Is there any way to do a strip map index on ArcGIS Pro?   This is for a pipeline route, Grid index doesnt work very well for this.


Trying to use 'GRASS FREE' from  . But i don't know where to put the python file, I have tried many but it's not working... I am on mac!


how to go back to previous head on commit on local machine

I was working on a project which was committed on GitHub. I made some changes and tried to commit it to the repo, But I got the error saying Your branch is ahead of 'origin/main' by 3 commits. So I tried to go back to the branch origin/main and I did git reset --hard origin/master Now I was on the main branch. So I pushed the code on Github. Code got pushed but it was not reflected in the repo. And When I came back to the editor all the changes I made on Local machine were gone it is not there. I need my changes made codes back on my local machine. Please Help!


How can I format a verbatim paragraph? I.e. break, fill and join input lines to produce globally balanced output with the lengths of each line approaching the target \textwidth as closely as possible.   Using the listings package I can break lines, but I cannot join short lines.. That is, the following   \documentclass{article} \usepackage{listings}  \lstnewenvironment{exampleA}{\lstset{%    language=,   basicstyle=\ttfamily,    breaklines=true,   prebreak=+,   postbreak=->,   columns=fullflexible,   breakindent=5pt} }{}  \begin{document} \begin{exampleA} Long line Long line Long line Long line Long line Long line Long line Long line Long line Long line Long line Long line Long line Long line Long line Long line Long line  Short Line  Short Line  Short Line  \end{exampleA} \end{document}   produces    What I would like to achieve is similar to what LaTeX does by default with paragraphs.. That is, e.g.  \documentclass{article} \newenvironment{exampleB}{\tt}{} \begin{document} \begin{exampleB} Long line Long line Long line Long line Long line Long line Long line Long line Long line Long line Long line Long line Long line Long line Long line Long line Long line  Short Line  Short Line  Short Line  \end{exampleB} \end{document}   will produce:   The problem with using the latter approach is that I cannot use special symbols like # or % in the verbatim text.. So I need to use a verbatim environment like lstlisting or fancyvrb's Verbatim environment. (As mentioned: in the lstlisting environment, automatic line breaking is possible, however for the Verbatim environment this feature seems also to be missing)    EDIT: (This a comment to Frank's answer below)   Now there seems to be a problem with lines becoming too short.. The following input  \noindent\hrulefill  \begin{myverbatim}   xxxxxxx xxxx xxxxx: 1234567890123456789012345,   123, 1234567890, \end{myverbatim} \noindent\hrulefill\   now produces    (I would now like to have the word "123" at the end of the first line, as there are certainly plenty of space for it there :))  Update   The above problem has now been solved, see comments in Frank's answer below..


Install many applications using one command

after reinstall system I need install applications again. Is it possible to make bash script or own package where cancan I add needed application and after reinstall system will I install them all using one command?


When I read Django code I often see in models what is called a "slug". I am not quite sure what this is, but I do know it has something to do with URLs. How and when is this slug-thing supposed to be used?   (I have read its definition in .)


I am quite new to LaTeX so my question may be trivial, but I haven't found a good solution so far.  I am preparing some lecture notes and I would like to have 2 different versions: one for myself, containing all the info I need during the lecture, and one for the students, with some of the text and/or graphics and/or equations blanked out (with some white space occupying the same space on the page, so the students could fill the gaps). I know of \phantom, but it does not seem very efficient as I would have to prepare 2 versions of the same document. I have also seen the censor package, but it does not seem to play nicely with equations. Any other suggestion on how to do this cleanly and efficiently?


Where can I ask for help finding a resource I've seen before but can't remember where?

I'm looking for something very specific I read once about unit test reporting for product owners. I'm pretty sure it was in one of the Robert C. Martin series of books and I thought it was in Mike Cohn's book Agile Estimating and Planning, although I wasn't able to find it again.  Would a question about this be on-topic on Stack Exchange? Which would be the best site to ask on?


I just finished up the last quest on Korriban, and my companion, Khem Val keeps saying, "I want to speak with you."  So... I right click him, and he says: "I want to speak with you."  So, I'm at a loss. How do I speak with the big lug?


Aggregate function that append columns values of each group?

I have a similar table to this:  Id     Name    CommitDate  Commits ------ ------- ----------- -------- 1      Ahmed   2018-07-05  2 1      Ahmed   2018-07-07  6   I need this output:  Id     Name    Summary ------ ------- ------------------------------------------------- 1      Ahmed   2 commits on 2018-07-05\n 6 commits on 2018-07-07   Actually, I stopped at this:  SELECT Id, Name, '' AS Summary  FROM Commits GROUP BY Id, Name   and couldn't continue, as every GROUP BY clause I used before came with a simple aggregate function, I'm unable to figure out if there is an aggregate function that can append grouped columns together!


In classical geometry why is a line considered to be parallel to itself?

A definition in classical geometry (for example, Birkhoff's formulation, but I suppose it could be all of them) is that a line is always considered to be parallel to itself. I understand this is probably for convenience, but in my mind since two distinct lines are parallel if they have no points in common and a line has infinitely many points in common with itself. Perhaps the idea is to ease the definition that two (non-parallel) lines intersect at one and only one point?   Q: What's the purpose/what inconvenience would be caused if we didn't have that definition?


How to evaluate/select cross validation method?

How can I decide which cross validation method is appropriate for my problem and data type? For instance, choosing among leave-one-out, or K-fold (and which K is appropriate?). Most of my searches end up on selection of model rather than selection of cross validation method.


I have a problem with updates.  During update, i receive the following message.  Failed to download repository information Check your Internet connection. W:Failed to fetch ppa.launchpad.net/ gwendal-lebihan-dev/ cinnamon-stable/ ubuntu/ dists/ precise/ main/ source/ Sources  404  Not Found   and also a couples of broken patheses, that are not allowed to post, according to link policy i this site  I am a newby in this, so please help.  Yeah. Ubuntu 12.04


I just read the discussed topic "look here vs. look at here":  It's got me wondering.  What is the reason for not using the preposition at before here?  Is it because here is an adverb and it is wrong to use a preposition before an adverb?  What if we use here with its nominal meaning, as in "get away from here", or "It's really hot in here", and then say "Look at here" meaning "Look at this place"?    If it is wrong and there is some other reason why at here is incorrect but in here and from here are correct, what is it?


Google Scholar: Where/How to send Emails to make corrections to them?

It looks to me that various articles of mine have huge parts of missing citations from various published papers from other people. For example, by checking adsabs.harvard.edu, I find many more citations to my papers, but they are not included properly thus missing in Google Scholar.     Where/How do I send emails to Google Scholar to reach out for this issue?


Convert a List of string to Int or Float as available

I have list as:  list = ['67.50', '70.00', '72.50', '75.00', '77.50', '80.00', '82.50']   I want to check if the string is a foat then it should be converted to float and if the string is a int then it should be converted to int.  Desired Output:  list = [67.50, 70, 72.50, 75, 77.50, 80, 82.5]


I'm a beginner so bear with me. I had my laptop come with OEM Windows 10 UEFI/GPT (whatever that is). I read online that I need to install Ubuntu according to UEFI not MBR, so I followed . I had my Windows 10 installed on the SSD with it's own EFI, Recovery, OS partitions. I installed Ubuntu on the HDD with EFI, Swap, /, /home partitions. After it's done installing I reboot and it boots to windows. I tried installing grub it's not working. I tried changing boot priority but only Windows shows up there. I tried bcdedit /set {bootmgr} path /EFI/ubuntu/grubx64.efi. That also didn't work.  Please help me out! I natively work on Mac tho.


I installed ubuntu after the windows 10 and lost windows partitions I saw in "disks" there are two partitions one FAT and other one is ext4

so please tell me whether the windows data is wiped out or still it is accessible


I had a client's site and I was trying to stop MySQL Injection on it. The code is so messed up(wasn't coded by me) that I cant use PDO so I tried mysql_real_escape_string() but it is also not stopping attack as according to my research it only works when MySQL DB structure is in UTF8 so I tried to stop the attack manually so I wrote this code  $input = $_REQUEST; foreach ($input as $key=>$value){     $input[$key] = preg_replace("/[^A-Za-z0-9\. ]/", "", $input[$key]);     if($input[$key] =='')     $input[$key]=1; }   I limited only alphanumeric and few other characters for Chatting purposes but this is also not preventing the attack as I run again vulnerability scanner and it says the GET value was set to 6%c0%00xa7%c0%a2 which prompted SQLi error again. Its a HEX value that was converted to 6xa7. Is there any other best approach to stop this attack?


How can i put letter on the top of each column of matrix?

\documentclass{article} \usepackage{amsmath,booktabs}  \begin{document}  \[  \implies \mathbf{B}^c= \begin{bmatrix}  \begin{array}{@{}ccc|ccc|c@{}}   \mathbf{-I} & \mathbf{0} & \mathbf{0} & \mathbf{I} & \mathbf{0} & \mathbf{0} & \mathbf{0} \\ \mathbf{0} & \mathbf{-I} & \mathbf{0} & \mathbf{0} & \mathbf{I} & \mathbf{0} & \mathbf{0}\\  \mathbf{0} & \mathbf{0} & \mathbf{-I} & \mathbf{0} & \mathbf{0} & \mathbf{I} & \mathbf{0}\\  \mathbf{0} & \mathbf{0} & \mathbf{0} & \mathbf{-I} & \mathbf{0} & \mathbf{0} & \mathbf{I}\\  \end{array}  \end{bmatrix}   \]  \end{document}


How can I permanently set a route table in Ubuntu kernel IP routing table? When I restart my PC the route table entry is getting auto flushed. I am using this command for route table entry:  route add -net 0.0.0.0 netmask 0.0.0.0 gw 192.168.1.1 dev ens4


I have 3 servers (server1, server2 and server3) with Apache and SCP (and/or FTP server). These servers are behind a router. I have another server with a public IP used as a proxy for Apache. So, if I'm trying to access website1 (hosted on server1) my requests are proxied to server1. The same for website2 and website3.... Now, I would like to do the same thing for FTP or SCP. Is this possible? e.g.: If I install an FTP server on server1, server2 and server3, can I proxy my requests based on the hostname? ftp.website1 to the ftp server on server1 and so on.... I can also use SCP, there is no difference, and I have full access to proxy and 3 servers.


