Let $X_1$ and $X_2$ be two independent random variables with distribution $U(0,1)$. Let $Y=|X_1-X_2|$. Find the distribution function and density of $Y$.   Solution:  f(x1)=1 whenever x1 between 0 and 1          =0 Else where f(x2)=1 whenever x2 between 0 and 1          =0 Else where f(x1,x2)=1 whenever x1,x2 between 0 and 1           =0 Else where G(y)= P[-y <= x1-x2 <= y]       =\int_{-y}^y \int_{x1_y}^{y+x1} 1 dx2 dx1       =\int_{-y}^y -2y dx1       =4y^2 when y between 0 and 1       =0 when y less than 0       =1 when y greater than 1 Thus, g(y)= \diff G(y) =8y  Is it correct?

Let $X$ and $Y$ be independent random variables, uniformly distributed in the interval $[0,1]$. Find the CDF and the PDF of $|X - Y|$?  Attempt Let $Z = |X - Y|$, so for $z \geq 0$, the CDF $F_{Z}(z) = \mathbf{P}(Z \leq z) = \mathbf{P}(|X - Y| \leq z) = \mathbf{P}(-z \leq X - Y \leq z)$, which is where the algebra becomes confusing. Since they are independent, the joint pdf of $X$ & $Y$ is simply 1, as long as $(X,Y)$ belong to the unit square. The solution suggests a plot the event of interest as a subset of the unit square and find its area. Any hints?


I've gone through all of the other reports of this but when ever i follow the instructions and it opens my sources.list there are no numbers lines and there is barely anything in it.  i saved my sources.list to pastebin, here is the link   Screenshots of my software sources:   Please help my figure out what the problem is.

I have unistalled and reinstalled the Ubuntu Software Center as per info I found in a similar thread and I got the same response about line 91 or something like that.  I just tried to upload a screen shot but since I'm new it won't allow me to.  I also can not figure out how to cut and paste anything so I have to hand type what the error screen says, both when I attempt to open the software center and nothing happens, when I try to enter commands into the terminal to uninstall, reinstall, whatever I get the same following:  COULD NOT INTITIALIZE THE PACKAGE INFORMATION An unresolvable problem occured while initializing the package information Please report t:his bug against the 'update-manager' package and include the following error message: 'E: Malformed line 91 in source list/etc/apt/sources.list (dist parse)  E: The list of sources could not be read.,  E: The package list of status file could not be parsed or opened.   How do I report bugs?  What can be done about this.  I have searched and everything everyone says to do leads me back to the same line error message.  So, I don't know how to get to line 91 in the source list; to tell you what it says. Sorry, I'm really new to this. That is what I need is to find out how to get there and fix what it says. I would really like to NOT have to re partition my hard drive and start from scratch, so I'm really looking forward to getting this problem solved. I need to be able to install new software.


I'm trying to use one of the cloth presets in the Simulations tab, but I've accidentally deleted a couple of the presets and I don't know how to get them back. I've tried restarting blender with a new file, but the cloth sim. still didn't have the Presets. And I even Tried to Load Factory Settings  as well and it still wouldn't work! If anyone can tell me whats going on, that would be great. Thanks!

I accidentally clicked the 'remove preset' button and now I am missing "rubber".  Is there a way to restore the preset?  Thank you!


I need to save the data of a java program into a file. The problem is, it returns a "The filename, directory name, or volume label syntax is incorrect" error when I add the %DATE% and %TIME% variables into the filename. Without the date time variables it works fine.   As well I need to output the result into the console and the file. As far as I have seen, there is no direct possibility to do so. Workaround: I'm just reading the file again into the console. When doing that with the date time variable, I get the same error.  set datetime="%DATE%-%TIME%"  java -Xmx1024m -jar org.hl7.fhir.validator.jar generated.json  -version 4.0.1 -ig hl7.fhir.uv.livd > "errlog/%datetime%.log"  type "%CD%\errlog\%datetime%.log"   I never write batch files so could be a very "stupid" problem. Thanks in advance!

Update: Now that it's 2016 I'd use PowerShell for this unless there's a really compelling backwards-compatible reason for it, particularly because of the regional settings issue with using date. See @npocmaka's     What's a Windows command line statement(s) I can use to get the current datetime in a format that I can put into a filename?  I want to have a .bat file that zips up a directory into an archive with the current date and time as part of the name, for example, Code_2008-10-14_2257.zip. Is there any easy way I can do this, independent of the regional settings of the machine?  I don't really mind about the date format, ideally it'd be yyyy-mm-dd, but anything simple is fine.  So far I've got this, which on my machine gives me Tue_10_14_2008_230050_91:  rem Get the datetime in a format that can go in a filename. set _my_datetime=%date%_%time% set _my_datetime=%_my_datetime: =_% set _my_datetime=%_my_datetime::=% set _my_datetime=%_my_datetime:/=_% set _my_datetime=%_my_datetime:.=_%  rem Now use the timestamp by in a new ZIP file name. "d:\Program Files\7-Zip\7z.exe" a -r Code_%_my_datetime%.zip Code   I can live with this, but it seems a bit clunky. Ideally it'd be briefer and have the format mentioned earlier.  I'm using Windows Server 2003 and Windows XP Professional. I don't want to install additional utilities to achieve this (although I realise there are some that will do nice date formatting).


I'm not able to update anything. I'm on 13.10.   When I try to install updates I get this:  dpkg: error processing /var/cache/apt/archives/librhythmbox-core7_3.0.1-0~13.10~ppa1_amd64.deb (--unpack):  trying to overwrite '/usr/lib/librhythmbox-core.so.8.0.0', which is also in package librhythmbox-core8 3.0.1-1ubuntu5~ppa0 dpkg-deb: error: subprocess paste was killed by signal (Broken pipe) Errors were encountered while processing:  /var/cache/apt/archives/librhythmbox-core7_3.0.1-0~13.10~ppa1_amd64.deb E: Sub-process /usr/bin/dpkg returned an error code (1)   Does anyone have a solution ?

For example:  $ sudo apt-get install curl Reading package lists... Done Building dependency tree Reading state information... Done You might want to run 'apt-get -f install' to correct these: The following packages have unmet dependencies: bsh : Depends: libjline-java but it is not going to be installed groovy : Depends: libjline-java but it is not going to be installed rhino : Depends: libjline-java but it is not going to be installed E: Unmet dependencies.   Try 'apt-get -f install' with no packages (or specify a solution).   I get the same or similar errors when I attempt to install clojure1.3, leiningen, and several other packages.   When I try the suggestion made in the error message, this is what happens:  $ sudo apt-get -f install  Reading package lists... Done Building dependency tree        Reading state information... Done Correcting dependencies... Done The following packages were automatically installed and are no longer required:   diffstat linux-headers-3.2.0-26-generic linux-headers-3.2.0-26 dh-apparmor dkms html2text libmail-sendmail-perl libsys-hostname-long-perl Use 'apt-get autoremove' to remove them. The following extra packages will be installed:   libjline-java Suggested packages:   libjline-java-doc The following NEW packages will be installed:   libjline-java 0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded. 23 not fully installed or removed. Need to get 0 B/72.0 kB of archives. After this operation, 129 kB of additional disk space will be used. Do you want to continue [Y/n]? Y (Reading database ... 226243 files and directories currently installed.) Unpacking libjline-java (from .../libjline-java_1.0-1_all.deb) ... dpkg: error processing /var/cache/apt/archives/libjline-java_1.0-1_all.deb (--unpack):  trying to overwrite '/usr/share/java/jline.jar', which is also in package scala 2.9.2-400 Errors were encountered while processing:  /var/cache/apt/archives/libjline-java_1.0-1_all.deb E: Sub-process /usr/bin/dpkg returned an error code (1)  $ sudo apt-get upgrade Reading package lists... Done Building dependency tree        Reading state information... Done You might want to run 'apt-get -f install' to correct these. The following packages have unmet dependencies:  bsh : Depends: libjline-java but it is not installed  groovy : Depends: libjline-java but it is not installed  rhino : Depends: libjline-java but it is not installed E: Unmet dependencies. Try using -f.


We are trying to make an antique bell work I'm told it needs 12v .1 /  amp or 100milli amp  Our current power system is 24 volt 20 amp can you please help us step this down . We were going to use a common 24 to 12 volt resistor to drop the voltage but unsure of how to drop the amps down to .1

Power supplies are available in a wide range of voltage and current ratings.  If I have a device that has specific voltage and current ratings, how do those relate to the power ratings I need to specify?  What if I don't know the device's specs, but am replacing a previous power supply with particular ratings?  Is it OK to go lower voltage, or should it always be higher?  What about current?  I don't want a 10 A supply to damage my 1 A device.


Edit 2: I have read the answer in the linked duplicate. I however do not understand if in my case it is a serious concern or only a concern related to accomodation (as it was purely touristic purpose). And also the fact that they haven't checked any other boxes and only the one i mentioned. I'm unable to think of any other reason as we completely satisfy all other requirements including more than required money in bank accounts, stable jobs, leave approvals etc. And also given that I've never had a visa issue before. I still hold a valid USA visa. Myself and my husband applied for a Schengen visa with the French embassy in Bangalore, India. Our plan was to visit Paris for 10 days and spend the time entirely doing touristic things and sight seeing. We have submitted all the necessary documents along with hotel and flights. However, after submitting the application, our hotel was cancelled due to the fact that they don't accept debit cards but only accept credit cards. So at the time of visa processing the hotel accommodation we had given was already cancelled. The result of our application is a visa refusal. Could the hotel cancellation be the exact reason for refusal? The reason embassy gave is:  "The information submitted regarding the justification of purpose and the conditions intended to stay were not reliable".  I have previously obtained a Schengen visa and I have also traveled to many countries including the USA, the UK etc. This is my first visa refusal and I can't help but think it's strongly due to the hotel cancellation. Should we immediately reapply with a new hotel accommodation? Or should we just wait and try another time? Edit: This is not a duplicate of the question tagged because, the refusal letter has multiple options. And our letter was only checked for the above mentioned reason. Please also note that below two reasons are different:.  "Justification for the purpose and conditions of intended stay was not provided". "The information submitted regarding the justification of purpose and the conditions intended to stay were not reliable".

Schengen refusal formulae can be difficult to understand sometimes.  Sometimes an applicant receives a refusal with:       Justification for the purpose and conditions of the intended stay was not reliable.     often accompanied by:       Your intention to leave the territory of the Member States before the expiry of the visa applied for could not be ascertained.   What is meant by this refusal reason?  What are they trying to say?


