I have a file in this format which I want to sort  RNU2-46P    0 RNU2-2P 9 RNU2-63P    5 RNU2-36P    6 RNU2-56P    8 RNU2-17P    0   I want to sort it on column 1 and get this output  RNU2-2P 9 RNU2-17P    0 RNU2-36P    6 RNU2-46P    0 RNU2-56P    8 RNU2-63P    5   I tried the sort command but it is not sorting the way I want. Help!!  Thanks


15.04 Server fails to update with failed to fetch temporary failure resolving errors

I can't do sudo apt-get update; when I try it gives me loads of failed to fetch everything. I have no idea what could be wrong. I searched for what the sources.list file should look like and it looks the same to me.  Err http://nl.archive.ubuntu.com vivid InRelease Err http://nl.archive.ubuntu.com vivid-updates InRelease Err http://nl.archive.ubuntu.com vivid-backports InRelease Err http://nl.security.ubuntu.com vivid InRelease Err http://security.ubuntu.com vivid-security InRelease Err http://archive.canonical.com vivid InRelease Err http://nl.security.ubuntu.com vivid Release.gpg   Temporary failure resolving 'nl.security.ubuntu.com' Err http://security.ubuntu.com vivid-security Release.gpg   Temporary failure resolving 'security.ubuntu.com' Err http://archive.canonical.com vivid Release.gpg   Temporary failure resolving 'archive.canonical.com' Err http://nl.archive.ubuntu.com vivid Release.gpg   Temporary failure resolving 'nl.archive.ubuntu.com' Err http://nl.archive.ubuntu.com vivid-updates Release.gpg   Temporary failure resolving 'nl.archive.ubuntu.com' Err http://nl.archive.ubuntu.com vivid-backports Release.gpg   Temporary failure resolving 'nl.archive.ubuntu.com' Reading package lists... Done W: Failed to fetch http://nl.archive.ubuntu.com/ubuntu/dists/dists/vivid/InRelease W: Failed to fetch http://nl.security.ubuntu.com/ubuntu/dists/dists/vivid/InRelease W: Failed to fetch http://nl.archive.ubuntu.com/ubuntu/dists/dists/vivid-updates/InRelease W: Failed to fetch http://nl.archive.ubuntu.com/ubuntu/dists/vivid-backports/InRelease W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/vivid-security/InRelease W: Failed to fetch http://archive.canonical.com/ubuntu/dists/vivid/InRelease W: Failed to fetch http://nl.archive.ubuntu.com/ubuntu/dists/dists/vivid/Release.gpg  Temporary failure resolving 'nl.archive.ubuntu.com' W: Failed to fetch http://nl.archive.ubuntu.com/ubuntu/dists/dists/vivid-updates/Release.gpg Temporary failure resolving 'nl.archive.ubuntu.com' W: Failed to fetch http://nl.archive.ubuntu.com/ubuntu/dists/vivid-backports/Release.gpg  Temporary failure resolving 'nl.archive.ubuntu.com' W: Failed to fetch http://nl.security.ubuntu.com/ubuntu/dists/dists/vivid/Release.gpg  Temporary failure resolving 'nl.security.ubuntu.com' W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/vivid-security/Release.gpg  Temporary failure resolving 'security.ubuntu.com' W: Failed to fetch http://archive.canonical.com/ubuntu/dists/vivid/Release.gpg  Temporary failure resolving 'archive.canonical.com' W: Some index files failed to download. They have been ignored, or old ones used instead..


Current electricity and static electricity

I am new to subject static electricity and I really got confused by some questions?   if the electrons in insulators are tightly bound to the nucleus why when rubbing two insulators electron jump from one to another?  in conducting wires when an electron jump from one atom to another they repel each other and form an electrical current but why when electron transfer from one insulator to another the the electrons from the second insulator doesn't repel the electron transferred from first insulator?


I have a dict as in below:   saving = {0: (1, 2, 9.0), 1: (1, 3, 603.0), 2: (1, 4, 396.0), 3: (1, 5, 9.0), 4: (2, 3,     206.0)}    I want to sort descending this dict order by the third value. I tried sorted and sort() but I couldn't sort the dict. I don't know much about the usage sort and sorted functions.  Can you help me ?  Thanks.


Function $f(x)$ is defined as: $f(x) =0$ when $x=0$, and $f(x) = n$ when $x \in (\frac{1}{n+1}, \frac{1}{n}]$. Calculate $\int_0^1 f(x) dx$.  Assuming that we can safely ignore when $x=0$, then when $x\in (\frac{1}{n+1},\frac{1}{n}]$, we essentially have  $$1\times\left(1 - \frac{1}{2}\right)+2\times\left(\frac{1}{2}-\frac{1}{3}\right)+\cdots=\sum_{n \ge 1} n\left(\frac{1}{n}-\frac{1}{n+1}\right)=\sum_{n \ge 1}\frac{1}{n+1}$$  But then the series diverges by integral test. So I am confused.


Renamed Web project, now finding ambiguous namespaces

I have an ASP.NET web project, which was named "OldProject".  For whatever reasons, it was decided to rename the project and its namespaces to "NewProject".  Now when the site starts up, it complains about ambiguous controller names:  Multiple types were found that match the controller named 'Admin'. This can happen if the route that services this request ('{controller}/{action}/{id}') does not specify namespaces to search for a controller that matches the request. If this is the case, register this route by calling an overload of the 'MapRoute' method that takes a 'namespaces' parameter. The request for 'Admin' has found the following matching controllers: OldProject.Controllers.AdminController NewProject.Controllers.AdminController  I have searched the entire solution, including the Web project's csproj file, and cannot find a single instance of the string "OldProject". How to resolve this false ambiguity?


UnboundLocalError trying to access variable from outer closure inside a generator

I'm quite new to Python, but I'm trying to implement my "Line file reader" and I came across an error that I don't understand why it wouldn't work.  UnboundLocalError: local variable 'i' referenced before assignment  The generator can see the file variable in the closure just fine, why can't it see i? import contextlib   @contextlib.contextmanager def myOpen(name):     file = open(name)     i = 0     try:          def wrappedFileGen():             for line in file:                 i = i + 1 #<-- UnboundLocalError: local variable 'i' referenced before assignment                 print('Line:', i)                 yield line          yield wrappedFileGen()      finally:         print('Total lines read:', i)         file.close()   with myOpen('test.txt') as file:     for line in file:         print('Content:', line)         # raise "Oops"   If I declare i inside the generator it works         def wrappedFileGen():             i = 0 #<---- HERE             for line in file:                 i = i + 1                 print('Line:', i)                 yield line  I need i in the outer scope, because I want to finalize it


Change Runlevel In CentOS 7 with SystemD

In CentOS 7 I wanted to start httpd service only in runlevel 3 and 5, in other runlevels such as 2 and 4 the service shouldn't start.   In CentOS 6 we can achieve this by using "chkconfig" command. Looking for similar solution in CentOS 7 environment.


Consider the complex polynomial $p(z) = z^4+z+1$. I want to check that this polynomial has exactly one zero in each quadrant of $\Bbb C$. I do not want to solve the equation $z^4+z+1 = 0$ (as I strongly believe that's overkill here).  Since the coefficients are real, $z$ being a zero implies that $\overline{z}$ is also a zero. I believe that the strategy is using Rouché's Theorem in some way. So far, I know that all the zeros are in $1/2 < |z|<2$. Trying to use Rouché in, for example, the curve that: joins $0$ to $2$ by a straight segment, then $2$ to $2i$  by a counterclockwise circular arc, and then goes down to $0$ again, seems complicated, as the dominating part of the polynomial can vary.  On the other hand, by the Argument Principle, I could analyze the integral of $p'(z)/p(z)$. But then I would have to tackle the integral: $$\frac{1}{2\pi i}\int_\gamma \frac{4z^3+1}{z^4+z+1}\,{\rm d}z.$$Maybe I just don't remember my calculus well and this integral is actually easy to deal with, but otherwise I'm  stuck. Can someone give me some ideas? Thanks.


Is an attack a check, or only similar to a check?

The Barbarian's Rage ability gives advantage on Strength checks and saving throws.  Does this mean that the Barbarian gets advantage to attack rolls as well? Is an attack a check, or since saving throws are mentioned, that means it does not apply to attacks?


For the past few weeks I have been noticing the code in my index.htmls on my host, changing by it self. The other day Chrome and Firefox have started to list the sites hosted on my server as attack sites.  I am pretty sure my computer is clean and I'm not uploading the virus via ftp.  It's a script in my server somewhere, but I have no idea how to get rid of it, any help would be very much appreciated.


How can a post be viewed 7 times and downvoted 8 times? Is it a bug?


Computing $\int_0^{\infty}\frac{\cos x}{x^2+a^2} dx $

Compute the following integral using residues: $$\int_0^{\infty}\frac{\cos x}{x^2+a^2} d x $$  $\int_0^{\infty}\frac{\cos x}{x^2+a^2} dx =\frac{1}{2}\int_{-\infty}^{\infty}\frac{\cos x}{x^2+a^2} dx =\frac{1}{4}\int_{- \infty}^{\infty}\frac{e^{ix}+e^{-ix}}{x^2+a^2} dx$. After the substitutions $z=e^{ix}$ and $\cos(x)=\frac{1}{2}(z+\frac{1}{z})$ I get: $\frac{1}{4}\int_{-\infty}^{\infty}\frac{e^{ix}+e^{-ix}}{x^2+a^2} dx =\frac{1}{4}\int_{-\infty}^{\infty}\frac{z+\frac{1}{z}}{e^{2iz}+a^2}\times{dz}{ie^iz}=\int_{-\infty}^{\infty}\frac{z^2+1}{z(2ie^{3iz}+2a^2ie^{iz})}dz$ In the expression $\frac{z^2+1}{z(2ie^{3iz}+2a^2ie^{iz})}$ I detected only one residue at 0, which is a simple pole. However my computation is giving me the result  $\lim_{z\to 0}\frac{z^2+1}{z(2ie^{3iz}+2a^2ie^{iz})}=\frac{1}{2i+2a^2 i}$ which is wrong according with the solution. Questions: What am I doing wrong? How should I compute this integral? Thanks in advance!