Short story about a man who realizes every day is a repeat of yesterday but no one else thinks so

In 1988 I read a short story about a man who was on his way to work. He meets a friend at the bus stop and they engage in small talk, then get on the bus and go to work. They come home and go to sleep. The next morning, the guy goes out to the bus stop and meets his friend, and is surprised to hear his friend saying the exact same things he said the day before.   All day at work things happen exactly as they did the day before. The next morning is a repeat of the same, and he begins trying to get his friend to see that they are living in some kind of time loop, but his friend doesn't know what he's talking about.  The guy ends up staying home the next day, hiding in his house. Finally someone comes to his door and tells him he has been part of an experiment. Every night when they go to sleep their minds are erased. Scientists are observing behavior to see if in a given scenario there is any deviation in word or action  if a person is subjected to the same stimuli repeatedly, if they have no knowledge of ever having done it before. For some reason, they forgot to erase his memory and he began remembering the previous days.   He doesn't believe what he is being told until he looks out the window and sees a giant in a lab coat. Turns out his house is just a small model on a train-type layout sitting on a table and he is one of many miniature "people" the scientists made to test their theories.  No idea who the author is or what the title was. I took a science fiction class in high school and this was one of the stories we had to read and then answer questions about.


Yes, it's time for me to complain about plagiarism again.  We already have Suggested Edit audits, but I would like to see Tag Wiki and Tag Wiki Excerpt audits that specifically introduce copied content for that tag without including the appropriate source(s), and warn people who approve it that they just approved a tag with plagiarized text.  For example, an audit for the  tag could be:     Microsoft SQL Server is a relational database management system developed by Microsoft. As a database, it is a software product whose primary function is to store and retrieve data as requested by other software applications, be it those on the same computer or those running on another computer across a network (including the Internet). There are at least a dozen different editions of Microsoft SQL Server aimed at different audiences and for different workloads (ranging from small applications that store and retrieve data on the same computer, to millions of users and computers that access huge amounts of data from the Internet at the same time). Its primary query languages are T-SQL and ANSI SQL.   Anyone who spends 15 seconds Googling this will see where it came from -- the problem is, most people don't.  I know with Suggested Edit Audits, it's just random text to catch the most egregious reviewers; for this, you would have to most likely select a small sample of tags, and then create their copy-and-paste entries for audits.    The whole point of this would be to raise awareness for people who have figured out how to recognize and pass Suggested Edit audits, but still don't understand the finer nuances of reviewing.


I still can't understand what does Community Wiki do?

I have read Help Center and immunity FAQ, but I still can't understand Community Wiki, I mean, isn't reputation the most important factor on this site, and by denying giving reputation to Community Wiki, it seems unfair. Why would SE create Community Wiki mode?


RFC: Better chat @mentions – A prototype

Status: 75% - We have a prototype to play with the UI Previous RFC:  Problem Statement & Background Please see the . Proposed solution The feedback to the solution I proposed in the  was . We now have a prototype of the chat input box's behavior under the new regime. It incorporates some of the suggestions made in response to the original post. This is just that: a prototype. I'm not looking for bug reports on every minor issue; rather, I'd like to know whether it feels comfortable and non-awkward for you to compose chat messages in this way, and if it in any way breaks your flow and muscle memory when chatting. For now this is intended to work in desktop Chrome and Firefox, it may or may not work completely in other browsers. Again, finding cross-browser bugs is not the purpose of this RFC. Of course the final version is supposed to work in all our supported browsers, including mobile ones. Link to the prototype:  Known issues  Undo/redo is spotty at best. Not that it's great in the current chat input box, but I'd like it to be better before release. The way that @mentions are displayed seems to suggest that you can interact with them (e.g. click on them to display the well-known user info popup), but that's not currently the case. See the next section for more.  Open questions  Can you work with this? Does it break the way that you're used to chatting? If so, how so? If you use assistive technology (e.g. screen readers), does it work for you? I know our chat is anything but the archetype of an accessible web application, but I certainly don't want to make matters worse. What should happen when you click a mention? Would you rather see the current behavior, which is closer to what you would expect from a normal text input box, or would you rather see the user info popup (or something else entirely)? Relatedly: At the moment, the underlying @[123] is exposed when you move the text cursor onto a mention. On the one hand, this keeps the behavior closest to that of a "real" text box (in particular, Ctrl-A Ctrl-C Ctrl-V works in obvious way). On the other hand, this may be too much of a power user-only thing to expose (I am not suggesting to break copy&paste in either case). What are your thoughts on this? Anything else?  If possible, when describing any behavior that felt irritating, also describe what you would've expected to happen instead.


Why is it "ladies and gentlemen" instead of "gentlemen and ladies"?

Is there a specific reason for this? After all, it is "boys and girls", rather than "girls and boys". If the boy (male) comes first here, why doesn't it come first in "ladies and gentlemen"?


Which seller is matched to a buyer in the stock market when there are multiple matches?

Let's say investor A owns a certain stock and is looking to sell 10 shares with an ask price of $1.  Investor B owns the same stock and also wants to sell 10 shares at $1.  The market maker sets the price of the stock at $1.  A buyer comes along and makes a bid of $1 for 11 shares.  How does the transaction end up taking place in detail?  How does the market facilitate this transaction?  How many shares are investors A and B each left with?  Also, would the answer be the same if the buyer only wanted 10 shares (i.e. a single seller could fulfill the entire trade)  This question is not a duplicate of the one that was marked.  That question asks about orders filling.  My question is about an order that is certain to fill, but what actual trading takes place.  This is not addressed in the answer marked as a duplicate.  My specific question is about what each of the two SELLERS in my example will find in their brokerage account after this event.


What are some of the names of chemical compounds (minerals our what not) which make the healthy (sandless) pink salt pink?


How to calculate resistors for transistor driver circuit

This is related to , I want to find the values for the two resistors so that the led will get 100mA.    Vcc will be 5V and I have either 2N2222 or 2N3904 transistors. Let's say I use the 2N3904.  They mention the equation: hFE(VCC-VBE)/RB. (Is the full equation hFE(VCC-VBE)/RB = ICC?)  I tried to plug in the values: Vcc = 5, Hfe = 30 (from the sheet), VBE = 40*10^-3R since the arduino's pwm output is 40mA and from ohm's law, ICC = 100mA (the desired current for the led).  so we get: 30*(5-40*10^-3R)/R = 100*10^-3 => R = 3.3/(100*10^-3/30 + 80*10^-3) = 39.6.  This is not even close to 1000 like in the answer, so I'm doing something wrong here.   So how are you supposed to find the B line resistor value? Also, how do you find the C line resistor value?  This is the led I will use btw:   "Arduino" is Arduino UNO for now (Wemos D1 mini later).  I don't think it's a duplicate since my circuit is a little different and what I ask for is different. I also have no idea what is that ...


Continuous gradient over multiple shapes

In adobe illustrator, I have multiple shapes that I want to share a single gradient with. Right now, when I apply a gradient fill each shape handles it's own gradient.  Is there a way to make all the shapes share one?


Given two holomorphic functions on a region find two other such that...

Let $\Omega$ be a region in the complex plane and let $f_1$ and $f_2$ be holomorphic functions on $\Omega$ having no common zero. Show that there exist holomorphic functions $g_1$ and $g_2$ on $\Omega$ such that, $f_1g_1+f_2g_2$ is identically equal to one on $\Omega$.


List all file extensions in an arborescence and count number of occurences of each

I am looking for a simple shell function (bash prefered) to list all file extensions in an arborescence and count the number of occurences of each.  For example, list_extensions . would return something like :  pdf 134 tex 42 cpp 30 ...   A plus would be to also count the file without extensions.


I am quite new to C# and was trying to use lambda expressions.   I am having a list of object. I would like to select item from the list and perform foreach operation on the selected items. I know i could do it without using lambda expression but wanted to if this was possible using lambda expression.  So i was trying to achieve a similar result          List<UserProfile> users = new List<UserProfile>();        ..load users with list of users         List<UserProfile> selecteditem = users.Where(i => i.UserName=="").ToList();         foreach(UserProfile item in selecteditem)         {             item.UserName = "NA";         }   it was possible to do        users.Where(i => i.UserName=="").ToList().ForEach(i=>i.UserName="NA");   but not something like this       users.select(i => i.UserName=="").ForEach(i=>i.UserName="NA");   Can someone explain this behaviour..


How to prove the following :   Given $(X, \tau)$ a topological vector space on $\mathbb{R}$,  If {0} is closed then $\tau$ is separated.  Thank you.


Best way to disassociate my name and/or delete my profile?

Becuase I used google + as a sign up, now my name brings up my stack overflow user account when companies search my first name. This is really annoying since I'm job hunting.


email field or username for logging in an application?

What is the best solution for an app : Email or username field?  I like email because:   it's unique user will easily remember it's personal (which can be a disadvantage sometimes; Multiple users on the same account)   Unfortunately we usually have to type more letters to login (write the name + @domain.com)


How do planets prevent a Gravity-type event?

Lots of things blow up near planets in Star Wars (Coruscant in Episode III being an obvious example). Why doesn't this end up more like the movie Gravity?


Uploading code to arduino gives me the error: "avrdude: ser_open(): can't open device "/dev/ttyACM0": Permission denied"

My OS is Ubuntu 18.04 and arduino was working until now.  Although there are a few solutions, none of them seems to work for me.  I followed  on the arduino website.  Then I tried , which should work in cases where the first solution didn't. The answer says we should create a few rules on /etc/udev/ruled.d/ path.  But none of them worked for me.  I also tested arduino in Windows 10 to see if it was a hardware problem, but it worked fine.  Does anyone have any other ideas on how to solve this issue?  UPDATE:   My username, sergio, is part of both groups (tty and dialout); I logged out and back in as arduino official tutorial explains; In Arduino IDE, the configurations are correct: Arduino UNO and ttyACM0 This is the output of ll /dev/ttyACM0 after running the tutorial commands:  crw-rw-rw- 1 root dialout 166, 0 Jul 15 05:41 /dev/ttyACM0    UPDATE 2:  I've created a script to solve this:


This is what I have so far:   First, we will attempt to show $A-(B-C) \subseteq (A-C) - C.$     Let $x \in A -(B-C)$.      Then $x\in A$ and $x \notin (B-C)$. By DeMorgan's we have that  $$x \notin (B-C) = x \notin B \vee x \in C.$$     We have that $x \in A \wedge (x \notin B \vee x \in C)$.      Then we have that $(x \in A \wedge x \notin B) \vee (x \in A \wedge x \in C)$.  So by definition of $\cup$ and $\cap$, we have $x \in (A-B) \cup (x\in (A \cap C))$. I'm kind of stuck here.  I can see a contradiction here in that LHS says $x \in C$ but the RHS says $x \notin C$.   Can anyone tell me what to do from here? I'm not quite sure how to formally state that the statement is false. I feel like I'm not being complete here.


I want to locate all text-files within a directory tree containing two words, word1 and word2 (for example). I cannot just grep for word1 word2, because this will only find occurrences where the two words appear consecutively. I want to find all files that contain both these two words, but not necessarily consecutive.  Ideally, the search should print file names as well as the context where the terms were found inside the files. This would be very helpful. A GUI wouldn't hurt.  How can I do it?