This has been discussed before (e.g. ) but the explanations point to something other than the edit.  Every time I try to just add four whitespace characters to convert a code block to actual code, it is rejected with the following error:        Is this desired behavior or is there something about my account that prohibits me from making those changes?

I tried to update a jQuery code block that was missing a curly brace. The code is incorrect, but I cannot edit it since changes under 6 characters are not allowed (at least at my level of rep?).  I understand why you don't want to allow minor copy-editing, and I agree that's fine for textual descriptions and regular writing, but 1 character can make a big difference in code.


Me and a lot of people are confused about the expression and / or used by a government entity in the following context: "Vaccination certificate and / or a negative PCR test result" My interpretation: Travelers are required to hold a vaccine certificate AND a negative PCR test result OR Travelers are required to hold a negative PCR test result ONLY Is this correct?

What's the difference between "and" and "and/or"?  How do we decide whether to use one or the other?  Note: Also it would be great if someone could explain how do we actually pronounce "and/or" verbally in a sentence...


I want to buy either an UMFT200XD-01 or an UMFT201XB-01 from FTDI. According to the datasheet of the UMFT200XD the     "UMFT200XD is a USB to I2C breakout module"   After I searched for a difference between these two modules I came across this post   Does this mean I cannot connect one of the modules mentioned above to my Win7 PC and read data from an I²C device (e.g. TMP102)?

I got the  in order to interface with an I2C peripheral through a USB port on my Windows 7 computer.  The VCP drivers seem to install correctly, and a COM port is assigned to the module, and can be opened by a terminal emulator. However, I cannot seem to get any signal in or out of the module. That is, I see no activity when I send data through the port, or receive any data when I connect an I2C device to it (this was debugged using a scope). I have also verified that the RESET isn't on.  I found very little helpful information out there on how to get this module to work, so if anyone has experience with it, or with similar FTDI modules, my question is: what are the steps that I need to take in order to get the module to communicate?


Using partial fractions: $$ \sum\limits_{k=0}^\infty \frac{1}{n^2+1} = \lim_{n \to \infty} \left(\frac{i}{2} \sum\limits_{k=0}^n \frac{1}{k+i} - \sum_{k=0}^n \frac{1}{k-i} \right) $$ Expanding and rationalising end up with: $$ \lim_{n \to \infty} \frac{i}{2}\left( -i +  \frac{1-i}{1^2+1} + \cdots +  \frac{n-i} {n^2+1} +\left( -i  \frac{1+i}{1^+1} -\cdots-  \frac{n+i}{n^2+1}  \right)\right) $$ Simplifying I end up with an expanded version of what I started with: $$ \lim_{n \to \infty} \left( 1 +\frac{1}{1^2+1} + \frac{1}{2^2+1} + \cdots + \frac{1}{n^2+1}\right) $$ How can I solve this problem? I feel like I am just going in circles.

This is a homework question whereby I am supposed to evaluate:  $$\sum_{n=1}^\infty \frac{1}{n^2 +1}$$  Wolfram Alpha outputs the answer as   $$\frac{1}{2}(\pi \coth(\pi) - 1)$$  But I have no idea how to get there. Tried partial fractions (by splitting into imaginary components), tried comparing with the Basel problem (turns out there's little similarities), nothing worked.


A few weeks ago, I inserted my pendrive into my college's PC to transfer my assignments, but it was not working. It was corrupted and was asking to format. I couldn't even copy files, and was forced to format.  After formatting, my pendrive's size was reduced from 8GB to 3.96MB.  Since then, I've been trying restore it. From diskpart to third-party software, Windows to Linux, watching several youtube videos, but nothing has worked.  I already have looked at , but nothing worked.  PS: I'm using 64-bit system to achieve restoration.

My USB drive used to be originally 8GB when I bought it.  I'm trying to reformatted in Windows 7 by right clicking on the drive and selecting Format.... But the capacity only shows 250MB.  Is there something I can do to get the original size back? Maybe it got partitioned in a weird way?   The  flash drive is a SanDisk Cruzer Micro 8GB. I got it from Wal-Mart but this is the same drive.


On every Stack Exchange site except Stack Overflow, in the  (<sitename.com>/legal/moderator-agreement) page's The agreement section contains two links.  The first link is pointing to the specific site's  (<sitename.com>/legal/terms-of-service) page, but the second link is pointing to the Stack Overflow's  (https://stackoverflow.com/legal/privacy-policy) page.  Since each site has its own Privacy Policy page, and the first link is already pointing to the current site's terms of service page, why is the second link all the sites pointing to Stack Overflow's page?  Is this intentional or wrongly linked to Stack Overflow's page?  Screenshot from the agreement section:

I noticed that each site in the network has its own copy of the Terms of Service, e.g. , , , etc.  But the link to the terms in the footer of each site just goes to Stack Overflow's version, not the local per-site copy.  In the past, there used to be a single copy of the terms on stackexchange.com, but since the terms were recently changed in May 2018, the current arrangement of having a copy on each site was adopted.  What's the point of having a copy of the terms on each site if the footer link just goes to Stack Overflow's version?  (Side note: the old link to the terms hosted on stackexchange.com now redirects to Stack Overflow's version as well.)


Which value does this expression converge to? $$\frac{1^2}{2^1}+\frac{2^2}{2^2}+\frac{3^2}{2^3}+\frac{4^2}{2^4}+\frac{5^2}{2^5}+...+\frac{n^2}{2^n}$$  The expression above can also be written as $\sum_{n=1}^\infty \frac{n^2}{2^n}$.

I have to decide whether the Series $\sum_{n=1}^\infty \frac{n^2}{2^n}$ Converge or Diverge only by using the Comparison test or by $\frac{1}{n^p}$ test.  What I noticed is that it converges by the De'lamber test ($\lim_{n\to \infty}\left|\frac{a_{n+1}}{a_n}\right|$).  But I'm having trouble finding a way proving it with the provided tests.  Would appreciate your advice


The diameter of observable universe is 93 billion light years but the age of universe is only estimated to be 14 billion years. So how does light have 46.5 billion years to travel from the boundary of observable universe to us? I mean if the radius is 46.5 billion light years then that should mean light took 46.4 billion years to go from there to here right?

I was reading through the Wikipedia article on  and came across the fact that the most distant Quasar is 29 Billion Light years. This is what the  exactly says      The highest redshift quasar known (as of June 2011[update]) is ULAS-J1120+0641, with a redshift of 7.085, which corresponds to a proper distance of approximately 29 billion light-years from Earth.   Now I come to understand that the  singularity is believed to be around 13.8 Billion years ago.  So how is this possible? Does the presence of such a quasar negate the Big Bang Theory?   I'm not a student of Physics and was reading this out of (whimsical) curiosity. Is there something I'm missing here or the "proper distance" mentioned in the fact is a concept that explains this?  Edit: My Bad! Here's how..  A simple google search led me to  which says the farthest quasar found is 12.9 billion LYs and not 29 billion. So in the end we have just proven that wikipedia needs more moderation.


I found this sentence in a book:  A large percentage of the population smokes too much.  The author treated the phrase 'a large percentage of' as singular. I am so confused with the use of verbs after 'a large percentage of' as some folks on the Internet consider 'a large percentage of' plural. Do we have any rules for the phrase? Thanks!

According to Garner's fourth edition  When the verb precedes the noun percentage, a singular verb is required. That is, a higher percentage of them are, but there is a higher percentage of them  I'd love to have some elaboration on this point because I could't find any related information at all. Does this singular have to do with the pronominal there itself in general? EDIT:  Though serving as a plural when the need arises, series is ordinarily a singular noun. But it is also a noun of multitude, so that phrases such as a series of things take a plural verb. However, the collocation there {has been - is} a series has predominated in print sources. Common nouns of multitude: lot, majority, mass, minority, multitude, percentage, proportion, variety.  According to Microsoft® Encarta® 2009,  If you put the indefinite article a before percentage, use a plural verb when the noun or pronoun in any subsequent prepositional phrase is regarded as a countable plural, not a unit or a whole: A large percentage of the errors are found in this text. If the noun or pronoun object in such a phrase is singular or is regarded as a unit or a whole, use a singular verb: A large percentage of the electorate remains undecided.  However, a counterexapmle:  If you are speaking of the senators as individuals, say A majority of the senators have cast their votes


I just want to ask if anyone knows how to make background grey while using HDRI so it would be the same as in Substanse painter "Environment Opacity slider" or basically the same as in Material Preview Mode in Blender? Is it possible to make it without options that listed below?:  Not a transparent background and then add grey background picture in photoshop;  Not a heavily blurred background (I found this option here but it still has colors);  Without adding a grey plane at the back while rendering   Just pure grey

I have my scene perfectly lit without the use of a HDRI, however I would now like to add one just so I can have some world reflections in my glossy objects. I can't seem to get the HDRI reflecting in my objects without it also adding light to the scene, though. Is there any way to use an HDRI solely for reflections, and not have its light also affect the scene? I am using Cycles.  Thanks


I want to display a stopwatch but i don't want to clean my console for each dislay ,              Stopwatch chrono = new Stopwatch();             chrono.Start();              bool isMyComputerOn = true;             while (isMyComputerOn)             {                 Console.WriteLine("Time :  "+chrono.Elapsed);             }   Any idea ?

I have a console application project in C# 2.0 that needs to write something to the screen in a while loop. I do not want the screen to scroll because using Console.Write or Console.Writeline method will keep displaying text on console screen incremently and thus it starts scrolling.  I want to have the string written at the same position. How can i do this?  Thanks


How can you create and enable workspaces in Ubuntu 20.04. I can't seem to find the option to make them and enable them in GNOME desktop.

Any idea how to have more than 2 workspaces on Ubuntu 18.04.1?


How can I find out as what user a command executes? (I'm running Ubuntu, but I suspect the answer applies to Unix in general).  What I'm trying to do is  and logging to /var/log/msmtp. I've set the owner and group of that file to mail, then added my user to the mail group via sudo adduser dandv mail:  $ ls -al /var/log/msmtp.log -rw-rw---- 1 mail mail 0 Jul 24 18:45 /var/log/msmtp.log $ groups dandv dandv : dandv mail sudo   Yet when when I run  cat testmail | msmtp dan@example.org -v   I get a permission denied:  msmtp: cannot log to /var/log/msmtp.log: cannot open: Permission denied   What is msmtp's problem?

I changed permissions of a file (chmod g+w testfile) and running ls -l testfile gives:  -rwxrwxr-x 1 user1 user1 0 2011-01-24 20:36 testfile   I then added a user to that group ("/etc/group" has user1:x:1000:user2 line), but am failing to edit that file as user2. Why is this so?


