Sorry if I am not using the right terms for naming these "backspace chars".  I would like to clean up a directory that contains two files which looks like they contain backspace in their name. If I list the directory:  ls -la   I get this:  -rwxrwxrwx    1 guy guy        729 Jun 26 2007  z_regular.mk -rwxrwxrwx    1 guy guy          1 Sep  7 2016 -rwxrwxrwx    1 guy guy       3220 Sep 27 2   I am thinking I mistakenly imputed the file names with "backspace chars", so we do not see the names any more.   How do I rename these last two files?  I don't know how to call them. Is there an ls option allowing me to display the file names in hexa or something, and how could I use the latest in an mv command? I'm with AIX Unix TLS v6.  edit:  the files are respectively 2 and 4 del chars:  ls -lb   gives   -rwxrwxrwx    1 guy guy          1 Sep  7 2016   \177\177 -rwxrwxrwx    1 guy guy       3220 Sep 27 2      \177\177\177\177\177   But solutions found at  doesn't work for my case in AIX.  I tried the below without success so far:  l>ls -l $'\0177\0177' $\0177\0177 not found l>ls -l '\0177\0177' \0177\0177 not found l>ls -l '\177\177' \177\177 not found

I somehow managed to create a file that doesn't seem to have a filename. I found some information regarding how to get more details of the file in the following   However, I tried some of the suggestions listed and can't seem to delete the file. I'm not sure what I did to create it, but it happened while trying to copy an xml file.   Some info on the file is as follows;  > ls -lb total 296 -rw-r--r--   1 voyager  endeavor  137627 Jan 12 12:49 \177  > file * :               XML document  > ls -i  417777      I tried to find using the inum switch and then pipe that to rm as that seemed like the most foolproof way of getting rid of it. However, the example given at the bottom of the thread linked below failed for me. Example was:  > find -inum 41777 -exec ls -al {} \; find: illegal option -- i find: [-H | -L] path-list predicate-list   so I tried using the path list first like the following, but that didn't work either:  > find . -inum 41777 -exec ls -al {} \;   I'm not sure what the non-printable character \177 is or how I can pass that to an rm command, but I really want to make sure I don't mess up any other files/directories in my attempt to delete this file.


What will be the impact, if we add some extra space in id or class in HTML.  Like if we write like this,
This is a div
   Will the CSS or JS break?  Will there be any effect on class or id selection in JavaScript or CSS?

When creating the id attributes for HTML elements, what rules are there for the value?


I am working on a graph coloring problem. Right now I'm stuck on a step that should be very simple. I've created a dictionary that includes all possible colors for each node (different colors are represented by the integers 0, 1, 2 ,3). See below. (Apologies in advance if the formatting of the question doesn't come out correctly. This is my first time asking a question here).         node_count = 4         colors = [0,1,2,3]          sol_dict = {node:colors for node in range(0,node_count)}          print(sol_dict)   Output:         {0: [0, 1, 2, 3], 1: [0, 1, 2, 3], 2: [0, 1, 2, 3], 3: [0, 1, 2, 3]}   All I want to do is remove elements from some of these lists when I apply a constraint. For instance, if my algorithm discovers that node 1 in the dictionary cannot take the color value 0, I want to remove 0 from the list associated with the dictionary key 1. To do this I write:         sol_dict[1].remove(0)          print(sol_dict)   Output:         {0: [1, 2, 3], 1: [1, 2, 3], 2: [1, 2, 3], 3: [1, 2, 3]}   As you can see, this removes 0 from all items in the dictionary. I am at a loss to why this is happening. Let me know what you think. I've been stuck on this a while.

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'm making a sign up system. After user successfully sign up, form->ajax->php, ajax adds html to a premade empty message div.  $("#register_form").submit(function(event) {     var $data = $(this).serialize();     var result = "";      $.ajax({         cache   : false,         type    : "POST",         url     : "php/register.php",         data    : $data,         success : function(response) {               if(response === "OK"){                   result  = "
You have successfully registered!
";                   result +=     "Please check your mailbox for the activation link. It may take a few minutes.
";                   result +=     "Resend Confirmation Email";                   result += "
";                   $("#register_form").slideUp(500);               }               else{                   result = '
' + response + '
';               }                $("#register_response").html(result);               $("#register_response").slideDown(500);         }     });      event.preventDefault(); });   I put the 'resend confirmation email' in there, just an empty link waiting to be clicked on. But it seems the sign up page's javascript (which is the same file the above script is in, I did $("#resend").click(...) ) doesn't apply to it. Where do I put the javascript so that this will work?  Also, if this is not a good way to add html using javascript, what's a good way to achieve this?

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.


First of all,  doesn't answer my question. I've tried almost all of those and they mostly match within explicitly specified 1 extra new line. The question: say i have dictionary, or any other JSON-like object. I have many of them in the file and i want to match every of them. For example: some_var = {     'foo': 'bar',     'list_foo': ['bar1', 'bar2'], } other_var = [     {         'foo1': 'bar1',         'foo2': True     },     {         'foo_list1': ['bar3', 'bar4'],         'foo2': 'bar2'     }, ]  Values may be anything, but dict. So no nested dicts. My ultimate goal is to match everything that lays between each set of {} including the figure brackets (optional, but desirable). So that when i run the regex, i will get these matched: {     'foo': 'bar',     'list_foo': ['bar1', 'bar2'], } {     'foo1': 'bar1',     'foo2': True } {     'foo_list1': ['bar3', 'bar4'],     'foo2': 'bar2' }  One of my closes attempt is: \{(.*\n)*\}  But it matches everything between the very first { and very last } in a file. There was many other attempts, but none worked for variable dict size. I'm running this regex in PyCharm in an attempt to quickly refactor some code. Please, do not provide workarounds. I have already solved the problem in a different way, but am still curious about this exact solution.

Unfortunately, despite having tried to learn regex at least one time a year for as many years as I can remember, I always forget as I use them so infrequently. This year my new year's resolution is to not try and learn regex again - So this year to save me from tears I'll give it to Stack Overflow. (Last Christmas remix).  I want to pass in a string in this format {getThis}, and be returned the string getThis. Could anyone be of assistance in helping to stick to my new year's resolution?    Related questions on Stack Overflow:


I am going to make a UK visa application for my wife who is currently working as an engineer in a firm for the last 6 months. She gets her salary by cash in hand and we usually keep it with us at home. She will be supporting herself for the visit as she will be travelling alone. Now although her bank account is active for more than 6 months but she has recently deposited all her savings in the bank. How can I prove the recent sudden increase in her bank balance. What evidence should I submit for the proof of this deposit other than her payslips and salary certificate.

The UK Visas and Immigration Directorate publishes  that provides helpful tips that can result in successful visa applications. Section 2 of this guidance opens is entitled "other documents you may want to provide" (emphasis mine).  Section 2: other documents you may want to provide – all visitors This section provides guidance on the types of documents that you may want to provide to help us consider your application against the Immigration Rules. Previous travel documents/passports, which show previous travel. Financial documents showing that you have sufficient funds available.  These must clearly show that you have access to the funds, such as:  bank statements building society book proof of earnings such as a letter from employer confirming employment details (start date of employment, salary, role, company contact details) where a third party (who is either in the UK or will be legally in the UK at the time of your visit) is providing financial support to you e.g. a business, a friend or a relative, documents to show that they have sufficient resources to support you in addition to themselves and any dependant family should be provided   The first item is "bank statements" and this ties in with the , which says...  evidence that you can support yourself during your trip, eg bank statements or payslips from the last 6 months  (Note 'eg' is a Latin abbreviation meaning "for example"; this appears to be optional rather than a fixed requirement.) Question: How should someone interpret this such that the chances of success are maximized? How many statements should I submit? What are they looking for and what do my bank statements tell about me?


My mic stopped working recently. Trying to fix it made things worse. now I don't have audio. would like to at least go back to where the audio works. Here's my lspci -v  00:1f.3 Audio device: Intel Corporation Device 9dc8 (rev 11) (prog-if 80)     Subsystem: Lenovo Device 2292     Flags: bus master, fast devsel, latency 64, IRQ 16     Memory at ea23c000 (64-bit, non-prefetchable) [size=16K]     Memory at ea000000 (64-bit, non-prefetchable) [size=1M]     Capabilities: <access denied>     Kernel driver in use: snd_soc_skl     Kernel modules: snd_hda_intel, snd_soc_skl, sof_pci_dev   originally I didn't have the snd_soc_skl nor the sof_pci_dev  how do I remove those drivers? and use the snd_hda_intel?

I recently updated firmware on my Thinkpad Carbon X1 (last gen, 7th I guess) and since (I'm not sure it is the cause of my problem, but it happens simultaneously), I only have a "dummy device" in sound configuration panel on Ubuntu 18.04. I tried a lot of stuff suggested around the web and still, the result of aplay -l is always no sound card detected. The output of lspci -nnk | grep -A2 Audio is :  Audio device [0403]: Intel Corporation Device [8086:9dc8] (rev 11)     Subsystem: Lenovo Device [17aa:2292]     Kernel driver in use: snd_soc_skl   Any suggestion how to fix this ?


I am trying to create a function that takes an arbitary number of strings and then outputs them all on a single line. I want this function to be a static member function of my Utils class.  Utils::output("I","am","a","sentence"); // --console-output--> I am a sentence   Here's what I've attempted:  Utils.h:  class Utils{ public:     template<typename First, typename ... Strings>     static void output(First arg, const Strings&... rest); };   Utils.cpp:  void Utils::output() {     std::cout<<std::endl; }  template<typename First, typename ... Strings> void Utils::output(First arg, const Strings&... rest){     std::cout<<arg<<" ";     outputs(rest...); }   main.cpp:  int main() {     Utils::output("I","am","a","sentence");     return 0; }   My project is currently not even compiling! I am getting this error:  error LNK2019: unresolved external symbol "public: static void __cdecl Utils::output<char const *,char [3],char [2],char [9]>( referenced in function _main First.exe : fatal error LNK1120: 1 unresolved externals

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


Is there a difference in whether brother is explicitly possessive in sentences like this?   A friend of her brother's called  A friend of her brother called    Perhaps both are correct; do they have a subtle (or not-so-subtle) difference?

I have seen them both in my reference book, which is written by a native speaker. I wonder why there are two different phrases to describe the same meaning and am looking forward to some reasonable details to explain why this is so.


I was wondering how I can create a background like this using Adobe Illustrator ( ignore the images at the corners, I am only interested at the Orange background ).  Thanks!

I am looking for an easy way to create in Illustrator vintage style corners like on the picture provided.  I have some technical ideas, but they are time consuming, there should be an easier way I believe.


I want to make a all of the tabs on a tabcontrol disappear/not be visible once a button is pressed. I've been trying some things, but they haven't worked out.  If someone could help me figure out how to do this, that'd be great.  This is in a regular C# project (made with forms).