I have an array.  $a_input = array(1,2,3,4,5)   I want to remove 1 from array . out put is :  array(2,3,4,5);   remove 2 => output:  array(1,3,4,5);   remove 3 => output :  array(1,2,4,5);   ..... how to do this with for loop ?


In Gmail, how to find messages that are in the 'All Mail' folder, but nowhere else?

In Gmail, how does one determine which email messages are in All Mail, but nowhere else? I'm referring to email messages that are not in the Inbox (or another folder) and do not have any labels assigned.


How many roots have a complex number with irrational exponent?

If a rational exponent on a complex number $z^q$ is the representation of a finite number of roots, then if the exponent is irrational this mean that there is infinite countable roots?  If this is the case... the cardinality of the number of roots is the same for any irrational exponent? Thanks in advance.  NOTE: there are different questions about irrational exponents but no one answer what Im searching so please dont mark this as repeated.


I have a Windows 2008 server running as a domain controller. The details are as follows:  Domain: corp Server Name: oxygen   The workstations are all running Windows XP SP3 and have fixed IP addresses.  I am trying to use the net send functionality to be able to send simple messages to either individual machines/users and also to all machines. This is so I can send a message to a user to alert them about something, or likewise alert everyone of something such as the server being rebooted.  Is this possible using Windows Server 2008? If so, what would the command be?


i am in the process of creation of simple Document Map for the following C# source.  public class Person {     public string Name { get; set; }     public int Age { get; set; }      public string DoSomething(string x)     {         return "Hello " + x;     } }   The results should be presented in treeview or listview, in following manner:  Person -- Name -- Age -- DoSomething()   So, question is, is there a regex or library which handles C# source code?


I want to travel the US with ESTA a lot of times

I arrived in the states in July. I got admitted. Now I want to fly from NY to LA in Sept. I will have problems at entering again back to the country if my passport ( Hungarian ) is stamped till October?


linked question considering deleted answers

linked questions list, at right side of post is not getting updated when an answers is deleted.         It should be excluded as deleted answers is only visible to 10k users so it might be confusing.


How to duplicate objects while keeping modification on both duplicates?

I'm making a soldier with night vision goggles on his head with Illustrator.  I have duplicate the right half of the NVG into the left half.  However, if I were to make any changes on the right half, the changes wouldn't carry over to the left half. The other way around wouldn't work either.  Is there a way to sort of "bind" them together, so that changes to one will carry over to the other?


How do I force TeX to completely use the 1st column?

How do I force TeX to completely use the 1st column before writing to the second column?  Right now I dont have enough content to fill one whole page. So the left and right columns are equally filled, leaving 25% symmetrical empty page at bottom. How do I fill the left column first, and then the right?  \documentclass{article}  \usepackage{multicol} \usepackage[scale=0.9]{geometry} \usepackage{amssymb} \renewcommand{\labelitemi}{\tiny$\blacksquare$} \begin{document} \begin{multicols}{2}      %lots of text goes here  \end{multicols} \end{document}


Fibonacci proof question: $f_{n+1}f_{n-1}-f_n^2=(-1)^n$

Show that  $$f_{n+1}f_{n-1}-f_n^2=(-1)^n$$ when $n$ is a positive integer and $f_n$ is the $n$th Fibonacci number.


I really wonder if an IP Address with all its bits off can  be used or not. Please do answer if you know where its used or it can not be used.


How to automate setting up of "keyboard-configuration" package?

I'm writing a script to install Ubuntu 16.04 server into a chroot jail, using debootstrap (on an Ubuntu 16.04 server machine).  During the setting up of the keyboard-configuration package it asks for the keyboard type:  Setting up keyboard-configuration (1.108ubuntu15) ... debconf: unable to initialize frontend: Dialog debconf: (TERM is not set, so the dialog frontend is not usable.) debconf: falling back to frontend: Readline Configuring keyboard-configuration ----------------------------------  The layout of keyboards varies per country, with some countries having multiple common layouts. Please select the country of origin for the keyboard of this computer.    1. Afghani                                     48. Irish   2. Albanian                                    49. Italian ...       28. English (UK)                               75. Slovak   29. English (US)                               76. Slovenian ...   45. Icelandic                                  92. Vietnamese   46. Indian                                     93. Wolof   47. Iraqi Country of origin for the keyboard:    I want to automate this, so that it doesn't ask, and just continues with the install.  How can I do this?


The way cartesian coordinations are presented and used is kinda confusing.  When working with 2D the vertical axis is Y, though when working with 3D the vertical axis is Z and Y becomes the "depth" axis.  Basically I'm thinking the correct way, and best way would be to use the layout of axis.    Though Blender (3D modelling program) and other program, a lot games, present the axis in the "weird order" (my opinion)    Also if you read on Wikipedia about cartesian coordinates, your are presented with that layout of axis.    Is there any specific or logical reason for this "flip" of axis?


What are the basic steps to start blocking spam on an internal Exchange 2016 server?

Recently I have taken over as both onsite IT and also head of our internal IT as the last IT guy resigned on my second day. Currently they just switched to an internal Exchange 2016 server and they're getting tons of spam now. I just barely figured out how to get the SSL cert setup correct and fix all the cert errors being thrown around.   I know there are basic anti-spam features in Exchange 2016, but I was wondering if anyone had some general guidelines on how to start off. I didn't want to enable all the filtering without having a solid grasp of what I'm doing since I'm not even sure how to check what emails were blocked in case I am blocking important customer emails. Any anti-spam advice in general for Exchange 2016 would be appreciated. Thanks!


Emission texture won't show light in viewfinder or rendered image

Brand new to Blender here and not sure what I'm doing wrong. Have a texture as a plain emission with a white color but if the mesh it's attached too isn't visible to the camera, it doesn't emit any light.


It should be trivial, and it might even be in the help, but I can't figure out how to navigate it. How do I indent multiple lines quickly in vi?


How to change login id for stack overflow?

Open ID is really a nice feature. But if i wish to change my email id there, Stack Overflow i guess considers it as a prime key and won't allow to change.  For instance i had used my company's mail id while signing up using google OpenId but now i wish to switch the account over to my personal email id. So that i can login using my personal email id.  Is there any way we can do so?


...before a bunch of economists jumps, or jump, down my throat?

In a piece I'm writing about financial markets, I'm worried that I'll stir controversy amongst economists. Do I write: I'll clarify this before a bunch of economists jumps down my throat. or I'll clarify this before a bunch of economists jump down my throat. Does the verb conjugation refer to the singular "bunch", or the plural "economists"? I see a somewhat related question  but I'm not sure it's exactly the same grammatical situation.


Finding integer solutions for $6x+15y+20z=1$

Problem: Find integers $x$, $y$, and $z$ that satisfy the equation $6x+15y+20z=1$.  I noticed that $\gcd(6,15)=3$, $\gcd(15,20)=5$, and that $\gcd(6,20)=2$. And of course $\gcd(6,15,2)=1$.   Of course I know to set one of the variables (x, y, or z) to be zero. But I want to know how to get the more trivial answers. But where do I go from here to find the solutions?


How can I use my blender animation on my website?

I'm extremely new to blender and need to know, before I get going, if it is possible to use my animation on websites. I develop websites and am looking for an animation software to make my websites even better, so before I start putting a lot of time into learning blender, I need to make sure it is possible to use it on my website.


Give moderators the ability to mark reviews as "bad"

From what I've seen, many SO moderators trawl completed reviews and watch out for robo reviewers; and manual banning them when they see enough (>= 3?) bad reviews. This is inefficient because:   It doesn't integrate into the audit system. There's no "memory" to it. If mod A finds that user X has made two (any number less than the threshhold) bad reviews, he may make a mental note but there probably won't be any permanent/shared memory of this. If moderator B finds this user at a later date, he will have to look through the entire history, including stuff that mod A has already checked.    What I propose is that moderators get the ability to mark individual reviews as "invalid" from the completed review page. This is only to be used for reviews where any reviewer who is paying attention (and knows the rules) would choose the opposite reason (spam and other low quality stuff).   These bad review flags are treated like audits for a user -- if the number of failed audits and bad reviews is enough, the user gets autobanned. The nice thing is that this system should (probably) easily be able to , fixing the "Why was I manual banned?" problem.  This could also be integrated well with .


Let $f:\mathbb{R}\to\mathbb{R}$ satisfy $f\big(x-f(y)\big)=f\big(f(y)\big)+x\cdot f(y)+f(x)-1$ for all $x,y\in\mathbb{R}$.

Let $f:\mathbb{R}\rightarrow \mathbb{R}$ be such that    $$f\big(x-f(y)\big)=f\big(f(y)\big)+x\cdot f(y)+f(x)-1$$   for all $x,y \in\mathbb{R}$.  Then, what is the value of $|f(16)|-25$?   what i try  put $f(y)=z.$ then $f(x-z)=f(f(x))+xz+f(x)-1$  put $f(x)=t.$ then $f(x-z)=f(t)+zx+t-1$  How do i solve it Help me please


have or has following "something and something"

My work experience and education have provided me with an extensive background in business.  Do i use have/has here?


Which Laptop for Lightroom, Photoshop CC 2015.5 and Premier Elements

I have spent months looking into a new laptop. It's primary use will be editing and developing photos in Lightroom but I will also be putting together photo and video slideshows in Premier Elements and maybe even premier pro in the near future. What I cant decide is what is more important; dedicated graphics card like the higher end Surface Book or more processing power like in the Dell Xps with Core i7 and 16GB of RAM. Can anyone give me a definitive answer. My budget is up to £1600 - I think.


Is it costly to do array.length or list.count in a loop

I know that in JavaScript, creating a for loop like this: for(int i = 0; i < arr.length; i++) is costly as it computes the array length each time. Is this behavior costly in c# for lists and arrays as well. Or at compile-time is it optimized?  Also what about other languages such as Java, how is this handled?


If $n$ is a positive integer greater than 1 such that $3n+1$ is perfect square, then show that $n+1$ is the sum of three perfect squares.  My work: $3n+1=x^2$ $3n+3=x^2+2$ $3(n+1)=x^2+2$ $(n+1)=\dfrac{x^2+2}{3}$  I have no clue what to do next. Please help!


According to  and system responses I use sh screen_ts.sh , the content of which is #!/bin/bash scrot -s zkoSCR_IMG.png tesseract zkoSCR_IMG.png zkoSCR cat zkoSCR.txt|xclip -i -selection clipboard . The Terminal responses  Tesseract Open Source OCR Engine v3.02 with Leptonica, but the text is recognized with too many errors, even in the Terminal window itself. The ABBYY Screenshot Reader in Windows XP is far better. Can I achieve such better results in the Ubuntu? How? Thanks.