Ubuntu 18.04 + Dell XPS 9360 = Suspension doesn't work when I close the lid

I upgraded to 18.04 after 16.04 had no way to make the touchpad work.   The only issue with 18.04 is that when I close the lid (with or without external monitor) the laptop does not suspend.  How can I patch this? I read some instructions for 16.04 - 17.10 that point to edit /etc/systemd/logind.conf and change the file to this:  #  This file is part of systemd. # #  systemd is free software; you can redistribute it and/or modify it #  under the terms of the GNU Lesser General Public License as published by #  the Free Software Foundation; either version 2.1 of the License, or #  (at your option) any later version. # # Entries in this file show the compile time defaults. # You can change settings by editing this file. # Defaults can be restored by simply deleting this file. # # See logind.conf(5) for details.  [Login] #NAutoVTs=6 #ReserveVT=6 #KillUserProcesses=no #KillOnlyUsers= #KillExcludeUsers=root #InhibitDelayMaxSec=5 HandlePowerKey=suspend HandleSuspendKey=suspend HandleHibernateKey=suspend HandleLidSwitch=suspend HandleLidSwitchDocked=suspend #PowerKeyIgnoreInhibited=no #SuspendKeyIgnoreInhibited=no #HibernateKeyIgnoreInhibited=no #LidSwitchIgnoreInhibited=yes #HoldoffTimeoutSec=30s #IdleAction=ignore #  This file is part of systemd. # #  systemd is free software; you can redistribute it and/or modify it #  under the terms of the GNU Lesser General Public License as published by #  the Free Software Foundation; either version 2.1 of the License, or #  (at your option) any later version. # # Entries in this file show the compile time defaults. # You can change settings by editing this file. # Defaults can be restored by simply deleting this file. # # See logind.conf(5) for details.  [Login] #NAutoVTs=6 #ReserveVT=6 #KillUserProcesses=no #KillOnlyUsers= #KillExcludeUsers=root #InhibitDelayMaxSec=5 HandlePowerKey=suspend HandleSuspendKey=suspend HandleHibernateKey=suspend HandleLidSwitch=suspend HandleLidSwitchDocked=suspend #PowerKeyIgnoreInhibited=no #SuspendKeyIgnoreInhibited=no #HibernateKeyIgnoreInhibited=no #LidSwitchIgnoreInhibited=yes #HoldoffTimeoutSec=30s #IdleAction=ignore #IdleAction=ignore #IdleActionSec=30min #RuntimeDirectorySize=10% #RemoveIPC=yes #InhibitorsMax=8192 #SessionsMax=8192 #UserTasksMax=33%


Does anyone know if this is possible?  I'm a Star Trek fan, and there's this screensaver that's for Windows that mimics a Star Trek systems panel, and I'd love to have that on Ubuntu (so would some of my friends).


ArcGis using the time slider to animate multiple data frames

I'm creating an animation of a map that has a zoomed in data frame, in one of it's corner.  How do I get the time slider to act on both data frames at once?


Selecting unique rows based on the maximum date

I am using PostgreSQL and I am trying to create a view of data:  forecast_datetime, file_date, thing_id, thing_name, facts...   The forecast_datetime column is a datetime for each 30 minute interval. The issue is that the forecast is for 1 month into the future which causes a lot of duplicate data. (so today, there will be a forecast for 2016-12-25 01:30:00 and then tomorrow there will be a forecast for the same interval, over and over again potentially until the period actually happens.).  The view I want to create is to just take a look at the last forecast which was appended to the table. This is indicated by the file_date column (as the name suggests, I receive a daily forecast file which is appended to the database. This column indicates the date from the filename).   I basically want to filter all rows for each thing_id and select the forecast_datetime columns where there file_date was the maximum date for that forecast. So each thing_id should only have one row per unique forecast_datetime interval which is based on the latest file_date.  CREATE OR REPLACE VIEW schema.view AS  SELECT DISTINCT ON (thing_id, forecast_datetime, file_date)        forecast_datetime,        interval,        time_zone,        file_date,        thing_id,         thing_name,        other_cols... FROM   schema.orig_table ORDER  BY  file_date DESC    Would that query do the trick? I can do this in pandas/python easily, but I am newer to SQL and wanted to try a view instead of writing a new physical table.  Here is some sample data after applying the query I wrote above this. Because I included the the file_date in the SELECT DISTINCT query, there is still a repeat row which duplicates each forecast_datetime. This causes issues when I join this data based on the thing_id and forecast_datetime back to the actual results table.  forecast_datetime   file_date   thing_id 2016-12-12 20:30    2016-12-11  99 2016-12-12 20:30    2016-12-10  99 2016-12-12 20:30    2016-12-09  99 2016-12-12 20:30    2016-12-08  99   I would like to only have the row with the max file_date. In the example above, that would be the first row (2016-12-11). The other rows would be dropped from the view.


Real and apparent depth not looking perpendicular to the interface

What is the formula for Real vs Apparent Depth, when not looking perpendicular to the interface?   I know the formula $$\frac{\text{real depth}}{\text{apparent depth}}=n$$   but I'm not looking for this.


How to upgrade my samsung galaxy ace plus GT -S7500 from Gingerbread to Jellybean

I would like to know How to upgrade my samsung galaxy ace plus GT-S7500 from Gingerbread to Jellybean.?  Details are as follows   Model Number: Samsung GT-S7500  Android version: 2.3.6 Baseband Version: S7500DDME1 Kernel Version: 2.6.38.6                dpi@DELL235#1 Build Number: GINGERBREAD.DDMF2   Please help...


Alignment problem in 2 vector shapefiles with the same projection

I have 2 vector shapefiles of Manila that are supposed to align, but they do not (screenshot attached). I have projected them to the same projection (World Mercator WGS 84, EPSG 3395). One shapefile appears to be shifted to the right and does not align with the Google Street basemap and the other shapefile. I am using QGIS 2.14.16.  The pixelised shapefile in the picture was actually from a MODIS 500m raster image which I polygonised. The other shapefile is the administrative outline of Manila, from GADM.  I understand that MODIS data may have some misalignment issues that may be the cause of this problem, which I have not seen in other forums.   Any ideas as to what could be the problem and solution?      Tried to change the shapefiles to EPSG 3857 to match Google Street's projection as suggested by AndreJ. Unfortunately both shapefiles are more misaligned.


If a player has a +1 Dagger (example), and then he score a critical hit, is the "+1" thing doubled too or just the damage dice? Will the damage be 2d4 +1 +ability mod or 2d4 +2 +ability mod? If a sword deals 1d6 +2 necrotic damage, is only the "+2" necrotic or all of the damage? On the 2nd question, if crits, the +2 is doubled too?   I'm trying to use only the official rules.


The 80s TV cartoon The Mysterious Cities of Gold depicts an ornithopter called . I love its design and have been trying to build my own small-scale replica using EPP foam, but I'm not sure what mechanism the real one uses to take off and land. How does the Golden Condor take off and land? Does the show explain this?


I would like to know how to put text in a textbox when the page loads. Example: If I have a login page, I would have 2 textboxes named "username" and "password". When the page loads I want the the textbox to load with "username" written inside, so I won't have to put a label for that outside. But when the user clicks inside textbox it should disppear. How do I do this?


Nodes linked by a horizontal arrow in enumerate environment

Alright, here's what I need. I need links between nodes a la , but, unlike that package, I need linking arrows that appear beneath the sentence as opposed to linking arrows that appear in the right margin.   And here's another constraint. I would like this to work in an enumerate environment. So, for example, I would like to be able have something like this      \begin{quote}     \begin{enumerate}     \item[(1)] \node{A man} walked in. \node{He} sat down.      \end{enumerate}     \end{quote}   where there is an arrow that starts with the pronoun he and which then points back to the noun phrase a man. And like the arrows in tkz-linknodes, I want this to be a non-curved arrow with right angles.  Maybe this can be done easily in TiKz, but I'm having trouble doing this in a way that plays nice with the enumerate environment and I can't seem to get tkz-linknodes to do this either.  Any help would be greatly appreciated!


Non-singlet and singlet flavor combination

In the perturbative QCD, specific partonic distribution functions (pdf) linear combination is called "flavor singlet" or "flavor nonsinglet" combination.  What is the combination, and why are they called flavor "singlet" or "non-singlet" combination? Does evolution equation (DGLAP equation) of these specific linear combination of pdf functions take a particular form?


Distant aliens receive signal with instructions on how to construct humans, long after Earth is extinct

I'm looking for a specific scifi book that I read years ago, I only partially remember the story, and I don't remember the author or the title.  What I remember of the story is:   An alien race picks up a signal from humans that includes instructions on how to make their own humans (genetic instructions). The humans grow up knowing they are created and are taught by the alien race. They are eventually given resources to build a ship, and go looking for their origins. They eventually find the solar system, but nobody answers. They find some stations orbiting earth and find that the station is very old, so old in fact that humans have long been extinct and other creatures have reached local space, and have been looking around the station as an archeological dig. I think they refer to two developed races from earth, but one developed from rats.   If anyone know what story this is, and can point me at it, its been driving me crazy for at least 15 years, and I think it's actually been much longer, since I can't remember when I read it.


