice a user to do something he/she doesn't have the privilege to do.  My opinion is that moderators should see the relevant privileges, as it is important when writing out a response. New, low-rep users take what moderators respond to flags for granted, and if the advice is wrong due to grounds that user hasn't got enough privileges, it's a really mixed message that will lead to unneeded frustration.  Here's  where lack of seeing the privileges has lead a moderator to do a wrong decision.

When reviewing flags, either from the queue or from the flagged post, I often want to know what the flagger could have done in addition to, or instead of, flagging for mod attention.  Does he have the rep to downvote?  To comment?  To vote to delete?  Knowing this doesn't necessarily affect how I handle the flag, but if there's a possible teaching moment there I use the flag response to point it out.  But I can't find this out unless I click through to the user's profile (unless I already know this user, of course).  Would it be possible to get the flagger's reputation in a tooltip, like what's already done for comments?


I know it seems like a weird question, as these rules are simply a direct application of the limit definition of the derivative of a function.  What I am saying is, could these rules be explained somehow by using intuitive examples and analogies? For example, in my calculus textbook, in the section about the chain rule, the author gives the following note:   "The chain rule should make sense intuitively as follows. We think of dy/dx as the (instantaneous) rate of change of y w.r.t x, dy/du as the rate of change of y w.r.t u & du/dx as the rate of change of u w.r.t x. So, if dy/du=2 (which means that y is changing at twice the rate of u) & du/dx=5 (u is changing at 5 times the rate of x), then it should make sense that y is changing at 2*5=10 times the rate of change of x, or dy/dx=10).   Of course he is refering to the expression (dy/dx)= (dy/du)*(du/dx).  So, is it even appropriate/logical to ask such a question, about the intuitive explanation of these particular rules or rules similar to them? & if not, why?   I'd just like to note something, I am completely convinced that the rule is correct and that it works, because we can just check and confirm it quite easily. And I do not have a problem with applying it.   What I'm just wondering about is wether it can be explained in other ways than just the direct application of the definition of the derivative.

Can anyone think of an intuitive explanation of the product rule? I'm not asking for a derivation. To me it seems like quite an un-untuitive result, as apposed to the chain-rule (which is ironically harder to derive).


Why do photons have zero chemical potential and what is its the physical significance?  From what I know the chemical potential could be interpreted as the energy per unit particle that is put into a (thermodynamic) system... but surely photons also carry energy?

Why massless particles have zero chemical potential?


Let $X$ be a pathwise-connected topological space. Prove that $X$ is simply connected iff every continuous $f:S^1\to X$ can be extended to a continuous function $g:D^2\to X$.  How can I use the fact that there is an identification mapping between $[0,1]\times [0,1]$ and $D^2$ which collapses three of the four sides to a point?  Thank you

Working on this problem.      If any $f:S^1\rightarrow X$ extends to a $F:D^2\rightarrow X$, then $\pi_1(X, x_0)$ is trivial.    We can turn any loop $f^\prime:I \rightarrow X$ in $\pi_1(X, x_0)$ into an $f:S^1\rightarrow X$ by defining $f(x) =f^\prime \left(\frac{1}{2\pi}\operatorname{Arg}(x) \right) $.   I want to finish without explicitly showing that $f$ is homotopic to a constant map. (This is part of the "the following are equivalent proof" with that as part (a) so I would like to avoid assuming that or proving it midway. I should be able to do it with the extension map only.) I think I am supposed to use induced maps here and make some kind of diagram but I'm not sure how.


I'm using the following contrib module:   How do I add a recaptcha to my form programatically, since the form I'm using isn't listed under forms on the config page of the module?  The following doesn't seem to work:  $form['recaptcha'] = array(   '#type' => 'recaptcha' );

I need to add a reCaptcha to my form; creating the form then adding the form ID to the reCaptcha settings did nothing.


I am trying to make an electric go-kart. I am new to the forum, so I may be missing some information but any help is greatly appreciated. After doing some math and discussing with friends I found the following with the given information. I have 4, 24V 14A motors, all connected to a read drive axle. I have 2 pairs of motors on each side of the drive axle. The motors have an 11 tooth sprocket that is chained to a 68 tooth sprocket that is connected to the drive axle. I currently have 2, 12V 7Amp 20 hour lead-acid batteries, which provide my 24V. Each pair of motors is connected in parallel to ensure they both get the 24V. However, the motors do not spin, even when there is no load (The wheels aren't contacting the ground). I believe that this may be because the motors do not have enough amps, only receiving 7 Amps of the 14 Amps from the batteries, because there are 2 motors in each pair. My main goal is to get the kart moving. I weigh about 130lbs, and the kart is likely around 30lbs. Would getting a battery/batteries with move amps (28A) allow the motors to run properly? Any advice is really appreciated. All the information I know Each motor is a DC motor that needs 14A and 24V The motor has a sprocket of 11 teeth The Watts of each motor is 250 The motors are rated to have an RPM of 2750 or around 45.83Hz The drive axle has a sprocket of 68 teeth. The 68 toothe sprocket is 5.5" The wheel diameter is 10" If my math is correct, given the ratio of the motors to drive shaft. Each motor produces 5.45Nm of torque, and after the sprockets, the torque is 33.69Nm. I don't know what impact the 4 motors would have on the torque, nor do I know what the torque is for each side. I really just want this kart to move. Would removing motors allow my vehicle to move? I think that my power supply does not provide enough amperage to my motors. Would having 1 or 2 motors be better in this situation?