Detect internet connection status with JavaScript

it is possible to know when user has internet connection and when no. I've tried this:  window.addEventListener('online', () => {   // some stuff }, false);  window.addEventListener('offline', () => {   // some stuff }, false);   as well have tried window.navigator.online.  All above things works fine just when go to network tab from developer tools and disable/enable it, but it doesn't work when you go and disable WiFi or turn off the router for example.  It is possible somehow to subscribe to this network changes in js?  Many thanks!


How to fix boot into initramfs prompt and "mount: can't read '/etc/fstab': No such file or directory" and "No init found"?

Installing a new system using a GPT partitioned disk dedicated to a single partition, ext4 formatted, extlinux (version 4.05) as bootloader, Ubuntu Core version 13.10 amd64 as rootfs, and Ubuntu linux-image-3.11.0-18-generic as kernel, and extlinux-update to generate bootloader configuration.  The result after reboot (still inside a KVM based virtual machine) is an (initramfs) prompt and these messages:  mount: can't read '/etc/fstab': No such file or directory mount: mounting /dev on /root/dev failed: No such file or directory mount: mounting /sys on /root/sys failed: No such file or directory mount: mounting /proc on /root/proc failed: No such file or directory The filesystem doesn't have requested /sbin/init. No init found. Try passing init= bootarg.   BusyBox is v1.20.2.  Regression:   the file system has been checked with fsck.ext4   Check for root existence  (initramfs) ls -l /dev/[hs]da* ls: /dev/[hs]da*: No such file or directory   Root boot argument  (initramfs) cat /proc/cmdline initrd=/boot/initrd.img-3.11.0-18-generic ro quiet BOOT_IMAGE=/boot/vmlinuz-3.11.0-18-generic   Check loaded modules  (initramfs) cat /proc/modules e1000 145368 0 - Live 0xffffffffa0000000   /boot folder content  $ sudo ls -l boot -rw------- 1 root root 3296162 Feb 18 22:37 System.map-3.11.0-18-generic -rw-r--r-- 1 root root 1007681 Feb 18 22:37 abi-3.11.0-18-generic -rw-r--r-- 1 root root  163258 Feb 18 22:37 config-3.11.0-18-generic drwxr-xr-x 2 root root    4096 Mar 17 20:13 extlinux -rw-r--r-- 1 root root 4995000 Mar 16 23:35 initrd.img-3.11.0-18-generic -rw------- 1 root root 5634192 Feb 18 22:37 vmlinuz-3.11.0-18-generic   How to make this system boot to the expected default bash prompt?


How do I change the angle of the axis without changing the angle of the object?

Hey guys I am currently working on a scene with multiple objects.  There is one object (a wheel) that I need to rotate the origin for without rotating the wheel itself.  I have the exact angle that I need so a manual solution would be the best.  Any help would be much appreciated. I am used to parametric modeling and Blender is a little out of my depth.


Position of "yet" in a causative sentence

If I have to write a causative sentence in Present Perfect, where should I put yet, at the end of the question or right after the negation?        She hasn't had her doors mended by the carpenter yet.    She hasn't had her doors mended yet by the carpenter.    Has she had her doors mended yet?      Could I say this:         She hasn't had yet her doors mended.    Has she had yet her doors mended?      Which is the right order, or are both acceptable?


Strange Biblatex behaviour when citing two different entries with the same first author

I have two different references with different years but same first authors. I expect the outcome of citings to be Doe et al. (2005) and Doe et al. (2007). However the produce output is John, Mike, and Dave (2005) and John, Mike, Plank, et al. (2007)  What is going on here and how can I fix it?  \documentclass[11pt,a4paper,oneside]{article}     \usepackage[utf8]{inputenc}     \usepackage[T1]{fontenc}     \usepackage[a4paper, top=2.5cm, right=2.5cm, bottom=2.5cm, left=4cm]{geometry}     \usepackage[backend=biber, style=authoryear, date=year, firstinits=true, natbib=true]{biblatex}     \usepackage{csquotes}     \usepackage{filecontents}   \begin{filecontents*}{\jobname.bib}   @article{doe1,   title={Lorem ipsum dolor sit amet},   author={John, D. and Mike, L. and Dave, O. },   journal={Some Journal},   volume={14},   number={10},   pages={2959-2967},   year={2005}, }  @article{doe2,   title={Placeholder placeholder placeholder},   author={John, D. and Mike, L. and Plank, R. and Dave, O. },   journal={Another Journal},   volume={7},   number={5},   pages={757-762},   year={2007}, }  \end{filecontents*}   \addbibresource{\jobname.bib}   \begin{document}  \section{mwe} {  \citet{doe1}, lorem ipsum dolor sit amet, consectetur adipiscing elit. Vivamus a fermentum tortor. Curabitur lacinia feugiat eros. \citet{doe2}, aenean sagittis pulvinar orci id sodales. Aenean vulputate leo elit, vitae euismod odio cursus sed. Integer nec risus semper, lobortis arcu nec, sodales urna. Sed convallis vitae justo nec vehicula. Maecenas eleifend, erat sit amet ultricies ultricies, mi nibh hendrerit arcu, in consequat leo dui vitae eros.   }  \printbibliography \end{document}


How could I use linux firewall (iptables)  to allow ssh , telnet ,ftp from selected ips only ?


Prove that simple graph $G$ is orientable

I am a student in an introductory class for graph theory and this question is on our first homework assignment and I don't know where to start to prove the following:     Suppose that $n \geq 3$ and a simple graph G has $n$ vertices and at   least $(n^2 - 3n + 6)/2$ edges. Prove that G is orientable.   Thank you for your time. Any hints or help will be greatly appreciated.  EDIT: A graph g is orientable if it is the underlying graph of a strongly connected digraph. A digraph is strongly connected if for all vertices $v$ and $w$ there exists a walk $v-w$.


Understanding this pandas series slice a[::-1]

Please help me understand how this particular slicing reverses the order of the series. I constantly have trouble understanding slicing using the []. Is there a page that explains it. I think I understand how slicing works with iloc and loc on pandas dataframes. Here is a working exampe  a=pd.Series(range(0,10)) a[::-1]


Where do I set the Stack Exchange clock for my time zone? I live in the  (ET), Daylight Savings or Summer Time. At 11:00 each night (UTC 3:00, according to the notice at the top), the records for my reputation points switch over to a new day, as though my clock is set for a time zone further east. Is there a way for me to change this in my account settings? I think my time zone is UTC -5 by some standards. I am unable to find my primary account with settings, name, email, etc. I never log out. I guess I'm lost.


Joining two sentences into a compound predicate sentence using conjunction "and"

Which is the correct way to join the sentences and make a compound predicate sentence?  The boys are playing football. They are enjoying themselves.   The boys are playing football and enjoying themselves.   Or   The boys are playing football and are enjoying themselves.


Why would anyone want to pay off their debts in a way other than "highest interest" first?

Looking at the math, it is clear to many people that, given a number of debts at different interest rates, if you are trying to eliminate your debt, you will pay less interest overall if you pay off the highest interest rate debt first and work your way toward the debt with the lowest interest rate.  However, it is sometimes suggested that people pay off their debts in order from smallest to largest.  What are the advantages to this method?  Why might it be a good idea to do this?    Please note: This question is not "Which method is the best?"  The question is specifically asking for the advantages, if any, to the "smallest to largest" method.  Also note: This question is not a duplicate of ""  The "smallest to largest" method still chooses only one debt to focus on at a time; that question is asking about paying extra on multiple loans at once.


Proving that there exists a solution to $f\bigl(x+\frac1n\bigr)-f(x)=0$

Given $f:[0,1]\to\mathbb R$ which is continuous, $f(0)=f(1)$, and $n\in\mathbb N^*$ (doesn't include $0$), show that $f\bigl(x+\frac1n\bigr)-f(x)=0$ has a solution.  This was shown to me by an acquaintance who told me that if we consider $h(x)=f\bigl(x+\frac1n\bigr)-f(x)$, then the fact that $\sum_{k=0}^{n-1}f\bigl(\frac kn+\frac1n\bigr)-f(\frac kn)=0$ somehow tells us that there are two opposite terms in that sum, and, as such, we can apply the IVT to $h(x)$. Clearly the sum is null because it is in the form $f(1) + (f(a)-f(a)\text{ same argument a})+(f(b)-f(b)\text{ same argument b})+...-f(0)$ and $f(1)=f(0)$, not because there somehow exists two different in argument terms that cancel $f(a)+f(b)=0$. In any case, we require a $h(a)$ and a $h(b)$ such that $h(a)h(b)<0$, not in terms of $f$. But, from what I have understood, this is the correction given by their professor, so maybe I am missing something? EDIT: Ignore the following nonsense... I thought of going about it by contradiction, but the use of a limit leaves me undecided as to whether this counts as a solution. The negative of the proposition is $\exists n\in\mathbb N^*\,|\,\forall x\in\mathbb R,\,f\bigl(x+\frac1n\bigr)-f(x)\neq0$, i.e $f\bigl(x+\frac1n\bigr)<f(x)$ or $>$. In both cases, if we take $n\to\infty$, we get $f(x)<f(x)$, which is impossible. Any comments? Thank you!


Extraneous solution from substituting in equations

I came across this example of how you could end up with an extraneous solution but I was wondering how it arose. We have the equation: $$x^2+x+1=0 $$ Since x=0 does not satisfy the equation, you can divide by x on both sides which yields: $$x+1+\frac{1}{x}=0$$ which is equivalent to our first equation. From our first eqution we can conclude that: $$-x^2=x+1$$ We now substitute that into the second equation to get:$$x^2=\frac{1}{x}$$ which results in $$x^3=1$$ which is equivalent to our previous equation since x cannot be 0. However, one solution from our last equation is x=1, which is not a solution to our original equation. I have a vague idea that it may have to do with the fact that you get a cubic equation and you began with a quadratic, and that steps imply the following and not vice versa, but can you provide a very detailed answer as to why it arises? Can you please provide more examples?


How does gravity cause nuclear fusion in stars?

I am a bit confused regarding the nuclear fusion that occurs during star formation. For example, suppose there is a huge hydrogen cloud. It gets more mass and therefore pulls in more and more hydrogen, but it could just do this endlessly and get endlessly big. What causes it to stop growing? Is it because of the heat generated by the huge mass?