How to hide TabPage from TabControl in WinForms 2.0?


Does it makes sense to use the const qualifier for input parameters in C++ when the parameter is passed by value ?  For example if I pass a primitive type like integer:  void function( const int aValue );   does it gain any benefit over the same function without using the const:  void function( int aValue );   Is there any difference if I pass my own data type ?  void function( Data aData ); void function( const Data aData );

How far do you go with const?  Do you just make functions const when necessary or do you go the whole hog and use it everywhere?  For example, imagine a simple mutator that takes a single boolean parameter:  void SetValue(const bool b) { my_val_ = b; }   Is that const actually useful?  Personally I opt to use it extensively, including parameters, but in this case I wonder if it's worthwhile?  I was also surprised to learn that you can omit const from parameters in a function declaration but can include it in the function definition, e.g.:  .h file  void func(int n, long l);   .cpp file  void func(const int n, const long l)   Is there a reason for this? It seems a little unusual to me.


Can someone just explain to me the basic process of what is going on here? I understand everything until we start adding 1's then after that it all goes to hell. I just need some guidance. The Problem with the solution is attached.   Thanks in advance..

How do I efficiently compute $a^b\bmod c$:  When $b$ is huge, for instance $5^{844325}\bmod 21$? When $b$ is less than $c$ but it would still be a lot of work to multiply $a$ by itself $b$ times, for instance $5^{69}\bmod 101$? When $(a,c)\ne1$, for instance $6^{103}\bmod 14$?  Are there any other tricks for evaluating exponents in modular arithmetic?  This is being asked in an effort to cut down on duplicates, see  and .


After running apt update I noticed that update info is being downloaded using HTTP.    After running upgrade, I see that upgrades are being downloaded from HTTP too.     My understanding is that HTTP is essentially insecure, i. e. open to intercept and replacement of data. Are the upgrades thus unsafe? Or do I misunderstand something?

Are repository updates secure?  As a bear of little brain from the developer side, I cannot understand why the repository list is http://security.ubuntu.com and the other http(unsecured) sites listed in /etc/apt/sources.list.  Without a certificate chain match this appears as "ask any responder for a list of packages to update" instead of "ask the ubuntu.com site..."  Can any network choose to spoof the update sites, and is this a common practice to provide a locally cached and vetted copy?


On Workplace.SE (A)  is marked as a duplicate of (B)  (at the moment I write this, already 4 votes).  (A) is more recent than (B)  But (A) has much higher scores and more/better answers then (B), so I'd rather see (B) being closed as a dupe of (A). (A) can then be refered back to as the best Q/A available.  What to do?   Voting to leave open will not have the desired effect because the copycat behavior on duplicate flags will quickly get this question 5 close votes Do nothing, because 2a. (A) is more recent than (B) and "that's the rule we follow" (assumption) 2b. questions marked duplicate will remain visible anyway 2c. other... Flag for moderator attention with the request to reverse the direction. I will not do that now because (a mod reading) this meta question will probably trigger such an action if this is the desired one. Other...   [Edit] BTW  is very much related, but the two question compared at that time were about equal in weight

I have seen this many times, a question is being asked because a previous, duplicate question was asked and answered a few years ago and has no longer relevant answers.  The  is to edit the old question, or add new answers to it, but it is not always happening.  I was wondering, should I still mark it as duplicate and vote to close it? Or just leave it as is?


I'm facing an annoying issue with Google Play over and over again. There are some apps (currently Deezer and Teamtreehouse) which can't be updated/installed due this error:  "Can't install App" (Error code: -504)  FYI: This is not a 504 but negative 504 error  The only working solution what I found is the factory reset an wiping the whole phone, which is really annoying doing this every month. My question is, someone has easier solution for this error?  I have tried all solution what I found:   force stopping play store / play store framework clearing data clearing cache of google play store & google service framework removing  gmail account side-loading apps directly installing apks searching apps related files on phone and removing them   Image of the error:    My phone details: Xperia M4 Aqua  Android 5.0

Yes. I've read all other questions regarding this problem. Like this one:  It's the same problem as this one but with more background information and an other app:   The details: My device is an Ulefone Be Touch 2 running Android 5.0.  My connection is perfect. To be sure I tried different networks, among them are 3G, 4G and wifi on ADSL, VDSL, cable and fiber. I've also used Tor and 3 different VPN providers in 3 countries on 2 continents. Let's say I ruled the network out.   A single app does not install: OpenKeychain.  Currently I have 126 apps installed. It does not install via desktop browser > play store > install button.    I have enough free space (40GB). The app is 7MB.   Re-adding Google account and clearing caches did not work.    Even a complete device wipe and re-install didn't work.     Downloaded the apk and tried manual installation, same error.   I also own a Nexus 7 (2013 wifi) and the app installs fine on that device.


So, new here so...  I downgraded my ubuntu drive from 18.04 to 16.04 (For tensorflow 1.12 and cuda 9. Had to downgrade.) My question is how would I keep it at 16, so that I can use 'sudo apt-get upgrade' safely in a way that doesn't break the whole system...?

How can I switch on the option to be notified for a new Ubuntu version, which you usually find in      Dash --> System Settings --> Software & Updates --> Updates --> Notify me of a new Ubuntu version`   from command line to never?


Setting user to automatic login does not permit starting a session on Ubuntu 18.04 without entering the password.   How to fix this?

I have selected the setting 'Automatic Login' from within the default Gnome 3 Ubuntu 17.10 control panel app, but it keeps resetting to 'off' after every restart and does not allow me to automatically login.  Any ideas?


I had windows 10 previously installed on my Dell Vostro. It had 3 partitions which were lost and combined into one when I installed Ubuntu 16.04. All my data has been lost that included important videos. Please explain me steps to recover my lost data if possible.

About two weeks ago I had a problem with my PC that my brother wrote a question about at .  I still haven't solved the problem, so my PC is unusable now.  Now I think that it would be simpler to re-install both Win7 & Ubuntu than repair them, but there're some data on their partitions. I want to recover this data.  These partitions are not mountable for some reason. I don't know why.  sudo fdisk -l about the problematic partitions:     Device    Boot      Start         End      Blocks   Id  System /dev/sda1            2048     147912703    73955328   83 Linux /dev/sdb2            206848   174079999    86936576    7  HPFS/NTFS/exFAT   And in GParted:      And the error of the mount command:  Failed to mount '/dev/sdb2': Invalid argument The device '/dev/sdb2' doesn't seem to have a valid NTFS. Maybe the wrong device is used? Or the whole disk instead of a partition (e.g. /dev/sda, not /dev/sda1)? Or the other way around?   And the exact same message for /dev/sda1  How can I recover my data from those HDDs?  EDIT     I have tried to specify the type of the drive:  $ sudo mount -t ext4 /dev/sda1 /olddisk mount: wrong fs type, bad option, bad superblock on /dev/sda1,        missing codepage or helper program, or other error        In some cases useful info is found in syslog - try        dmesg | tail  or so $ sudo mount -t ntfs /dev/sdb2 /olddisk NTFS signature is missing. Failed to mount '/dev/sdb2': Invalid argument The device '/dev/sdb2' doesn't seem to have a valid NTFS. Maybe the wrong device is used? Or the whole disk instead of a partition (e.g. /dev/sda, not /dev/sda1)? Or the other way around?   EDIT     sudo ntfsfix /dev/sdb2 returns:  Mounting volume... NTFS signature is missing. FAILED Attempting to correct errors... NTFS signature is missing. FAILED Failed to startup volume: Invalid argument NTFS signature is missing. Trying the alternate boot sector Unrecoverable error Volume is corrupt. You should run chkdsk.


Imagine that I have the following table:     ItemCode WhsCode MinStock MaxStock AvgPrice     123 01 1 4 600   123 02 0 1 200   512 01 0 2 100   489 01 0 6 50   489 02 2 7 72   489 03 5 10 80   489 04 1 4 65   258 01 2 5 45     I want to select the row with MAX(AvgPrice) for each item, only from warehouses 01 and 02 (WhsCode). So the result that I want should look like:     ItemCode WhsCode MinStock MaxStock AvgPrice     123 01 1 4 600   512 01 0 2 100   489 02 2 7 72   258 01 2 5 45     What I tried, in my original code, was: SELECT T0."ItemCode", T3."MinStock", T3."MaxStock", T3."AvgPrice" FROM OITM T0 LEFT JOIN (SELECT              MAX(AvgPrice) AS AvgPrice,             ItemCode,             MinStock,             MaxStock  FROM OITW  WHERE WhsCode = '01' OR WhsCode = '02'  GROUP BY ItemCode,MinStock,MaxStock) T3  ON T0."ItemCode" = T3."ItemCode"  But, since I'm also grouping by MinStock and MaxStock, of course I'll have repeated values for each item, because MinStock and MaxStock are almost never the same for each WhsCode. So what I want to select is ItemCode, MinStock and MaxStock ONLY for the row with the MAX(AvgPrice). Dialect used is SQL Server 2019. I'm very new to SQL and couldn't find the answer here in an existing post.

I often need to select a number of rows from each group in a result set.  For example, I might want to list the 'n' highest or lowest recent order values per customer.  In more complex cases, the number of rows to list might vary per group (defined by an attribute of the grouping/parent record). This part is definitely optional/for extra credit and not intended to dissuade people from answering.  What are the main options for solving these types of problems in SQL Server 2005 and later? What are the main advantages and disadvantages of each method?  AdventureWorks examples (for clarity, optional)   List the five most recent recent transaction dates and IDs from the TransactionHistory table, for each product that starts with a letter from M to R inclusive. Same again, but with n history lines per product, where n is five times the DaysToManufacture Product attribute. Same, for the special case where exactly one history line per product is required (the single most recent entry by TransactionDate, tie-break on TransactionID.


I tried dual booting Windows 8.1 and Ubuntu 14.04. Everything worked fine, and I know that I installed both operating systems on different partitions. Now, it only boots to Ubuntu, and it wont show me the Grub menu to boot into Windows 8.1.

I installed Windows on my computer, followed by an installation of Ubuntu. However, now I'm unable to boot into my Windows install.  What can I do to fix this?