I was reviewing the queues for the first time and was asked to evaluate the accepted answer for the question below, as an audit:    Of course I didn't know it was an audit (I didn't even know they existed), and I was very intrigued by the answer.  I opened the question page, as part of my investigation on it (I think the review mentioned there were other answers, so I wanted to compare).  There, I found an answer with the exact same response, by someone who was not a first-time user.  I clicked on the down vote, then, to which the page responded with the "STOP! Look and Listen." warning.  My line of thought was that someone was trying to trick the system, by adding a copy of a valid answer, so they'd get past the 'first post' audits.  If the reviewer does not open the original page to look for other answers, they may even up vote the fake answer.  That would be a very easy way to automatically get past that kind of audit, as it is easy to programmatically get the accept answer and resubmit it.  Perhaps Stack Exchange already have that kind of verification on its code, but I was surprised by the behavior.  So, my question is twofold:   Should we be concerned by this kind of attack on the audit system, or are there already builtin protections for it? Is the current implementation the best interface for that kind of audit?  I think my concern was valid.  I didn't lose reputation points or anything, but it did look 'unfair' :)   Note. I'm not sure why I did the downvote, instead of flag. I'm not sure if the flag option was available, as that would make more sense.

I recently received this rather amusing message while reviewing a user's first post:  Congratulations! This was only a test, designed to make sure you were paying attention. This post has already been removed, but thanks for taking time to leave feedback for the author.   What is the purpose of this test? How does the audit work? What happens if I fail? Why was the system expecting me to negatively review a good post, or positively review a bad post? A review is obviously an audit. Should I report it? Do review audits count toward the Reviewer badge? Do robo-reviewers dream of electric sheep?


I've been stuck on this particular problem for a while now:  Let $f: [a,b] \rightarrow \mathbb{R} $ be an increasing function. If $x_1, ... ,x_n \in [a,b]$ are distinct, show that $\sum\limits_{i=1}^n o(f, x_i) < f(b) - f(a)$.  It is clear that this is true, but I am finding it difficult to find a way to prove this in a manner that is valid. The proof that I did have for this problem seems to lack any substance and seems to draw on too many implicit assumptions that makes me almost certain it isn't correct. I think this comes from that fact that I do not see this problem in the way it should be seen, but I am just not exactly sure on what that is. I've tried other approaches that seemed promising at first, though it hasn't been of much help.   I would greatly appreciate any hints or guidance that will point me in the right direction of solving this problem.   Thanks.  Edit:  Note: $o(f, x_i) =  \lim_{\delta \to 0} [M(a, f, \delta) - m(a,f, \delta)]$  My proof: Assume $\sum\limits_{i=1}^n o(f, x_i) \geq  f(b) - f(a)$. Since $f$ is increasing, we can add $\sum\limits_{i=1}^n o(f, x_i)$ to $f(a)$. But this result is clearly not equal to $f(b)$, because $f$ is defined as increasing, nor is it greater than $f(b)$ because that would be outside of our range. Hence $\sum\limits_{i=1}^n o(f, x_i) < f(b) - f(a)$.

Let $f$ be an increasing function defined on $[a,b]$ and let $x_1 < x_2 < \dotsb < x_n$ be $n$ points in the interior of $[a,b]$. Show that $\sum_{k = 1}^n [f(x_k^+) - f(x_k^-)]\leq f(b^-) - f(a^+)$.   The proof I have is very wordy and sketchy. I know it would be easier if I could find a telescoping sum but I've got a road block in my mind. :/


So, most of us are familliar with Euler’s equation stating that $e^{i\pi}+1=0$. But I was wondering: how can an irrational number to the power of another irrational number equal a whole integer? And if that works, then how can $e^{i\pi}+1=0$ if $i$ isn’t even real?

Hi I was asked by a friends child who is in middle school why $e^{i\pi}+1=0$. Now I couldn't think of a way to explain it so he would understand. Albert Einstein once said “If you can't explain it simply, you don't understand it well enough” so how would I explain it.


So this is my code for the RESET button. it's pretty complex and long.    textBox1.Text = string.Empty;  comboBox1.Text = string.Empty;  textBox2.Text = string.Empty;  radioButton1.Checked = false;  radioButton2.Checked = false;  checkBox1.Checked = false;  checkBox2.Checked = false;  comboBox2.Text = string.Empty;  textBox3.Text = string.Empty;  textBox4.Text = string.Empty;  textBox5.Text = string.Empty;   I Was Wondering can i just simplify this command using Looping or something?

I do remember seeing someone ask something along these lines a while ago but I did a search and couldn't find anything.   I'm trying to come up with the cleanest way to clear all the controls on a form back to their defaults (e.g., clear textboxes, uncheck checkboxes).  How would you go about this?


I want to disable Address Space Layout Randomization(ASLR) by echoing 0 into /proc/sys/kernel/randomize_va_space. But I failed to do so in normal user mode even with prefix sudo: $ cat /proc/sys/kernel/randomize_va_space 2 $ sudo echo 0 > /proc/sys/kernel/randomize_va_space zsh: permission denied: /proc/sys/kernel/randomize_va_space  When I tried the same process after login as root user, I succeed. $ su  # cat /proc/sys/kernel/randomize_va_space 2 # echo 0 > /proc/sys/kernel/randomize_va_space # cat /proc/sys/kernel/randomize_va_space 0  I wonder why commands running with prefix sudo failed but as root user succeed. What is the difference between sudo and root? I tried this experiment on a Linux system and a WSL and they all exhibit the same phenomenon. The two profiles of my experimented environments are 5.10.0-kali3-amd64 #1 SMP Debian 5.10.13-1kali1 (2021-02-08) 4.4.0-19041-Microsoft #488-Microsoft Mon Sep 01 13:43:00 PST 2020

I've been given sudo access on one of our development RedHat linux boxes, and I seem to find myself quite often needing to redirect output to a location I don't normally have write access to.  The trouble is, this contrived example doesn't work:  sudo ls -hal /root/ > /root/test.out   I just receive the response:  -bash: /root/test.out: Permission denied   How can I get this to work?