I am stuck on a problem in having my counter increment.  I'm not sure what I am doing wrong though. Sorry if this is a beginner mistake, but I have not found a solution where I understand or helps yet.    public static int duplicates(String[] text, int numWords){             int currentCount = 1;             for (int i=0; i<numWords-1; i++){                 for (int j=i+1; j<numWords; j++){                     if (text[i] == text[j]){                         currentCount++;                      }                 }                }              return currentCount;         }


I have noticed people use this sentence to reply to written mails but I often ask myself; why use "hear" when you "read" ?  Is it just a generally accepted phrase or people do use it wrongly ?


grep -- list file name where match is found

I have a bunch of .html files in a directory.  I want to look through each file and match a pattern (MD5).  All of that is easy enough.  The problem is I need to know what file the match was found in.  cat *.html | grep 75447A831E943724DD2DE9959E72EE31   Only returns the HTML page content where the match is found, but it doesn't tell me the file which it was found in.  How can I get grep to show me the filename where my match is found?


In The Martian, the "Hab" explodes at some point in the film, specifically the time that the airlock blows out.   Is it explained what exactly happens that causes this? I watched the film in the U.S. and English isn't my first language, so some details may have been lost for me.


Why is an electronic shutter not common in most SLR even though is so practical?

Many point and shoot cameras have an electronic shutter. I only know of one good reason to have the electronic shutter: No flash synch speeds limitations; And that reason by itself i would think suffices to include it in any decent modern SLR.


Did compositing in Cycles, went to eevee for the background, went back to cycles... and all my compositing had been deleted

How do I solve that? I had a beautiful planet and now the planet is all pink and plain, not really what I want. Everything that was in the compositing editor is not there anymore.


How does a sarlacc gain any energy if it keeps victims alive for a thousand years?

When eaten by a sarlacc, according to C-3PO,     In his belly, you will find a new definition of pain and suffering, as you are slowly digested over a thousand years.   I imagine that keeping a victim alive for a thousand years takes much more energy than is available to the sarlacc from the body of the victim.  Thus, keeping victims alive for so long would seem to be a net loss of energy for the sarlacc.  Is there a canon answer to resolve this conundrum?  Did the sarlacc have another energy source (for example, ability to harvest sunlight)?


"Unverified org Wide Email Address" Error on Workflow in sandbox even if email is verified

We have a org wide email addressed which has been "Verified" into our sandbox. I understant org wide email addressed is unsupported metadata, so this was achieved as pre deployment step.   Into our repo, we have a workflow that send email alert to that org wide email address. "  Workflow   ... <senderAddress>noreply@mycompany.com.au</senderAddress> <senderType>OrgWideEmailAddress</senderType>    The problem we are facing is that we are still getting the following error even if this org wide email address is verified:      You must specify a verified Org Wide Email Address for this sender   type.   Is that a bug in the metadata api or expected behaviour ? Ideally we would like to not have to do that as a post deployment step.   PS: We are running DX under api version 43.0


My laptop is overheating and there is hot air coming out of it

There's hot air coming out of my laptop and I can't focus on my work I have a HP laptop running windows and I've had it for almost two years.


For $n\in \mathbb N$, $n>1$ prove that $$2^n-1 \neq k^y$$ for all $k,y \in \mathbb N_{\geq 2}.$ Assuming for contradiction that there exists $(k,y)$ such that $2^n-1 = k^y$, I succeeded to prove that the pair does not exist for an even k, and for an even y. I need to prove that it does also not exist for an odd y. I need to use in this proof that $$\frac{x^{2k+1}+1}{x+1} = x^{2k} -x^{2k-1}+\cdots+1.$$ Thank you!


What went wrong with a regular expression?

I have a specific regular expression, \Good .+\.\. To my understanding that means, match each pattern that starts with "Good ", then any number of word characters (one or more) and finally end with a dot ('.').  So "Good morning." could is a pattern that this regex is matching, also "Good afternoon.", "Good day.", etc. But somehow it also matches the pattern "Good morning. Good afternoon. Good day." as a whole.   How is this possible?


Evaluate $\int_0^{\frac{\pi}{2}}\cos^nx\cos nxdx$ where $n$ is a positive integer. The choices are  a.$\frac{\pi}{2^{n-1}}$  b.$\frac{\pi}{2^{n+1}}$  c.$\frac{\pi}{2^{n}}$  d.$\frac{3\pi}{2^{n}}$  e. None of these  My approach:   $$e^{inx}=\cos nx+i\sin nx$$  $\int_0^{\frac{\pi}{2}}\cos^nx\cos nx\,dx$ = Real part of $\int_0^{\frac{\pi}{2}}\cos^nxe^{inx}\,dx=\int_0^{\frac{\pi}{2}}(\cos xe^{ix})^n\,dx$   After this step I am not able to approach.


Short story about pollster who discovers residents grouped by behavior type for easy manipulation

Sophisticated, wheelchair-bound pollster/ad man discovers voters have been grouped in residential neighborhoods by behavior type for easy manipulation.  Triggered by smells, sounds, etc., they converge/attack & he barely escapes, using every tool built into his high-tech conveyance. It’s 40+ years since I read this.  I have no recollection of title or author, but my memories of the story theme have been especially vivid through the Trump era.


"wifi not working" on HP ENVY x360 - 15-w107ne

Just a standard wifi-not-working question. A fresh Ubuntu 16.04 and is up to date. Laptop model number in title.  I used the "Wireless info script" in the  and there's the result:    TIA :)


I am stuck on this question.  Could somebody give some advice on how to tackle/solve this question? I believe that with „always one“ the question means at least one. (otherwise it will not work)  Your help would be very appreciated.  Michal     For a big group of people we know that:   If we select any four persons from the group, that there is always one of the four persons that will be friends with the other three persons.   Therefore, for any four persons selected from the group, will there always be one person that is friends will all people from the whole group?


adding a string with spaces as an element to array

I am reading and extracting some filenames from a directory and trying to add them into an array. The given directory has duplicate files so I would be extracting some duplicate file names also. Original file names in the directory as: 100_abc strategy-42005_04May2020_0000-04May2020_first_file.csv    100_abc strategy-42005_04May2020_0000-04May2020_second_file.csv    101_xyz statitics strategy_04May2020_first_file.csv  Script used:  #!/bin/bash  c=0  for filename in /home/vikrant_singh_rana/testing/*; do         #stripping a file name          GroupName=$(basename "$filename" ".csv" | awk -F "_" '{print $2}' | awk -F "-" '{print $1}')         echo "$GroupName"          var=["$c"]="$GroupName"         c=$(($c+1)) done echo "print my array" echo "${var[*]}"   the file name it extracts from directory contains spaces with them. for example. abc strategy abc strategy xyz statistics strategy  so when I print my array it would be printing like as abc strategy abc strategy xyz statistics strategy  above code is adding same file name again to array if it encounter same file again while reading. so I have added a if statement in order to prevent that, which is not working as expected. I was expecting that array should have unique file name as an element only. for filename in /home/vikrant_singh_rana/testing/*; do         GroupName=$(basename "$filename" ".csv" | awk -F "_" '{print $2}' | awk -F "-" '{print $1}')          if [[  "${var[@]}"  =~ "$GroupName" ]]; then                 echo "I am here "                 c=$(($c+1))                 var["$c"]="$GroupName"         fi  done


How and why did the top journals become top journals?

Journals like Nature and Science have impressive impact factors. How and why did these top journals become top journals? Why are they able to sustain their statuses?


Dynamically reformatting man pages on terminal dimension changes

One common workflow of mine is to open a manual page in a terminal, then another terminal in which to test things. The man page is formatted to the initial dimensions of the first terminal. When I now resize my windows (or have my WM do that for me automatically), there is either a gap to the right of the preformatted page, or lines wrap. At this point I usually q(uit) and !! (run again), which loses my position in the page.  I assume the formatting process is quite CPU intensive, or maybe it stems from ancient times of fixed terminal sizes. The less pager dynamically reacts to terminal resize events, so it should be possible in theory.  I tried perusing man pages, searching the Web, asking on IRC -- the whole lot -- but couldn't come up with anything.   Can I trigger reformatting from within or outside of the man utility? Is there a version of the man utility that resizes the page dynamically?  Is there way to customize some part of the formatting/display process to make it update on SIGWINCH?


I'm trying to recode the function strcat featuring an auto-malloc inside it. I can see in few tests that there are some data leaks (I don't know the correct word) in my function.  Here's my code :   char    *my_strcat(char *a, char *b) {   char  *result;   int   i;   int   j;   int   la;   int   lb;    la = -1;   lb = -1;   while (a[++la] != '\0');   while (b[++lb] != '\0');   result = malloc(sizeof(char) * (la + lb) + 1);   i = -1;   while (a[++i] != '\0')     result[i] = a[i];   j = -1;   while (b[++j] != '\0')     result[i + j] = b[j];   result[i + j] = '\0';   return (result); }   So when I try to use my my_strcat in a while loop with some one-length strings I get a :   a.out: malloc.c:2392: sysmalloc: Assertion `(old_top == initial_top (av) && old_size == 0) || ((unsigned long) (old_size) >= MINSIZE && prev_inuse (old_top) && ((unsigned long) old_end & (pagesize - 1)) == 0)' failed. Aborted (core dumped)   I'm trying to find where my memory leak comes from. But I can't figure out.  Here's the calling part :   while (!is_line_ended(read_result)) {   read(fd, read_result, READ_SIZE);   result = my_strcat(result, read_line(read_result, fd)); }   Here's MY_STRLEN :  # define MY_STRLEN(s) (sizeof(s)/sizeof(s[0]))   Please notice that I'm limited to one file and one header. I'm limited to 5 functions by file, and I'm not allowed to use string functions.


The home page of  currently shows "6 visitors/day". Alarmed by this number (instead of, say, 600 visitors per day), I visited , where the number was 3. I then checked the moderator tools and the statistics claim that there have been zero or one visits on most days, apart from the period April 6–11. (I will not reproduce moderator-only data here.) It looks as if visits are not only no longer recorded, but also most of visit history is erased.  I don't have mod tools on other site, but for another data point the  says that there were zero visits per day. The issue is thus not limited to Latin, but I don't know how broad it is.  What's up with the visit counts? Is this a temporary glitch that should resolve itself?