I have an excel file which gets generated from various database servers on fly by executing sql. Separate sheet gets generated for each server. Now I simply want to combine data of all sheets. Each sheet has same number of columns and headings. In combined sheet heading should appear at top only once.   For e.g North sheet  Sales Person | Item | Quantity | Sales | James | Ball | 100 | 2000| Jack | Bat | 50 | 100 | James | Bat | 25 | 50 |    South sheet Sales Person | Item | Quantity | Sales | Sara | Racket | 100 | 2000| Lucy | Ball | 50 | 100 | Sara | Racket | 25 | 50 |    Combined sheet    Sales Person | Item | Quantity | Sales | James | Ball | 100 | 2000| Jack | Bat | 50 | 100 | James | Bat | 25 | 50 | Sara | Racket | 100 | 2000| Lucy | Ball | 50 | 100 | Sara | Racket | 25 | 50 |

I have hundreds of excel files which are all of the same format (i.e. 4 worksheets per Excel file). I need to combine all the files into 1 all singing and dancing file which must have the same format as the originals (i.e. maintain the four separate worksheets, which are all identically named).  While each file is structured the same, the number of columns (and the heading names) between sheet 1 and 2 (for example) is different. So it can’t be combined into one file with everything in one sheet!  There are two complications:   I need to create an EXTRA column in the merged file (on EACH sheet) to identify the source file (“file name”). The files contain a lot of zero data entries (e.g. 55 rows of useful data followed by hundreds of rows of zeros) which I need to remove from the merged file.   I’ve never used VBA, but everyone has to start somewhere I suppose.


We really need a C.H.I.P category in Stack Exchange! That would be great!  For those of you who don't know what that is, it's a raspberry-pi-zero-like computer for 9$ CAD. It's mostly like the RPI zero in performance and "computerness", but it uses a ARMv7 architecture instead of rpi's ARMv6. It has 80 GPIO ports, built in Wi-Fi and Bluetooth 4.0, and has the option of buying additional add-ons (HDMI port, etc.)  The point is, because the C.H.I.P is just so amazing for its price, () it needs its own category right here in Stack exchange!

I have an idea or subject that should have a Q&A, and want to propose a new site. How can I do this?  Related:


I've already used the Intermediate Value Theorem to show that there is at least one real root. $f(1)=-3116<0$ $f(-1)=912>0$ Using IVT to $N=0,$ there exists $c \in (-1,1)\;$ such that $\;f(c)=0.$ I can use Rolle's Theorem to show that there is at least $2$ real roots, but how do I show that the equation has at least three real roots?

Prove that the equation $x^5 − 1102x^4 − 2015x = 0$ has at least three real roots.  So do I sub in values of negative and positive values of $x$ to show that there are at least three real roots? The method to do this question is not by finding the factors of $x$ right? Because it will be too tedious so I want to ask whats the other solution to prove this? Help appreciated. Thank you very much.


Let $a<c<b$, $f:(a,b)\to \mathbb R$ be continuous. Assume that $f$ is differentiable at every point of $(a,b)\setminus\{c\}$ and $f'$ has a limit at $c$. Then Which of the following are correct?  (A) $f$ is differentiable at $c$.  (B) $f$ need not be differentiable at $c$  (C) $f$ is differentiable at $c$ and $\lim_{x\to c}f'(x)=f'(c)$  (D) $f$ is differentiable at $c$ but $f'(c)$ is not necessorily $\lim_{x\to c}f'(x)$  Here, $\lim_{x\to c^+}f'(x)=\lim_{x\to c^-}f'(x)=L$(given). I tried to draw a curve satisfying this with sharp points(My aim is to show that $f$ need not be differentiable). But not able to find. So, $f$ is differentiable at $c$. But I am not able to prove analytically.

Assume we have a function $f : \mathbb{R} \rightarrow \mathbb{R}$ such that  $f$ is differentiable for all non-zero $x$, $f$ is continuous at $0$ and  $$\lim_{x \uparrow 0} f'(x) = \lim_{x \downarrow 0} f'(x) < \infty. $$  Is it then true that $f$ is also differentiable at $0$?  If we drop the hypothesis that $f$ is continuous, this is not true since the signums function is a simple counterexample. But what if $f$ is continuous? I don't think this is true but I can't find a counterexample...


When writing a paper whose I am the sole author, should I use "I" or "we" when referring myself?

Which personal pronoun is appropriate in single-author papers - 'I' or 'we'? Could the use of 'I' be considered egotistical? Or will the use of 'we' be considered to be grammatically incorrect?


I think it was a short story or novella. A wormhole or some other portal is discovered and all attempts at automated study of what is on the other side fail - all recordings come back blank. They send people, but they come back insane so they have people trained as councilors to gently bring them back to reality. Also tied with my memories of this story is the concept of flowers - like maybe in the name or figures in the story.

It'd be great if anyone could remember the source of this short story I only dimly remember, but recall finding quite haunting back in my youth.  I read it maybe 20 years ago in a paperback that probably dated from the '80s.  It begins with the protagonist (a young man) being being woken by a deafening noise coming through his cochlear implant.  He's on a spaceship, and has volunteered to be put in a capsule and fired off to a remote part of the solar system.  Once in place in their capsule, the volunteers are visited by what is (presumably) a highly intelligent alien life-form, and gifted with some artefact containing priceless knowledge, like, for example, the cure for cancer.  The (unexplained) encounter leaves the them completely and irrevocably insane, perhaps terrified out of the minds.  Yet despite this, volunteers still clamour to be chosen for the mission.


My team is discussing changing the way we collect phone numbers. Currently, we have a single input to collect the phone number. However, since we have an international market, the team is considering splitting this phone number input into multiple parts to better handle users from various countries.  The platform is a booking site. One situation where this change could be useful is when an employer is booking for an employee in another country—the employee's phone number may not match what the employer inputs for country.  We're looking for the best way to handle edge cases like this and attempting to make it intuitive for the user. Might this be a usable way to minimize errors and ensure accuracy?

Working on a form dealing with phone numbers, I've seen two methods to capture user input .   In past practices example 2 (image below) has proved effective in controlling phone number lengths on forms.   However with responsive in mind it would seem example 1 is considered a more popular pattern on forms. I've researched both patterns with the findings below.     Example 1  Pros   1 input = less taps on mobile device 1 input = less coding   Cons   could be difficult to control phone number format (1-555-555-5555, +22444455555, and etc)   Example 2  Pros   easier to control phone format reduced user error   Cons   3 inputs = more taps on mobile device more inputs = more coding   Both inputs have pros and cons and I'm not such which method would provide the best user experience for responsive environments. Can anyone share some insight or provide a better way to use phone number inputs?


I am trying to create JButtons and add them to a JScrollPane as well as a vector of JButtons. When I try to add them to the vector the program throws an exception.  Here is the code:  public class DirectorySelectionWindow extends JFrame {  Vector<JButton> directoryButtons; String selectedDir;  DirectorySelectionWindow(){     super("Select Directory");     this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);      String cwd = System.getProperty("user.dir");     System.out.println(cwd);      File currentDirectory = new File(cwd);      String filesInDir[] = currentDirectory.list();      JScrollPane pane = new JScrollPane();      for (int i = 0; i < filesInDir.length; i++) {         if (filesInDir[i] != null) {             if (!filesInDir[i].toString().startsWith(".")) {                 System.out.println(filesInDir[i]);                 JButton button = new JButton(filesInDir[i]);                 directoryButtons.addElement(button);                 pane.add(directoryButtons.elementAt(i));             }         }     }      this.add(pane);     this.pack();     this.setVisible(true);     }   I catch the exception when I try to add the button to the vector (the directoryButtons.add() line).

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?


The following limit evaluates to $1$.  $\lim_{x\rightarrow 0}x\left[\frac{1}{x}\right]$  , where [ ] is the floor function.  I still think that the left hand limit diverges to negative infinity while the right hand limit diverges to positive infinity.

I'm studying calculus right now but I'm stuck at solving a limit involving floor function.  The problem is to find $$\lim_{x\to 0}x \left\lfloor\frac{1}{x} \right\rfloor$$ where $\lfloor\cdot\rfloor$ denotes the floor function.  My first thought was to let $x=1/t$ so when ${x\to 0+}$ then ${t\to \infty}$ so it seems $\lim_{t\to \infty}[t]/t$ doesn't exist. But I can't go any further and don't know whether my thought is correct. It seems $t=N+\delta$ doesn't help because t goes to infinity. Can it be proved by the epsilon-delta method or something else? Thank you for your help.


When does the Community♦ "user" reject suggested edits? What was bad about this particular suggested edit, please?

Why does the Community user sometimes approve or reject edits? How does a machine know if my edit is valid? What does it mean if my edit was rejected by Community?     See also:


I get this message after trying the update manger:  W:Ignoring file 'Untitled Document 1' in directory '/etc/apt/sources.list.d/' as it has no filename extension, E:Type 'eb' is not known on line 2 in source list /etc/apt/sources.list.d/ehoover-compholio-precise.list   I am new to Ubuntu. What should I do?

Every once in a while I see users having issues to update due to errors like this:  E:Type 'ain' is not known on line 1 in source list /etc/apt/sources.list.d/some-ppa.list'   with varying types/line numbers/source list files (often after removing a PPA).  How can such an error be fixed?


I have a page in which there is some text that needs to be in two languages. Here is my code:    $('#english').hide();  $('#enButton').on('click', function() {    $('#english').fadeIn();   $('#french').fadeOut();  }); #french {   margin-top: 40px; }  #english {   display: block;   position: absolute;   top: 90px;   left: 150px; }  #frButton {   top: 30px;   left: 145px;   position: absolute;   cursor: pointer; }  #enButton {   top: 30px;   position: absolute;   right: 135px;   cursor: pointer; }

FRA

ENG

Text in French....

Text in English...

      The last two rules are for buttons. When you click on the "English" button I want to trigger some jQuery to hide the French text and make the English appear and then do the opposite when you click back on "frButton". But this is not working and I have both texts on top of each other as the method   $( '#english' ).hide();   is not even working. I have been at this for an hour now and the #english id is not being targeted at all. Any ideas why?  The content of "about" is loaded using ajax by the way.

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 want to submit certain web pages to Google so they can be indexed after they have been added or updated, but currently Google seems to be requiring a web master to login to do this.  I do not want to login to Google to submit my pages.  Is there any way to submit web pages to Google for indexing without logging in?

How can I notify Google's search engine of the existence of a website without opening an account with that company?


On linux, is there an easy way to recompress a zip file (changing compression-level) with preserving as most meta-data as possible (timestamps etc.)?

I have a large number of zip files that were compressed using the zip command. I would like to recompress them with the -9 flag to improve the compression ratio. Does anyone know if that can be done without manually decompressing and then compressing.  PS. I need to keep them as zip files since they are served to windows users( and as such have white spaces in their names)


when I copy a pose (ctrl + c) and then flip it with this shortcut(shift+ctrl+c) the I see some weird result don't know why.    then this happens after I've pasted it    You can check the  if you want. I've uploaded it in my google drive.