I am sorry for the previous problem, I am a beginner of this forum.  I have written the following code, in order to draw 2 coupled horizontal oscillators with dampers:  \documentclass{article} \usepackage{tikz} \usetikzlibrary{decorations.pathmorphing,patterns} \usetikzlibrary{calc,patterns,decorations.markings} \usetikzlibrary{positioning}  \begin{document}  \begin{tikzpicture}[every node/.style={draw,outer sep=0pt,thick}] \tikzstyle{spring}=[thick,decorate,decoration={zigzag,pre length=0.3cm,post length=0.3cm,segment length=6}] \tikzstyle{damper}=[thick,decoration={markings,   mark connection node=dmp,   mark=at position 0.5 with   {     \node (dmp) [thick,inner sep=0pt,transform shape,rotate=-90,minimum width=10pt,minimum height=3pt,draw=none] {};     \draw [thick] ($(dmp.north east)+(2pt,0)$) -- (dmp.south east) -- (dmp.south west) -- ($(dmp.north west)+(2pt,0)$);     \draw [thick] ($(dmp.north)+(0,-3pt)$) -- ($(dmp.north)+(0,3pt)$);   } }, decorate] \tikzstyle{ground}=[fill,pattern=north east lines,draw=none,minimum width=0.5cm,minimum height=0.3cm]  \begin{scope}[xshift=7cm] \node (M) [minimum width=1cm, minimum height=1cm] {$m$} node[draw=none,fill=none,pos=.5,below] {1};  \draw [<-,thick](-2.6,.6) -- (-1.5,-.2);  \node (wall) [ground, rotate=-90, minimum width=2cm,yshift=-3cm] {};  \draw (wall.north east) -- (wall.north west);  \draw [spring] (wall.120) -- ($(M.north west)!(wall.120)!(M.south west)$) node[draw=none,fill=none,pos=.5,above] {$k_1$};  \draw [damper] (wall.20) -- ($(M.north west)!(wall.20)!(M.south west)$) node[draw=none,fill=none,pos=.5,below] {$d_1$}; \end{scope}  \begin{scope}[xshift=10cm] \node (M1) [minimum width=1cm, minimum height=1cm] {$m$} node[draw=none,fill=none,pos=.5,below] {2};  \draw [spring] (M.10) -- ($(M1.north west)!(M.10)!(M1.south west)$) node[draw=none,fill=none,pos=.5,above] {$K$};  \draw [damper] (M.-40) -- ($(M1.north west)!(M.-40)!(M1.south west)$);  \draw [->,thick](1.4,-.2) -- (2.5,.6); \end{scope}  \begin{scope}[xshift=10cm] \node (wall1) [ground, rotate=90, minimum width=2cm,yshift=-3cm] {};  \draw (wall1.north west) -- (wall1.north east);  \draw [spring] (wall1.60) -- ($(M1.north east)!(wall1.60)!(M1.south east)$) node[draw=none,fill=none,pos=.5,above] {$k_2$};  \draw [damper] (wall1.-160) -- ($(M1.north east)!(wall1.-160)!(M1.south east)$) node[draw=none,fill=none,pos=.5,below] {$d_2$}; \end{scope}  \end{tikzpicture}  \end{document}     I would need help to fix the following issues:   The notations "d_1" and "d_2" of the two dampers should be placed with about 3mm, under the dampers. The notations "1" and "2" of the two blocks should be placed under the rectangles and not at the interior. The right-side point of the second damper should start from the vertical rule of the right wall, not from those north east lines.

What packages do you use and recommend for creating graphics in your LaTeX documents?     As this is a community wiki post, please add your package to the accepted answer (or add a comment, and someone with >100 rep will add it to the CW answer), and include a brief description of what differentiates it from others and how it can be used (GUI drawing tool which generates code, type in raw text, or generates image for inclusion in document).   We'll eventually sort these answers under headings.


I was having problem with booting Ubuntu. Then I used Easeus partition manager to delete the partition that has Ubuntu. Maybe I have done it wrong. Because now I have also lost Windows. Luckily I came to know of a tool called boot repair from this forum. I used and here is the result from it . Can someone please decipher what this says and possibly help me out. Thanks.

I have absolutely no experience with Linux, and I desperately need to get my computer back up and running again with Windows.  How do I remove Ubuntu and reinstall Windows?    Editor's note: many of the answers are about removing Ubuntu from dual-boot but keeping Windows (which is a bit complicated), while other answers are about removing Ubuntu from single-boot (which is easy: basically just format the disk while installing Windows). The question as written is ambiguous between dual-boot or single-boot.


Is it possible to create a Ubuntu Phone ROMs for Nokia X Family (launched in 2014)? It would be really helpful since Microsoft isn't giving any updates.

I would like to port Ubuntu Touch to a device that is currently not supported. What are the requirements for doing this and where do I begin?


I cant get this lever off to take the face plate off. I took off the screw behind the lever but still won’t come off.

My exterior door deadbolt has gotten stuck - it'll open with the lever but not the key. By spraying WD-40 inside the lock, I've been able to get it to work but it's very stiff. I'd like to remove the lock and inspect the inside, either to clean/lube it or replace it. But I can't figure out how to remove the lock; there's no obvious way to do this. (I'm used to seeing two screws on the inside of the deadbolt, usually under the lever arms when it's horizontal.)    How do I remove this? I can loosen the cover plate on the inside but it doesn't do anything other than rotate a few degrees.