How to organize files in accordingly named directories from command line under Linux

I have a directory filled with various files, differently named (i.e. not named with a specific pattern) and with different extensions, and I want to put each file in a newly created subdirectory named after each file; what's the best way to accomplish that from the command line under Linux? This sounds a bit confusing, let me make and example: let's call a random file in the directory ./filename.ext, I'd like to put it in a subdirectory called ./filename so that effectively the new path will be ./filename/filename.ext.  I did some trials with the following steps:   I've created some test files, from file-1.txt to file-9.txt, inside a test directory with for num in {1..9}; do touch file-$num.txt; done  I've created a directory named after each filename with for name in $(eval ls | cut -b 1-6); do mkdir $name; done I've moved the source files in their respective directories with for name in $(eval ls | grep -e ".txt" | cut -b 1-6); do mv $name.txt $name/$name.txt; done   As you can see, this solution works, but its huge drawback is that it works just in this case, with files of that extact filename lenght and with that particular extension. If I have some files with different names and extensions, this would be of no use at all. The use of cut command is not the ideal solution here, I suppose, but I haven't found anything better at the moment.  As a bonus, it would be cool to find a way to create the subdirs automatically when moving/renaming the files, without having to use mkdir previously (so when I ls to actually rename, I don't have to worry about excluding the newly created directories); but in the end this is a secondary problem.


compact embedding in sobolev spaces ($W^{1,1}(\mathbb{R}^n)$ in $L^1(\mathbb{R}^n)$

i have this question :  in an example of the compact embedding, the autor gives a demonstration of : the sobolev space $W^{1,1}(\mathbb{R}^n)$ is not compactly embedded in $L^1(\mathbb{R}^n)$ and it is this one :  So let $F\in D(\mathbb{R}^n)$(=the space of smooth functions with a compact support in $\mathbb{R}^n)$ ., not identically equal to zero and $\{x_n\}$ a sequence such that lim $x_n=+\infty$ when $n\rightarrow \infty$. so $F_n(x)=F(x-x_n)$ is bounded in $W^{1,1}(\mathbb{R}^n)$ and it converge a.e. to 0.  so if it converge strongly in $L^1$ we will have :$||F_n||_{L^1}=||F||_{L^1}=0$, an this is a contradiction .  my question is : where is the contradiction and how to prove that the embedding is compact in "this case or in normed (Banach) spaces (general case)"?  thank you very much.


VGA Controller is Intel's but graphic card is AMD/ATI, and 3d acceleration is not supported

I typed lspci -nn in the Terminal. And this is what it says :  00:00.0 Host bridge [0600]: Intel Corporation 3rd Gen Core processor DRAM Controller [8086:0154] (rev 09) 00:01.0 PCI bridge [0604]: Intel Corporation Xeon E3-1200 v2/3rd Gen Core processor PCI Express Root Port [8086:0151] (rev 09) 00:02.0 VGA compatible controller [0300]: Intel Corporation 3rd Gen Core processor Graphics Controller [8086:0166] (rev 09) 00:14.0 USB controller [0c03]: Intel Corporation 7 Series/C210 Series Chipset Family USB xHCI Host Controller [8086:1e31] (rev 04) 00:16.0 Communication controller [0780]: Intel Corporation 7 Series/C210 Series Chipset Family MEI Controller #1 [8086:1e3a] (rev 04) 00:1a.0 USB controller [0c03]: Intel Corporation 7 Series/C210 Series Chipset Family USB Enhanced Host Controller #2 [8086:1e2d] (rev 04) 00:1b.0 Audio device [0403]: Intel Corporation 7 Series/C210 Series Chipset Family High Definition Audio Controller [8086:1e20] (rev 04) 00:1c.0 PCI bridge [0604]: Intel Corporation 7 Series/C210 Series Chipset Family PCI Express Root Port 1 [8086:1e10] (rev c4) 00:1c.3 PCI bridge [0604]: Intel Corporation 7 Series/C210 Series Chipset Family PCI Express Root Port 4 [8086:1e16] (rev c4) 00:1d.0 USB controller [0c03]: Intel Corporation 7 Series/C210 Series Chipset Family USB Enhanced Host Controller #1 [8086:1e26] (rev 04) 00:1f.0 ISA bridge [0601]: Intel Corporation HM76 Express Chipset LPC Controller [8086:1e59] (rev 04) 00:1f.2 SATA controller [0106]: Intel Corporation 7 Series Chipset Family 6-port SATA Controller [AHCI mode] [8086:1e03] (rev 04) 00:1f.3 SMBus [0c05]: Intel Corporation 7 Series/C210 Series Chipset Family SMBus Controller [8086:1e22] (rev 04) 01:00.0 Display controller [0380]: Advanced Micro Devices, Inc. [AMD/ATI] Mars [Radeon HD 8670A/8750M] [1002:6600] 02:00.0 Network controller [0280]: Intel Corporation Centrino Advanced-N 6235 [8086:088e] (rev 24) 03:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller [10ec:8168] (rev 06)   As you can see, VGA controller is Intel's but Display controller is AMD/ATI's,  and I have 'RADEON GRAPHICS - AMD' sticker on my laptop.  However,  says like I should only check VGA compatible controller, not Display controller.  Another problem is that my 3d acceleration is not working.  When I type fglrxinfo or /usr/lib/nux/unity_support_test -p, it says  X Error of failed request:  BadRequest (invalid request code or no such operation)   Major opcode of failed request:  136 (GLX)   Minor opcode of failed request:  19 (X_GLXQueryServerString)   Serial number of failed request:  22   Current serial number in output stream:  22   This also occurs when I try to play 3D games, of course.  However, as you can see, my graphic card is one of Radeon HD 8xxx series (a.k.a. OLAND).  I think that's why the Ubuntu drivers didn't work.  Is there any unofficial drivers to make my 3D acceleration work?


"this Apple ID has not y used with the iTunes Store tap to review " when I tap review nothing happens what do I do?

i just got a iPad mini and I set it all up. Tried to download free apps but kept saying "this Apple ID has not yet been used with iTunes Store tap to review" when I tap review nothing happens what do I do ???


I struggling with R.K. Sundaram 1.7.43 exercise:   Let $S$ be a finite set. Show that any function $f: S \rightarrow \mathbb{R}^n$ is continuous on S. What if $S$ is countably infinite?  I saw that by  the definition of continuity is simple, but i'm havind douts with finite set definition.  Any thought would be appreciated.  tks


Why does About This Mac show different values for storage?

On my MacBook Pro, the Storage section on about my Mac shows that I have 730.21GB free out of 999.7GB, but it also says that my apps take up 545.33GB.    Why is this happening? How much storage do I actually have available?


When I run apt-get --yes upgrade in a script it sometimes stops and prompts for input.  Today in 14.04 LTS it is prompting for what to do for grub/menu.lst.   I don't know what could be asked for in a future upgrade.  I tried running this with a newline piped in.  I also tried just a carriage return.  neither worked (seems like the input was lost). I did not find a suitable option in apt-get such as --no-prompts.  I tried the answer  but it still gives me a menu prompt asking what config choice I want.  Any idea how to bypass this prompt?


Number of different ways of filling $N \times 4$ rectangle with Dominoes

Given a Nx4 (width = N and height = 4) rectangle. How many different ways are there to fill with Dominoes (2x1 or 1x2)?  I have found an OEIS sequence   for this.   The recurrence given in the link is a(n) = a(n-1)+5*a(n-2)+a(n-3)-a(n-4).     Any combinatorial proof? or how to get the recurrence?


What is the best format to capture addresses for a universal user-base?

What is the best and most usable format to capture address information from a universal user base? I was thinking to have the system detect the country by IP address and have that selected by default, and then state/province droplist would be populated accordingly. But the issue is some countries have states and provinces and some do not. Some have postal codes and some do not. Is there a universal standard to capture complete address info to ensure efficiency for most users?  FYI: I did research on here and while there are some questions that are close, none are about this exact same question (unless I missed something)


Gravitational lensing redshift around a Kerr black hole

Light from a source passes by a Kerr black hole on two sides at the equator and converges at the observer. The axis of rotation of the black hole is perpendicular to the direction of light. Two rays of light pass through the spacetime regions of a significant frame dragging, on one side along and on the other side against the direction of light.  Would frame dragging cause a red shift of one ray and a blue shift of the other? Or would both rays come to the observer with the same frequency?


Saints Row 3 (The third) Comes with most of the things done for me

I recently bought the whole PC series of Saints Row and after I began the third, after I leveled up, I saw that most of the power upgrades were already done for me and many clothing items were already bought.  I know the game is quite easy  economically but I want to start a game in which I can actually level up, not sideways.  Is it possible to begin a game in which (preferably) everything is locked?  I probably have all the downloadables of the game.


I have the following equation  where $ T_0(x) $ measures the temperature in Celsius at point x.    The parameter values are as follows.   My question is how to handle the second term $Q_m \over \omega_bp_bc_b$, which should give a unit of Celsius right?    What conversions in these terms do i have to make in order to measure the temperature in Celsius     I am trying to include the effect from exercises as well to this equation and modify the equation by adding a extra $Q_e\over \omega_bp_bc_b$ term. The exercise intensity $Q_e$ is measured by the unit MET. 1 MET is also defined as $58.2W/m^2$ . Can someone please tell me how to handle the units of $Q_e\over \omega_bp_bc_b$ to come up with Celsius temperature


Who is the authority -- scientists, or linguists -- on the definitions of everyday words referring to types of animals?

For instance, biologists these days like to say that the word "dinosaur" is inclusive of modern birds, since birds are descended from dinosaurs. This is consistant with biologists' tendency to categorize things monophyletically -- that is, if it is descended from something, it "is" that something.  A bird is descended from a dinosaur, so it must be a dinosaur.  Linguists (such as those employed by dictionaries e.g. Webster and Oxford) tend to be more pragmatic -- concerned more about communication and usefulness rather than strictly adhering to monophyletic categories. They consider "dinosaur" to only refer to those animals that lived in the mesozoic period....that is, they explicitly exclude modern birds from the definition, because when most people use the term "dinosaur," they are not talking about birds.   This is similar to the way we exclude tetrapods (amphibians, reptiles and mammals) from the definition of "fish", even though tetrapods are descended from fish. That is, "fish" is, by definition, a paraphyletic category.  Other examples are  "monkey" and "ape", which, by definition, are paraphyletic and therefore exclude humans.  So who is the authority on the definition of these words?  And if biologists are, isn't it being inconsistant to define the word "fish" to exclude a subset of its decendants, while refusing to do the same with the word "dinosaur"?


I had the bad surprise that wget doesn't redownload when a file of the same name already exist.  Is there an option to force him to redownload without deleting the file first on linux ?


What are the No Man's Sky technology levels?

I've seen different "levels" of technology, such as Theta, Tau, Sigma, even an Omega.   The problem is I don't know which ones are better than the others. Is there a list of the different levels of technology from smallest to largest?  I'd like to be sure I'm upgrading my technology efficiently without accidentally downgrading.


Is there an easy way to calculate the eigenvalues of the partial transpose of a given matrix?

Consider the state $$|\psi\rangle=(\cos\theta_A|0\rangle+\sin\theta_A|1\rangle)\otimes(\cos\theta_B|0\rangle+e^{i\phi_B}\sin\theta_B|1\rangle).$$ To calculate the $\rho^{T_B}$ I first calculate the $\rho$ and the change it into a matrix form but It was very complicated to compute the eigenvalues for that matrix. Is there any easy way to calculate the eigenvalues of $\rho^{T_B}$?