If X is a Geometric random variable with parameter p, find p that maximizes P(X=k)

The full question is,     If X is a Geometric random variable with parameter p, what value of k ∈ {1, 2, . . .}   maximizes P(X = k) = (1 − p)^(k-1) * p? This is referred to as the mode of the distribution.   Through trial and error (plugging in random values), I found that p = 1/2 yields the highest value of P(X=k).  Is there a way to figure this out without trial and error?


What's the Linux equivalent to Windows batch files?

I have a batch file which I use to create an .apk file on my Windows machine. Now I need to be able to create the .apk file in Ubuntu but I don't know how translate my .bat file to a script to be able to run it on Ubuntu.  Below is the batch file which works fine on Windows.  Will you please give me some hints on how I can run it on Ubuntu?  @echo off set PAUSE_ERRORS=0 :user_configuration  :: Path to Flex SDK  set FLEX_SDK=C:\sdk\flex_sdk_4.5.1.21328  :: Path to Android SDK set ANDROID_SDK=C:\sdk\android  :validation if not exist "%FLEX_SDK%\bin" goto flexsdk if not exist "%ANDROID_SDK%\platform-tools" goto androidsdk goto succeed  :validation if not exist "%FLEX_SDK%\bin" goto flexsdk if not exist "%ANDROID_SDK%\platform-tools" goto androidsdk goto succeed  :flexsdk echo. echo ERROR: incorrect path to Flex SDK echo. if %PAUSE_ERRORS%==1 pause exit  :androidsdk echo. echo ERROR: incorrect path to Android SDK in 'bat\SetupSDK.bat' echo.  if %PAUSE_ERRORS%==1 pause exit  :succeed set PATH=%PATH%;%FLEX_SDK%\bin set PATH=%PATH%;%ANDROID_SDK%\platform-tools  :: Android packaging set AND_CERT_NAME="PeymanApp" set AND_CERT_PASS=fd set AND_CERT_FILE=cert\SampleApp.p12 set AND_ICONS=icons/android  set AND_SIGNING_OPTIONS=-storetype pkcs12 -keystore "%AND_CERT_FILE%" -storepass     %AND_CERT_PASS%  :: Application descriptor set APP_XML=application.xml  :: Files to package set APP_DIR=bin set FILE_OR_DIR=-C %APP_DIR% .  :: Your application ID (must match <id> of Application descriptor) set APP_ID=air.com.doitflash.SampleApp  :: Output packages set DIST_PATH=dist set DIST_NAME=PeymanApp  :validation %SystemRoot%\System32\find /C "<id>%APP_ID%</id>" "%APP_XML%" > NUL if errorlevel 1 goto badid goto end_validation  :badid echo. echo ERROR: Application ID (APP_ID) does NOT match Application descriptor '%APP_XML%'     (id)  echo.  :end_validation  set TARGET= set PLATFORM=android  ::call bat\Packager.bat if "%PLATFORM%"=="android" goto android-config  :android-config set CERT_FILE=%AND_CERT_FILE% set SIGNING_OPTIONS=%AND_SIGNING_OPTIONS% set ICONS=%AND_ICONS% set DIST_EXT=apk set TYPE=apk goto start  :start if not exist "%CERT_FILE%" goto certificate :: Output file set FILE_OR_DIR=%FILE_OR_DIR% -C "%ICONS%" . if not exist "%DIST_PATH%" md "%DIST_PATH%" set OUTPUT=%DIST_PATH%\%DIST_NAME%%TARGET%.%DIST_EXT% :: Package  echo true echo. call adt -package -target %TYPE%%TARGET% %OPTIONS% %SIGNING_OPTIONS% "%OUTPUT%"     "%APP_XML%" %FILE_OR_DIR% -extdir lib/ echo. if errorlevel 1 goto failed goto end  :certificate echo Certificate not found: %CERT_FILE% echo.  if %PAUSE_ERRORS%==1 pause exit  :failed echo APK setup creation FAILED.  if %PAUSE_ERRORS%==1 pause exit  :end


What is difference between 'going to' and 'about to' in the given sentences?

I am going to buy a house.  I am about to buy a house.  I think both are planned actions that will happen in future. Is there any difference in the above sentences? Explain to me the correct meaning of above sentences and explain to me the correct usage of going to and about to in a sentence.


Hello I have a big problem,  When I am trying to sync my music with iPhone 4 using rhythmbox it just exits.   When I am trying to sync my music using banshee its just freezes.   anyone have ideas?


I've been given this bike that needs attention.  I have found no information on the web about a Raleigh "The Mission" bicycle that matches this type, though there's lots on the more recent rock hopper.  I'm wondering about its age, make up, market, -any information really.  It looks like it might make a good commuter for a small adult, which I'll have on my hands soon.


Why there is no dedicated Python community?

I was wondering why there is no dedicated python community in Stack Exchange like Drupal, Android etc? Isn't the language (Python) popular enough?  I am a Python user since last year. Would like to know more about this language and different problems faced by other programmers.


I was encrypting my USB flash drive using VeraCrypt and the encryption failed at 97%, thus making the flash drive RAW.  I have tried formatting the flash drive many ways, but nothing works. I have used 3 different third-party programs such as Minitool and AOMEI partition editor. They do detect the flash drive, but aren't showing any action options for it. I can't do anything with any of these programs. All the options in the action menu are grayed out for the flash drive.   The flash drive doesn't show up in the file explorer, "this PC". However it does show up in the Windows Disk Management, but again I can't access any of the options from it, all are grayed out when I right-click the drive. I have also tried to use diskpart command from an elevated command prompt. Whenever I use  clean command, it shows I/O device error.   I have also removed the write protection using attributes read-only in diskpart and it was successful, but again, the clean command gives I/O device error.  There is some data on the flash drive, which is accessible via data recovery software. I have a backup of my data, so I don't care if I lose the data.   Basically I need the flash drive to function again. Please note that I am unable to perform any kind of action with the flash drive, which includes - formatting, changing drive letter, deleting partition, etc. All the action options are grayed out in both the third-party software and in the Windows Disk Management.   I am attaching the screenshots of everything that I have tried.  Windows Disk Management:   (Click images to enlarge)  Options grayed out on right-clicking the USB disk:    Using AOMEI partitioning software:    Using Minitool partitioning software:     Using Diskpart, I/O device error:


Determining the extended interfaces of a Class

I need to determine if a Class object representing an interface extends another interface, ie:   package a.b.c.d;     public Interface IMyInterface extends a.b.d.c.ISomeOtherInterface{     }   according to  Class.getSuperClass() will return null for an Interface.       If this Class represents either the   Object class, an interface, a   primitive type, or void, then null is   returned.   Therefore the following won't work.  Class interface = Class.ForName("a.b.c.d.IMyInterface") Class extendedInterface = interface.getSuperClass(); if(extendedInterface.getName().equals("a.b.d.c.ISomeOtherInterface")){     //do whatever here }   any ideas?


I have a Philippine passport. I'm traveling from Guam to LAX (have a US tourist visa) and returning Houston to Guam. Both flights stopover in Narita, for 4 hours and 8 hours. Do I need a transit visa?   Thanks!


How to use rank() function with duplicate scores but without skipping rank?

By default, the rank function in Excel gives duplicate numbers the same rank but for the next score it will skip a rank. So if there are 2 scores on rank 5, the next score will get rank 7.  I want to use a function that will give the same scores the same rank but without skipping a rank.  See following example:  Score   rank 60       1 60       1 55       2 49       3 38       4 38       4 32       5   So the scores get a rank from high to low and there is no gap in the ranks.


Why Do I keep getting nullpointexception java scanner file reader

I don't understand why I keep getting the null exception. I've checked for null with while hasNextLine() loop. Here is my code. Please help me out! Thanks!      public class SpellCheckerTool {    private HashSet<String> hashedDictionary;   private ArrayList<String> listDictionary;    /**    * Instantiate this SpellCheckerTool.    * @param dictionaryFileName the dictionary to use for testing    * spellings   */   public SpellCheckerTool(String dictionaryFileName) {     // inialize both dictionaries     try{       Scanner sc = new Scanner(new File(dictionaryFileName));       while (sc.hasNextLine()){         String input = sc.nextLine();          hashedDictionary.add(input);         listDictionary.add(input);          }     }      catch (FileNotFoundException e){       System.out.println("File Not Found");     }


most secure way to send info between web pages

I am quite inexperienced with using php and javascript etc. but for my website I need to send mysql querys to a php page that will appear in a frame on the same page.  I know that hackers have so many ways to access the database with sql injection that with my inexperience I'm going to leave it wide open.  So I was thinking that instead of sending anything with post and get, I could save the query into a text file and then load the text file into the php script in the frame.   This seems more secure to me, but I expect I'm going to hear otherwise.  If that's not secure, then what is the best way to send 1 very long database query from one page to another?


I want to write this belongs to symbol in latex like this  x belongs to R^M. that you normally see in papers. Suggestions?


How to avoid "Unknown audio device" prompt

Everytime I plug my headset into my notebook, Ubuntu shows a "Unknown audio device" dialog asking me what kind of device I plugged in:     How can I avoid this dialog and use Headset as the default?


How could a human doctor save a poisoned Kosh, given that Vorlon biology is totally different from human?