Are there an algorithm that provides a fastest way to construct simple graph given a degree sequence?  Are there any other interesting problems around this area that I might be overlooking and should consider exploring?

Let's say I'm given several degree sequences like $$\begin{array}{l} \{4,3,3,2,2\} \\ \{3,3,3,3\} \\ \{5,3,3,2,2,1\} \end{array}$$ I can find the number of edges using the handshaking lemma $$ \sum_{v \in V} \operatorname{deg}(v)=2|E| $$ But how do I construct a graph just given these degree sequences? There are multiple types of graphs that satisfy the degree sequences, but beyond guess & checking, is there a logic/pattern to follow when making graphs? Right now I'm at the guess & check stage.


I got this computer from some one online and I don't know any of the passwords I manly need to just reset the authentication password is there a way to reset it without the authentication password

I'm working on a Ubuntu system, and my client has completely forgotten his administrative password. He doesn't even remember entering one; however it is there.  I've tried the suggestions on the website, and I have been unsuccessful in deleting the password so that I can download applets required for running some files. Is there a solution?


I'm looking for a random number generator in JavaScript which I can initialize with a certain seed and gives a deterministic result (according to that seed). It should be capable of providing random integers within a certain range, however I can work with a random number generator that spits doubles, too (just like Math.random()).  Basically I'm looking for an equivalent to java.util.Random as known in the Java World for JavaScript.  Is there something like this already built into JavaScript? Is there some (maybe HTML5 related API) which specifies such a thing? Is there a library providing such a random number generator?  I'm implementing a genetic algorithm in JavaScript and I need to be able to harvest the same results for the same inputs (including seed) for research.

The JavaScript  function returns a random value between 0 and 1, automatically seeded based on the current time (similar to Java I believe).  However, I don't think there's any way to set you own seed for it.  How can I make a random number generator that I can provide my own seed value for, so that I can have it produce a repeatable sequence of (pseudo)random numbers?


Suppose I have a function which returns a modified version of an input, say a sorting algorithm: def insertion_sort(listToSort):     for itemToSort in range(1, len(listToSort)):         for i in range(itemToSort, 0, -1):             if listToSort[i] < listToSort[i-1]:                 listToSort[i], listToSort[i-1] = listToSort[i-1], listToSort[i]             else:                break  Usually I'd expect that I need to return the new modified version. But in Python, it seems like actual parameters are not a copy of the input, but instead a "link" to the input. This is different from other languages I've worked with (C#, C++), is there a reason this choice was made or was it an arbitrary one?

I needed to create a list of lists in Python, so I typed the following: my_list = [[1] * 4] * 3  The list looked like this: [[1, 1, 1, 1], [1, 1, 1, 1], [1, 1, 1, 1]]    Then I changed one of the innermost values: my_list[0][0] = 5  Now my list looks like this: [[5, 1, 1, 1], [5, 1, 1, 1], [5, 1, 1, 1]]    which is not what I wanted or expected. Can someone please explain what's going on, and how to get around it?


I have created a lightning web component in which i am using lightning data table. Now, i am try to implement infinite lazy loading but unable to call my loadmoredata function. here is my code component code:  <lightning-datatable     key-field="Id"     data={searchData}     show-row-number-column     onrowaction={handleRowAction}     onsave ={handleSave}     draft-values={draftValues}     columns={columns}     sorted-by={sortBy}     sorted-direction={sortDirection}     onsort={handleSortdata}     enable-infinite-loading     is-loading={isLoading}     onloadmore={loadMoreData}>  </lightning-datatable>   Here is my js controller code:  loadMoreData(event) {     //Display a spinner to signal that data is being loaded     //this.isLoading = true;     //Display "Loading" when more data is being loaded       this.loadMoreStatus = 'Loading';       const currentRecord = this.searchData       const lastRecId = currentRecord[currentRecord.length - 1].Id;       Console.log('jdfnddk'+this.loadMoreStatus);         workItemList()         .then(result  => {             const currentData = result.sobList;             //Appends new data to the end of the table             const newData = currentRecord.concat(currentData);             this.data = newData;              if (this.data.length >= this.totalNumberOfRows) {                 this.loadMoreStatus = 'No more data to load';             } else {                 this.loadMoreStatus = '';             }         })         .catch(error => {             console.log('-------error-------------'+error);             console.log(error);         }); }

I am trying to use the built-in infinite loading capabilities of the lightning-datatable. But whenever enable-infinite-loading is set to true, the component repeatedly spams the onloadmore action, even if the user has not scrolled to the bottom of the table.  <template>     <lightning-datatable         key-field="Id"         columns={tableColumns}         data={data}         enable-infinite-loading={isLoaded}         onloadmore={onLoadMoreHandler}>     </lightning-datatable> </template>   import { LightningElement, track } from 'lwc';  export default class App extends LightningElement {     tableColumns = [         {label: 'Number', fieldName: 'Id', type: 'number'},         {label: 'Name', fieldName: 'Name'}     ];      @track data = [];     @track isLoaded = false;      addMoreDataCounter = 0;      connectedCallback() {         this.addMoreData();         this.isLoaded = true;     }      addMoreData() {         const offset = this.data.length;         let newData = [];          for(let i=offset + 1;i<=offset + 100; i++) {             newData.push({                 Id: i,                 Name: 'Test Row #' + i             });         }          this.data = [...this.data, ...newData];          this.addMoreDataCounter++;     }      onLoadMoreHandler() {         console.log('load more');         this.addMoreData();          if(this.addMoreDataCounter === 4) {             this.isLoaded = false;         }     } }   <?xml version="1.0" encoding="UTF-8"?> <LightningComponentBundle xmlns="http://soap.sforce.com/2006/04/metadata">     <apiVersion>46.0</apiVersion>     <description>Scroll Issue</description>     <isExposed>true</isExposed>     <masterLabel>Scroll Issue</masterLabel>     <targets>         <target>lightning__AppPage</target>     </targets> </LightningComponentBundle>    In this example, enable-infinite-loading is turned off after the fourth call to addMoreData() to prevent the application from crashing. This component is being used in a single column Lightning App Builder page, where it is the only component. This example is intentionally simplified to generate data on the client side, in order to reproduce the issue in a way that is easy to share.