Error on copy some text to clipboard in C# WPF

I am trying to copy a text to a clipboard using below command:  Clipboard.SetText(textToCopy);   but an exception is thrown:    Anyway, text is correctly copied to clipboard. I can catch the exception so the user does not see it but I would like to know what is happening.


How to convert a png file from from 600 x 800 into 600 x 400?

Get info on my source  png file.  file  old.png old.png: PNG image data, 600 x 800, 8-bit colormap, non-interlaced   I want to convert old.png from 600 x 800  into  600 x 400.  convert -resize 600x400  old.png  new.png   Check my output.  file new.png new.png: PNG image data, 300 x 400, 8-bit/color RGB, non-interlaced


Suppose that $a, m$ and $n$ are positive integers such that $(m, n)=1$. If $m\mid a$ and $n\mid a$, then $mn\mid a$.

prove or disprove :  Suppose that $a$, $m$ and $n$ are positive integers such that $(m, n)=1$. If $m\mid a$ and $n\mid a$, then $mn\mid a$.  I think it is true statement.  Let $m\mid a$ and $n\mid a$ then $mn\mid na$ and $nm\mid ma$ since $(m,n)=1$ then $mn\mid a$.  Ut is short answer and I am not sure if that is it complete answer?


How do I map points on a 2D map to a 3D illustration of the same area?

I'm looking for advice on how to build an algorithm that maps any point on a map to a point on another map, interpolating where needed.  Let me better clarify with an example of what I concretely need...  I have a set of elements and paths on a real top down map (think google maps or any gps-like system) and I have another non top down representation of the same area. Specifically I'm working on a typical ski resort map of piste and slopes like .  This second map is more like an illustration and it's typically a three dimensional representation of a section of mountains. The viewing angle is often selected so to offer the clearest view of the whole skiing complex and there's no guarantee that size or proportions are actually correct. It's more an artistic work than a precise map.  I want portable devices to be able to map themselves on this map, using the "real" coordinates they receive from their GPS chips.  I obviously assume that the "mapping" process is based on providing myself a certain number of reference points between the two maps. Corners of the map, start and finish of every pista, aerial ways, specific buildings, mountain tops... the more I feed to the algorithm the more precise it would probably be.  Obviously the tricky part is for it to be able to map everything in between hard coded reference points, by looking for the closest reference and averaging everything in between.  I'm sure this is done often in many similar contexts (think of games that constantly have to map things showing player locations or such) but I have no idea where to look for a concrete example. Any link to tutorials, sample code and the mathematical theory behind it would be great.


How to schedule server jobs more intelligently than with cron?

I run a job every minute to reindex my site's content.   Today, the search engine died, and when I logged in there were hundreds of orphan processes that had been started by cron.  Is there another way using some kind of existing software that will let me execute a job every minute, but that won't launch another instance if that job doesn't return (i.e. because the search engine process has failed)?


How do I unwrap this model for UV textures?

I'm trying to unwrap part of the model you see below.  But whenever I press "Unwrap", it just gives an error message saying "Object has non-uniform scale, unwrap will operate on a non-scaled version of the mesh". Does anybody know how to fix this?


Time for two relativistic objects to meet

How do you prove that the time for two objects traveling towards each other at relativistic velocities is still d/(v1+v2).  Answer seems to have something to do with velocity addition but I'm stumped...


Lagrangian formalism and dissipative systems

Why the central concepts of classical mechanics, viz. Lagrangian and Hamiltonian formalisms cannot address constraint forces like friction and others in dissipative systems?


How to dual boot windows 10 and Ubuntu 15.04 so that Ubuntu has a larger disk partition than windows

I have just bought a brand new Dell computer and have been trying to get it set up to my needs. But I seem to have run in to a bit of a problem.  I am going to use this computer for mostly programming. However, I am also going to need it for schoolwork as well. To meet both requirements, I have decided to do a dual boot with both windows and Ubuntu. But when I went to set up my disk partitions, the disk manager only let me cut my windows partition in half.  A quick google search told me that this was because windows put some really important files that are required to boot windows in the middle of their disk space. Not the way I would have done it.  Anyway, a simple solution would be to just do what windows wants and simply cut the drive in half. With a 1 terabyte hard drive, I'm sure I would have plenty for Ubuntu.  But it seems wasteful doesn't it, setting aside more than half of your hard drive to an operating system you will use a lot less than half the time. Plus, I'm sure there are other people who would benefit from knowing the answer to this question.  All that I've found so far as to solutions that don't involve sketchy third-party software, is I could make a recovery disk of windows, install Ubuntu over windows, set up my partitions, reinstall windows with the recovery disk, and finally update grub. This solution could, in theory, work. Or go terribly wrong and ruin my brand new computer.  If anyone can think of any other, better ways to accomplish this goal, your advice would be hugely appreciated.


How do I specify unique constraint for multiple columns in MySQL?

I have a table:  table votes (     id,     user,     email,     address,     primary key(id), );   Now I want to make the columns user, email, address unique (together).  How do I do this in MySql?  Of course the example is just... an example. So please don't worry about the semantics.


How do I mount my OSX partition from Ubuntu?

I'm currently dual booting OSX 10.13.3 and ubuntu 16.04. But today i think i messsed up my kernel cache and i could no longer boot OSX. I need to mount my OSX partition from ubuntu and manually delete the kernel cache. So I installed hfslus and i tried to mount, but it failed.  ➜ sudo fdisk -l Disk /dev/nvme0n1: 238.5 GiB, 256060514304 bytes, 500118192 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: gpt Disk identifier: 6CCD78C4-5E7F-428E-95C6-07B752925E72  Device             Start       End   Sectors   Size Type /dev/nvme0n1p1      2048   1050623   1048576   512M EFI System /dev/nvme0n1p2   1050624 262000639 260950016 124.4G Linux filesystem /dev/nvme0n1p3 262000640 466800639 204800000  97.7G unknown /dev/nvme0n1p4 466800640 500117503  33316864  15.9G Linux swap   My mount attempt    ➜ sudo mount -t hfsplus /dev/nvme0n1p3 /mnt/macdrive [sudo] password for seun:  mount: wrong fs type, bad option, bad superblock on /dev/nvme0n1p3,    missing codepage or helper program, or other error     In some cases useful info is found in syslog - try    dmesg | tail or so.   I checked syslog and found:  ➜ dmesg -wH | grep "hfsplus" [Feb10 11:00] hfsplus: unable to find HFS+ superblock [Feb10 11:11] hfsplus: unable to find HFS+ superblock [ +20.703327] hfsplus: unable to find HFS+ superblock


Prove that for all sets $A$ and $B$, $( A \cup B ) - B = A$ implies $A \cap B =\varnothing$.

In the following proof we harness properties such as: For all set $A$, (i) $A = A - \varnothing$ (ii) $A \cap\varnothing=\varnothing$ Proof: Let $A$ and $B$ be arbitrary sets and suppose $( A \cup B ) - B = A$. Given (i) then $$( A \cup B ) - B = A - \varnothing.$$ So then, $( A \cup B ) = A$ and $B = \varnothing$. That being so, $$A \cap B = ( A \cup B ) \cap \varnothing = \varnothing$$ If we apply (ii) to the foregoing equivalence relation. Therefore $$A \cap B = \varnothing$$ Is this proof right? if it is I would like to see alternative ones.


I have two different regular files:  myscript2 and myscript3 with word 'dash' inside. I want to grep them, but because of '-r' addition to grep I got hidden files as well. I tried to use 'grep -v' after pipe to get rid of hidden files. I failed. Why? What to do to solve my problem?  $ ls myscript2 myscript3 $ cat myscript2 dash $ grep -r -l 'dash' | grep -v '^.*'


What's the theoretical potential for how strong electromagnets can get? If you just kept coiling a solenoid longer and wider, and fed more and more current into the coil, would the field strength in the middle get arbitrarily dense?  This is the closest related question I could find:   I understand that the core will eventually saturate and thus stop helping to increase the field. But I think increasing the other parameters still makes for a stronger magnet.


Create an array of integers property in Objective-C

I'm having troubles creating a property of an array of integers in Objective-C. I'm not sure whether this is even possible to do in Obj-C so I'm hoping someone can help me in finding out either how to do it correctly or provide an alternative solution.  myclass.h  @interface myClass : NSObject {  @private int doubleDigits[10]; }  @property int doubleDigits; @end   myclass.m  @implementation myClass      @synthesize doubleDigits;     -(id) init {          self = [super init];          int doubleDigits[10] = {1,2,3,4,5,6,7,8,9,10};          return self;     }      @end   When I build and run, I get the following error:     error: type of property 'doubleDigits'   does not match type of ivar   'doubleDigits'


There is one problem, it seems that text won't appear on my program. The three images show the errors and also my laptop specs (I believe I just have very small amount of laptop power that makes Blender glitch).  Everything else works fine (zooming, panning, rotating, etc.) and the buttons are still there and do what they're supposed to do, but the text just won't appear.  Might anybody know how to fix this?        The drive update didn't help either. I know a way around it though, does anybody know a page which shows screenshots of more or less the buttons on blender


I have already been prequalified with 3.8% (but I am sure I can do better :)). Now, I am about to make an offer on a house. So, once the seller accepts my offer, how do I rate shop ?    Do I need to do the rate shopping before making an offer, or after the seller accepts my offer ?  When the seller accepts my offer, then I will go to a banker and submit a full application, so will it be legally binding for me to go with the approved mortgage application ?  Or, once the seller accepts my offer, may I simultaneously apply for a mortgage with 3-4 bankers, and then choose the lowest rate ?     I asked my realtor, but she recommends to go with just one banker (her friend), and not to do any rate shopping. Is it the right way ?   (I live in a state of Arkansas, so I am thinking of going with the local bankers)


Let the sum of all integers $n$ such that $(2n^2+9/n+3)$ is an integer be $A$, what is $|A|$?  I tried expressing it to:  $k$ is an integer, $(n+3)k + 0 = 2n^2 + 9$, $n(2n-k) + 3(3-k) = 0$, from which I couldn't move on,  I also tried $(n+3)k + 0 = 2n^2 + 9$, $k = 2n$, $2n^2 - 2n^2  + 9 - 6n$. $9-6n/n+3$ is an integer, $9 - 6n = 3(3-n)$ though now I also do not know how to move on.


How to triple boot windows and two linux distros

I just got a new pc and installed windows 10 and I am a big linux fan so of course I setup dual boot with ubuntu 15.10 but I would also like to setup linux mint. I have checked out other questions like this but they all start without ubuntu installed. Is it still possible for me to add another distro after I have installed ubuntu?