Here is an excellent paper on the math of asymmetric key encryption:     See the example on Page 6.    The public key = $55$ Primes used to calculate public key are $5$ and $11$.  $e = 3$  Now see the appendix: $L = \mathrm{LCM}(p-1, q-1) = 20$  The paper states $de = 1 \mod L$  I can't figure out how he gets the value of $d = 7$

When given $p = 5, q = 11, N = 55$ and $e = 17$, I'm trying to compute the RSA private key $d$.  I can calculate $\varphi(N) = 40$, but my lecturer then says to use the extended Euclidean algorithm to compute $d$. That's where I get stuck.    Here's my work so far:  First I use the Euclid algorithm to calculate:  40 = 2(17) + 6  17 = 2(6) + 5 6 = 1(5) + 1 = gcd   So I know the GCD is 1. Applying the 'extended' section of the algorithm:  6 = 40-2(17) 5 = 17-2(6) 1 = 6-1(5) 1 = 6-1(17-2(6)) 3(6) = 1 (17) 3(40 - 2(17)) - 1(17) 3(40) - 3(17)   I know the answer is $33$, but I have no idea how to get there using the extended Euclidean algorithm. I can't figure out why I'm getting $3(40) - 3(17)$ when I know the answer should contain $33$.


When I install a game why does the installer also install DirectX, C++ libraries or .NET components that I already have?. Are these different versions or extensions? Or is is because the game installers are unable to find out what I already have installed?

I am not very experienced with computers, and was wondering what Direct X actually does, on my PC.  Why do various games request different versions? Should the latest version cover all of them, or do certain games only support specific versions?


I am an Indian Passport holder, traveling from Chicago to New Delhi INDIA with Layover in Zurich of 2 hours. My US Visa is expired which is why I am traveling back to get the new visa stamped. Will I also need a Transit visa for Zurich? I have all the visa documents to show the approval through which stamping will be done in INDIA.

I found many related questions on this site but I am still not sure about the rules. How can I decide if I need a visa to transit? Schengen members as of May 2021 are as follows:  Austria Belgium Czech Republic Denmark (excluding Greenland and the Faroe Islands - but an open border with the Schengen Area is maintained) Estonia Finland France (excluding overseas departments and collectivities) Germany Greece Hungary Iceland Italy Latvia Liechtenstein Lithuania Luxembourg Malta Netherlands (excluding Aruba, Curaçao, Sint Maarten and the Caribbean Netherlands) Norway (excluding Svalbard) Poland Portugal Slovakia Slovenia Spain (except Ceuta and Melilla) Sweden Switzerland


I would like to get some kind of confirmation that the upload is success, I have my methods defined similar to the following. However the value of global variable is not changing. Please help  global upload_confirm upload_confirm = False  def confirm_upload():     upload_confirm = True  def start_new_upload():     confirm_upload()     while (upload_confirm != True):         print "waiting for upload to be true"         time.sleep(5)     if (upload_confirm == True):         print "start Upload"  start_new_upload()

How can I create or use a global variable in a function?  If I create a global variable in one function, how can I use that global variable in another function? Do I need to store the global variable in a local variable of the function which needs its access?


Too many users are passive aggressive (or they just have a superiority complex). I can almost read their minds: "Oh brother, another newbie asking a stupid question."  Stack Exchange should track those who close questions to determine if it is bordering on unjust.   Track how many seconds it takes for a user to click to read the question and then click to vote-to-close it. The quicker the close vote, the more unjust the action. Track if the user who votes-to-close at least wrote a helpful comment. The higher the percent of time no comment was made, the more likely the user is passive aggressive. Allow new users to flag any comments on their first question for being berating (i.e. non-helpful). If it happens to be made by a user who votes-to-close the question, then it cancels out the fact the comment was made thereby increasing the tracked percent above.   I already know that  (even the chosen answer seems passive aggressive to me).  ---- EDIT ---- Forget the above ideas - for reasons mentioned by others below, they will not work. Here is a new idea instead (very fair):   Rather than 6 votes being able to close a question, how about 10% of the daily users must have voted for it to be closed. (Laws being passed in Congress and Jury trials have even higher percent requirements)

I have question  I am sure this is valid question - I am not new on SO. It was closed no comments on the question. Given that the SO is here for a while - there are lot more users who can close questions (lot more than it was a year ago). Some users might not even understand the question but have power to close it. I think to prevent blatant actions - SO should implement a mandatory comment post if a user votes to close a question.


I have installed Google Chrome with following command line:  $ wget -q -O - https://dl-ssl.google.com/linux/linux_signing_key.pub | sudo apt-key add - $ sudo sh -c 'echo "deb http://dl.google.com/linux/chrome/deb/ stable main" >> /etc/apt/sources.list.d/google.list' $ sudo apt-get update $ sudo apt-get install google-chrome-stable   When try to open Google Chrome from command line ($ google-chrome), I am getting following error:  [5426:5426:0808/041800:ERROR:browser_main_loop.cc(209)] Gtk: cannot open display:     How can I fix this issue to open the Google browser?

I'm new to Ubuntu - sorry for novice questions. What I have - is Ubuntu server, to which I have access only via ftp and putty. What I would like to do - is to run firefox (or any other browser) from that Ubuntu machine.  I've managed to install firefox , but when I'm trying to run something like this:  x-www-browser http://google.com   It is saying:  Error: no display specified   I don't understand - there is no display at all at Ubuntu sever - it is just computer case on rack, the only display I have - is mine.  Don't know, how to redirect this display output to my machine (if this is possible at all).


I need your help my needs is i want to add space after the first two numbers and the rest is space by three numbers and repeat this algorithm after each comma ","  For example 123456789 => result: 12 345 678 9  12345,678910 => result: 12 345,67 891 0  I have input     <input onkeypress="myFunction(this)" type="text">   and in js :  > function myFunction(elem){ >         //var value=elem.value.replace// i need your help >         //elem.value=value; >     }

I don't really understand regular expressions.  Can you explain them to me in an easy-to-follow manner?  If there are any online tools or books, could you also link to them?


I tried to install systemd-container on brand new ubuntu 20.04 but I have following message: sudo apt-get install systemd-container Reading package lists... Done Building dependency tree        Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  systemd-container : Depends: systemd (= 245.4-4ubuntu3) E: Unable to correct problems, you have held broken packages.  But it's not obvious how to fix it because when I try, getting this sudo apt install systemd=245.4-4ubuntu3 Reading package lists... Done Building dependency tree        Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  policykit-1 : Depends: libpam-systemd but it is not going to be installed  systemd : Depends: libsystemd0 (= 245.4-4ubuntu3) but 245.4-4ubuntu3.2 is to be installed E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.  And so one till libpam-systemd sudo apt install libpam-systemd=245.4-4ubuntu3 Reading package lists... Done Building dependency tree        Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  libpam-systemd : Depends: systemd (= 245.4-4ubuntu3) E: Unable to correct problems, you have held broken packages.  And at this point, we got a circle. EDIT: found that I can $ sudo apt download systemd-container  $ sudo dpkg --force-all -i systemd-container_245.4-4ubuntu3_amd64.deb   And it's working but I got dependency errors all the time. Is there any better workaround? EDIT 2: apt-cache output apt-cache policy systemd systemd-container systemd:   Installed: 245.4-4ubuntu3.2   Candidate: 245.4-4ubuntu3.2   Version table:  *** 245.4-4ubuntu3.2 100         100 /var/lib/dpkg/status      245.4-4ubuntu3 500         500 http://pl.archive.ubuntu.com/ubuntu focal/main amd64 Packages systemd-container:   Installed: (none)   Candidate: 245.4-4ubuntu3   Version table:      245.4-4ubuntu3 500         500 http://pl.archive.ubuntu.com/ubuntu focal/main amd64 Packages         100 /var/lib/dpkg/status  EDIT 3: Quick way to reproduce error on ubuntu 20.04: adam@adam:~/$ systemd-nspawn  Command 'systemd-nspawn' not found, but can be installed with:  sudo apt install systemd-container  adam@adam:~/$ sudo apt install systemd-container Reading package lists... Done Building dependency tree        Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  systemd-container : Depends: systemd (= 245.4-4ubuntu3) E: Unable to correct problems, you have held broken packages.  Best

After upgrading from 10.04 to 12.04 I am trying to install different packages.  For instance ia32-libs and skype (4.0).  When trying to install these, I am getting the 'Unable to correct problems, you have held broken packages' error message.   Output of commands:  sudo apt-get install -f Reading package lists... Done Building dependency tree        Reading state information... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.   After running this:  sudo dpkg --configure -a foo@foo:~$ sudo apt-get install -f Reading package lists... Done Building dependency tree        Reading state information... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.


I am trying to clone a graph using DFS in Java iteratively, but on compiling it keeps on showing NullPointerException. I know the code using recursion is uch simpler, but wanted to try out in iterative way. The code is shown below:   /**  * Definition for undirected graph.  * class UndirectedGraphNode {  *     int label;  *     List<UndirectedGraphNode> neighbors;  *     UndirectedGraphNode(int x) { label = x; neighbors = new ArrayList<UndirectedGraphNode>(); }  * };  */  public UndirectedGraphNode cloneGraph(UndirectedGraphNode node) {     if(node==null) return null;     Map<UndirectedGraphNode, UndirectedGraphNode> hm = new HashMap<>();     Stack<UndirectedGraphNode> st = new Stack<>();     st.push(node);      while(!st.isEmpty())     {         UndirectedGraphNode n = st.pop();          UndirectedGraphNode copy = null;         if(!hm.containsKey(n)) //if n is cloned before, no need to clone it again         {             copy = new UndirectedGraphNode(n.label); //clone parent             hm.put(n, copy);         }         else             copy = hm.get(n);           for(UndirectedGraphNode neighbor: n.neighbors)         {             if(!hm.containsKey(neighbor))             {                 UndirectedGraphNode copy_neighbor = new UndirectedGraphNode(neighbor.label);                 copy.neighbors.add(copy_neighbor); //clone child.                 hm.put(neighbor, copy_neighbor);                 st.push(neighbor);             }else                 copy.neighbors.add(hm.get(neighbor));//this handles parent node as well.         }      }     return hm.get(node);    }   Here, what I am tryig to do is get a node from the graph and traverse to it's next connected node or as in this case neighbor.  The NullPointerException is being shown in this line :  copy.neighbors.add(copy_neighbor);   StackTrace  java.lang.NullPointerException at line 55, Solution.cloneGraph at line 102, __Driver__.main

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?