I need to create and navigate to a directory with one line of command. And it needs to be inside a function. I'm new to terminal and shell scripting and don't know much about it.  My process goes like this:  I write the name of the directory and it is stored to $dirname variable, and then type "create" and it is stored to another variable named $thecommand, to create the directory with the name I gave, and navigate to it.   I have a create() function. Inside the function I did mkdir ./$dirname, and then cd $dirname. Then I applied a condition: if what the user wrote in $thecommand variable (BTW both $dirname and $thecommand are read, so the user writes the value) is equal to "create".   The directory was created, but it didn't navigate to it. So I tried creating an alias p="$dirname", and applied the alias in the function, still, it created the directory, but didn't navigate!   I would appreciate if someone helped me with this.  Here is my code:  echo "Write Folder name" read dirname echo "Write -create- to create the folder" read thecommand  p="$dirname"  function create() {     mkdir ./"$p"     cd "$p" }  if [ "$thecommand" == "create" ] then     create fi

I'm trying to write a small script to change the current directory to my project directory:  #!/bin/bash cd /home/tree/projects/java   I saved this file as proj, added execute permission with chmod, and copied it to /usr/bin. When I call it by: proj, it does nothing. What am I doing wrong?


How to know which word in British English ends with '-ise' or '-ize' (e.g. organise and realize)? I am an editor and this has been a constant matter of confusion for me.

I have trouble understanding why some words change "s"-es to "z"-s from BE to AE and some not. For example:   analyse -> analyze characterise -> characterize hypnotise -> hypnotize   But:   compromise -> compromise   Is there any rule to this?  Slightly related:


In my essay, I want to use a phrase that would best express 'the act of  transforming real events into words.' I know that initally sounds a bit awkward, but I will give the context to clarify this.     News feed, social media, and television where many sought their repose were only repeating what was going on    So, instead of writing repeating I want to use something like liquidify or transcribe. But both these words do not really connotate the idea I want to give. I want to say that these news feeds were just transforming what was outside into words, which made people feel even more besieged.   Any suggestions?   Also, is the question mark in my question text placed correctly?

Is there a word that means "expressed using words", as opposed to an idea that is expressed through pictures? I first thought of "articulate" or "explicit" but those aren't quite right. (For context, I'm writing a paper that attempts to compare visual art, literature, and music and the differences in how they express their ideas.)


Everything here is only about Nautilus and adding a folder to the left panel.  Recently due to insufficient space in the home partition, I had to remove the downloads folder through the recovery method. But after reboot, the Downloads folder shortcut did not appear in the left panel in Nautilus.   Is there any way to add the Downloads folder shortcut back into place?  Not as a bookmark.  Currently, I'm using Ubuntu 18.04 (Bionic Beaver).

I somehow deleted my Desktop from nautilus places, it does not show in the places part of Nautilus anymore as you can see from the picture.    And also now my Desktop lists the contents of my home folder, not the Desktop folder. How can I fix this? I use Ubuntu 14.04 and GNOME 3.


I'm trying to retrieve some data from a table using a Cursor to display it in a TextView, but I'm getting an error.    Please care to help me. Here's my code   public class DisplayBudget extends AppCompatActivity implements  View.OnClickListener {   SQLiteDatabase db;   TextView bname,name,limit;   Button del;   protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.budget_details);     bname = (TextView) findViewById(R.id.textViewbname);     name = (TextView) findViewById(R.id.textViewname);     limit = (TextView) findViewById(R.id.textViewlimit);     del = (Button) findViewById(R.id.button2);     del.setOnClickListener(this);     DBController dbController = new DBController(this);     dbController.openToDisplay();     Cursor cursor = db.rawQuery(" select *from "+DBHelper.TABLE_NAME+ " where id = 1 ",null);     cursor.moveToFirst();     name.append(cursor.getString(cursor.getColumnIndex(DBHelper.OWNER_NAME)));     bname.append(cursor.getString(cursor.getColumnIndex(DBHelper.BUDGET_NAME)));     limit.append(cursor.getString(cursor.getColumnIndex(DBHelper.BUDGET_LIMIT)));     cursor.close(); }   Here's the LogCat  12-25 00:39:46.440  30123-30123/com.example.rajkumar.budget W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0xb0d40b20) 12-25 00:39:46.440  30123-30123/com.example.rajkumar.budget E/AndroidRuntime﹕    FATAL EXCEPTION: main Process: com.example.rajkumar.budget, PID: 30123 java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.rajkumar.budget/com.example.rajkumar.budget.DisplayBudget}: java.lang.NullPointerException         at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2184)         at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2233)         at android.app.ActivityThread.access$800(ActivityThread.java:135)         at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)         at android.os.Handler.dispatchMessage(Handler.java:102)         at android.os.Looper.loop(Looper.java:136)         at android.app.ActivityThread.main(ActivityThread.java:5001)         at java.lang.reflect.Method.invokeNative(Native Method)         at java.lang.reflect.Method.invoke(Method.java:515)         at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)         at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)         at dalvik.system.NativeStart.main(Native Method)  Caused by: java.lang.NullPointerException         at com.example.rajkumar.budget.DisplayBudget.onCreate(DisplayBudget.java:28)         at android.app.Activity.performCreate(Activity.java:5231)

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


Let $A:V\to V$ be an endomorphism of a vector space $V$ such that $A^2=id$.   Then the only possible eigenvalues of $A$ are $\pm 1$ and of course $1$ is an eigenvalue of $A$. Are those in fact eigenvalues of $A$?