I am trying to create a web page that will fill the screen on a mobile phone.  However I haven't found a clean way to do this yet (without fixing sizes of things)  especially when scrollable areas are involved.  I have a fixed sized body (in the example set to 200px to test although would be 100% normally) with a
 within it. There is a scrollable
 who's height I would like to be that which is available. This is within the
. Now with the #page there is a #top, #main, and #footer-div.  The verical size of
 is set to the size of body.
 and
 end up being whatever size they need to be for their contents. Now I need #main to be #page.height - #top.height - #footer.height.  How do I do this ?  I have looked at various methods including the flex system, but this does not seem to do the job. The questions that could be duplicates don't cover the issue (see comments).  Consider the simplified following code. this has a fixed size for #main to make it work(ish).    html {   height:  100%;   margin:  0px; }  body {   height:  200px;   margin:  0px;   font:   100% Verdana, Helvetica, Arial, sans-serif;   background: #999999;       color:   Black; }  #page {   height:  100%;   margin:  0px; }  #top {   background-color: #CCDDDD; }  #main {   /* height: 100%; */   height:  calc(100% - 40px);   background: white; }  #footer {   font:   80% Verdana, Helvetica, Arial, sans-serif;   font-weight: bold;   background:  #7AB5E5;   border-top:  1px solid #436976;   border-bottom:  1px solid #436976;   clear:   both;   float:   none;   padding:  0.1em 0.1em 0.1em 0.1em;   text-align:  left; }  div.MessageScroll {   height:  100%;   margin:  0px;   overflow-y: auto; } <!DOCTYPE html>         <title>Test</title>     <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />     <meta name="viewport" content="width=device-width, initial-scale=1.0">

         Header

             Some Text.1
             Some Test 2
             Some Test 3
             Some Test 4

             Some Text.1
             Some Test 2
             Some Test 3
             Some Test 4

             Some Text.1
             Some Test 2
             Some Test 3
             Some Test 4

             Some Text.1
             Some Test 2
             Some Test 3
             Some Test 4

             Some Text.1
             Some Test 2
             Some Test 3
             Some Test 4

             Some Text.1
             Some Test 2
             Some Test 3
             Some Test 4

             Some Text.1
             Some Test 2
             Some Test 3
             Some Test 4

             Some Text.1
             Some Test 2
             Some Test 3
             Some Test 4

         Footer

I am working on a web application where I want the content to fill the height of the entire screen.  The page has a header, which contains a logo, and account information. This could be an arbitrary height. I want the content div to fill the rest of the page to the bottom.  I have a header div and a content div. At the moment I am using a table for the layout like so:  CSS and HTML    #page {     height: 100%; width: 100% }  #tdcontent {     height: 100%; }  #content {     overflow: auto; /* or overflow: hidden; */ }

...

...

     The entire height of the page is filled, and no scrolling is required.  For anything inside the content div, setting top: 0; will put it right underneath the header. Sometimes the content will be a real table, with its height set to 100%. Putting header inside content will not allow this to work.  Is there a way to achieve the same effect without using the table?  Update:  Elements inside the content div will have heights set to percentages as well. So something at 100% inside the div will fill it to the bottom. As will two elements at 50%.  Update 2:  For instance, if the header takes up 20% of the screen's height, a table specified at 50% inside #content would take up 40% of the screen space. So far, wrapping the entire thing in a table is the only thing that works.


I require my footer to stick to the bottom of the page. Currently sticks to the bottom when the view port is full and doesn't extend. However when I use a smaller resolution I get a vertical scroll bar, and the footer remains where the view port was originally and doesn't stick to the bottom of the page.  Link:   Any help would be appreciated. I have tried multiple techniques which only seem to work in the view port and not when vertically scrolling is involved.

I have a simple 2-column layout with a footer that clears both the right and left div in my markup.  My problem is that I can't get the footer to stay at the bottom of the page in all browsers.  It works if the content pushes the footer down, but that's not always the case.


I’m trying to call MainActivity.my_method() from a different class, but I get: non-static method my_method(Context) cannot be referenced from a static context. MainActivity.java public class MainActivity extends Activity {      public void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         my_method(); //WORKS WELL     }      public void my_method(Context context) {         context.startActivity( new Intent( Settings.ACTION_REQUEST_IGNORE_BATTERY_OPTIMIZATIONS, Uri.parse( "package:" + context.getPackageName() ) ) );     } }  My_view.java class My_view extends SurfaceView implements SurfaceHolder.Callback {      class My_viewThread extends Thread implements SensorEventListener, OnTouchListener{        …        private Context mContext;        …        public void my_calling_method() {             MainActivity.my_method(mContext);        }        ....                        Any help will be very appreciated.

The very common beginner mistake is when you try to use a class property "statically" without making an instance of that class. It leaves you with the mentioned error message:     You can either make the non static method static or make an instance of that class to use its properties.   Why? I am not asking for solutions. I would be grateful to know what is the reason behind it. The very core reason!  private java.util.List<String> someMethod(){     /* Some Code */     return someList;             }  public static void main(String[] strArgs){                // The following statement causes the error. You know why..     java.util.List<String> someList = someMethod();          }


I understand apple has my wellbeing at heart by trying to lower the volume when listening to music (with the volume set to full), but this makes no sense why I am connected to a bluetooth speaker. It doesn't even ask me 'are these headphones?' like it does when you connect something to the lightning port. How can I make it realise these are not headphones that are being connected?

I regularly get interrupted in watching and listening to video by the volume randomly getting lowered without me asking for it. I get a system notification telling me "the volume was lowered", telling me it's protecting my hearing based on the last 7 days of use. I've never been asked about enabling such a feature. I have already disabled what relevant items I can find under Sound & Haptics, which is given as the source of the notification. It apparently doesn't matter though because it's not being respected. How can I make this stop? iPhone 8, iOS 14.2


I have a object variable representing a vector: let pos = {x: 0, y: 0}. Then i have an array to put those vectors. If i change the x and y from the object pos every element in the array changes to the recent value. Why is this? let pos = {x: 0, y: 0}; let arr = []; arr.push(pos); // arr: 0: {x:0 , y: 0} pos.x = 5; pos.y = 9; arr.push(pos); // arr: 0: {x:5 , y: 9} 1: {x:5 , y: 9}  And i want arr: 0: {x:0 , y: 0} 1: {x:5 , y: 9}

I have an object x. I'd like to copy it as object y, such that changes to y do not modify x. I realized that copying objects derived from built-in JavaScript objects will result in extra, unwanted properties. This isn't a problem, since I'm copying one of my own literal-constructed objects.  How do I correctly clone a JavaScript object?


How can you know when to use a and when to use the? I do not know how to do and my teacher only says that one is here and one isn't. What does this mean? I want to know how to use "a" and "the" when talking about an object. Thank you.

How do I know whether to use the definite (the) or indefinite (a, an) article, and when to omit it altogether?


Is there a canonical way to specify a (per-user, or system wide) preferred terminal emulator, just like the EDITOR environment variable specifies the preferred text editor?

There's already  which point to various executables (with or without full path). , not necessarily the name of the executable (in xterm it's xterm-color, and in gnome-terminal it's xterm-256color). Is there a variable which is expected to contain the name or path of the executable to use as the default terminal in Linux? (Or Arch Linux, if there is a custom convention.) Maybe this is nonsensical, since GUI programs are rarely spawned from shells which know of these variables…


Let $p(x)\in K[x]$ and $q(x)\in K[x]$, $F$ is an extension of field $K$. Will $gcd(p(x),q(x))$ over $K[x]$ equal to $gcd(p(x),q(x))$ over $F$.  My guess is yes. I couldn't find an elegant way to prove it.

Let $E/F $ be a field extension and $f,g$ $\in$ $F[x]$ (the polynomial ring with coefficients in $F$ ). Let's denote with $\gcd_F(f,g)$ the greatest common divisor of $f$ and $g$ in $F[x]$. Is it true that $\gcd_F(f,g)$ $=$ $\gcd_E(f,g)$ ?


Can Anyone explain the description for acquiring the "Electorate Gold Badge"?  The description says as,  Vote on 600 questions and 25% or more of total votes are on questions   Voting 600 Questions and 25% Votes on Questions?  P.S. I saw other similar questions, but still couldn't understand though.

Formerly List of all badges with full descriptions.  What are badge name's requirements? Why didn't I get badge name ? Which badges can I earn multiple times?    Jump to:                    Note: Some badges are awarded based on score. The term score means the total number of upvotes minus the total number of downvotes.  Any badge with a *** next to it is one of 20 badges that count towards the  displayed on a moderator candidate in an election. The candidate score is a total of 40 points: the first 20 are awarded based on the user's rep divided by 1000 and rounded down; the second 20 represents the total number of unique badges earned of the 20 that count. Note that if the same badge is earned multiple times, it will only count once towards the candidate score.  Any badge with a "(retired)" next to it is no longer awarded, but is retained by users who previously earned them. See  for more info on what it means for a badge to be retired.       Visit the  of the  on any site to see a complete list of badges that you can filter by earned, unearned, or type.


I have the following setup: I have a binary logistic regression analysis with a couple of independent variables. They include a nominal variable that is coded in a dummy form with $k-1$ predictors. It happens to be the case that one dummy is all 1's with the dependent variable, i.e., perfect separation. This produces a very high estimate (~16) with very high standard errors (~1250). Albeit insignificant, this looks a little strange. It is only a control variable, therefore, I don't want to complicate things overly... Is there a way to handle this "problem"? Do I violate any assumptions by including such a dummy?

If you have a variable which perfectly separates zeroes and ones in target variable, R will yield the following "perfect or quasi perfect separation" warning message:  Warning message: glm.fit: fitted probabilities numerically 0 or 1 occurred    We still get the model but the coefficient estimates are inflated.   How do you deal with this in practice?


when i am creating TAR of a directory which contents files,  the TAR archive folder size is more than the original folder size.  why does it so? checking file size by using ls -ltr directoryname