When Kosh was poisoned, Dr Benjamin Kyle saved him. How could a human doctor be able to save a Vorlon when the Vorlon biology is so different from humans'? In fact, the Vorlon had no physical form and seemed to exist in some kind of floating gaseous form like a ghost. How can that be even treatable in the first place by a human doctor?


Automatic installation of DbSecurityspt folder

We have an Amazon EC2 instance.  The folder DbSecurityspt gets automatically installed in c:/ProgramFiles and the associated service also starts automatically. Removing them, installs them again the next day. After googling, it was found be a trojan.   We have scanned our system using Windows Defender but the scan resulted clean. We tried the process of removing it manually, but no relative locations were found.  Blocking outbound port 587 resolves the issue. But since our website uses mailing service we need to open this port. Closing this port slows the response time.  How can we identify the connection between blocking this particular port and installation of this malware?  How can the response speed be improved even on keeping port 587 closed?


I am using biblatex with the authoryear styles.  So far I've been able to find everything I need easily in the excellent documentation, but I'm stuck on one thing.   With my current settings (below) citations only have the year hyperlinked to the bibliography entry. I think prior to using biblatex I would have the whole citation (authors + year) as a reference - I think this is easier to click etc. when browsing.  Is there an easy way to get this (or does it involve creating a new style).  \usepackage[style=authoryear,             bibstyle=authoryear,             citestyle=authoryear,             natbib=true,             hyperref=true,             backref=true,             abbreviate=true]{biblatex}


How to concatenate the text when group by a particular column in SQL Server

Hi I have a table StudentNote with three fields 'StudentID','Notes','Date'.i have the following values    Now my requirement is ,i wanted to group the above table on StudentID  and Concatenate Note and Date Fields like    How can i write a sql to achieve this.  Thanks in advance


I'm trying to understand the Maxwell's Equation example from David Tongs QFT notes. He uses the Lagrangian: $$  L = -\frac{1}{2}(\partial_{\mu}A_{\nu})(\partial^{\mu}A^{\nu})+\frac{1}{2}(\partial_{\mu}A^{\mu})^2 $$ To compute the equations of motion. I understand the Einstein summation notation but I don't understand how one computes $ \frac{\partial{L}}{\partial(\partial_{\mu}A_{\nu})}$  Can someone explain to me the steps to compute: $$ \frac{\partial{L}}{\partial(\partial_{\mu}A_{\nu})} = -\partial^{\mu}A^{\nu}+(\partial_{\rho}A^{\rho})\eta^{\mu\nu} $$


Is it possible to create a procedural spiral around a tube?

I have been struggling to create a bump that goes spiraling around a tube, sort of like a toilet paper tube.  Basically, it is a line that wraps around the tube several times, continuously.  I cannot figure out the math to make it happen.


I've changed my password for SE and am trying to learn it. So I want to be logged out of SE when I close my browser or turn off the computer or similar, so that I learn the password by typing it lots. But when I log out and try to log back in, it logs me straight in without asking me for a password. Don't get me wrong, any other time that's a useful feature, but is there a way I can disable it, and a setting I can change so that I have to relog every time I leave my browser, or similar? I'm using Chrome, I cleared out the saved passwords and unticked "Offer to save your web passwords" in Chrome settings, but my password is still saved for SE.  I don't know enough about scripts to use a programmatic solution, so if there is no way I can do this through either site settings or Chrome settings, I'll grin and bear it.


Google sheets grouping function in excel equivalent or workaround?

I know you can't do it in Google sheets. I think the grouping function in Excel is one of the most useful things out there with the ability to expand or collapse rows and columns by grouping them.   Has anybody found a good work around for the grouping feature in Excel? If so, please share.


how to calculate distance between two geographic points

I am developping a UWP application, and now im trying to calculate the distance between two points I alreday have their latitude and longitude . any ideas how to do that ?


Which listener should I use for JTextField?

In my logo quiz game I have to take the value written in text Field when the user press ENTER key and compare it with the correct answer.Which listener should I use. I used Action listener but it's not working. I am new to programming.   private JTextField textField=new JTextField("");  textField.addActionListener(new ActionListener() {         public void actionPerformed(ActionEvent e) {             result();         }     });      textField.setBounds(0, 241, 264, 31);     getContentPane().add(textField);     textField.setColumns(10);     private void result(){      answer=textField.getText();      if(answer=="apple"){         JOptionPane.showMessageDialog(this, "right answer");     }     else{         JOptionPane.showMessageDialog(this, "wrong answer");     } }}


How will I upgrade Ubuntu 12.04 to 13.1 internally without the iso file . Please help .


Prove that for all real numbers x, the inequality $2^x$ + $3^x$ - $4^x$ + $6^x$ -$9^x$ < 1 holds

Prove that for all $x \in \mathbb{R}$ the inequality $2^x + 3^x - 4^x + 6^x - 9^x < 1$ holds.   Firstly, I rewrote the inequality as: $2^x + 3^x - (2^x)^2 + (2^x \cdot 3^x) - (3^x)^2 < 1$ and then tried to analyze a function for $x > 1$ and $x < 0$. Thank you for your responses.


I am trying to get the event handler without doing any changes in MyControl class. I tried to use reflection but I am not able to get the handler. Following is a code sample. Thanks  public class MyControl : Control {     public void Register()     {         SizeChanged += MyControl_SizeChanged;     }      void MyControl_SizeChanged(object sender, EventArgs e)     {         // Do something     } }  //[TestFixture] public class MyControlTest {     //  [Test]     public void RegisterTest()     {          var control = new MyControl();         control.Register();          var eventInfo = control.GetType().GetEvent("SizeChanged", BindingFlags.Public | BindingFlags.Instance);          // Need to get the handler (delegate) and GetInvocationList().Count         EventHandler handler = ...;          var count = handler.GetInvocationList().Count();         Assert.That(count, IsolationLevel.EqualTo(1));     } }


Does "until [date]" mean "before that date"?

What does until mean in the following?     You need to deliver this product within 2 days (until August 18, 2011)   to meet your deadline and get paid.   Does this mean that I have to deliver the product by 23:59 on 17 August 2011 or 23:59 on 18 August 2011? The order time is 21:04 on August 16 2011.


I have a Dell Precision 3510, running 14.04.6 currently on Kernel 3.19.80. After software update I have lost all connectivity to Ethernet and wireless.  Entering the grub menu and switching to kernel 3.19.23 allows me to connect via Ethernet.  When I run   sudo lshw -C network   The output is:  *-network UNCLAIMED         description: Network controller    product: Wireless 8260    vendor: Intel Corporation    physical id: 0    bus info: pci@0000:02:00.0    version: 3a    width: 64 bits    clock: 33MHz    capabilities: pm msi pciexpress cap_list    configuration: latency=0    resources: memory:ec100000-ec101fff *-network    description: Ethernet interface    product: Ethernet Connection (2) I219-LM    vendor: Intel Corporation    physical id: 1f.6    bus info: pci@0000:00:1f.6    logical name: eth0    version: 31    serial: 28:f1:0e:13:e1:40    size: 1Gbit/s    capacity: 1Gbit/s    width: 32 bits    clock: 33MHz    capabilities: pm msi bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation    configuration: autonegotiation=on broadcast=yes driver=e1000e driverversion=2.3.2-k duplex=full firmware=0.8-3 ip=151.159.19.39 latency=0 link=yes multicast=yes port=twisted pair speed=1Gbit/s    resources: irq:124 memory:ec300000-ec31ffff   When using the latest 3.19 kernel the Ethernet is also UNCLAIMED.  Please advice.  Edit:  is the same issue for Ubuntu 15, not 14.04. Will the same solution work?


Proof that integrating f(x) between a and b is the same as integrating f(a+b-x) over the same bounds?

$$\int_a^bf(x)dx=\int_a^b f(a+b-x) dx$$  Is anyone able to show me a rigorous proof of this identity. I understand using a substitution of $u=a-x$ gives rise to the RHS in terms of $u$ but don’t know how to show this implies that it’s also true for $x$?


Can I install Windows Home Premium over Windows 7 Professional?

Some context: I have been tasked with repairing a PC which is running non-genuine Windows 7 Professional. The PC does come with an OEM license for Windows 7 Home Premium, and I will be offering to help the owner go genuine by reinstalling this version. But there are a lot of personal files stored on the PC, and it is preferable that I leave these files in place rather than backing them up and restoring them afterward, because of reasons.  If I install Windows 7 Home Premium from disc, can I do so non-destructively i.e. without erasing the existing user account and information?  (This question is similar to some others, but those I can find seem to be either about upgrading rather than downgrading, or about downgrading without a reinstall, as opposed to reinstalling without erasing the target disk first.)


Deriving posterior for weights in bayesian linear regression

Given is a linear model $y_i=x_i^T+e_i$ where $e_i \sim N(0, \sigma^2)$. The precision is defined as $\tau = \frac{1}{\sigma^2}$. I am asked to derive the posterior $\pi(\beta|x,\tau)$.  Would I compute the posterior by doing the following: $\pi(\beta|x,\tau) \propto p(x, \tau | \beta) p(\beta)$ or $\pi(\beta|x,\tau) \propto p(x,|\tau, \beta) p(\tau |\beta) p(\beta)$?  I would assume the above relations to be equivalent; How do the mathematical expressions of the pdfs of $p(x, \tau | \beta)$ and $p(x,|\tau, \beta$) differ?