In the following text I don't get bibliography citation. I want Fricker (1995: 396--7) in the body of the text to be a hyperlinked to the bibliography at the end of the document.    \documentclass[preprint,12pt]{elsarticle} \usepackage[english]{babel}  \usepackage{graphicx} \usepackage{amssymb} \usepackage{cite} \usepackage{lineno} \usepackage[colorlinks=true]{hyperref} \usepackage{natbib} \usepackage{footnotebackref}  \journal{Journal Name} \begin{document} \begin{frontmatter} \title{\textbf What there is} \end{frontmatter}  \section{Prelude} \label{S:1} It is \footnote{that can be found in \cite{Fricker(1995: 396--7)} in the recent decades, the awareness about the political role.}  \begin{thebibliography}{99}  \bibitem{Fricker(1995: 396--7)} Fricker, E. (1994). Against gullibility. In B. K. Matilal \& A. Chakrabarti (eds.), \textit{Knowing from words} (pp. 125-61). Dordrecht: Kluwer Academic Publishers.  \end{thebibliography} \end{document}

I want "Smith (2003: 22-3)" in the footnote to appear as a hyperlink to the same reference mentioned in the bibliography section. How should I do that?  \documentclass[preprint,12pt]{elsarticle} \usepackage[english]{babel}  \usepackage{graphicx} \usepackage{amssymb} \usepackage[superscript]{cite} \usepackage{lineno} \usepackage[colorlinks=true]{hyperref} \usepackage{natbib} \usepackage{footnotebackref}  \begin{document}  \begin{frontmatter}  \title{\textbf{Title}}   \begin{abstract} this is abstract \end{abstract}  \begin{keyword} \hspace{-0.5cm} social epistemology, testimony, manipulation, truth, knowledge \end{keyword} \end{frontmatter} \section{one} That is widely accepted.\footnote{for example see Smith (2008: 22-3) as one example.}  \section{Bibliography} \begin{thebibliography}{99}  \bibitem Smith, D. (2003). Perception. Oxford University press.    \end{thebibliography} \end{document}


Let $A,B\in M_n(F)$. Set $C(A)=\{X\in M_n(F) \mid XA=AX\}$. Similarly $C(B)$ is defined. If $C(A)\subseteq C(B)$, I have to show $B\in F[A]$. ($F$ is a field.)

There have been many questions in the vein of this one, but I can't find one that answers it specifically.     Suppose $A,B\in M_n(\mathbb C)$ are two matrices such that, for any other matrix $C\in M_n(\mathbb C)$, $$AC=CA\implies BC=CB.$$ Prove that $B=p(A)$ for a polynomial $p\in\mathbb C[t]$.    Nothing is assumed about $A$ being diagonalisable or having distinct eigenvalues or being invertible.  Edit: after further work, this might not actually be true. If it's not, a counterexample would be great.


I encounter a contradiction.   Many resources state that a digital sensor are unsensitive to UV light. Even wikipedia, "However, newer photographic film and digital cameras are highly insensitive to UV wavelengths." .  Digital Photography Review goes even to the point that a digital photographer won't even need it on a beach (an UV-light rich area). "digital sensors are not and hence do not need UV filters in even bright sunlight".   While other resources state that digital sensor are sensitive to UV light.    Can someone clarify this contradiction?  My prognosis is that a digital sensor is sensitive to UV light, but sensor manufactures include an UV blocking system on the sensor. But I don't know if that's true. I do know that IR light is blocked through a IR-absorption glass on the sensor itself.   Is my prognosis correct?

Is there any way, shape, or form that ultraviolet light is recorded by a digital sensor?  Ideally, this question is related strictly to the sensor, without even a glass lens in between which could cut or block UV light.  But of course I don't take pictures with a bare sensor, I also have a lens, so I'd also like to know how much UV gets to the sensor to begin with.


I am working on a website, I have done it on-page nearly complete. I am using 160 words description.   In SERP I see meta description half from 160 words and half from website page.

When you do a Google search, there is typically a snippet of sample content from the page. I seem to recall that the Meta Tags can influence this choice of descriptive sentences. Is that correct(?) and if so, is it the Meta Description Tag?  Also, how many characters is Google's descriptive sentences limited to?


We know that acceleration of a falling body relative to earth is G*M_earth/(R_earth)^2 What would the acceleration formula if the earth's mass is same as sun's mass but with  same earth's radius? Is there algabreac simple closed formula according to GR for the acceleration of falling body relative to an observer in rest relative to the earth?, or we just must solve GR differential equations numerically?

The gravitational force on your body, called your weight, pushes you down onto the floor. $$W=mg$$ So, what is the weight equation through general relativity?


I upgraded to 16.04 from 15.10 today.  Now I can no longer perform software updates. Running sudo apt-get update results in the following:  Hit:1 http://archive.ubuntu.com/ubuntu xenial InRelease Get:2 http://security.ubuntu.com/ubuntu xenial-security InRelease [94.5 kB] Hit:3 http://archive.canonical.com/ubuntu xenial InRelease                      Hit:4 http://archive.ubuntu.com/ubuntu xenial-updates InRelease                 Hit:5 http://archive.ubuntu.com/ubuntu xenial-backports InRelease               Fetched 94.5 kB in 1s (83.7 kB/s)     and it just sits there.  I left it like this for 4 hours.  Top shows that after running the command, appstreamcli goes to 100% cpu and stays there.  PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND                                        6741 root     20   0  120556  37456   9340 R  99.7  0.5   1:22.71 appstreamcli       Looks like I may not be the only one experiencing this...

I tried to install crossover and after downloading the .deb from their website, I followed the steps as indicated when opening it with Ubuntu Software Centre:     On 64-bit flavors of Debian and some Ubuntu variants, first open a   terminal and run sudo dpkg --add-architecture i386 ; sudo apt-get update   Since I have Ubuntu 16.04 LTS 64 bit I perform the command.  But when copying and pasting that command into my terminal, it stopped at Fetched 535kb in 7sec and stalled there for about 20 minutes. I ended up  closing it and tried to run both commands separately but after doing the sudo apt-get update command it also stalls again after "Fetched XXKb in XXsec."  I restarted my computer and decided to run the software updater and it stays stuck at roughly 75% for hours.


I've tried to use scale, but it doesn't work in this case. Have you guys any idea how can I achieve this?

I would like to scale an image file for each dimension differently for example 50% of the x dimension or 25% of the y dimension. Thank you very much.


this is my code package pack; import java.awt.*; import javax.swing.*; public class MySwing { MySwing() {      JFrame.setDefaultLookAndFeelDecorated(true); JFrame f = new JFrame("This is my Frame"); JTabbedPane jtb= new JTabbedPane(); JPanel p1 = new JPanel(); JPanel p2 = new JPanel(); JPanel p3 = new JPanel();jtb.addTab("employee Info", p1); jtb.addTab("employee Dept", p2); jtb.addTab("employee Salary", p3); f.add(jtb); JLabel l = new JLabel("User Name"); l.setForeground(Color.blue); JTextField tf = new JTextField(20); tf.setFont(new Font("Coronet",Font.BOLD,20)); tf.setHorizontalAlignment(JTextField.RIGHT); tf.setBackground(Color.black); tf.setForeground(Color.yellow); JLabel l1 = new JLabel("Password: "); JPasswordField pf = new JPasswordField(20); JTextArea ta = new JTextArea(10,20); JScrollPane sp = new JScrollPane(ta);  String str[]={"select the city","Noida","Delhi","Faridabad"}; JComboBox c= new JComboBox(str); JList li = new JList(str); JCheckBox cb1= new JCheckBox("I.Sc",true); JCheckBox cb2= new JCheckBox("B.Sc"); JCheckBox cb3= new JCheckBox("M.Sc");      ButtonGroup cbg = new ButtonGroup(); JRadioButton cb4= new JRadioButton("Male",true); JRadioButton cb5= new JRadioButton("Female",false); cbg.add(cb4);cbg.add(cb5); JButton b = new JButton("save"); p1.add(l);p1.add(tf);p1.add(l1);p1.add(pf);p2.add(sp);p2.add(c);p2.add(li);p2.add(cb1);p2.add(cb2);p2.add(cb3); p3.add(cb4);p3.add(cb5);p3.add(b); f.setSize(600,400); f.setLocation(200,100); f.setVisible(true); f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); } public static void main(String arg[]) {      new MySwing(); } }   here this is the issue MySwing.java uses unchecked or unsafe operations recompile with -xlint:unchecked for details help me to resolve this this is not a error but my system doesn't run it resolve it

For example:  javac Foo.java Note: Foo.java uses unchecked or unsafe operations. Note: Recompile with -Xlint:unchecked for details.


I have some loop cuts. I have clicked around and done a few more things and now I want to adjust the amount of loop cuts I made a while ago. How do I go in and edit the count of them?

When you first add a cylinder, you have the option to change the number of vertices, etc, but once you do anything else in blender, it seems you no longer can edit those parameters.   Is there a setting anywhere or an add-on that allows these parameters to be edited later on? If not, how easy would such an addon/feature be to create for anyone reading this?


class test {  public static void main(String[] args) {     String a = "Hiabc";     String b = "abc";     String c = "abc";     System.out.println(a.substring(2,5)==b);     System.out.println(b==c); } }  output: false true   As far as I understand, Java's == look for addresses of the two compared objects. Yet, I don't understand why b==c is true because they must have different addresses. Also, if b==c, then why is a.substring(2,5), which is "abc" == b false?

I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?


\documentclass[mode=present,style=elcolors]{powerdot} \pdsetup{ lf=my first presentation, rf=for some conference, trans=wipe, theslide=\english{slide}, randomdots,dmaxdots=80 } \begin{document} \begin{slide}{basic itemize} Contents of the slide. \end{slide} \section{first section} \begin{slide}[<slide options>]{another slide} Contents of the slide. \end{slide} \begin{note}{personal note} The note. \end{note} \end{document}   error messages:  ! Undefined control sequence. <recently read> \c@lor@to@ps l.12 \end{slide} The control sequence at the end of the top line of your error message was never \def'ed. If you have misspelled it (e.g., `\hobx'), type `I' and the correct spelling (e.g., `I\hbox'). Otherwise just continue, and I'll forget about whatever was undefined. ! Undefined control sequence. \XC@usec@lor ...\expandafter \c@lor@to@ps #1#2\@@ \else \expandafter \expand... l.12 \end{slide} The control sequence at the end of the top line of your error message was never \def'ed. If you have misspelled it (e.g., `\hobx'), type `I' and the correct spelling (e.g., `I\hbox'). Otherwise just continue, and I'll forget about whatever was undefined. ! Undefined control sequence. <recently read> \c@lor@to@ps l.12 \end{slide}


g is a list of list, I use it as a 2d array. But when I assign values to g[i][j], it doesn't work.  Here is my code.   m=3 n=4  g=[[0]*n]*m for i in range(m):     for j in range(n):         g[i][j]=i         print(g[i][j])  print(g)   the output is  0 0 0 0 1 1 1 1 2 2 2 2 [[2, 2, 2, 2], [2, 2, 2, 2], [2, 2, 2, 2]]

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?