Suppose $A$ is a matrix over a field $F$ of characteristic $\neq 2$, with $A\cdot A=I$. Show that $A$ is similar to a diagonal matrix whose entries are either $1$ or $-1$.


I couldn't make the WiFi work on Ubuntu 12 after installing alongside OS X for a try. I tried everything and nothing worked, now I'd like to completely remove it since it's too complicated, is it safe to just remove the partitions it created?

I have dual booted Ubuntu 12.04 on my Mac using disk utility and the rEFIt tool.The battery life is very bad and therefore I want to switch back to Ubuntu 10.04 . How can I completely remove the 12.04 partition?


Lets say you are writing a book, making a cardboard game or composing a music.   After a while you are so invested into your creation and know it so well from inside and out. You can no longer see the major flaws in the design or errors you made. And only way is to get a feedback from other people who can give you a fresh perspective.  Is there a term for this "author's blindness"?

Back in the day, I used to do a lot of CAD drafting.   There is a well known phenomena whereby your ability to see mistakes, errors, omissions or plain nonsense in your drawing diminishes sharply after working more than a couple of hours on the same drawing or draft.   Our engineering department even had a policy, that required every drawing, no matter how simple, had to be reviewed or "Redlined" (used a red marker on a printout to circle mistakes) by at least one peer drafter before submitting it to your supervisor, This saved a lot of embarrassment to everyone, especially the company (it saved a lot of money too) since simple mistakes were caught even before hitting version control or structural assessment, even production line assembly, let alone the final customer.  Most of the errors caught by peer re are simple, basic omissions like a missing dimension, missing notes boilerplate required by specification, etc. Sometimes glaring errors are caught like personal work-notes or calculations making it to the final document, duplicating sections of the drawing, etc... however the drafter that had been working on the drawing was simply "blind" to the error until someone else pointed it out.  Also, incidence of this is noticeably higher when working on a computer (v. gr. CAD Drafting) vs doing "old school technical drafting" by hand on paper using a drawing board.  Quite frequently, simply printing or plotting your CAD draft to paper, will make you see and catch some errors, invisible to you on-screen, but a "fresh pair of eyes" will catch some that you yourself can't see even on paper.  This also known to happen in other professions that require working for extended periods on a computer document, for example, Software programmers, lawyers, technical writers, etc.   In spanish we call this phenomena "Ceguera de taller" literally "Workshop blindness" however my research (below) shows it does not translate well to english.  I thought of "Mental fatigue" however I don't think it conveys the same meaning, since mental fatigue reduces your overall awareness and acuity, and you would be blind to other's mistakes on a similar drawing or document, however (surprisingly) if you look at a document that you didn't work on yourself, you'll notice immediately any mistakes even if you have just committed them on your own work.  I came up with 3 alternatives for a literal translation (Workshop Blindness, Drafter's Blindness, and Drafter's fatigue) and , but none of them yielded any results, so they are probably meaningless or nonsense. Ceguera de taller, however,  which matches the time period when PCs became affordable.  so, in short:  What would be a well understood term or idiom for the inability to see your own mistakes or omissions after working for some time on the same document.    Many thanks to everyone for all the wonderful and enlightening anwers! I tried several in actual conversation and tunnel vision required the least explanations, although several ideas here work in different situations. Like "Im having tunnel vision issues with this document” when explaining I am having the condition, or the very friendly, funny and kinda ice-breaker captain obvious!  Again, thank you to this wanderful community


I want to convert list into string with unix command. X is a variable and store in new variable Y. X =  ['8922','9292','3220'] to '8922,9292,3220' How can I do this. Please suggest.

I want to remove brackets [] and quotes around each value and add quotes at start and end. X= ['8922','9292','3220'] I want output as below. Y = '8922,9292,3220' How can I do this. Please suggest.


I want to executed command from file (which is script) in current shell in terminal.  Example: I have file ch_dir contains following:  #!/bin/bash cd /usr   Now if I execute file usually as following then it executes commands in different shell:  pandya@pandya-desktop:~$ ./ch_dir pandya@pandya-desktop:~$   Here cd /user is executed in different shell.  But I want to execute in Current shell. How do I do that?  Note: Here cd is only used to explain. Question's aim is to execute any command in current shell

I just want to write a script which changes my directory.  I put the below commands in the file /home/alex/pathABC  #!/bin/sh cd /home/alex/Documents/A/B/C echo HelloWorld   I did   chmod +x pathABC   In the Terminal, while in /home/alex, I ran ./pathABC, but the output is just HelloWorld and the current directory is not changed.  So what is wrong?