I'm trying to build a teleporter. I want the player to be teleported from the first sign(left) to the right sign(right). So, when the player steps on the red wool on the left, he will automatically be teleported to the red wool on the right. I do not want to use any pressure plats.It might work with the testfor comment, but I didn't figure out, put that only works with a radius. BTW I'm in 1.10.2 bou I could probably change the version if necessary.     The testfor command block should activate the teleport command block,when the player is detected. Now, I'm not really the expert, so I know non of the commands that you would need to build this construction. Please help, I would highly appreciate it! If you need any more details, ask me!


Reducibility of polynomial in rational field

Let $f(x)\in \mathbb{Q}[x]$ be a polynomial of degree $n>0$. Let $p_1, p_2, \dots ,p_{n+1}$ be distinct prime numbers. Show that there exists a non-zero polynomial $g(x)\in \mathbb{Q}[x]$ such that $fg=\sum_{i=1}^{n+1} c_ix^{p_i}$ with every $c_i\in \mathbb{Q}$.


when using arrows with Triangle Caps, tikz draws the part surrounding the junction between the line and the tip twice. This leads to unwanted results when using opacity; in addition, the part appended to the tip is not bendable.  \documentclass{article} \usepackage{tikz} \usetikzlibrary{arrows,arrows.meta}  \begin{document} \tikz {      \draw [line width=10mm,opacity=0.5,-{Triangle Cap[]}] (0,0) -- (6,0);     \draw [line width=7mm,opacity=0.5,-{Triangle Cap[]}] (0,1)                                 .. controls (1.5,0.5) and (1,4) .. (2,4); }  \end{document}   Result:    Any thoughts, solutions?  Thanks in advance!  uzahnd


Can somebody please explain how an initialization vector works.  My current understanding is that it is used to prevent 2 of the same messages looking identical after encryption, but isn't this the same as what a salt does?  How is it different from a salt?


$$\int_{ - \pi /2}^{\pi /2} \frac1{2007^{x} + 1}\cdot \frac {\sin^{2008}x}{\sin^{2008}x + \cos^{2008}x} \, dx .$$  This integral stuns me for a while, I just can't solve it! I tried integration by recurrence since here it seems that we have something that looks like a recurrence, but nothing comes up. I also tried all the integration techniques I'm aware of but they just don't work.  So I fear like this integral uses something like Fourier, or some Laplace transform thing or something of that sort but I don't know them.  That's why I will be very thankful if they could explain me how to solve it.  Thank you.


How to create simple xml and test for parallel testing using junit?

I am using JUnit as a framework and I am trying to set parallel testing, everywhere I lookedonline I can only find examples for TestNG. I have the Grid up and running and I can test cross platform and cross browser but I need to wait for each test to finish in order for the next to start? I just need a basic example to get me started which I think will be of great help to others like me using JUnit.


The gold tag badge description reads     Earned at least 1000 total score for at least 200 answers in the [sometag] tag.   It is not clear if score means reputation or (up)votes.  Applies to bronze and silver badge as well.  Edit: New wording should explicitly mention votes, since the term "score" is only seldomly used on SO, while "votes" and "reputation" are well known. As has been pointed out in the comments, the term "score" even has been inconsistently used in the glossary for the definition of "reputation".  Proposed new wording:      Earned at least 1000 net votes for at least 200 answers in the [sometag] tag.   Or with clarification:     Earned at least 1000 net votes (upvotes minus downvotes) for at least 200 answers in the [sometag] tag.


Animating the origin point location. Is it possible?

I want to animate the rotation of a plane (I need to move it from position 1 to position 2, using 2 turns and rotating by Z axis) as in the picture below. However to do so, I need the origin point to move from the left to the right side of a plane. Is it possible to keyfame the origin point location?


File size different between Explorer and Hard drives Properties

We have a MAC machine running on BootCamp for Windows 8.1 as well as the MAC. It's been runing for almost 1 year.  We found that on the Windows side (C:\ - BOOTCAMP) that this machine is only 4GB free space out of 371 GB. So we are starting to troubleshoot to find out what causing this.   We checked on C:\ drive (including Hidden file/folders) and select all the files and right click PROPERTIES to see the size and we found is 306 GB. So we are missing 66 GB !!!  Any ideas what causing this?  BTW ... we are running Windows 8.1 and we backing up via File History to external network device. But we now the fact that if the machine is not connected to the network, it backup to local disk. Now, we did setup to cache offline 5% of the disk BUT could be this is  the issue?  Thanks


So far, I've deduced that if the rank of A is n, then all the columns of A are linearly independent since A has n columns. As a result, m must be greater than or equal to n.  In the case that m = n, then A is a square matrix and we can just use matrix operations to distribute the inverse operation over the parenthesis; then we can apply the associative property and compute A*A-1 and AT-1 * AT first, eventually giving that the expression inside the norm is just the identity matrix, where the 2-norm of the identity matrix is obviously 1.  I'm having trouble for the case where m > n. I've identified that the expression inside the norm is actually the matrix of orthogonal projection, but I'm not sure if that will help me with the proof. Help is greatly appreciated, thanks.  This problem is from the text of "Matrix Computations" 3rd edition by Golub after covering a section on orthogonality and SVDs for some background.


I was reading the book "Essential Grammar in use" Third Edition by Raymond Murphy.   In page no.56, there were some questions about using Past Tense and Present Perfect Tense. In that, one question confused me a little. I've given it below,     The washing machine was broken, but it's OK now. It __________ (repair).   My answer at first sight was "was repaired" (wrong answer) because I thought the action was completed in the past.  But the correct answer given in the book was "has been repaired". It confused me a little. However, I understood it later that the action's result "It's OK now" has been related to the present. So the answer "has been repaired" seemed correct to me.  However I always confuse this below examples,     "I sent an email to you yesterday."      "We despatched a parcel to you yesterday."   vs.      "I have sent an email to you."      "We have despatched a parcel to you."   The first one should be the most common or correct answer. But what's wrong with the second one? Can I use it? Because the mail sent / parcel despatched has some connection with the Present, because it hasn't reached them yet.  Also please clarify, whenever I use Past tense, Is it always required to tell the time of action? Eg. "I sent an email to you yesterday."  I have already asked similar questions here. But still, I have some little confusions. As a non-native English speaker, most of the time, I think that something I did in the past has some connection with the present moment and I feel like I need to use " Present Perfect".  Please help me. Thanks in advance.  Update:  This question has been marked as duplicate. The other question was also asked by me. However this one is different & more in detail than the other question. That question was about the time markers (yesterday) with Present Perfect tense. But this is about no time markers, but I'm asking that, is it OK to use Present Perfect tense when the action was happened some hours ago however the action is still connected to the present moment.


I can't delete this folder which contain virus, it keeps being recreated when deleted

So today I was desperate to find a space for my c drive since I want to install something new. in that case I'm scanning my c drive for extra space. and I found this weird folder with weird content. I don't think far so I just delete it. suddenly, I can't use firefox because of certificate issue. I already sorted this out, fortunately. apparently, there is this process going on ZGU5ODFhYThhMjNkMT.exe that make firefox detect it as a man in the middle. I recognize that name which is from the weird folder I deleted. when I open c program files again, I found the weird folder is still there.  so this folder is recreated and begin the process when deleted? I don't know  anyone know how to actually delete this folder? or trace back what caused it to be recreated?  edit: i found that my windows defender keeps adding exceptions for these folder/programs. so windows defender scan won't be any use


Award additional badges for above 2,000 review tasks

While some gold badges are cumulable without huge effort, like  (10,000 views) or  (score of 100), it seems that the time spent in reviewing cannot be rewarded anymore past 1,000 review tasks, as the  badge can only be awarded once (per queue).  I propose that reviewing way above the current Steward threshold should still award something. This could maybe or maybe not help to pop the , but at least it would be nice to recognize the work of super active reviewers.  Possible rewards ideas (open to discussion):   a silver Steward every 1,000 review tasks above 1,000. Maybe a different name? a gold Steward every 1,000 * 2^n review tasks for n in 0 … ∞.


In a raid 5 setup, you get 4 TB of usable space out of 3 x 2 TB disks. How is that possible?  Simple minded as I am, I would think that you need 4TB to store your things, and use the remaining 2TB for recovery. But how can I recover 4TB out of only 2TB? If 1kb is gone, I only have 0.5kb to recover from. And if that is sufficient, why not use 0.5kb for storage right from the start.  I know this is a naive question. But what is the answer?


It surprises me when I hear someone using "do" in situations where I think it is unnecessary, as in these two examples.     I do need help.      I do have the strings.   Are these correct? Does this 'do' make any difference to the sentences I would expect to see here?     I need help.      I have the strings.


How can the Army of the Dead be free from Iluvatar's gift?

As Tolkien specified, Iluvatar granted the gift of death to the men, according to which men die inevitably and their souls travel into unknown place after the Halls of Mandos, how could there possibly be the army of ghosts, 'stuck' between life and death?


Black patches on home screen after upgrading to Ubuntu 20.04 from 18.04

I'm using a Dell Inspiron 5530 laptop with 8 GB RAM, integrated 4 GB Intel graphics and a 1 TB HDD. I upgraded Ubuntu from 18.04 to 20.04 yesterday. On starting my laptop, the desktop wallpaper has many blackish-yellow squares all over the screen, as shown here:  Also, some of the icons on desktop disappears and sometimes the laptop freezes. What should I do? Is Ubuntu 20.04 still unstable or is it some issue of my laptop. Can someone help?


Displaying geometry points from database layer using QGIS?