Would we be able to tell if an entire neighboring galaxy was made up of anti-matter? What would we see in its signals? It seems like the anti-matter could be stable if it was completely surrounded by other anti-matter.

Given that  galaxies are theoretically possible, how would they be distinguishable from regular matter galaxies?  That is, antimatter is equal in  and all properties, except for the opposite reverse charge of the particles, identical to regular matter. Hence a star composed of antimatter hydrogen would fuse to anti-helium in an analogous way to our own Sun, and it would emit light and radiation at the same wavelengths as any regular matter star and would cause the same gravitational forces for planetary systems to form as in any other star system.  Hence, what would be a telltale sign if you were observing a galaxy made up entirely of antimatter?  Also, is there any evidence for that half of all galaxies are not made of antimatter -- while general theories currently assume that there is an imbalance of matter over antimatter in the universe, then what is the rationale for not assuming that there is in fact an even balance between the two?


Suppose we have two $n \times n$ square matrices A and B such that $AB=BA$. It is known that A, B and AB all have n distinct eigenvectors that is a basis of $\mathbb{C}^n$. Can we then show that there is a basis of $\mathbb{R}^n$ that comprises entirely of vectors that are eigenvectors of both A and B?      I have no idea on solving this problem. Any form of help is appreciated. Thanks!

Let $V$ be a vector space of finite dimension and let $T,S$ linear diagonalizable  transformations from $V$ to itself. I need to prove that if $TS=ST$ every eigenspace $V_\lambda$ of $S$ is $T$-invariant and the restriction of $T$ to $V_\lambda$ ($T:{V_{\lambda }}\rightarrow V_{\lambda }$) is diagonalizable. In addition, I need to show that there's a base $B$ of $V$ such that $[S]_{B}^{B}$, $[T]_{B}^{B}$ are diagonalizable if and only if $TS=ST$.  Ok, so first let $v\in V_\lambda$. From $TS=ST$ we get that $\lambda T(v)= S(T(v))$ so $T(v)$ is eigenvector of $S$ and we get what we want. I want to use that in order to get the following claim, I just don't know how. One direction of the "iff" is obvious, the other one is more tricky to me.


agung@agung-K43SJ:~$ steam Running Steam on ubuntu 15.04 64-bit  STEAM_RUNTIME is enabled automatically  Installing breakpad exception handler for appid(steam)/version(0)  libGL error: unable to load driver: nouveau_dri.so  libGL error: driver pointer missing  libGL error: failed to load driver: nouveau  libGL error: unable to load driver: swrast_dri.so  libGL error: failed to load driver: swrast   Before that, I also tried installing Steam from Terminal, but it didn't launch after having downloaded the update.  Can anyone help me finding a solution to install Steam?

Actually I have installed the new Ubuntu 15.04 64bit, and when I'm trying to install Steam on it, there is a problem. In fact I have downloaded the deb package from steam website, installed it and when I start it nothing happens. I tried to start it from terminal and what I've got  $ steam Running Steam on ubuntu 15.04 64-bit STEAM_RUNTIME is enabled automatically Installing breakpad exception handler for appid(steam)/version(0_client) libGL error: unable to load driver: r600_dri.so libGL error: driver pointer missing libGL error: failed to load driver: r600 libGL error: unable to load driver: swrast_dri.so libGL error: failed to load driver: swrast


I tried to output to a text file using redirection operators > and >> from a java class but it ignores line feed \n from java when the .txt file is opened with the Notepad from windows 10. It's interesting because on the prompt the line feed works just fine and if I use System.out.println("") it works normally in the Notepad.   Class with \n line feed:  class n{      public static void main(String[] args){          System.out.print("This\n");         System.out.print("Should\n");         System.out.print("Be\n");         System.out.print("Separated.\n");       }  }   Class using System.out.println(""):  class ln{      public static void main(String[] args){          System.out.println("This");         System.out.println("Should");         System.out.println("Be");         System.out.println("Separated.");      }  }   Output in the prompt:    Output in text file from class n (n.txt) opened with Notepad:  ThisShouldBeSeparated.   Output in text file from class ln (ln.txt) opened with Notepad:  This Should Be Separated.   These two above should be equal.  I tested with the class n public but it didn't change the result.  I've searched and found about how to echo a line feed, that's not what I want, I want the redirected text file working like the prompt.  One interesting detail is when I paste the text from n.txt in here (writing a question), in the Microsoft Word, Notepad++ or WordPad (or open the file in the programs cited) it "fixed" the error and was equal the result from class ln.  EDIT  I think it's not a duplicate because when I wrote the question I didn't even think about the possible Notepad problem. The title is completely different so I answered my own question for people who didn't think that the problem is the Notepad, like me before, may get an good solution.  If I'm wrong I would be happy to be corrected.

Most documents I'm opening in notepad.exe under windows 7 lately, there are no linebreaks... everything just runs together.  The same documents in any other program, even previewed directly in Explorer, will show the linebreaks correctly.  this is happening with many .info files, .css, .js.. but not all of them.   I am guessing it's some kind of character encoding unix line endings something or other, but wondering if there's anything I can do or if anyone else has experienced similar and if I can make notepad work correctly. I prefer it to notepad++/other text editors for certain uses.


I was learning java stream api and I found this issue in code. Here is my code  long s = System.currentTimeMillis();  IntStream.range(1, 10).parallel().forEach( x ->{       System.out.println( "Thread -> "+ Thread.currentThread().getName() +" "+ x );  });  long e = System.currentTimeMillis();  System.out.println("Time taken "+ (e-s) + " ms");   System.out.println("---------------------");   s = System.currentTimeMillis();  IntStream.range(1, 10).forEach( x ->{      System.out.println( "Thread -> "+ Thread.currentThread().getName() +" "+ x );  });  e = System.currentTimeMillis();  System.out.println("Time taken "+ (e-s) + " ms");  Here is the output Thread -> main 6 Thread -> ForkJoinPool.commonPool-worker-7 2 Thread -> ForkJoinPool.commonPool-worker-7 5 Thread -> ForkJoinPool.commonPool-worker-13 1 Thread -> ForkJoinPool.commonPool-worker-11 4 Thread -> ForkJoinPool.commonPool-worker-3 3 Thread -> ForkJoinPool.commonPool-worker-15 9 Thread -> ForkJoinPool.commonPool-worker-9 7 Thread -> ForkJoinPool.commonPool-worker-5 8 Time taken using parallel stream 29 ms ------------------------------------- Thread -> main 1 Thread -> main 2 Thread -> main 3 Thread -> main 4 Thread -> main 5 Thread -> main 6 Thread -> main 7 Thread -> main 8 Thread -> main 9 Time taken simple stream 1 ms  I have tried this code on sts and inteliJ IDE, results are same. Parallel is taking longer time than sequential. Is there a problem with my jdk? please suggest.

How do you write (and run) a correct micro-benchmark in Java?  I'm looking for some code samples and comments illustrating various things to think about.  Example: Should the benchmark measure time/iteration or iterations/time, and why?  Related:


What is the formula for following sequence?  $$\frac12 + \frac12 \cdot \frac34 + \frac12 \cdot \frac34 \cdot \frac56 + ... + \frac12 \cdot \frac34 \cdot \frac56 ... \frac{2n - 1}{2n}$$  This is a question from my Calculus class about sequences.

How to find infinite sum How to find infinite sum $$1+\dfrac13+\dfrac{1\cdot3}{3\cdot6}+\dfrac{1\cdot3\cdot5}{3\cdot6\cdot9}+\dfrac{1\cdot3\cdot5\cdot7}{3\cdot6\cdot9\cdot12}+\dots? $$   I can see that 3 cancels out after 1/3, but what next? I can't go further.


Currently, I am using OAuth2 authorization code flow to authenticate REST services, but when i am doing request to get authorization code like  But it required the login & allow access then it redirects to my callback URL with accessCode. So I want to skip this process & auto-approve it because I am using it as background service & not interacting with the user. So how to auto-approve Salesforce REST API OAuth2 authorization_code flow to not show allow pop-up.

I'm trying to follow the instructions in  and get an invalid request with an error description of "refresh_token scope is required and the connected app should be installed and preauthorized."  In the documentation it says I should "Install and preauthorize the app" - but I have no idea how to go about this, and I can't find the appropriate docs. I've looked around several config screens for the app and can't see anything obvious. As a salesforce novice I'm stuck!


Currently I read about the  of . Mainly it's the problem that in the equation $X-X$ for $X$ being an interval the following is calculated: $$X-X=\{x-y:x\in X, y\in X\}$$ instead of $\{x-x:x\in X\}$. Both $X$ in $X-X$ are treated as different inputs. Thus $X-X\neq \{0\}$ so that there is no additive Inverse in interval arithmetic.  My Question: Is there a known solution for the dependency problem such that there is an additive (an multiplicative) inverse in interval arithmetic? Is there an extended version of interval arithmetic where addition is a group?  What I have found so far: I read about the centered form. For example, instead of calculating with $f(x)=x^2+x$ one can calculate with $(x+\tfrac 12)^2-\tfrac 14$ where $x$ only occurs once. The centered form helps, but does not provide an additive inverse...


I have debian.iso + windows 7 and qemu. I don't know windows absolutely. How can I run debian.iso using qemu? What command I need to use for running debian?

I am trying to use Qemu 1.3 for windows to run lubuntu on a USB stick with Windows 7. After downloading and unpacking Qemu on my usb stick, if I click on qemu.io.exe, I get  qemu-io.exe>   How do I start my downloaded linux .iso file? It sounds basic but its not clear to me from the Qemu website.


I am totally new to setting up a home server, Ubuntu and Linux programming.  I installed Ubuntu 14.04 LTS server and I can see the Ubuntu server under networks in Windows 7, but I cannot see any files when I go to the file browser. I have noticed during the boot process that smb/cifs file and active directory is failing to boot.  I have reinstalled the software several times hoping that it would correct itself but it did not. I have scoured the wikis and read many forums trying to solve the issue myself. Can someone guide me in the right direction please..?