Prove that for any $a,b,c>0$ we have: $$\frac{a^2}{b}+\frac{b^2}{c}+\frac{c^2}{a}+a+b+c\ge\frac{(a+b)^2}{b+c}+\frac{(b+c)^2}{c+a}+\frac{(c+a)^2}{a+b}$$  Can someone help me? I tried Radon inequality for $p=1$, and I obtained  $$2\left(\frac{a^2}{b}+\frac{b^2}{c}+\frac{c^2}{a}\right)\ge\frac{(a+b)^2}{b+c}+\frac{(b+c)^2}{c+a}+\frac{(c+a)^2}{a+b}$$ but that's the far I could go.

Show that for $x,y,z > 0$ the inequality is true: $\frac{x^2}{y}+\frac{y^2}{z}+\frac{z^2}{x}+x+y+z \geq \frac{(x+y)^2}{y+z}+\frac{(y+z)^2}{z+x}+\frac{(z+x)^2}{x+y}$  I have tried Holder, but i had no luck. Please give me a hint of how to start.


Can I safely eat raw uncooked chicken that has been in my freezer since April 2018 (over a year)?

How do I know if a given food or ingredient I have is still good, or if I should discard it?  How can I best preserve a food or ingredient?     This broad question is intended as a "general reference" question to quickly answer many how long will food keep for? questions. Please feel free to edit this question to expand and clarify as needed.


After installing mysql using sudo apt-get install mysql-server, no question was asked to me to fill a specific password for root account. Logically, it means password is empty. It is confirmed when I have a look in the /var/log/mysql/error.log where I can find this information =>  2019-04-28T20:31:35.761063Z 1 [Warning] root@localhost is created with an empty password ! Please consider switching off the --initialize-insecure option.   But now, when I connect to PHPAdmin with root login and empty password, I have a message:  #1698 - Access denied for user 'root'@'localhost'   with a few more details:   mysqli_real_connect(): (HY000/1045): Access denied for user 'phpmyadmin'@'localhost' (using password: YES)   How do I solve this issue?

I used apt install mysql-server to install MySQL on Ubuntu 16.04 but during the installation, it did not ask for root password.  After installation I got ERROR 1045 when I tried to login as root and mysql_secure_installation threw the same error. I purged and autoremoved then reinstalled but it does not work.  How could i fix this? Can I set the root password if I didn't set it during installation?  This is my installation log:   The following additional packages will be installed:   libaio1 mysql-client-5.7 mysql-client-core-5.7 mysql-server-5.7   mysql-server-core-5.7 Suggested packages:   mailx tinyca The following NEW packages will be installed:   libaio1 mysql-client-5.7 mysql-client-core-5.7 mysql-server mysql-server-5.7   mysql-server-core-5.7 0 upgraded, 6 newly installed, 0 to remove and 0 not upgraded. Need to get 0 B/17,9 MB of archives. After this operation, 160 MB of additional disk space will be used. Do you want to continue? [Y/n] y Preconfiguring packages ... Selecting previously unselected package libaio1:amd64. (Reading database ... 227144 files and directories currently installed.) Preparing to unpack .../libaio1_0.3.110-2_amd64.deb ... Unpacking libaio1:amd64 (0.3.110-2) ... Selecting previously unselected package mysql-client-core-5.7. Preparing to unpack .../mysql-client-core-5.7_5.7.12-0ubuntu1_amd64.deb ... Unpacking mysql-client-core-5.7 (5.7.12-0ubuntu1) ... Selecting previously unselected package mysql-client-5.7. Preparing to unpack .../mysql-client-5.7_5.7.12-0ubuntu1_amd64.deb ... Unpacking mysql-client-5.7 (5.7.12-0ubuntu1) ... Selecting previously unselected package mysql-server-core-5.7. Preparing to unpack .../mysql-server-core-5.7_5.7.12-0ubuntu1_amd64.deb ... Unpacking mysql-server-core-5.7 (5.7.12-0ubuntu1) ... Selecting previously unselected package mysql-server-5.7. Preparing to unpack .../mysql-server-5.7_5.7.12-0ubuntu1_amd64.deb ... Unpacking mysql-server-5.7 (5.7.12-0ubuntu1) ... Selecting previously unselected package mysql-server. Preparing to unpack .../mysql-server_5.7.12-0ubuntu1_all.deb ... Unpacking mysql-server (5.7.12-0ubuntu1) ... Processing triggers for libc-bin (2.23-0ubuntu3) ... Processing triggers for man-db (2.7.5-1) ... Processing triggers for systemd (229-4ubuntu4) ... Processing triggers for ureadahead (0.100.0-19) ... Setting up libaio1:amd64 (0.3.110-2) ... Setting up mysql-client-core-5.7 (5.7.12-0ubuntu1) ... Setting up mysql-client-5.7 (5.7.12-0ubuntu1) ... Setting up mysql-server-core-5.7 (5.7.12-0ubuntu1) ... Setting up mysql-server-5.7 (5.7.12-0ubuntu1) ... update-alternatives: using /etc/mysql/mysql.cnf to provide /etc/mysql/my.cnf (my.cnf) in auto mode Checking if update is needed. This installation of MySQL is already upgraded to 5.7.12, use --force if you still need to run mysql_upgrade Setting up mysql-server (5.7.12-0ubuntu1) ... Processing triggers for libc-bin (2.23-0ubuntu3) ...


Show that every element of Sn can be written as an arbitrary product of the elements (01) and (01...n-1).   I understand that this can be solved using induction, and I've set up my base cases. However, I'm not sure how I can prove that if the proposition is true for k, it must also be true for k+1.  Any help would be appreciated.

Show that $S_n$ is generated by the set $ \{ (12),(123\dots n) \} $.  I think I can see why this is true. My general plan is (1) to show that by applying various combinations of these two cycles you can get each transposition, and then (2) to show that each cycle is a product of transpositions.  I'm just having trouble on the first step. Any ideas?