I have an Access Database with a table of Lats and Longs (as well as other attributes).  I can create a layer using an ODBC connection and can open the attribute table etc but can't figure out how to display the points on the screen.  I could create a shapefile of the points separately and link this to the Access file but would prefer not to have to do this.  Is there an easy way of doing this?


Pass a variable containing multiple arguments as the argument

Let's say we have a function, x_add:  def x_add(x,y):     k = x + y     return k   And I want a variable to hold the arguments for x,y:  p = (2,4)   Then I want to perform the funciton with this variable as the argument:  x_add(p)   Resulting in:  TypeError: x_add() takes exactly 2 arguments (1 given)   Is there any way to do this?


What's the relation between GetHashCode and Equals in a IEqualityComparer implementation?

I have a class A that inherits from a class B and implements IEqualityComparer<A>. This means class A provides its own implementation of both Equals and GetHashCode methods. So far so good. The problem is that I don't understand why the code behaves in the following way:  debugger will only reach A's Equals implementation breakpoint if A's GetHashCode implementation returns  this.GetHashCode() instead of obj.GetHashCode(), with "obj" being the parameter that GetHashCode's signature defines(a variable of type A, in my case).  Intuitively, I thought that I should return the hashcode of the object I received, but doing so makes the compiler ignore the instance's Equals implementation.  Why does this happen?  Code demonstration:  public class A : B, IEqualityComparer<A> {     public bool Equals(A x, A y)     {         //my implementation...     }      public int GetHashCode(A obj)     {         //return obj.GetHashCode(); -> this makes my Equals implementation above be ignored! Why?         return this.GetHashCode(); -> my Equals implementation is used     } }


Disable ClearType (blurry fonts) in Internet Explorer 10 on windows 7

I've installed recently the latest Internet Explorer 10 and found out again what was my issue with the previous upgrade -- blurry fonts aka ClearType! Unfortunately there are some apps that use IE engine and thus all content there is blurry too :/  I know about  but unfortunately it seems that it is only for IE9. Is there any other solution to disable CT in IE10?  (and for clarity - I don't like CT, I've tried tweaking it but for me it's just blurry and case pain in my eyes no matter what I do... it's probably related to the low dpi of my monitor)


Should I use   What fraction of the residents are married?  or  What fraction of the residents is married?  Technically, as fraction is singular, I would use the latter version. Am I correct?


Neat method to show that $\mathbb{Q}(2^{1/3}) \ne \mathbb{Q}(3^{1/3}) $?

I am wondering how to show looking obvious $\mathbb{Q}(2^{\frac{1}{3}}) \ne \mathbb{Q}(3^{\frac{1}{3}}) $?  This question has appeared to compute the order of $\text{Gal}(\mathbb{Q}(2^{\frac{1}{3}},3^{\frac{1}{3}},\xi_3)/\mathbb{Q})$ where $\xi_3$ is a primitive root of unity.  I already know to show this by brutal force by assumimg $2^{\frac{1}{3}}=a+b\cdot2^{\frac{1}{3}}+c\cdot 2^{\frac{2}{3}}$ for some $a,b,c\in \mathbb{Q}$ and take 3rd power on both side and compare their coefficients. But its too boring.  Is there any neat method?


What does "no talloc stack frame..." mean?

I am using Ubuntu 14.04 on my Dell XPS 13 9333.  Everytime I use the command line (succesfully or not) a short line is being put out instead of the usual fresh and empty line which you normally get if the command you used was succesfully processed. The line is always the same and it says:  no talloc stackframe at ../source3/param/loadparm.c:4864, leaking memory   Any idea what this means?


Double absolute value proof: $||a|-|b||\le |a-b|$

I guess, I know how to solve inequalities with absolute value, but I have problems with this one.  $||a|-|b||\le |a-b|$  $a,b\in \mathbb{R}$  I tried to solve the inequation like this:  case1: $a>0$   case2: $a<0$   I started with case 1. than we have two possibilities $b<0$ and $b>0$   Firstly I took $b<0$ and I had another two possibilities  $|a+b|>0$  $|a+b|<0$  I take $|a+b|>0$ and in this case I had two possibilites according to to right side of the inequation  $|a-b|>0 ........... a+b\le a-b ......b\le-b$  $|a-b|<0..........a+b\le -a+b .......a\le -a$  I can do the same with other possibilites, but how do I know, if my solution (or even method) is right? there are so many conditions, that I am lost in them.  Thank you for your time.


What's the point of the Legendary Detect action?

Every Ancient Dragon has Detect as a Legendary Action:     Detect. The dragon makes a Wisdom (Perception) check.   Unless I'm missing something, this seems to be a worthlessly ambiguous action. PHB 174 (under "Ability Checks") reads:     The DM calls for an ability check whenever a character or monster attempts an action (other than an attack) that has a chance of failure. When the outcome is uncertain, the dice determine the results.   In other words, after an action is declared, if it can fail, dice must be rolled. But the Dragon isn't attempting a fallable action; it's just rolling perception dice with no means or ends, with no attempted action attached to them. It's skipping the part where it attempts an action and it's going straight to the dice rolls.  Can the dragon attempt anything that the GM could justify as a perception check? Or does it have a more specific purpose, such as locating a hiding character or identifying an illusion? If so, why is it termed so ambiguously? If not, what does the Detect action actually do?


Simple Power Series Expansion for Problems similar to $f = (1 + \epsilon \,x)^{1/\epsilon}$

I was flicking through a book on perturbation methods and saw a simple question asking the reader to expand the following expression for $f$ in a power series (up to the first 2 terms):  $f = (1 + \epsilon \,x)^{1/\epsilon}$, where $\epsilon$ is a small parameter. I'm sure this is very simple, but I wasn't certain about the best way to approach this. A quick look at mathematica tells me the solution is $e^x - \frac{1}{2} (e^x x^2) \,\epsilon + ...$. How would I go about getting this answer - and more importantly, how would I systematically find series expansions for problems similar to this one?


Can you have more than 3 horses stabled, or is that all the horses we get? Or can we have 3 stabled and 1 to ride?   I would like to have all the superior horses if possible, but if not I'm going to have to pick my favorite 3 and go with those.


Time synchronization of machines on LAN to GPS NTP server on the LAN

I have 4 computers on a LAN that need to have their system clocks closely synchronized within a ms or so if possible.  I have just installed a GPS based time server (ESE-104A) on the LAN.  At this point the LAN is connected to a router and the internet but the router will not be connected to the internet when operational.  In operation the whole system will be started when power is applied to the machines, NTP server, and router.   How can I set Ubuntu to sync every so many minutes and calculate what the period should be?  How can I get an idea of how long it takes to settle down and what the quality of the time keeping is? I found a reference, from around 2000 perhaps, that suggests that the hwclock should be synched from the system time only at shut down.  Should I do this and how? What log files should I keep?   Here's the results of "ntpq -      remote   refid       st t when poll reach   delay   offset  jitter     *nts   .M-@M-(^AM-R.  1 u  29  128   377    38.912  -7.739   7.195   Here's my ntp.conf (I use IPv4 only)      driftfile /etc/ntp.drift      statistics loopstats peerstats clockstats     filegen loopstats file loopstats type day enable     filegen peerstats file peerstats type day enable     filegen clockstats file clockstats type day enable      server 192.168.1.210      restrict -4 default kod notrap nomodify nopeer noquery     restrict -6 default kod notrap nomodify nopeer noquery      restrict 127.0.0.1     restrict ::1


How to determine the $\lim_{n\to \infty} \frac{1+2^2+\ldots+n^n}{n^n}=1$.

I stuck to do this,     $$\lim_{n\to \infty} \frac{1+2^2+\ldots+n^n}{n^n}=1.$$   The only thing I have observed is $$ 1\le \lim_{n\to \infty} \frac{1+2^2+\ldots+n^n}{n^n}$$ I am unable to get its upper estimate so that I can apply Sandwich's lemma.


How do we prove $n^n \mid m^m \Rightarrow n \mid m$?

I'm not sure I've got this right. When proving $a^n \mid b^n \Rightarrow a \mid b$, can we do this indirectly? In short,  "Suppose $a$ does not divide $b$, this implies that $a^n$ does not divide $b^n$. But $a^n \mid b^n$, hence $a$ divides $b$."  How about $n^n \mid m^m \Rightarrow n \mid m$? Can we do this the same way?


How does light interference explain colour mixing?

I've grown curious about the phenomenon of light interference. If two light sources of different wavelengths that correspond to two arbitrary colours, say blue and yellow, constructively join, they will result in a green central fringe, as any colour mixing chart would tell us. Is this because the two electromagnetic waves add up and create a new wave with the colour yellow, or is it just our brains tricking us into seeing a merged colour? (As many colours are made-up and not physically real, like pink, for instance). Thanks so much in advance.


Incorporate Google Streetview into a Leaflet map

The person who asked the question at the link below way back in 2011 said, "I understand that it is possible to incorporate Google StreetView into non-Google apps".  Can anyone tell me how this is possible? I'd like to add street view functionality to my leaflet map.


Let $G$ be a group and $a,b\in  G$ such that    $a^{-1}b^2a=b^3$ and $b^{-1}a^2b=a^3$. Then prove that $a=b=e$, where $e$ is the identity of group.   If we are able to prove $ab = ba$ then we are done. But i am unable to show that. Can we use somewhere that $\gcd(2,3)=1$, or if we write $b^2a=ab^3$ and $a^2b=ba^3$ then finding some relation between $a$ and $b$ to prove that.


How to install latest version of nodejs and npm on Ubuntu 14.04 LTS?