I have a media computer which I recently reformatted to Ubuntu 10.04. I am probably just missing something obvious but I can't figure out how to share folders and files, so that I can browse to them on my Windows computers in order to copy files to/from the computer.  How do I do this?


I am trying to figure out a discrete solution for alternate low and high at the output for varying input. Consider the discrete solution as a block.  Input to the system consist of a push-button. Normally input to the system will be high. When pressed the push-button, input to the system will be low. Each time prasing the push button(that is input goes to low), output should change the state from previous state( that is low (0) to high (1) or high (1) to low (0)).   Any lead to the solution will be helpful.

What are the simplest, cheapest, smallest ways to make a momentary switch produce a 2-state toggling output (latching momentary switch)?  In other words, the output is continuously low, and when you momentarily press the button/tact switch, the output changes to continuously high, and then when you press it again, it switches back to low.


I have some blue LEDs that are listed at having a Vf of 3.3V @ 20mA.  If I want to drive them from a 3.3V source,  do I need a dropper resistor?  Methinks I do, but R = (3.3 - 3.3) / 0.02 = 0 Ohms!  I know that LEDs can be finicky about how they're driven, so is there a rule of thumb? (There's no data sheet as they're unbranded.)

Modern electronics industry has developed very efficient LEDs with nice and fancy colors (“true green” , “cyan”, and “blue”) based in InGaN technology, or similar. Some of these LEDs are specified as having forward voltages of 3.2 to 4.2 V. Here are examples of such LEDs, , or surface-mount .  But the usual MCUs are powered from 3.3 V supply, and the GPIO output is usually at 3.1-3.2 V, which seems to be barely enough to drive these LEDs . How can I use these LEDs as indicators of some signal statuses, or power rail status? Do I need a series resistor R1 here?    If yes, how do I choose its value?  DISCLAIMER: This "question-answer" comes as elaboration of the original question , to address the particular use case of LEDs as logic state indicators.


How can I enter this 'F' in LaTeX?   \mathcal{F} looks quite similar to it, but a little bit different.  I prefer not to use additional package if possible.

As can be seen in above picture, there are lots of fonts or font styles that can be used in math mode.  What are all the fonts or font styles I can use in math mode, and which packages are required in order to use them?  Let's assume I'm using standard Computer Modern or Latin Modern (lmodern) fonts.  Edit: It'd be great to see examples of what the different styles look like, probably via images.    I'm not interested in a reproduction of the picture, which can be found at ; the picture is for illustration purposes only. Furthermore, this is supposed to become a one-catches-all question for questions like the beforementioned. If I actually were looking for these fonts, I wouldn't just lazily ask here but look e.g. at  , tables 3.14 and 6.4 first.)


I'm curious which I should use of the following:   If you or someone you know are having troubles logging on to VMware, please ask Bob Smith for help. If you or someone you know is having troubles logging on to VMware, please ask Bob Smith for help.   Where VMware is the name of a computer network system / software.

How are the wife and kid?   How is the wife and kid?      Which is more correct?


Q1: Please what can I do next? Q2: What does it means for me in future and when I re-apply again? Q3: Is it good idea to reapply back in 1 month time?

Many of the UK visa refusals we see here share a common pattern and the prevailing reasons refer to V 4.2 (a) and (c).    I do understand that, while the applicants may describe very different individual circumstances, there's a consistent pattern and, broadly, fall into specific categories:    Credibility (lifestyle, lack of ties, visit history, lies & omissions) Funding (insufficient funds, provenance of funds, funds parking) Sponsorship (family, friends, employer)   Question: What most commonly triggers a UK visa refusal where V 4.2 (a) and (c) are given as the grounds?  Secondarily: Given that there is a clear pattern, to what extent are these refusals predictable? Does sponsorship make a difference? Is there a set of personal circumstances, however abstract, where a refusal is all but guaranteed? For example, why do those we see here on TSE who sought entry for the PLAB or British Army appear to be refused with a common theme? Is there a uniform shortcoming or is it just discrimination?   PLAB: What is about applications for a visa, for the purpose of sitting the Professional and Linguistic Assessments Board (PLAB) exam, that seem to invite refusals. After all, the test is given so that international medical graduates can show that they qualify to practise medicine in the UK. The first part, PLAB 1, can be taken in centres outside of the UK. However, PLAB 2 can be taken only in the UK. Why can't you can't get a visa just to sit the exam, promising that you'll leave immediately after?    British Army: Since Commonwealth citizens are eligible to apply online to join, even those who don't reside in the UK, why is it so difficult to get a visa just to attend an interview to see whether you are suitable? Even with an invitation from the Army, such visa applications seem to be unsuccessful. Isn't a career in the British Army a valid reason?     Lastly:  After such a refusal, what approaches would increase the chance of a successful application?


Suppose in a society where every family wants a boy in their family at least: The family give births to children until the first boy is born. As soon as the first boy is born, they stop making babies.  Will such practice result in the society having more males than females?  what if I change the question to "every family stops making baby as soon as two boys are born"?

I have came across a question in job interview aptitude test for critical thinking. It is goes something like this:     The Zorganian Republic has some very strange customs. Couples only   wish to have female children as only females can inherit the family's   wealth, so if they have a male child they keep having more children   until they have a girl. If they have a girl, they stop having   children. What is the ratio of girls to boys in Zorgania?   I don't agree with the model answer given by the question writer, which is about 1:1. The justification was any birth will always have a 50% chance of being male or female.  Can you convince me with a more mathematical vigorous answer of $\text{E}[G]:\text{E}[B]$ if $G$ is the number of girls and B is the number of boys in the country?


I want to show "hello" message on the screen but my app is not working.  What is causing "java.lang.NullPointerException"?  the debugger says value of longitude is null. Even if that is the case, shouldn’t my "hello" message still appear?  I have the following code:   package autogenie.maptrial;   import android.Manifest;   import android.content.Context;  import android.content.pm.PackageManager;  import android.location.Location;  import android.location.LocationManager;  import android.support.v4.app.ActivityCompat;  import android.support.v7.app.AppCompatActivity;  import android.os.Bundle;  import android.widget.Toast;  public class MainActivity extends AppCompatActivity { private Location location; private Double latitude, longitude; private LocationManager locationManager;   @Override protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.activity_main);      if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {         // TODO: Consider calling         //    ActivityCompat#requestPermissions         // here to request the missing permissions, and then overriding         //   public void onRequestPermissionsResult(int requestCode, String[] permissions,         //                                          int[] grantResults)         // to handle the case where the user grants the permission. See the documentation         // for ActivityCompat#requestPermissions for more details.         return;     }       locationManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);      location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);      longitude=location.getLongitude();     latitude=location.getLatitude();        Context context = getApplicationContext();     String s="hello";     int duration = Toast.LENGTH_LONG;      Toast toast = Toast.makeText(context,s, duration);     toast.show();   } }   What debugger shows:    After that it crashes.

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?


I have my concerns about a Druid being better thief than a Rogue of the same level. As a DM, should I prevent using the Wild Shape as a high-end burglary tool, and how? The Wild Shape feature  for an animal size, which makes this feature quite tempting for any rogue, from my understanding.  Starting at 2nd level, you can use your action to magically assume the shape of a beast that you have seen before. You can use this feature twice. You regain expended uses when you finish a short or Long Rest. Your druid level determines the Beasts you can transform into, as shown in the Beast Shapes table. At 2nd level, for example, you can transform into any beast that has a Challenge rating of 1/4 or lower that doesn't have a flying or swimming speed.  PHB gives examples of turning into wolves, crocodiles and eagles. But really overpowered is turning into a very small animals, like spiders or mice: The greatest thief At 2nd level, the Druid becomes an ultimate escape artist and completely overshadows the Rogue: Infiltrate a heavily guarded territory. Forget Stealth checks, making a disguise or bribing guards. Just turn into a little mouse and go through the main entrance. Or you can turn into a spider and climb walls unnoticed. Pass a reinforced locked door. Again, turn into a spider and climb through a keyhole or under the door. Since all the equipment can be merged into a Wild Shape, you can take your loot with you. Hide in an empty room. Enemies are about to find you, but you don't know the Invisibility spell? Turn into a mouse! Besides from Stealth checks advantage you will get Total Cover even behind the smallest objects. Or you can turn into (again!) a little spider and just sit on a ceiling. A ghost that leaves no traces. Pass traps, walk on pressure plates... Escape from any ropes and chains. Being chained into manacles, you don't need to make DC 20 STR or DEX check. Just turn into a mouse. Escape from a prison. There are plenty of rats in prisons and dungeons. Turn into one, slip through the cell bars and be free. As a DM, how can I limit the Wild Shape feature, to make the Rogue on par with the Druid?

In the last few sessions, our druid has been using the tactic of transforming into a spider or other bugs and scouting out entire floors of dungeons by slipping under doors and remaining unseen.  Is there anything RAW/RAI to prevent him from doing this, or is it considered an acceptable use?


I just received three Yearling badges in the span of a few minutes...        That seems odd, is this a bug or intended behavior?

Here is a screenshot showing this:    Originally I thought it was due to the  today, but on most if not all of these sites, I had 200 rep or more both before and after the recalculation.  Is everybody getting this effect in their notifications?


I use AJAX to call a PHP script and replace some HTML with the results data so a user can confirm the data.  The initial button is "Fetch Data" and then I swap that out with 2 new buttons "Confirm Data" and "Try Again" (in case the user doesn't want to validate the script result.  HTML button being replaced:
         <button type="button" id="fetch_btn" value="fetch_it" class="btn-btn btn btn-dark border-light center-button mt-2">
                     Fetch Data
         </button>
   Ajax works just fine:       $("#new_case_form").submit(function(e){       e.preventDefault();       var county_name = $("#county_select").val();       var case_number = $("#case_num").val();       // console.log($("#county_select").val());       var the_url = "fetch_case.php?county="+county_name+"&case_number="+case_number;       var response = $.ajax({           url: the_url,           type: "GET",           dataType: "text",           success: function(data){               $("#case-confirm").html(data);               $("#btn-container").html("<button type=\"button\" name=\"confirm_btn\" id=\"confirm_btn\" value=\"confirm\" class=\"btn-btn btn btn-dark border-light center-button mt-2\">
Confirm Case
</button><button type=\"button\" name=\"try_again\" id=\"try_again_btn\" value=\"try again\" class=\"btn-btn btn btn-dark border-light center-button mt-2\">
Try Again
</button>");           }       });   });   Here is the new HTML in a more readable format:  <button type="button" name="confirm_btn" id="confirm_btn" value="confirm" class="btn-btn btn btn-dark border-light center-button mt-2">
         Confirm Case
 </button> <button type="button" name="try_again" id="try_again_btn" value="try again" class="btn-btn btn btn-dark border-light center-button mt-2">
         Try Again
 </button>   This is the jQuery I use in trying to do anything with the Try Again button once it's clicked:    $("#try_again_btn").click(function(e){       console.log('confirm btn clicked');   });   I have also tried    $("#try_again_btn").on("click",function(e){       console.log('confirm btn clicked');   });   I have also used #try_again_btn_text because I nested an HTML tag inside the <button> and thought maybe when the text is clicked it doesn't fire the trigger on the parent button but that didn't work either.