I used ls -lS command in my home directory. This command is supposed to list down the contents of a directory by size. This is what I got after running this command  total 10148 -rw-rw-r--  1 rahul rahul 8053159 May 15 15:35 Costa_ODE.pdf -rw-rw-r--  1 rahul rahul 1755507 May 15 17:33 gnuplot.pdf -rw-rw-r--  1 rahul rahul  218048 May 13 22:14 out.log -rw-rw-r--  1 rahul rahul   98131 Feb 16 01:53 hs_err_pid8639.log -rw-rw-r--  1 rahul rahul   12364 Apr 19 14:01 Untitled 1.csv drwxr-xr-x  4 rahul rahul   12288 Jun  6  2016 cfitsio -rw-r--r--  1 rahul rahul    8980 Feb  7  2016 examples.desktop drwxrwxr-x  2 rahul rahul    4096 Mar 10 12:24 bin drwxrwxr-x  8 rahul rahul    4096 May  8 14:51 boxfitv2 drwxrwxrwx  2 rahul rahul    4096 Jan 30 11:50 dao2 drwxrwxr-x  2 rahul rahul    4096 Mar 12  2016 deja-dup drwxr-xr-x  6 rahul rahul    4096 May 16 02:12 Desktop drwxr-xr-x  3 rahul rahul    4096 May 15 10:53 Documents drwxr-xr-x  5 rahul rahul    4096 May  8 14:09 Downloads . . . .   and its a pretty big list. But I want you to focus on sub-directories, for example Desktop. Its size is shown as 4096 bytes. But when I tried to see the details of Desktop, this is what I got.    In short, the command ls -lS is not calculating the size of the contents of Desktop and other sub-directories. Is there any way to do it?    EDIT:  Output of ls -lsh command  total 10M 4.0K drwxrwxr-x  2 rahul rahul 4.0K Mar 10 12:24 bin 4.0K drwxrwxr-x  8 rahul rahul 4.0K May  8 14:51 boxfitv2 4.0K -rw-rw-r--  1 rahul rahul 3.2K May 13 13:28 c.c  12K drwxr-xr-x  4 rahul rahul  12K Jun  6  2016 cfitsio 7.7M -rw-rw-r--  1 rahul rahul 7.7M May 15 15:35 Costa_ODE.pdf 4.0K drwxrwxrwx  2 rahul rahul 4.0K Jan 30 11:50 dao2    0 -rw-rw-r--  1 rahul rahul    0 May 13 20:37 default.txt 4.0K drwxrwxr-x  2 rahul rahul 4.0K Mar 12  2016 deja-dup 4.0K drwxr-xr-x  6 rahul rahul 4.0K May 16 17:11 Desktop 4.0K drwxr-xr-x  3 rahul rahul 4.0K May 15 10:53 Documents 4.0K drwxr-xr-x  5 rahul rahul 4.0K May  8 14:09 Downloads  12K -rw-r--r--  1 rahul rahul 8.8K Feb  7  2016 examples.desktop . . .   Output of du -sh ~/Desktop command  80M /home/rahul/Desktop


It seems there is an unexpected behavior regarding lists with Python 3.8.1:      > l = [[]] * 4     > l[0].append(1)     > l     [[1], [1], [1], [1]]   I would expect l to be equal to [[1], [], [], []].  Should not the lists inside l correspond to different "objects"?  On the other side the following code behaves as expected.      > l = [ [] for i in range(4)]     > l[0].append(1)     > l     [[1], [], [], []]

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?


Need to find $\lim\limits_{n\to\infty}(a_1^n+\dots+a_k^n)^{1\over n}$ Where $a_1\ge\dots\ge a_k\ge 0$  I thought about Cauchy Theorem on limit $\lim\limits_{n\to\infty}\dfrac{a_1+\dots+a_n}{n}=\lim a_n$ and something like what happen if all $a_i=0$ or $a_1=\dots=a_k$, but may be something I am thinking wrong?  Maybe it is too simple but I am not getting it; please help.

If we are in a sequence space, then the $ l^{p} $-norm of the sequence $ \mathbf{x} = (x_{i})_{i \in \mathbb{N}} $ is $ \displaystyle \left( \sum_{i=1}^{\infty} |x_{i}|^{p} \right)^{1/p} $.  The $ l^{\infty} $-norm of $ \mathbf{x} $ is $ \displaystyle \sup_{i \in \mathbb{N}} |x_{i}| $.  Prove that the limit of the $ l^{p} $-norms is the $ l^{\infty} $-norm.  I saw an answer for $ L^{p} $-spaces, but I need one for $ l^{p} $-spaces. Besides, I didn’t really understand the $ L^{p} $-answer either.  Thanks for your help!


As we know C# provides an AS keyword which automatically performs a check whether the Object is of a type and if it is, it then casts it to the needed type else gives a null. public class User { }  Object obj = someObj; User user = obj As User;  Here in the above example, An Object obj can be of type User or some other type. The user will either get an object of type User or a null. This is because the As keyword of C# first performs a check and if possible then performs a casting of the object to the resulting type. So is there any keyword in Java which is equivalent to the AS keyword of C#?

There are situations, where it is practical to have a type-cast return a null value instead of throwing a ClassCastException. C# has the as operator to do this. Is there something equivalent available in Java so you don't have to explicitly check for the ClassCastException?


We are a small business with two HP Servers(HPE ProLiant DL380) virtualized with ESXi, containing 7 VMs of Windows Server OS(2016).  As per Hardware documentation, each server has single processor with 10 cores each. So that should make 20 Cores total.  I did search about Microsoft Licensing and it says core based can have two licenses if 16 Core licenses are purchased.  Can anyone help me about    How many Windows Server 2016 STD Licenses should I purchase to accommodate 7 VMs.  If I purchase 1 Remote Desktop Device CALs for each of VM's (Total:7), multiple users in the domain can RDP login to the server?   Edit: The confusion here is only with Core Based Licensing from Microsoft.

This is a  about Licensing.    Questions on licensing are off-topic on Server Fault.  If your question has been closed as a duplicate of this question, then this is because we want to help you understand why licence questions are off topic rather than just telling you "it just is". In all likelihood, this question will not address your question directly, it was not meant to.    I have a question regarding software licensing. Can the Server Fault community please help with the following:   How many licenses do I need? Is this licensing configuration valid? What CALs do I need to be properly licensed? Can I run this product in a virtual environment? Can I downgrade this product to an earlier version? Am I entitled to feature X with license Y?


I (Indian) have a travel itinerary from Dublin to India via UK Heathrow airport. From the airline website, it says that I need to move from Terminal 2 to Terminal 3 of Heathrow airport. As I have never been to Heathrow before, do I need to pass the border check/immigration? If so then do I need to have UK transit visa or some sort? I'm a work visa holder in Ireland. Please help me with this guys. Thanks!

Is there a website or some other way to find out if I need a transit visa for a short stop in the UK on my way somewhere else? Ideally this should give me the answer for all nationalities, and take into account any other visas I may have.


I recently broke my space-key I've copied the space and I paste it to get the space when I'm typing. Can I get help mapping my key with Karabiner for Mac or any other key-mapping software?

I spilled a juice on my MacBook-Pro keyboard. Consequently, some keys like 2, esc and tab don't work anymore on my keyboard.   Is there anyway to change those disabled keys with combination of some other keys, like Fn,Ctrl, Option+ something, using an app or a command?


I ordered online for a Lenovo 65W AC adapter for Lenovo G550 laptop.  My original adapter had specifications: 19V 3.42A (64.98W)  While the one I got has specifications: 20V 3.25A (65W)  I want to know if it is safe to use the second adapter with my laptop.  Edit 1: The new adapter is also from Lenovo.

I have a Toshiba Satellite laptop. My charger has stopped working.  I have access to a Lenovo charger. Can I use this charger on my laptop?


CI(p) = (a, b)  People sometimes interpret this interval by saying that      there is a 95% probability that the true p belongs to (a, b)   The statement is incorrect (there is no probability associated with p which is not a random quantity). The correct interpretation is that if take 100 new samples from the same population and construct the 100 confidence  intervals, then we expect (on average) 95 of them to cover the true p. In other terms,      there is a 95% probability that (a, b) covers the true p   How do you explain the difference between these two interpretations to a layman?

It seems that through various related questions here, there is consensus that the "95%" part of what we call a "95% confidence interval" refers to the fact that if we were to exactly replicate our sampling and CI-computation procedures  many times, 95% of thusly computed CIs would contain the population mean. It also seems to be the consensus that this definition does not permit one to conclude from a single 95%CI that there is a 95% chance that the mean falls somewhere within the CI. However, I don't understand how the former doesn't imply the latter insofar as, having imagined many CIs 95% of which contain the population mean, shouldn't our uncertainty (with regards to whether our actually-computed CI contains the population mean or not) force us to use the base-rate of the imagined cases (95%) as our estimate of the probability that our actual case contains the CI?   I've seen posts argue along the lines of "the actually-computed CI either contains the population mean or it doesn't, so its probability is either 1 or 0", but this seems to imply a strange definition of probability that is dependent on unknown states (i.e. a friend flips fair coin, hides the result, and I am disallowed from saying there is a 50% chance that it's heads).  Surely I'm wrong, but I don't see where my logic has gone awry...


Super newbie here, so bear with me. I have an old laptop HP Compaq 8710 workstation with a faulty nvidia graphics card and I want to keep using it, without spending cash to fix the card itself. The problem is that if I update the graphics card drivers the laptop will go into a reboot mode and won't start the OS at all. Thus I installed a clean version of Lubuntu 18.04 and it seems to be working fine until now, without doing any updates at all. My question is, is there a way to do "all" the updates in the terminal with the sudo apt upgrade but exclude any graphics? Probably don't need to do most of the updates for basic PC usage, but I don't want to feel missing out. :P Any suggestions/tips are appreciated! :D

Because of  I'd like to prevent apt-get upgrade and Update Manager from updating the "libgtk2.0-0" package.   How can this be achieved?


Let $A, B ∈ M_{n×n}$ If   $A\cdot B = A  $, then $B$ is the identity matrix. I can't find a theorem that proves this statement. Could it be false? Edit: A is NOT the zero matrix.

If matrix multiplication $AB=A$, does it mean $B$ must be an identity matrix? If not, why? What conditions?  $A$ is not a zero matrix.


I am searching an editor which supports the regex syntax like python does.  I want a GUI like gedit.  The old school editors vi, vim, emacs are no solution, since the editor should be easy to use.  I use PyCharm for software development, but sometimes I just want to do a a simple re.sub() on some content from the clipboard.  The tool gedit is not bad (except pressing ctrl-f again does not do what you usually intent) but unfortunately it does not support the python regex flavour.  I know that gedit support regular expressions. But Python flavor regex syntax is required!


example: x^x = 3 I know that I can solve this equation by plotting both of the terms as a function, f(x) = x^x and g(x) = 3, and finding their intersection. But I was wondering whether there was an approach to this equation with an algebraic method or any approach that doesn't involve calculating the intersection of these functions.

Given that   $x^x = y$; and  given some value for $y$   is there a way to expressly solve that equation for $x$?


I know that $f(t)=\frac{1}{t}$ does not have a Laplace transformation but I don't know the right(formal) way to prove it.  Here is my way:  Using the fact:  $L[\frac{f(t)}{t}]=\int_{s}^{\infty}F(t)dt$,  I have:  $L[\frac{1}{t}]=\int_{s}^{\infty}\frac{1}{s}dt = \frac{1}{s}|^{\infty}_{s}$   this is divergent and therefore the Laplace transformation of $f(t)=\frac{1}{t}$ does not exist.  However, I think my way is not rigorous. I hope I can receive a explicit proof of it (Maybe by definition to integrate).  Thank you so much!    Edit:  Actually, I do not know how to actually prove that $\int_{0}^{\infty}e^{-st}\frac{1}{t}dt$ diverges. Please help me with this!

Does the laplace transform of $1/t$ exist? If yes, how do we calculate it? Putting it in $$\int_0^\infty (e^{-st}/t) dt$$ won't solve.  Is there any other way? If not, why?  Thanks!