I installed Nodejs via package   curl -sL https://deb.nodesource.com/setup_4.x | sudo -E bash - sudo apt-get install -y nodejs   Then I check version of nodejs and npm   nodejs -v v0.10.25 npm -v 1.3.10   Current version of nodejs are v4.4.2 LTS and v5.10.1 stable. What's wrong?


Indroductory books about Philosophy for young people

I'm looking for a book about philosophy to give me a push or to help me get in touch with philosophy properly.


Do academic peer reviewers receive any salary? If yes, what is the annual average?


PHPMailer email goes to Spam folder after Authentication Test Passed. What is wrong?

MY PHPMailer email goes to Spam for YahooMail and Hotmail, but not for Gmail. After running Port25's authentication verifier test to make sure my email settings were good these were the summary of the results:      Summary of Authentication Verifier    - SPF check: pass    - DomainKeys check:neutral    - DKIM check:neutral    - SpamAssassin check: ham   (Message me if you want the full details)   WHAT I'VE TRIED:    SMTPAUTH = TRUE DOMAIN NOT BLACKLISTED: voozlr.com Authentication Verifier Test Passed REMOVED ALL IMAGES REMOVED ALL CONTENT EXCEPT FOR BODY: TEST   I'm hosting my site and email server on Interserver.net, and they made sure everything is working from their end, but I still go to SPAM.      So what are the best practices for my PHP code to avoid the spam folder?  Someone please give me an example code or better yet edit my code to show me what SPAM free PHPMAILER code looks like.  PHP CODE:  $mail2 = new PHPMailer(); $mail2->IsMail(); $mail2->Host = "mail.mydomain.com";  $mail2->CharSet  = "UTF-8"; $mail2->SMTPAuth = true;  $mail2->Username = "name@mydomain.com";  $mail2->Password = "password1234";  $mail2->SMTPSecure = 'TLS';                       $mail2->Port = 25;                              $mail2->setFrom('support@mydomain.com', 'Support'); $mail2->AddAddress("$email"); $mail2->AddReplyTo('support@mydomain.com'); $mail2->WordWrap = 50;  mail($to, $subject, $message, $headers);  $mail2->Subject = "Testing";  $headers .= "MIME-Version: 1.0\r\n";  $headers .= "Content-type: text/html; charset=iso-8859-1" . "\r\n"; $headers = "From: " . strip_tags($_POST['admin@mydomain.com']) . "\r\n"; "Reply-To: support@mydomain" . "\r\n";  $message .= 'test'; $mail2->Body = $message; $mail2->AltBody = $message;  if(!$mail2->Send()) { echo "Message could not be sent. Please reload the page and try again. <p>"; echo "Mailer Error: " . $mail2->ErrorInfo; exit; }


does space-time expansion affect on fundamental particle?

does space-time expansion affect on fundamental particle or point particle?


Direct speech inside another direct speech

Please, I'm not sure how in American English this "direct speech inside another direct speech" should be written properly. Here it is this sentence:     "He was five and a half meters from her and he was talking to her, softly. He told her: 'Please, try to calm yourself down. Everything will be OK'."   The use of the quotation marks is it correct? Thank you everybody in advance for your help!  Andrea Iovinelli


In almost every Dravidian language, there are two versions of you, one is friendly version and another one is a  respect version.    Is there any respected version of you in English?


const T& reference initialized to a temporary

For the following code:  const int &Rtest = 0;   I'm unsure why g++ accepts this (would all compilers accept this?). I thought that reference types must reference objects, not arbitrary numbers, so what is Rtest at this point? How is it used in programming?  In contrast:  int &Rtest = 0;   Will not compile, and this makes sense to me, because reference types must reference objects.  So why does making the type reference const int& make it acceptable?  (I know int does not matter, this is just the type I happened to use.)


Find the power series of $f(x)=\frac{1}{x^2+x+1}$

I want to find the power series of $$f(x)=\frac{1}{x^2+x+1}$$ How can I prove the following? $$f(x)=\frac{2}{\sqrt{3}} \sum_{n=0}^{\infty} \mathrm{sin}\frac{2\pi(n+1)}{3} x^n  \,\,\,\, |x|<1$$  In particular I would like to know how to proceed in this case. The polinomial $x^2+x+1$ has no roots so here I cannot use partial fraction decomposition: what method should I use?


What is the fastest 4 seater car in Grand Theft Auto 5?

For a good getaway vehicle which is the fastest 4-seater car in Grand Theft Auto 5?  As @turbo mentions in the comments below acceleration is also an important consideration.


What is the difference between adding to PATH on the CLI vs in bashrc

In an online video lecture the teacher has explained how to add to PATH both on the command line and via .bashrc, and has indicated that the proper way of doing this is through .bashrc but has not adequately explained why.    My question is what is the difference between executing the following from the command line:  $ export PATH=/home/username/bin:$PATH   Or simply adding the line: export PATH=/home/username/bin:$PATH to my ~/.bashrc.


The bad sectors amount has been going up a lot

I currently have 928 bad sectors and it's been increasing by the minute, but aside from the bad sectors count increasing at an incredible amount, there is no other sign that my hdd is failing, no weird sounds, no freezing, no slowing down, any help? EDIT: Here's a smart log.


Proving $\big(n!^{\frac1n}\big)_{n\in\mathbb N^*} \to \infty$

By definition, for any $a\in\mathbb R$, there exists $k\in\mathbb N^*$ such that, if $n\in\mathbb N+k$, then $n!^{\large\frac1n}>a$. Therefore, by induction, I must:   find some $k$ that satisfies $k!>a^k$; show that, for each $n\ge k$, if $n!>a^n$, then $(n+1)!>a^{n+1}$.   For the 2nd part, it's enough that $k\ge a-1$. I noticed the smallest adequate $k$ is $4$ for $a=2$ and $7$ for $a=3$, and I'm convinced that one can always find a $k$, but I would like a function of $a$ to make an actual argument.  Definition aside, methods other than this one are welcome. I tried picking a sequence dominated by $\big(n!^{\large\frac1n}\big)$ that went to infinity as well, but couldn't find any.


Why can I put a resistor at either lead of this LED and still see its effects?

Just to add a little bit of context to the question, I am using an Arduino Uno and a breadboard.  I have a 5V power source running to the positive (longer) lead of an LED (rated at about 2v and 20mA). I then have a 150 Ohm resistor connecting to the negative (shorter) lead of the LED. The resistor is then connected to ground.  I am using a breadboard, so whenever I remove the resistor and connect it from the power source to the positive (longer) lead of the LED, I still see the same amount of resistance.  In other words, with no resistor, the LED is at X brightness. However, with a resistor attached to either lead of the LED, there is the same amount of resistance (thus, the LED is dimmer, at X÷resistance brightness.)  Based on my very limited knowledge of electronics, I would've assumed that you would have to connect the resistor to the power source, and then to the positive lead of the LED, so that the voltage and current would drop before they got to the LED. This seems to be false, based on my little "experiment" here.  Why is this the case?


Why is this answer flag rejected, moderators don't need help?

I flagged this answer as "not an answer":    For the users who cannot see the content of the linked answer:  "Sorry for the late answer , I've found another way for this . as you said , using DataSource but What I would like to know now , is how to Load in it from SQL Server Database"  Surely this is a comment to the other answer, but my flag was rejected, and I don't know why?  Sure at least one of moderators believes that it's not an answer to the question, because they deleted this answer (). Surely this kind of rejection (which happens sometimes) disappoints users. And a next time someone like me is not going to flag such things (as "not an answer").   Maybe some moderators are accepting and rejecting flags in a bulk manner, but when someone flags as "not an answer", they should read the question and answer carefully, and if they cannot understand they should leave it to other moderators, instead of bulk accepting or rejecting. (This particular answer is very clearly a comment to the other answer and the user couldn't leave a comment  because of low reputation, and provided it as an answer, in this case a moderator checked it in blind manner).  My previous  was about not an answer, answers and moderator rejection, which means this pattern is usual.


How can I automate Find & Replace to change font colours in Google Docs?

How can I automate a find & replace function to change the font colour of all suit symbols document wide?  I write bridge articles (card game), and I need to automate this formatting constantly:  Find all "♣" and color the text green (#00b700). Find all "♦" and color the text orange (#ff8100). Find all "♥" and color the text red (#ff0000). Find all "♠" and color the text blue (#0000ff).  Answered: Mark and Michael helped build Google Apps Scripts to do this (see below). .


Difference between $\mathbb{F}(a)$ and $\mathbb{F}[a]$

If $\mathbb{F}$ is a field, what is the difference between $\mathbb{F}[a]$ and $\mathbb{F}(a)$? To my understanding $\mathbb{F}(a)$ is the smallest field containing $\mathbb{F}$ and $a$ whereas $\mathbb{F}[a]$ would have to be the polynomials over $\mathbb{F}$? Am I missing something here?


How does super() work inside a function of the child class?

I have a class structure definition as follows:  What I fail to understand is, how does Super() use the code from the Super class in the function of the base class here?  class Std(object):         def __init__(self):         self.W = defaultdict(int)      def update(self, vect, label):         self.bias += label         for k, v in vect.items():             self.W[k] += v * label class Avg(Std):     def __init__(self):         super(Avg, self).__init__()         self.U = defaultdict(int)         self.beta = 0      def update(self, vect, label):         super(Avg, self).update(vect, label)         self.beta += label * self.count         for k, v in vect.items():             self.U[k] += v * label * self.count   Can someone explain to me how many lines code are actually there in the update method of the Avg class and how does the Super() work here?