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 don't know if there is, but I know that there is a reference to his mother in the secret mission in GTA V, but I was wondering if C.J. is referenced at all in the game?

I just bought Grand Theft Auto 5, and I am looking forward to playing it. But I'd like to know whether any of the old characters make an appearance in the new game.  I know the new game is based around new protagonists, but do any of the old characters (such as Carl Johnson, The Truth, Sweet etc) make an appearance? If so, is it simply a cameo, or are they interwoven into the storyline?


WordPress is installed in the root public_html directory. E.g.,   public_html/index.php public_html/wp-config.php public_html/wp-admin/   Now I want to run a totally separate PHP file in the same directory. E.g.,   public_html/mystuff.php   How do I run it without WordPress thinking it's part of it?

I want to extend my website in a way that is parallel to the wordpress theme.  Example:  My website with wordpress is at: www.mywebsite.com By ftp I added a directory named test, in which there is a php file test.php  The problem is that if I write in the url: www.mywebsite.com/test/test.php it redirects me to the "page not found" of my theme.  How can I deactivate this behavior?   Posting .htaccess:  # BEGIN WordPress <IfModule mod_rewrite.c> RewriteEngine On RewriteBase / RewriteRule ^index\.php$ - [L] RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule . /index.php [L] </IfModule>  # END WordPress  # # av:php5-engine AddHandler av-php5 .php  # # av:Toolbar SetEnv AV_TOOLBAR 1


After my opponent declares a blocking creature, I use an instant to deal 2 damage which kills it. Do they take combat damage to the face?

We are in the combat phase:   I declared my attackers  My opponent declared his blockers, stating which attackers he was blocking I cast an instant, which automatically kills his blocker. There is nothing blocking my attacker now   Now we're in the damage phase. I said that my attacker now does damage and  reduces my opponent's hit points. My opponent said that because my attacker was blocked no damage could be done. I pointed out that the blocker was destroyed before the damage phase, so therefore he wasn't blocking, but he wasn't having it. (My attacker does not have trample)  Is this covered by a specific section in the rules?


I need US zipcode areas (polygons) for a web map implementation. Can you tell me where to find it (free or paid)?

I've been searching the web for zip code shapefiles (or equivalents) for years 2000 to 2010, and have only managed to find the following:    which carries the following TIGER/Line releases:  1990 | 2000 | 2000 Urban Area | 2002 | 2004 1st Ed. | 2004 2nd Ed. | 2005 1st Ed. | 2006 2nd Ed.  and   which carries the following TIGER/Line releases: 2006 2nd Ed. | 2007 | 2008 | 2009 | 2010  These releases contain most of the Zip Code Tabulation Areas that I need. However, the 2002 release in the above link does not appear to contain ZCTAs, and I cannot find releases for years 2001 and 2003.  Does anyone have links to TIGER/Line releases for 2001, 2002, and 2003, or links to other sources that contain zip code shapefiles for those years? I've seen some online vendors that have this data available for a fee, but given the project's budget, free sources would be preferable.


I had Atom Editor in my machine and was using it using the atom command. But yesterday I installed Learn IDE which is a fork of atom with many changes and now whenever I use atom command it opens Learn IDE not the Atom Editor. I uninstalled Learn IDE using       sudo apt-get --purge remove atom       and found it is now removed from my system but using the atom command does nothing it says      bash: /usr/bin/atom: No such file or directory     Atom is still there on my system but I can't use the command atom. Please Help.

I'm new to Ubuntu Environment. I'm using Ubuntu 16.04.3 LTS. I'm learning Web Development my own. I heard some good words about using Linux for Web Dev. So I just dual boot my Windows laptop with Ubuntu. After installation and software update. I visit atom.io to install Atom Text Editor. I downloaded the .deb file. I clicked on it and it took me to Ubuntu Software. I clicked on Install button but nothing happened.


I have a dataset of energy measurements taken every minute from the energy footprint of home appliances. Based on that I am trying to detect human presence in the house. Since the data is sequential, I decided to use a recurrent neural network (LSTM) to model it.   Because the classes are unbalanced (~60/40) I am using confusion matrix metrics along with accuracy. The other main characteristic of the dataset is that it has a great deal of sparsity, especially in certain features.  I have a baseline of a deep feedforward network to compare the model against. During training of the feedforward variant I shuffle the dataset to return it to an iid setting and prevent overfitting.  I am using the negative log likelihood as my cost function in both cases. This is a binary classification setting so this, in turn, yields the binary cross entropy cost.  The feedforward network yields the following results:  accuracy: 86.37%  f1 score: 82.00%  precision: 82.98%  recall: 81.10%   The recurrent network, on the other hand, yields the following:  accuracy: 31.08%  f1 score: 38.35%  precision: 68.53%  recall: 58.34%   Clearly, the LSTM is performing significantly worse. My intuition is that it is overfitting the data (the training cost is decreasing steadily). I should mention that I do not shuffle the dataset during training of the LSTM, as I want to preserve the sequential structure of the data. Am I making wrong assumptions about training it? Should I actually shuffle the dataset? If that is not the problem, does anyone have any pointers on what could be going wrong?  I also thought sparsity is a problem but then again it doesn't seem to affect the feedforward variant too much.  Thanks in advance.

I'm training a neural network but the training loss doesn't decrease. How can I fix this?  I'm not asking about overfitting or regularization. I'm asking about how to solve the problem where my network's performance doesn't improve on the training set.    This question is intentionally general so that other questions about how to train a neural network can be closed as a duplicate of this one, with the attitude that "if you give a man a fish you feed him for a day, but if you teach a man to fish, you can feed him for the rest of his life." See this Meta thread for a discussion:   If your neural network does not generalize well, see:


How can I check if a given force is conservative or not? Is there a mathematical way of doing the same?

A  field is one in which all that matters is that a particle goes from point A to point B. The time (or otherwise) path involved makes no difference.   Most force fields in physics are  (conservation laws of mass, energy, etc.). But in many other applications, the time paths DO matter, meaning that the force field is not "conservative."  What causes a force field to be "non-conservative?" Could you give some examples (probably outside of physics)?


I heard someone say that I should never open links in new windows or tabs, because this will confuse the end-user. I've seen my mother do this several times - she tries to click the back button (even though it's greyed out). In many cases this results in leaving the website. I am not sure if I should open pages in new windows or tabs or in the current page. They both have their own advantages. My website is for a hosting company, so probably, many developers will visit the website. So what should I do? Err on the side of caution?  Where should I ask this question? I was thinking about Programmers.SE or Webmasters.SE but I'm not sure.

There seems to be more than a few computer science/programming Stack Exchange networks (is that the correct term?). Stack Overflow, being the first, has by far the most users, questions, and answers.  What is the reasoning for creating the others, and are there clear guidelines for which kinds of questions should be posted? I can see a large amount of potential overflow, many cases of people not getting a good answer to their question, because the person who has the answer isn't browsing that particular network at the moment.  I understand that they were probably created for organizational purposes, but wouldn't it almost make more sense to just have them as categories under Stack Overflow, keep them separated but still connected, instead of making people have to create multiple 'account's, one for each network?  I am sure there was a very good reason to break them up, but as someone that is new to SE, it can be somewhat intimidating to decide which one to post in to ensure you get a good answer. For example, if I am a computer science student, my first instinct might to be to post in the computer science network, until I see that it literally has 1% of the users as the Stack Overflow network, which still seems to be for programming/computer science related questions.  So my second instinct would then to be to post it into the Stack Overflow site on the basis that I have a significantly higher chance of my question being seen and getting a good answer. Then I notice that there is also a 'programmers' network, and I don't even begin to know where that fits in. I, and I am assuming most people, will probably just post on Stack Overflow to be safe.  My question is, other than the short little description blurb of each one, is there a clear cut set of guidelines which what each network is intended for, what kinds of questions should go to each one, and is anything being done to encourage people to post in these newer, smaller (more specialized?) networks as opposed to just posting in big daddy Stack Overflow?  Now again, this is for computer science/programming/"why isn't this code doing what I want?" related questions, I am not saying that if I had a question about Linux or WordPress or something I would have the same confusion.


I would like to see my sky texture and not be forced to go into render mode, because render mode is very slow to travel. Is there any way to have a sky and see it through solid mode?

I saw this happening in some tutorial, but have forgotten for the moment, What I want is : To make the HDR environment texture appear in 3D viewport without going into Render Mode. I can use the following :   Material Mode Texture Mode Solid Mode   Actually, there is some Setting (i suppose) through which this is achieved. Object textures are available but Environment texture is hidden in these 3 modes, and the Reason behind this question is that I dont want to burn my CPU, just in order to switch b/w modes to see the OBJECTs & HDR that they fit well or Not


I am trying to install netgear ac600 on Ubuntu 20.04 and use it instead of my internal WiFi card can someone please tell me how to set this up .I even have the install disk if that helps any ?

I am looking for a driver for the TP-Link AC600 Archer T2U Nano, on Kubuntu 18.04 (kernel version 4.15.0-51-generic).   I already tried different drivers, none of them worked.


I need help about regular expression matching with non-greedy option.  The match pattern is:     The text to match is:    abc     I test on   This expression matches all text from . I need it to match with the first encountered > after the initial <img, so here I'd need to get two matches instead of the one that I get.  I tried all combinations of non-greedy ?, with no success.

For example, this regex  (.*)<FooBar>   will match:  abcde<FooBar>   But how do I get it to match across multiple lines?  abcde fghij<FooBar>


I have a website and it's been 4 days since I have provided sitemap file to Google. None of URLs are shown in Google. Google Webmaster Tools shows 4 URLs indexed. My website is session protected is this creating a problem?

This is a general, community wiki  question and answer pair intended to address any questions   concerning the reasons a site or specific site contents do not appear   in search engine results.      If your question was closed as a duplicate of this question and you   feel that the information provided here does not provide a sufficient   answer, please open a discussion on .   My site (or specific pages on my site) is not appearing in search engine results.  Why isn't my content indexed and what can I do about it?