HTML <input type="number" required="" pattern="\d*" id="mobile">  jQuery var letters = /^[0-9]+$/; var mobile_backup=""; $(document).ready(function(){     $("#mobile").on("input", function(){         var mobile_value=$(this).val();         if(mobile_value==="")         {             mobile_backup=mobile_value;         }         else if(mobile_value.match(letters)===null){             $(this).val(mobile_backup);         }         else{             mobile_backup=mobile_value;         }     }); });  Current solution works in all devices (desktop, mobile, tablet). Is there any efficient approach available such that it works in all devices? I know I can use a pattern for number. But I don't want an alert. I just want to allow the numbers without a dot.

Is there a quick way to set an HTML text input (<input type=text />) to only allow numeric keystrokes (plus '.')?


Why am I getting strange output in case of StackOverflowError ?  public class Hello{       public static void main(String args[]){           System.out.println(new Exception().getStackTrace().length);           m1();       }       public static void m1(){           m2();       }       public static void m2(){           try{               m1();           }catch(StackOverflowError err){               System.out.println(err.getStackTrace().length);           }       }   }    Output (a)-         1         102410241024102410241024102410241024  Output (b) -         1024  Output (c)-         1         1024      When the above code executes I am getting Output (a).But when I am commenting first line of main method I am getting Output (b).  I should be getting Output (c) when I am executing the above code by keeping the first line in main method uncommented  Why is 1024 getting printed so many times in Output (a)?  I was trying to find out default stack size by raising StackOverflowError and purposely catching it.I printed stack size before calling m1 method from main method.

What is a StackOverflowError, what causes it, and how should I deal with them?


I am giving a function to write as part of my program that takes as input a short integer num, and a short integer parity mask. The function then return the number of 1’s that are in the same position in num and in the parity mask. for example, if you enter num as 0x8 and parity mask as 0x9 then it return 1. (since 0x8 = 00001000 and 0x9 = 00001001 so they both have a 1 at position 3).  I have looked everywhere online trying to find a simple way to implement it but couldn't find anything similar to it.  Could someone please explain to me how to write this function or give some suggestion on how to start?  Thank you

8 bits representing the number 7 look like this:  00000111   Three bits are set.     What are algorithms to determine the number of set bits in a 32-bit integer?


When I boot Ubuntu 18.04 at startup from grub menu, I get stuck on a black screen.  I tried changing in grub.cfg file, the line quiet splash to nomodeset and nomodeset quiet splash. It seem to have worked when it was loading all the system files but then it got stuck again.  Here are my system specs:   Asus ROG G551VW Intel core i7 6700HQ 16 GB RAM Nvidia Geforce GTX 960M Intel HD Graphics 530   Also fast boot is disabled and so is secure boot.  Sometimes it runs by nomodeset, but then again I have no idea how to load intel graphics driver in Ubuntu since I kept on getting 800x600 resolution and no other.  What to do?  Already tried this:   Now it's not starting with even nomodeset when I installed Nvidia drivers.

I am trying to boot Ubuntu on my computer.  When I boot Ubuntu, it boots to a black screen.  How can I fix this? Table of Contents:


I bought a laptop that came with Windows 8 installed. There were problems with my laptop and I couldn’t even use the Windows 8 refresh or restart, so I installed Ubuntu. I now have only Ubuntu on my laptop and was wondering if there was any way I could go back to Windows 8 without paying. In my BIOS, it says my factory installed OS is Windows 8, and I have the sticker on my laptop to prove it in case I have to send it in.  EDIT 1:  I called them and they said it would cost $30 to get another cd.  My sticker looks like the one on the left.    EDIT 2:   My laptop is an HP Pavilion g6 I have wiped the partition and there is only one with Ubuntu on it. I think I have my win 8 serial written somewhere Nowhere on the PC does it have any key. I have a legal Win XP SP2 cd (with key) if that helps.

I obtained a licence key for Windows 8 through DreamSpark. Is there a way to download a Windows 8 ISO image like you could for Windows 7? I am on a non-Windows machine, so I cannot use the Secure Download Manager to download Windows 8 directly using DreamSpark.


Example 1:   Person: Why are healthcare workers wearing masks if it wont protect us?  Me: Proper fitting N95 masks provide protection, others do not.  Person: Wow, why are you so rude?  Rudeness was not exchanged whatsoever.   Example 2:   Person: Hey can you grab me the tool?  Me: Yes, here you are. Gives tool without problem  Person: Whats your problem today?!?  The situation did not have any acts of aggression.  Person is genuinely suddenly under an irrational belief that another is being rude with no supporting evidence presenting as rude or being a problem. I am looking for a word that describes a random unfitting judgement or claim that doesnt make sense. Imagine youre having a conversation with someone, and they respond with something completely unrelated leaving you scratching your head.  Not slander because they arent intentionally trying to demean you. Not ad hominem because they arent attacking you instead of the conversation.

I really dont know how to describe this. Im having a discussion with someone, I was sharing information that I found on a topic. Randomly im called out as being rude when nowhere was there evidence of rudeness exchanged. This person seems to have a history of claiming people have a problem or are being rude out of the random blue.   Is there a word to describe these random accusations that dont connect to anything?


Although this question is very simple in the substance, I would like to ask it anyway. Visibly if I use the comma within the mathematical environment you can see a small space that I have underlined with a red horizontal line.  %% Compile and read me! \documentclass[a4paper,12pt]{article} \usepackage{amsmath} \begin{document} \[a=(3,15 \pm 0,22) \text{ cm}\] \end{document}     Surely the space, with the use of siunitx package it will disappear as it is a specific package for units and decimal numbers. To remove this space I use the command to have a negative space \!. In fact I obtain this:    \documentclass[a4paper,12pt]{article} \usepackage{amsmath} \begin{document} \[a=(3,\!15 \pm 0,\!22) \text{ cm}\] \end{document}   Are there any other alternatives without the use of siunitx package?  Are there possible contraindications if you do not use this package?

In math mode, LaTeX inserts a small space after a comma. This looks nice in $a,b,c$, for example. But I don't like the way it looks when using a comma as a thousands separator, e.g., $x = 100,000$. (There is no space after the comma when writing 100,000 outside of math mode.) Is there an easy way to avoid this? Some symbol I should be using instead of comma?


How to add bookmark in texmaker?  A bookmark  in the sense that mark a certain line in a certain latex file, and come back to that line later even you are opening another latex file.  The obvious different with the the question () is that, using approach in that question, bookmarks does not persist if I close Texmaker and open the same file again.

What is the usage of 1 2 3 here in the source viewer of texmaker?


On p.333 of Conceptual Mathematics 2nd ed. we are asked to compute the exponential object $A^{A}$ in the category of irreflexive graphs, where $A$ is the graph of a single arrow s -> t.  (For context there is a graph $D$ that is the graph of a single dot *.  The book suggests using the properties of exponentials and graphs. For example to find the number of dots in $A^{A}$, find the number of maps $D \rightarrow A^{A}$, which is equivalent to the number of maps $A \times D \rightarrow A$. This is the same as the number of maps from the dots of $A$ to $A$, of which there are 4.  Similarly we can find the number of arrows by counting the maps of $A \rightarrow A^{A}$ which is the same as counting the maps of $A \times A \rightarrow A$ which there are 4, which are..  (s, s) and (t, t) must be mapped to s and t respectively, but (s, t) and (t, s) can be mapped to either s or t, hence 4.  So I know there are 4 dots and 4 arrows.. but I don't know how to map the arrows onto the dots.  Context: In the category of graphs an object is two sets $X$ (the edges of the graph) and $P$ (the nodes of the graph) equipped with two arrows $s, t: X \rightarrow P$ which correspond to the source and target of the edge. An arrow between two graphs is two arrows $f: X \rightarrow X'$ and $g: P \rightarrow P'$ which preserves source and target:  $$ g \circ s = s' \circ f $$ $$ g \circ t = t' \circ f $$

(reference is Lawvere/Schanuel, Session 31, Ex. 1)  I'm trying to calculate the exponential object $A^A$ and its evalution map $e \colon A \times A^A \to A$ in the category of graphs, where $A$ is the "arrow graph" (ie. one arrow and two dots).  In the following, $D$ is the graph with one dot and no arrows, $1$ is the terminal object in this category (graph with one dot and one arrow, the loop).  So far I have:   The points of $\mathbf{1}\to A^A$ correspond to the maps $A\to A$ (via two standard isomorphisms), and since $\mathbf{1}$ is the loop, and there is one map of graphs $A \to A$, there is one loop in $A^A$. The dots $D\to A^A$ correspond to the maps $A \times D \to A$, of which there are four, hence four dots in $A^A$. The arrows $A \to A^A$ correspond to the maps $A \times A \to A$, of which there are four, hence four arrows in $A^A$.   But I'm stuck on how to put these together to constitute $A^A$ and its evaluation map.


If you are biking on level ground with no wind, I understand that there are losses inherent in your activity which you provide effort to overcome  (if you want to maintain a steady speed):   Air/wind resistance Rolling resistance Friction losses ?   I am wondering if there has been any significant analysis into what percentage of the overall energy exertion goes to which loss. Something like "70% of the energy loss is due to X, 15% to Y" etc.  I know that this will vary based on the type of bike, tire pressure, posture, speed, wind speed, etc, but I am curious if there has ever been an in-depth analysis into the breakdown of energy loss in cycling.   I care about far more than just drag, which is the only variable the related question addresses.

I am curious how to estimate drag for a bicycle. This has two different framings:   Find the amount of power required to ride at a certain speed. That is, when one is traveling at a constant speed, the power added to the system (with my effort and/or coasting on a descent) equals the power subtracted by aerodynamic drag, rolling resistance, ascending, deflecting objects thrown by spectators, etc. Find the amount of pushing force required to maintain a given speed (again, the pushing forward equals the pushing backward at constant speed). The most obvious example is aerodynamic drag, which one can feel “pushing” back when one is riding at speed.   Online calculators and formulas exist, but they assume coefficients of rolling resistance or aerodynamic drag, or assume that I can provide these coefficients. How do they make these assumptions, and/or how can I make those estimates myself?  (Credit goes to  for urging me to ask, in the commentary of .)


It seems that iOS 10 Public Beta 3 fixed all of this. All is good.    I've found this bug on mobile where some icons have white squares on them. Is this already reported? Or is this supposed to happen? I am on iOS 10 public beta #1…     App Version: 1.5.3.5 Device: iPhone 6 OS Version: Version 10.0 (Build 14A5297c)   Also it happened on mobile site...

As you can see in the below screenshot, some of the the icons (e.g. Stack Overflow, User Experience, and more) are showing with white box around them.         App Version: 1.5.3.5 Device: iPhone 6s OS Version: Version 10.0 (Build 14A5297c)   Can this please be fixed?