Maximum current when charging a device through a computer USB 3 port using a USB 2 cable?

Just got a new MacBook with USB 3 ports. I thought it would be able to charge my Nexus 4 phone much faster using USB 3 900 mA current.  However, I haven't seen any improvements compared to charging on a USB 2 port. Obviously, AC chargers can charge way over 500 mA using USB 2 cables.  Which brings me to question: can a (micro) USB 2 cable hooked up to a computer USB 3 port charge a device at 900 mA current, or is it limited by the USB 2 cable to 500 mA?


I get the warning "Undefined control sequence" with \mathbb

I am doing my first LaTeX work using TeXstudios and I'm having trouble with an Undefined control sequence.   When I've checked solutions on google it appears as this is caused by typos in the different commands.  However, I have used the TeXstudios implemented menus to generate the codes so it shouldn't be any problem with that.  The code I'm having trouble with is  $x\in\mathbb{R}^{n}$   which I intend to become x belonging to the real numbers with n as an exponent.   I get the error   Undefined control sequence $x\in\mathbb


I just changed my Minecraft name and now I can't join a server

I just changed my Minecraft gamertag and it was all ok, then when I try to join a server it says this "Failed to join server Error: Authentication to Minecraft.net Failed"


Is it really possible to intrude a fully ENCRYPTED Hard Drive? (Encrypted since installation of ubuntu 18.04 OS)

So I`m using ubuntu 18.04 LTS almost on every machine that I use in my lifetime.. WHether for programming, storing sensitive information, financial transaction, entertainment so on and so forth!!..  so let me know is it possible (for hackers) to invade and get access over the files and data of my hard drive (every hard drive is encrypted during installation itself)  is there any other way in Linux to master encrypt (encrypt entire hard drive) for non-OS partitions and drives?..  Also, asking basic question, why it`s not possible to change encrypted passwords after installing OS?.


What's the suitable wire size for 9VDC @25 Amps line?

I am trying to put together the requirements for a cable and I was wondering what would be the most suitable wire size to load the DUT with 25Amps @ 9VDC. I will have few other high current lines 13Amps @ 5VDC. There will also be 2 DC lines 160V @5Amps each.  I was wondering if all of this can be bundled (or what would be the key things to keep in mind) with some other wires carrying RF signals without causing any signal integrity issues.  I plan to use shielded Coax cables (at least 20) and bundle all of it along with some other signal lines (like DIO, SPI, CAN bus, etc) in one cable. The RF signals are not going to have a frequency higher than 15MHz but I will need to sample it quite fast to detect a time difference between 2 signals in 5 nanosecond range.  Would anyone suggest:   The right wire size for this application Would there be any issue in regards to RF measurements?   The overall cable length is going to be about 15ft.


Test if there are files matching a pattern in order to execute a script

I am trying to write an if statement to test whether there are any files matching a certain pattern. If there is a text file in a directory it should run a given script.  My code currently:  if [ -f /*.txt ]; then ./script fi   Please give some ideas; I only want to run the script if there is a .txt in the directory.


I've been stuck on this problem for a few weeks now. Any help?  Prove:  $\sum_{i=1}^{n}\prod_{j=0,j\neq i}^{n}\frac{x-x_j}{x_i-x_j}=1$  The sum of lagrange polynomials should be one, otherwise affine combinations of with these make no sense.  EDIT: Can anybody prove this by actually working out the sum and product? The other proofs make no sense to me. Imagine explaining this to someone who has never heard of lagrange.


If the verb ends with a vowel plus -l (as in travel or equal), then you need to double the l before adding -ed and -ing in British English.    Is it a general rule in British English? or there are some exceptions (feeling, kneeling ...)


How can an isolated system filled upto the brim with some fluid get more random?

This is probably stupid, but like an isolated tank which is completely filled with some liquid or stuff can't have any more entropy on its own right?


Writing projection in terms of projection matrix

I've been reading . The goal is to find projection of $b$ on the line $L$ which is determined by vector $a$. ($Proj_L(b)$)  In the document, It is mentioned that If $p$ is thought as approximation to $b$, then $e=b-p$ is the error in that approximation (the word approximation is little confusing though, Isn't $e$ the exact value? Although this is not the problem). Then we know that If $p$ lies on the line through $a$, then $p = xa$ for some $x$. We also know that, $p$ is orthogonal to $e$, therefore their dot product equates to zero: $a^T(b-xa)=0$ $a^Tb - a^Txa = 0$ $xa^Ta = a^Tb$ $x = \frac{a^Tb}{a^Ta}$ Solving for $p$: $p = ax = a\frac{a^Tb}{xa^Ta}$  First part was almost completely understandable, but in the second part this projection is written in the terms of projection matrix ("$P: p = Pb$"): $p = xa = \frac{aa^Ta}{a^Ta}$ where did $b$ go? $x$ and $a$ have changed places, but isn't dot product commutative? Then, $P$ is solved: $P = \frac{aa^T}{a^Ta}$ Somehow, $aa^T$ is 3x3 matrix. How was this concluded? From my knowledge, The general definition of projection matrix is $A (A^{T}A)^{-1} A^T \vec{x}$ (where $A$ is matrix) Does the definition above has any relations with the projection matrix that was represented in document? If not, how was it derived? Thank you!


I am teaching my girlfriend, we are exchanging knowledge. She read my previous questions and upvoted some of them. Today all the reputation from that is deleted. Why? Is this a scam as she really liked them? Also... I am a teacher and I can discuss some of the topics with my students. So now I wont stimulate them to make profiles in stackoverflow and upvoted the questions/answer they like (because as I see this is considered a scam, but its not)


move an object in custom direction using blender API

My greetings to the community. I have a specific task which i have managed to perform using python. I need to do the same task faster and i believe i found a way but i need some help with that. My problem is the lack of understanding of the problem in 3d-space and more specifically the matrix transformations in local/global coordinates. I have an object which i need to move in a specific direction by 1cm in local coordinates. the lower object in the figure is the original position and the upper is the target position. therefoer the movement is towards Z in local coordinates.  What i do is: new_location = Vector((0, 0, 1)) # move by 1cm in the Z-direction trans = Matrix.Translation(new_location)  # create transformation matrix object.matrix_world @= trans  mat = object.matrix_world verts = [mat @ v.co for v in object.data.vertices]  This works just fine but it is slow due to the translation of each vertice in the last loop. I think i can do the same (correct me if i'm wrong) using bpy.ops.transform.translate. something like this: bpy.ops.transform.translate(value=(0, 0, 1), orient_type='LOCAL',                             orient_matrix=((1, 0, 0), (0, 1, 0), (0, 1, 0)), orient_matrix_type='LOCAL',                             mirror=True, use_proportional_edit=False, proportional_edit_falloff='SMOOTH',                             proportional_size=1, use_proportional_connected=False,                             use_proportional_projected=False, release_confirm=True)  but what i can't figure out the correct values of "value" and "orient_matrix". thanks in advance


I was wondering a bit after I got a Santa Lucia Hat from several different SE-pages. For getting the SL-Hat you have to vote on 15th of december, but for example I got the SL-Hat on meta, even if I created the account here on 16th of december (according to my time zone). So, what is the relevant time zone for hats? And even if the time zone is UTC, I am in UTC +1, so that should not be the answer...


I'm making a site targeting Japanese market. Since it's in Japan, the main language is Japanese but I also added the English version.  There are 2 ways of structuring the URLs like this:  1st way   The root URL will be in Japanese example.com/ The English version will be example.com/en/   2nd way   The root URL will be in Japanese suffixed with ja (example.com/ja/) The English version is suffixed with en (example.com/en/)   One claimed that the 1st way is better since the site will show up in Japanese in Google result.  I did some research and people said the 2nd way is better.  Is there any proven practice on this?


So im rather new this whole linux stuff but i took a pc and installed 18.04 on it. after using that for a while i decided that i wanted a change in scenery so i upgraded to 19.10 since that was the version it told me was the latest... this all went fine, no complications at all. later on i was on my normal pc that runs windows and i made an ubuntu vm out of sheer boredom and saw that 20.04 was actually the latest release when i was looking for an iso as the one i had was still 18.04. so when i went back on to 19.10 machine i thought i would be as simple it was upgrading from 18.04, but boy was i wrong. the only error ive really gotten is "This version no longer supported. Please install a supported version." anyone have any ideas?


Clipping mask over photo doesn't show in PDF

I created a design where there is a clipping mask over a photo. When I save the AI file as a pdf the full photo shows without the clipping mask. I have tried to save it a variety of different ways including with the Illustrator editing capabilities checked.   I went back and expanded the clipping mask thinking maybe that would help but the full photo still showed up in the PDF.  I can't tell if its an issue with the PDF or with the native AI file (how I made the clipping mask et.)  Any ideas?  Thank you!


It is a common issue Mac users, when you try open NTFS external storage you allowed only read mode. And of course there are some solution. One of them it is NTFS 3G - free alternative.  I followed instructions     I set up FUSE then I set up Brew and eventually I set up NTFS 3G  But because lack of experience in Mac and English I can't understand what I need to do after all  According to link      Even though you have installed NFTS-3G, newly connected NTFS volumes will still be auto-mounted in read-only mode. To change this you need to replace Apple's NTFS mount tool /sbin/mount_ntfs with the one provided by NTFS-3G.   It says that I need to replace Apple's NTFS mount tool with the one provided by NTFS-3G...   How to do it? I don't know any tools provided by NTFS-3G...  Please help me to finish installing process  Edit  I found this two commands to solve my issue   sudo mv "/Volumes/Macintosh HD/sbin/mount_ntfs" "/Volumes/Macintosh HD/sbin/mount_ntfs.orig" sudo ln -s /usr/local/sbin/mount_ntfs "/Volumes/Macintosh HD/sbin/mount_ntfs"   After I execute first command I got follow output   mv: rename /Volumes/Macintosh HD/sbin/mount_ntfs to /Volumes/Macintosh HD/sbin/mount_ntfs.orig: No such file or directory   After I execute second command I got follow output  ln: /Volumes/Macintosh HD/sbin/mount_ntfs: No such file or directory   Edit2  Admins-MacBook-Pro:~ admin$ sudo mv "/sbin/mount_ntfs" "/sbin/mount_ntfs.orig"  Password:  mv: rename /sbin/mount_ntfs to /sbin/mount_ntfs.orig: Operation not permitted


Let $G$ be a finite abelian group, and let $K$ be a subgroup of $G$. Does $G$ necessarily have a subgroup $H$ such that $H\cong G/K$ and $H\cap K=\langle 0\rangle$?  I'm not sure where to start.