I have this database:     And I need to get the following data for each Client:   Client Name Contract Name(s) Project(s) Employees who logged hours to a project from the first day of the current month until the last day of the current month Total number of hours logged for each employee during the month Employee rate  Total Charges per employee (i.e. employee rate x employee hours worked) Billing contact(s) [name, address] for each contract   I have the following query so far, but I need to implement a MSSQL version of MySQL's GROUP_CONCAT( )  SELECT   Cl.LegalName AS ClientNames, Cr.ContractDesc AS ContractNames, P.ProjectName AS ProjectNames, ( E.FirstName + ' ' + E.LastName ) AS EmployeeNames, SUM( WH.HoursWorked ) AS TotalHours,  ( SUM( WH.HoursWorked ) * BR.Rate ) AS TotalCharges,  ( Ca.FirstName + Ca.LastName + ', ' + Ca.AddrLine1 ) AS BillingContacts  FROM Clients Cl JOIN Contracts Cr ON( Cl.ClientID = Cr.ClientID )  JOIN Projects P  ON( Cr.ContractID = P.ContractID )  JOIN EmployeesProjects EP ON( P.ProjectID = EP.ProjectID )  JOIN Employees E  ON( EP.EmpID = E.EmpID )  JOIN WorkHours WH ON( E.EmpID = WH.EmpID )  JOIN BillingRates BR ON( E.TitleID = BR.TitleID ) AND ( E.Level = BR.Level )  JOIN ContractsContacts CC ON( Cr.ContractID = CC.ContractID ) JOIN Contacts Ca ON( CC.ContactID = Ca.ContactID )  WHERE WH_Month = 4 AND WH_Year = 2013   When I started following  example, I got to here and stopped because I realized that I couldn't reference table aliases (Cr) from other subqueries (ProjectNames).  SELECT  Cl.LegalName AS ClientNames,  (     SELECT ContractDesc + ', '     FROM Contracts Cr     WHERE Cl.ClientID = Cr.ClientID      FOR XML PATH('') ) ContractNames, (     SELECT ProjectName + ', '     FROM Projects P     WHERE Cr.ContractID = P.ContractID     FOR XML PATH('') ) ProjectNames   FROM Clients Cl   How exactly do I go about doing this?

I'm trying to migrate a MySQL-based app over to Microsoft SQL Server 2005 (not by choice, but that's life).  In the original app, we used almost entirely ANSI-SQL compliant statements, with one significant exception -- we used MySQL's group_concat function fairly frequently.  group_concat, by the way, does this: given a table of, say, employee names and projects...  SELECT empName, projID FROM project_members;   returns:  ANDY   |  A100 ANDY   |  B391 ANDY   |  X010 TOM    |  A100 TOM    |  A510   ... and here's what you get with group_concat:  SELECT      empName, group_concat(projID SEPARATOR ' / ')  FROM      project_members  GROUP BY      empName;   returns:  ANDY   |  A100 / B391 / X010 TOM    |  A100 / A510   So what I'd like to know is: Is it possible to write, say, a user-defined function in SQL Server which emulates the functionality of group_concat?   I have almost no experience using UDFs, stored procedures, or anything like that, just straight-up SQL, so please err on the side of too much explanation :)


Let us say Alice wants to communicate state |T> (also a qubit) to Bob. Given, they have an EPR Pair shared amongst them. Alice interacts her qubit with |T> and then sends the measured state (classical information) of qubits to Bob. Depending upon the measured state of qubits(00,01,10,11) Bob uses the quantum gates to get back |T>. But instead of doing that Bob could have decided upon using  a particular quantum gate. So, he could have got the right information with a probability of 0.25 but at least he could have achieved faster than light teleportation with a probability of 0.25.

I apologize if this is a really silly question.   In the (textbook) quantum teleportation algorithm, in the step right after Alice has measured her system but before she has sent her classical information to Bob, she is about to send one of the following values: 00,01,10,11.   What if Bob doesn't want to wait and simply takes a guess? Wouldn't there then be superluminal communication 25% of the time?


I asked this question earlier and got a very useful hint, but I still can't get the full solution. Here is the original question:  I'm trying to show that for $b>1$, $x>0$ and $x$ irrational,  that $$\sup \{b^p:p\in Q,\;0<p<x\} = \inf \{b^q:q\in Q,\;x<q\}$$  I know this follows immediately if we define $b^x=\exp (x\log(b))$  and use the fact that the exponential function is strictly increasing and  continuous over $\mathbb R$, but I'm not allowed to do that. In fact, I only have  that $b^{m/n}=(b^{1/n})^m$, where $b^{1/n}$ means the positive $n^{th}$ root of $b$;  $b^x$ is not yet defined for irrational $x$.  I know that the supremum and infimum both exist because if $b>1$ and $p<q$, then $b^p<b^q$.  Also, by assuming that the inf $<$ sup, I got a contradiction. The part I'm stuck on is deriving  a contradiction from assuming that sup $<$ inf. Does anybody have any ideas?  The hint I got, courtesy of Greg Martin:  Try this one: let $S$ be the sup and $I$ be the inf. If $S<I$, then set $\epsilon =I−S$. Choose $p<x$ rational such that $b^p > S-\frac\epsilon{100}$ (say) and $q>x$ rational such that $b^q<I+ \frac \epsilon{100}$. Then with $r=\frac12(p+q)$, use some inequalities to show that $b^r>S$ and $b^r<I$, contradiction.  This was my reply:  I have the inequality $S-\frac\epsilon{100}<b^p<b^r<b^q<I+\frac\epsilon{100}$, and I'm trying to show that for all $n$, $S-\frac\epsilon{n}<b^r<I+\frac\epsilon{n}$. This would show that $S<b^r<I$. But $p$ and $q$ depend on $n$, and $r$, being their midpoint, depends on $p$ and $q$, and hence $n$. How do I proceed from here? That is, how do I show that $r$ doesn't change when $n$ changes?  Can anybody help? Thank you.  The link to the question:

I'm trying to show that for $b>1$, $x>0$ and $x$ irrational, that $$\sup \{b^p:p\in Q,\;0<p<x\} = \inf\{b^q:q\in Q,\;x<q\}$$ I know this follows immediately if we define $b^x=\exp(x\log(b))$ and use the fact that the exponential function is strictly increasing and continuous over $\mathbb R$, but I'm not allowed to do that. In fact, I only have that $b^{m/n}=(b^{1/n})^m$, where $b^{1/n}$ means the positive $n^{th}$ root of $b$; $b^x$ is not yet defined for irrational $x$.  I know that the supremum and infimum both exist because if $b>1$ and $p<q$, then $b^p<b^q$. Also, by assuming that the inf $<$ sup, I got a contradiction. The part I'm stuck on is deriving a contradiction from assuming that sup $<$ inf. Does anybody have any ideas?  Thank you.


Running Mojave on a MBP 2012 13" and I get that message every time I use the sudo command. It isn't preventing me to use sudo, but I get the feeling it'll bite me in the butt at some point in time, and rather have it fixed now then later.  I have tried many of the solutions from other questions asked before but none of them remove the message. I have two account, my main with my name, and an administrator account I used for a work around to get my account admin permissions (it was so long ago I forgot what the problem was before). Both of them can use sudo.  When I run an ls -ln command with sh I only get a ts account listed.  drwx------  3 0  0  96 May 27 12:40 ts   And an ls -la command gives me only one account with an account name I know I've made before, but don't remember where exactly.  drwx--x--x    3 brushie  wheel    96 Sep 24  2018 . drwxr-xr-x  106 root     wheel  3392 May 27 10:21 .. drwx------    3 root     wheel    96 May 27 12:40 ts   I've heard you should see your account somewhere in both of these lists, I'm pretty sure my issues are here but I don't know how to go about fixing it without screwing something up.

To run programs as sudo without password, I edited /etc/sudoers with wrong content.   Then I re-edited it with Mac's default text editor(course sudo cannot be used when /etc/sudoers is wrong).  I tried to run sudo agin, and get this error:   sudo: /etc/sudoers is owned by uid 501, should be 0 sudo: no valid sudoers sources found, quitting   What should I do? I cannot remember the root password (maybe I haven't ever set root password before).


When you use rtl language by default wordpress enqueue rtl.css file at the end of all stylesheets. what I need is how to enqueue a stylesheet after rtl.css stylesheet so the result should be like the following?   <link rel="stylesheet" href="http://example.com/wp-content/themes/mytheme/rtl.css" type="text/css" media="screen" /> <link rel="stylesheet" href="http://example.com/wp-content/themes/mytheme/responsive-rtl.css" type="text/css" media="screen" />   Thanks

Sorry if this is an ignorant question. I'm a first timer on working with rtl languages. Say we have a theme with standard style.css for English languages. so I use is_rtl() and this returns TRUE, we won't load the style.css and only rtl.css?  IF someone can provide an example on this on loading rtl.css on rtl languages and style.css on other languages (aside from the WordPress documentation which I already seen), I would be happy. Thanks.


I've been trying to work out the solution to this problem. Consider $\forall x \in \mathbb R $ the series $$\sum_{n=1}^{+\infty} \frac{1} {n} \sin(nx) $$ Find the values of $x$ for which the series converge (pointwise, uniformly or absolutely). My attempt: It is obvious that for every $x \in \mathbb R $, we have $ \vert \sin(nx) \vert \le 1$, and if we take the points $x=\frac{\pi} {2n}$ our series is exactly the harmonic series and it doesn't pass the Weierstrass M-test. So our series is not absolutely and uniformly convergent (at one time). Then if we take the points $x=k\pi, k \in \mathbb Z$, our series converges to 0, very easily. For the other values of $x$, I tried using other common tests, such as ratio and root test (I get the inconclusive 1), and figuring out useful bounds for the sequence, but didn't succeed. I suspect it converges, but I don't know how to go on. Am I mistaken? Are there any other tests?

Here is an exercise, on analysis which i am stuck.    How do I prove that if $F_{n}(x)=\sum\limits_{k=1}^{n} \frac{\sin{kx}}{k}$, then the sequence $\{F_{n}(x)\}$ is boundedly convergent on $\mathbb{R}$?


When I try to render my scene, there are no Lights at Final Render.    But if I use Shift+Z shortcut to see a preview, all works fine.    I really don't understand what is going on... Can you guys help this newbie? I installed Filmic Renderer that BlenderGuru recommended. Other than that, everyting are default, I think.

This is meant to solve this problem once and for all. What is every reason an object isn't showing up in a render or viewport in when using the cycles render engine?