I am trying to find a sci-fi story I read in early 1980s sci-fi anthology. It was told from the perspective of snake/devil hiding from a megolomaniac God. Any leads much appreciated. It was written in the first person, from the view point of Satan. I remember him as a snake, hiding from a mad God who has convinced the world that light and sound are necessarily good and darkness and quiet are bad. It's kind of a rumination - I don't recall any actual action.

Trying to identify a short story:  The last man on Earth is walking across a shattered wasteland. After a time he's joined by someone he's never met before, but our original person is still the last man on Earth, because the new companion is rather different, probably not a man.   Every hour or two a voice booms out of the sky saying something like, "Bow down before me!", or "I am the Alpha and the Omega!"... things of that nature. The companion is friendly, sensible and helps the man, who begins climbing to the top of a nearby mountain. After climbing for a while the loud voice booms out again, saying something like, "Worship me!" The man finally turns to his unusual companion and asks, "Was he always insane?" and the companion sadly nods his head and mournfully says, "Yes, he's always been insane." We realize the booming voice comes from God and the kind companion is the Devil.  ......Does anyone know the title or author, please?


I have following query  SELECT GETDATE()   which returns me as 2013-11-16 03:31:07.740 I want only the DATE part and omit Time part.   I have used   select convert(varchar, getdate(), 100) convertResult,100 style union select convert(varchar, getdate(), 101),101 union select convert(varchar, getdate(), 102),102 union select convert(varchar, getdate(), 103),103 union select convert(varchar, getdate(), 104),104 union select convert(varchar, getdate(), 105),105 union select convert(varchar, getdate(), 106),106 union select convert(varchar, getdate(), 107),107 union select convert(varchar, getdate(), 108),108 union select convert(varchar, getdate(), 109),109 union select convert(varchar, getdate(), 110),110 union select convert(varchar, getdate(), 111),111 union select convert(varchar, getdate(), 112),112 union select convert(varchar, getdate(), 113),113 union select convert(varchar, getdate(), 114),114  union select convert(varchar, getdate(), 120),120  union select convert(varchar, getdate(), 121),121  union select convert(varchar, getdate(), 126),126  union select convert(varchar, getdate(), 127),127  union select convert(varchar, getdate(), 130),130  union select convert(varchar, getdate(), 131),131 order by 2   But not any combination gives me the date section only.

SELECT GETDATE()   Returns: 2008-09-22 15:24:13.790  I want that date part without the time part: 2008-09-22 00:00:00.000  How can I get that?


I am using the memoir document class. My first paragraph is not indented, but all others are.   explains how to indent them all. I want none of them to be indented. I have good reasons for desiring this.  Is there a simple command to stop indenting paragraphs?

I'm using a template that I can't/shouldn't modify. This template forces that every time a new paragraph begins, there is an indentation added. In some rare cases this is just looking really ugly and that's why I'd like to avoid this indentation. Is there any way to do this without changing the template?


My system is not detecting any Bluetooth device and i checked similar questions such as these -  None of those links helped. I would like to know what to look for to identify whats missing at the first place. any help is appreciated  dmesg | grep -i blue [   23.314055] Bluetooth: Core ver 2.22 [   23.314074] Bluetooth: HCI device and connection manager initialized [   23.314077] Bluetooth: HCI socket layer initialized [   23.314079] Bluetooth: L2CAP socket layer initialized [   23.314088] Bluetooth: SCO socket layer initialized [   24.733996] Bluetooth: hci0: BCM: chip id 70 [   24.734998] Bluetooth: hci0: BCM: features 0x06 [   24.750996] Bluetooth: hci0: akash [   24.750999] Bluetooth: hci0: BCM (001.001.011) build 0000 [   24.943442] bluetooth hci0: Direct firmware load for brcm/BCM.hcd failed with error -2 [   24.943446] Bluetooth: hci0: BCM: Patch brcm/BCM.hcd not found [   26.976024] Bluetooth: hci0: command 0x1003 tx timeout [   26.976976] Bluetooth: hci0: unexpected event for opcode 0x1003 [   51.085298] Bluetooth: BNEP (Ethernet Emulation) ver 1.3 [   51.085300] Bluetooth: BNEP filters: protocol multicast [   51.085303] Bluetooth: BNEP socket layer initialized [  105.580132] Bluetooth: RFCOMM TTY layer initialized [  105.580152] Bluetooth: RFCOMM socket layer initialized [  105.580167] Bluetooth: RFCOMM ver 1.11 [ 8328.267411] Bluetooth: hci0: BCM: chip id 70 [ 8328.268372] Bluetooth: hci0: BCM: features 0x06 [ 8328.284464] Bluetooth: hci0: akash [ 8328.284477] Bluetooth: hci0: BCM (001.001.011) build 0000 [ 8328.315338] bluetooth hci0: Direct firmware load for brcm/BCM.hcd failed with error -2 [ 8328.315345] Bluetooth: hci0: BCM: Patch brcm/BCM.hcd not found [ 8330.341315] Bluetooth: hci0: command 0x1003 tx timeout [ 8330.342261] Bluetooth: hci0: unexpected event for opcode 0x1003 [ 9003.350396] Bluetooth: hci0: BCM: chip id 70 [ 9003.351370] Bluetooth: hci0: BCM: features 0x06 [ 9003.367383] Bluetooth: hci0: akash [ 9003.367395] Bluetooth: hci0: BCM (001.001.011) build 0000 [ 9003.367442] bluetooth hci0: Direct firmware load for brcm/BCM.hcd failed with error -2 [ 9003.367449] Bluetooth: hci0: BCM: Patch brcm/BCM.hcd not found

Bluetooth is on but can't find or be found by any other devices.  Output of sudo service bluetooth status:  ● bluetooth.service - Bluetooth service    Loaded: loaded (/lib/systemd/system/bluetooth.service; enabled; vendor preset: enabled)    Active: active (running) since ხუთ 2015-06-04 22:33:18 GET; 13min ago  Main PID: 26678 (bluetoothd)    CGroup: /system.slice/bluetooth.service            └─26678 /usr/sbin/bluetoothd -n  ივნ 04 22:39:14 Rangoo bluetoothd[26678]: Endpoint registered: sender=:1.63 path=/MediaEndpoint/BlueZ4/HFPAG ივნ 04 22:39:14 Rangoo bluetoothd[26678]: Endpoint registered: sender=:1.63 path=/MediaEndpoint/BlueZ4/HFPHS ივნ 04 22:39:14 Rangoo bluetoothd[26678]: Endpoint registered: sender=:1.63 path=/MediaEndpoint/BlueZ4/A2DPSource ივნ 04 22:39:14 Rangoo bluetoothd[26678]: Endpoint registered: sender=:1.63 path=/MediaEndpoint/BlueZ4/A2DPSink ივნ 04 22:39:14 Rangoo bluetoothd[26678]: bluetoothd[26678]: Endpoint registered: sender=:1.63 path=/MediaEndpoint/BlueZ4/HFPAG ივნ 04 22:39:14 Rangoo bluetoothd[26678]: bluetoothd[26678]: Endpoint registered: sender=:1.63 path=/MediaEndpoint/BlueZ4/HFPHS ივნ 04 22:39:14 Rangoo bluetoothd[26678]: bluetoothd[26678]: Endpoint registered: sender=:1.63 path=/MediaEndpoint/BlueZ4/A2DPSource ივნ 04 22:39:14 Rangoo bluetoothd[26678]: bluetoothd[26678]: Endpoint registered: sender=:1.63 path=/MediaEndpoint/BlueZ4/A2DPSink ივნ 04 22:39:14 Rangoo bluetoothd[26678]: Adapter /org/bluez/26678/hci0 has been enabled ივნ 04 22:39:14 Rangoo bluetoothd[26678]: bluetoothd[26678]: Adapter /org/bluez/26678/hci0 has been enabled   Output of lsusb:  Bus 003 Device 005: ID 0a5c:21d7 Broadcom Corp. BCM43142 Bluetooth 4.0   How can I fix it?


I am having a hard time understanding what is an imaginary number, and the purpose for studying them.  I can't stop my mind from thinking "if it doesn't exist and is not 'real' why is it being studied"?  Can someone please give an example of a applicaiton of imaginary numbers and how it solved an important problem in science?

I've always enjoyed solving problems in the complex numbers during my undergrad. However, I've always wondered where are they used and for what? In my domain (computer science) I've rarely seen it be used/applied and hence am curious.  So what practical applications of complex numbers exist and what are the ways in which complex  transformation helps address the problem that wasn't immediately addressable?  Way back in undergrad when I asked my professor this he mentioned that "the folks in mechanical and aerospace engineering use it a lot" but for what? (Don't other domains use it too?). I'm well aware of its use in Fourier analysis but that's the farthest I got to a 'real world application'. I'm sure that's not it.  PS: I'm not looking for the ability to make one problem easier to solve, but a bigger picture where the result of the complex analysis is used for something meaningful in the real world. A naive analogy is deciding the height of tower based on trigonometry. That's going from paper to the real world. Similarly, what is it that is analyzed in the complex world and the result is used in the real world without imaginaries clouding the problem?  The question:  is nice but covers a more mathematical perspective on interim results that make solving a problem easier. It covers different ground IMHO.


:       At the beginning of your upkeep, put the top card of your library into your graveyard. If it's an instant or sorcery card, transform Aberrant Researcher.   Considering I had two of these in play:  Two questions:  1) Would I put two into the graveyard at the start of my upkeep?  2) If an instant or sorcery is revealed do both flip at the same time?

Many abilities in MTG use a permanent's name in the ability. Does this mean that if I have 2 copies of that permanent, the ability will affect both permanents?  Activated ability example:  - If I activate the ability of one of my Vector Asps, can I choose which of them gain infect until end of turn? Or will they both gain infect?  Triggered ability example:  - If I cast a second Sin Collector, when it enters the battlefield, will each Sin Collector trigger and allow me to exile a total of 2 cards instead of 1?


I have this code in LaTeX, I compile with "latex+dvips+ps2pdf+See PDF"  \documentclass[a4paper,12pt]{article} \usepackage[spanish]{babel} \usepackage[utf8]{inputenc} \usepackage{graphicx} \begin{document} \begin{figure} [h] \centering \includegraphics [width=8cm]{CircuitoRC.pdf}  \caption{Carga de un condensador en un circuito RC.} \label{fig:circuito} \end{figure} \end{document}   In \includegraphics it says me this:      LaTeX Error: Cannot determine size of graphic in CircuitoRC.pdf (no BoundingBox).See the LaTeX manual or LaTeX Companion for explanation.Type H  for immediate help.... \includegraphics [width=8cm]{CircuitoRC.pdf}   I don't know why.