As in , votes can already mark better answer (though not always work especially when there are a lot of answers). Then except for giving asker 2 reps and answerer 15 reps, are there other benefits (BTW are the 2 and 15 reps really a benefit for the site?) of this feature? Obviously "mark an answer right or wrong" is not a benefit, since a feature like "tag any answer as right/wrong" will do a better job.

What does it mean to accept an answer? How do I accept an answer, and what are the rules? Can I accept my own self-answer? What are the reputation benefits? Which answer should I accept? Should I upvote the accepted answer? What should I do if none of the answers are suitable?      For more information, see "" in the .


The question is to solve the functional equation $$f(x+y)=f(x)+f(y)+y\sqrt{f(x)}$$ $\forall x,y \in \mathbb R$  I tried to put x=y=0,y=x and y=-x in the given functional equation.I ended up getting $$f(2x)=3f(x)+f(-x)$$ and $$f(x)+f(-x)=x\sqrt{f(x})$$ from where I am unable to proceed.Thanks.

If $x,y\in \mathbb{R}$ and $f(x+y)=f(x)+f(y)+y\sqrt{f(x)}$ and $f'(0)=0\;,$ Then $f(x)$ is   $\bf{My\; Try::}$ Using $$f'(x) = \lim_{h\rightarrow 0}\frac{f(x+h)-f(x)}{h} = \lim_{h\rightarrow 0}\frac{f(x)+f(h)+h\sqrt{f(x)}-f(x)}{h}$$  Now Put $x=y=0$ in  $$f(x+y)=f(x)+f(y)+y\sqrt{f(x)}\;,$$ We get $f(0)=0$  So we get $f(0)=0$  So $$f'(x) = \sqrt{f(x)}+\lim_{h\rightarrow 0}\frac{f(h)}{h}=\sqrt{f(x)}$$  So $$\int\frac{f'(x)}{\sqrt{f(x)}}dx = 1\int dx\Rightarrow 2\sqrt{f(x)}=x+c$$  Now Put $x=\;,$ We get $c=0$  So we get $2\sqrt{f(x)}=x\Rightarrow 4f(x)=x^2\Rightarrow \displaystyle f(x)=\frac{x^2}{4}$  Can we solve it some short way, If yes then please explain here, Thanks


I want to support both short and  long options in bash scripts, so one can:   $ foo -ax --long-key val -b -y SOME FILE NAMES   is it possible?

I wish to have long and short forms of command line options invoked using my shell script.  I know that getopts can be used, but like in Perl, I have not been able to do the same with shell.  Any ideas on how this can be done, so that I can use options like:  ./shell.sh --copyfile abc.pl /tmp/ ./shell.sh -c abc.pl /tmp/   In the above, both the commands mean the same thing to my shell, but using getopts, I have not been able to implement these?


#!/bin/bash for i in {1..$1}; do echo 'for the love of god please work'; done  but $ ./xgen2 5  does not print 'for the love of god please work' 5 times, it prints it once please 'for the love of god-' please help

How do I iterate over a range of numbers in Bash when the range is given by a variable?  I know I can do this (called "sequence expression" in the Bash ):   for i in {1..5}; do echo $i; done   Which gives:     1    2    3    4    5   Yet, how can I replace either of the range endpoints with a variable? This doesn't work:  END=5 for i in {1..$END}; do echo $i; done   Which prints:     {1..5}


I am using php mail() to send email from my website. But I am facing strange behaviour.    $headers  = "From: Saurabh Sharma <no-reply@example.com>\r\n";   $headers .= 'Reply-To: ' . $email . "\r\n";   $headers .= "Return-Path: me@example.com\r\n";   $headers .= "Organization: Saurabh Sharma\r\n";   $headers .= "X-Mailer: PHP\n";   $headers .= "MIME-Version: 1.0" . "\n";   $headers .= "Content-type: text/html; charset=iso-8859-1" . "\r\n";   But all the mails are landing in spam.  Also, I have added a rule on the server to send the copy of every mail to my personal email on gmail. I am able to receive the mail on gmail when I use php mail() (in spam) but can't see any mail on RoundCube on my server even if the receiving address is of my domain email address i.e me@example.com but I receive only the copy on gmail.  Also, If I send mails to/from Roundcube to my Gmail and vice versa, mail always lands in inbox in Gmail and Roundcube also shows the mail in inbox.  But strange things are happening in php mail();  The major issue is that email is not received on me@example.com but I can see the copy on Gmail.  Am I doing something wrong in headers?

This is a tricky one and I've always relied on techniques, such as permission-based emails (i.e. only sending to people you have permission to send to) and not using blatantly spamish terminology.  Of late, some of the emails I send out programmatically have started being shuffled into people's spam folder automatically and I'm wondering what I can do about it.  This is despite the fact that these particular emails are not ones that humans would mark as spam, specifically, they are emails that contain license keys that people have paid good money for, so I don't think they're going to consider them spam  I figure this is a big topic in which I am essentially an ignorant simpleton.


I'd like to write a python regex to replace the string FARM_FINGERPRINT() and anything inside that method call with the string '0'. For example, for the string:  s = 'FARM_FINGERPRINT(stuff(more stuff()), even more stuff), another_thing()'   The regex should replace it with '0, another_thing()'.  I'd be open to non-regex solutions as well.

I need a regular expression to select all the text between two outer brackets.  Example: some text(text here(possible text)text(possible text(more text)))end text  Result: (text here(possible text)text(possible text(more text)))