I'm trying to include graphics in my Latex-file, which I compiled with latex+dvipdf on OS X. Latex however returns this error: "Cannot determine size of graphic"  My graphic is exported from PowerPoint, so I have tried both .pdf and .png. I get the same errors for both.  Sample code that doesn't work:  \begin{figure}[htb] \begin{center} \leavevmode \includegraphics[width=0.8\textwidth]{graph.png} \end{center} \end{figure}   If I have to manually set some measurements of the image, please tell me how I can find out those measurements. I need the image to take up about 80% of text width and be centered. Thanks.


How can I create such a matrix with arrows in Latex?


Given two non zero natuals $m$ and $n$, it is asked to prove that  $$ \dfrac{1}{\sqrt[n]{m+1}}+\dfrac{1}{\sqrt[m]{n+1}} \ge 1$$  I don't see how to start. the presence of $k^{\text{th}} $ roots makes it hard to manipulate.  any ideas are welcome.

$m,n$ are integers bigger than 0.   I need to prove:  $$\frac{1}{\sqrt[n]{1+m}}+\frac{1}{\sqrt[m]{1+n}} \geq 1$$   I tried to multiply both sides by the common factor and raise both sides to the power of $m*n$ but it did not work for me, and I have no other idea how to proceed.  I don't want the full solution, but just a hint.  Thank you.


I would like to avoid "unchecked or unsafe operations" message from java compiler, but I have no idea how to do it, when I have a generic method, and would like to return the values from a generic Map. The Map's values should be the same generic type as the generic method, but I couldn't figure it out how to achieve.  I've created a bitbucket project to show the problem:   You can check the following snippet as a quick overview, but the best to clone the project and check it there.  public class VehicleServiceImplementation implements VehicleService {  private static Map<Long, VehicleResult> resultMap = new HashMap<Long, VehicleResult>();  static {     resultMap.put(5L, new VehicleResult<Car>(new Car(5L))); }  public <CAR extends Car> VehicleResult<CAR> retrieve(final CarRequest request) {     return resultMap.get(request.getId()); }}   Please note that I have no access to the interface itself, so I can't change it's signature  Please note that it's not about how to deal with Object returning methods, but about how to deal with generic methods.

Eclipse is giving me a warning of the following form:     Type safety: Unchecked cast from Object to HashMap   This is from a call to an API that I have no control over which returns Object:  HashMap<String, String> getItems(javax.servlet.http.HttpSession session) {   HashMap<String, String> theHash = (HashMap<String, String>)session.getAttribute("attributeKey");   return theHash; }   I'd like to avoid Eclipse warnings, if possible, since theoretically they indicate at least a potential code problem.  I haven't found a good way to eliminate this one yet, though.  I can extract the single line involved out to a method by itself and add @SuppressWarnings("unchecked") to that method, thus limiting the impact of having a block of code where I ignore warnings.  Any better options?  I don't want to turn these warnings off in Eclipse.  Before I came to the code, it was simpler, but still provoked warnings:  HashMap getItems(javax.servlet.http.HttpSession session) {   HashMap theHash = (HashMap)session.getAttribute("attributeKey");   return theHash; }   Problem was elsewhere when you tried to use the hash you'd get warnings:  HashMap items = getItems(session); items.put("this", "that");  Type safety: The method put(Object, Object) belongs to the raw type HashMap.  References to generic type HashMap<K,V> should be parameterized.


I have this MySQL table MONTHNAME generated by querying from the database using the following script using PHP.   $query = 'SELECT monthname(`dateAdded`) as MONTHNAME,sum(`shift1PinCount`+`shift2PinCount`) from `supervisorupdate` WHERE YEAR(`dateAdded`) = YEAR(CURDATE()) group by monthname(`dateAdded`) ORDER BY monthname(`dateAdded`) DESC'; $queryExecute = mysqli_query($conn, $query);     I want to show this table as it is into my HTML page using PHP. As from I know normally we use  while($row = mysqli_fetch_array($queryExecute)){    echo $row['someColumnName']; }   In this case, I can't do that since I am doing some calculations and getting output as a table. Can someone guide me on how to show this table?  Edit 1  Here is a picture of the result that I am getting using phpMyadmin. So the HTML table should be similar to this    So for HTML side, it should show something like this

       Month	       Sum

       January	       3456

       February	       443

I have two tables in my database:  NEWS table with columns:   id - the news id  user - the user id of the author)   USERS table with columns:   id - the user id   I want to execute this SQL:   SELECT * FROM news JOIN users ON news.user = user.id    When I get the results in PHP I would like to get associative array and get column names by $row['column-name']. How do I get the news ID and the user ID, having the same column name?


I learned "remember to" means "don't forget to" but it is only used in future or present things. For example, "I will remember to mail these letters." means "I will not forget to mail these letters.)  But when they become past tense, I hear that "I remembered to mail these letters." doesn't mean "I didn't forget to mail these letters". Is this right?  Does "I remembered to mail these letters." mean "I remembered that I mailed these letters" or other? Could you teach me?  I know the difference between "remember to" and "remember ～ing". I asked the difference between "remember to " and "remembered to" because I hear the meaning change beside it become past.

Remember is one of the verbs which we always put to + infinitive after it:     I always remember to do my homework.   But actually not always. This sentence is an exact example of what I mean:     Do you remember visiting Church of the Holy Sepulchre?   or     Do you remember to visit Church of the Holy Sepulchre?   I think the first sentence explains the meaning of your visiting to the church I really ask if you can remember that visit you made.  But think about the second sentence, it really asks if you remember to do what I've advised you (visiting the church)  I think it depends on meaning. I have to say that the first sentence is more accurate, which gives the meaning clearly.


I was wondering why the 4N27 optocoupler has a pin for base of the phototransistor - and of course how to connect it.  I've usually dealt with PC817 optocouplers and connected them according to the schematic.    Now I want to do the same with 4N27 (pinout on the picture below,) so do I have to leave the base pin floating, or pull down it?

I'm thinking about using  optocoupler - it has a separate lead for base of phototransistor. How do I use it? I suppose I can't leave it floating?


Let's say I have and extension method called MyExtensionMethod.  I want to use it like this:  var x = new MyClass() x.MyExtensionMethod()   Then, inside the extension method, I want to get the name of the reference that it was called on:  public static void MyExtensionMethod(this object param) {     //get the name "x" somehow }   Is this possible?

Let me use the following example to explain my question: public string ExampleFunction(string Variable) {     return something; }  string WhatIsMyName = "Hello World"; string Hello = ExampleFunction(WhatIsMyName);  When I pass the variable WhatIsMyName to the ExampleFunction, I want to be able to get a string of the original variable's name. Perhaps something like: Variable.OriginalName.ToString()  Is there any way to do this?


I understand that Boba Fett could have worked out the Falcon's destination from it's bearing/trajectory, but if the Falcon is "the fastest hunk of junk in the galaxy", how did Vader manage to "Arrive just before [they] did"?  This implies Vader beat the Falcon to Bespin, doesn't it? how would he have been able to negotiate  with Boba, and then still beat the ship to Bespin?  Unless by "they" (as in "they arrived just before you did"), Lando is referring to the Empire as an entity, and not to they physical presence of the Empire as Manifest by Vader?  Anyone have any canon answer?

How did the Millennium Falcon get from Hoth to Bespin without their hyperdrive? Are these locations so close together? I would think not, because Hoth is in the Hoth Sysem and Bespin is in the Bespin System.  The asteroid field in The Empire Strikes Back does seem to be in the Hoth System so there is not really an issue there.  I've looked on this site and on the Wookieepedia but I've yet to find a canon answer. This appears to be such a large plot hole, that there simple must be a canon (EU) explanation.  "", fandom.com  "", fandom.com  "", fandom.com  There is a barely-satisfactory theory here: "", mannveille.com but that does not appear to be endorsed by canon.


What happens if you contribute to your Roth IRA at the beginning of the year, but then find out that you're over the allowable income to be able to contribute?  You might not always know at the beginning of the year how much you're going to make and you don't want to miss out on a whole year of growth just to wait and see.  Does the IRS make you withdraw the money or can you keep it in there, but pay some kind of tax?

While doing my taxes, I came to the realization that my income for 2015 is above the limit to contribute the full $5500 to my Roth IRA, but below the limit where I am unable to contribute. My contribution limit for 2015 turned out to be $4400 but I had contributed the full $5500; I contributed an excess $1100.  I've seen different suggestions on how to deal with this, but I'm confused about what they all mean and what the ultimate implications are. It seems my options are the following.   Withdraw the excess from the Roth IRA Convert the excess to a Traditional IRA Pay a 6% tax penalty on the over contribution   It sounds like the withdrawal is the least painful, but it is now 2016 and I am unsure what the implications of doing this withdrawal would be since 2015 is over; is there an issue with this?  If the withdrawal is not an option, is there still time to do the do the Traditional IRA conversion (there is just under a month till April 15th)?  No matter what I do, is there any paperwork I need to file to ensure I do not get audited?  Note: it seems that  that at the time of asking does not yet have an answer.


In regression, you encode a categorical variable with n possible values using n-1 indicator variables. How about for neural networks?

To use SVM or Neural Network it needs to transform (encode) categorical variables into numeric variables, the normal method in this case is to use 0-1 binary values with the k-th categorical value transformed to be (0,0,...,1,0,...0) (1 is on the k-th position). Is there other methods to do this, especially when there are a large number of categorical values(e.g.10000) such that the 0-1 representation will introduce a large number of additional dimensions(input units) in Neural Network which seems not quite desired or expected?   I am asking about general strategies.


Let $D$ be a tetrahedron with corners $(0,0,0), (2,0,0), (0,6,0), (0,0,4)$. Find the volume of $D$ by setting up a triple integral.   The equation of the plane containing these points is $$6x+2y+3z-12=0.$$ My question is how do I set up the bounds on the three integrals to get a volume? Thanks for the help.

I have a triple integral of $\iiint xyz\,dx\,dy\,dz$  over the volume of a tetrahedron with vertices $(0,0,0)$, $(1,0,0)$, $(0,1,0)$, and $(0,0,1)$.   Normally I would just have limits 0 to 1 but that does not seem to work. How do I solve a problem like this?


I am using      mactex   to compile my .tex file. I want to      suppress all error and warning messages.   I have tried this using the below commands but none of them work:  Xelatex  xelatex report.tex --interaction=errorstopmode;  xelatex report.tex --interaction=batchmode   pdflatex  pdflatex report.tex --interaction=batchmode; pdflatex report.tex -quiet -f; pdflatex report.tex -quiet=true; pdflatex report.tex -interaction=nonstopmode;   Please help me figure out what should I do to stop all errors and warnings. My file compiles how I want it to, I don't want it to show me any messages, just compile in one line.  Thanks in advance.

I find the output of XeLaTeX excessively verbose. I am really just interested in errors (not warnings), and the offending line number. I also would like xelatex to halt (exit) on error. Is there a magic incantation that can produce this?


def add_binary(a,b):     return bin(a+b)[2:]  Why is "[2:]" used here?

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.