If $X$ and $Y$ are sets, their cartesian product $X\times Y$ is a set.

In ZFC set theory, every element object is a set. We know or feel that if $X$ and $Y$ are sets, their cartesian product $X\times Y$ is a set.  My question is: Why if $X$ and $Y$ are sets, their cartesian product $X\times Y$ is a set?


How to find the vector potential of the field $F = (-y,x,0)$?

Given the vector field $F = (-y,x,0)$, how can I find a vector potential of this field? I know that we have to find a vector field $G$ such that $F = \nabla \times G$, but I am struggling with finding a right solution.


Is there a single word that refers to the type of word that the words dawn, morning, afternoon, evening, ect are?  I'm looking for something more specific than 'time.'


How to export SVG in illustrator, and make object doesn't messy?

I've been struggling to create an icon in illustrator and convert it to SVG but the result is my SVG file becomes a messy object after I export it into SVG.  Can someone explain me why? I'm already trying different export setting but the issue still same.


Energy conservation of Virtual Particles - Quantum Fluctuation?

I (as a middle-school student) was wondering how virtual particles even conserve energy of the entire system? I don't mean just the particle's energy, but conservation with respect to the surroundings?  Let me explain more, Einstein proved that $E = mc^2$ and equivalently, we can say $m = \frac{E}{c^2}$ . We however know mass causes curvature in space-time (gravity well). Now that statement being completely valid we can use Quantum Fluctuation, implying energy and time can be related by the relation:  $\Delta{E}\Delta{t}\approx\frac{\hbar}{2}$ and by that simple relation we can make the following points:   As the energy increases, the time allowed to be "borrowed" decreases, before it gives it back to the universe. As time increases, the energy allowed to be "borrowed" decreases.    These are completely satisfactory points I've made, I believe.  Now, I have read that the vacuum is filled with constantly bubbling virtual particles that get created from the energy "borrowed" by the above relation and is destroyed again, which satisfies the energy conservation laws.   This seems to imply that  in the short time the virtual particle exists, they must have a very small mass which is: $m_{1} = \frac{\Delta{E}}{c^2}$ and using basic classical mechanics rather than GR (for sake of simplicity) we calculate that the gravitational force mediated by this short-lived virtual particle;  $F_{g}= G\frac{m_1 * m_x}{r^2}$   where $m_x$ is an particle\mass in question. Nevertheless since we know the force set upon an object moves the object in a direction, we can say it would increase its kinetic energy by this factor: $F_g = \frac{1}{2}mv^2$ which is equal to $G\frac{m_1 * m_x}{r^2} = \frac{1}{2}mv^2$.  Surely, this implies that every time quantum fluctuations happen, energy of real-particles\masses increases and therefore violates energy conservation, but what prevents this violation from taking place?  If virtual particles are not really present and interact with objects like I thought, how can Hawking radiation (currently a large concept in black hole physics) then be accepted in physics community?


Does zero correlation implies independence for linear models?

I know that in general if the correlation of two random variables is zero, it is always true that two variables are independent, and it is possible to provide some examples which are dependent with zero correlation. However, all examples that I have seen, use nonlinear relation between two variables. Can we say if two random variables have zero correlation will be independent (not using nonlinear relation but linear model)?


How do you use a variable in a regular expression?

I would like to create a String.replaceAll() method in JavaScript and I'm thinking that using a regex would be most terse way to do it.  However, I can't figure out how to pass a variable in to a regex.  I can do this already which will replace all the instances of "B" with "A".  "ABABAB".replace(/B/g, "A");   But I want to do something like this:  String.prototype.replaceAll = function(replaceThis, withThis) {     this.replace(/replaceThis/g, withThis); };   But obviously this will only replace the text "replaceThis"...so how do I pass this variable in to my regex string?


A function such that $f:\mathbb C \to \mathbb C$ such that $f(z)f(iz)=z^2$ satisfies $f(z)+f(-z)=0$.(MADHAVA-2020)

Suppose $f$ is a function such that $f:\mathbb C \to \mathbb C$ such that $f(z)f(iz)=z^2$, then we have to show that $\forall z\in \mathbb C f(z)+f(-z)=0 $.   Actually I have solved this problem and have no doubt about it but actually this question came in MADHAVA-2020. So I posted it on this site.   I am not answering the question and inviting all users to answer it.  It is a nice problem.   I will answer it within a week, but I am letting everyone try.


How to assign mouse button to Mission Control's 'Application windows' feature?

I have a button on the side of my mouse that Mission Control sees as Mouse Button 4.  In Mission Control's preferences, I can assign this button to either 'Show Desktop', 'Mission Control' or 'Show Dashboard'.  All three of these works fine, but if I try to map it to 'Application windows' the mouse button doesn't respond.  I'm able to bring up 'Application windows' using the keyboard shortcuts though.   My new iMac is 2 days old, so it's on fresh and up to date macOS Sierra. Same problem on my brand new MacBook, again with macOS Sierra.  Is the mouse shortcut just broken for this? Can anyone else reproduce it?  [Updated] My mouse is a Logitech G400 Optical Gaming Mouse. I've since installed the Logitech driver software, which also allows you to assign a button to Mission Control (which I did, and then unassigned it from system prefs).  This doesn't work properly either, but rather than not responding, all windows move a couple of pixels and then revert back to their original position. Almost like its trying to invoke Mission Control but something is aborting it. I can map the buttons to any other feature and it works fine


How to create (UEFI) multiboot USB drive?

I want to create multiboot USB flash drive that contains Windows 10, Windows 7 installers and hirens DVD with Windows 10 PE for rescue purposes. And I want to make it compatible with UEFI.  I used to use YUMI tool and it works great for legacy BIOS, but for UEFI it's not good. Any suggestions?


I've often heard that a population, human or otherwise, will continue to grow as long as there is food available (assuming nothing else is killing them off).  It makes sense: if you have food you can live, and if nothing is hunting you you'll survive to reproduce.  I recently designed a piece of software to simulate an ecosystem, with groups of creatures of different species eating and hunting and reproducing alongside each other.  It was very simplified (each animal had simple attack/defense/speed/stealth values, etc), but something became rapidly apparent: in every simulation the predators overwhelmed the prey, reproducing until their numbers could not be sustained by the herbivores, and leading to an inevitable die-off of both groups.  I could delay the die-off by adjusting different values and initial population counts, but it would always happen eventually.  The predators would eat and breed and eat and breed until the entire system collapsed.  At first I thought it was just the product of my over-simplified system, but it got me thinking: what prevents predators from overpopulating in real life?  It seems like the natural tendency would be for (for example) the sharks to continue breeding and eating until all the fish are gone, or the wolves to eat all the deer, etc.  Obviously some predators have predators of their own, but that's just putting off the question: if the hyenas don't overpopulate because the lions eat them, then what's keeping the lions from overpopulating?  I can't come up with anything that would prevent the apex predators from growing too numerous, then fighting each other over a dwindling prey population, then dying off entirely when there was no more food to find.  Do predator populations self-regulate to prevent putting undo stress on their prey populations?  Or is there some other mechanism to keep the predator hierarchy from becoming top-heavy?


Don't join chat rooms automatically when following a link

Currently, when you follow a link to a chat room, you'll automatically join the room. This means, everyone in the room sees who's just entering that room.  For me personally, this is almost never the desired behaviour. I want to read the contents of the room, joining a room is an entirely separate decision for me. I almost never join a room unless I intend to participate in the discussion.  This behaviour is for one surprising, I don't think everyone expects that they'll be publicly joining a particular chat room just by following a link. This is made even worse by the "convert comments to chat" function, which leaves chat links scattered on the main sites. I can't just read the converted comments, I have to join the chat because it's the only link there (unless I manually try to find the room). For me this means that I never actually follow the links to chat unless it's something really important to me.  Joining a chat room is an active action to me, not something that should automatically happen without the user's consent. It has privacy implications, other users get notified that you're looking at that chat room at that specific point in time. It can also provoke reactions, suddenly I'm greeted by someone I don't know because they noticed I entered that room. As I'm a moderator they might also suspect that there is some kind of trouble which caused me to enter that room.  Following a link to a chat room should not automatically make you join that room. The easiest way would be to just redirect to the transcript, but that could be confusing for people that aren't familiar with SE chat. The other option would be to still go to the live chat page, but without joining chat. So the bar at the bottom would have a big "join this chat room" button instead of the message box.


Proving that median of list $[x_1,x_2,...,x_n]$ minimises the sum $\sum_{i=1}^{i=n} |x_i-m|$ where $m$ is some number

The problem is in the title. Here is a detailed description:  Let's say we have list $[x_i]_{i=1}^{i=n}$ where $x_i\in\Bbb{N}$. I want to pick such $m\in\Bbb{N}$ which minimises the sum $\sum_{i=1}^{i=n} |x_i-m|$.  In my computer science class we had a problem which was equivalent to the upper one. And apparently the answer was that the $m$ we should choose is the median of the list. But no one has proven it, and I have a hard time seeing why that is the case and not for example arithmetic mean of the list.   What strategy should I use in order to prove that?


biblatex and new line for DOI, URL and Eprint

I've been playing around with biblatex a little and, since I am tired of broken DOIs, URLS and other eprint links, I would like to use a biblatex style which implements a new line for these fields. I started from the standard.bbx file and in the article style, I replaced  \newunit\newblock \usebibmacro{doi+eprint+url}   by  \newline \usebibmacro{doi+eprint+url}   There is something wrong since a dot (.) is added at the beginning of the DOI line in the final bibliography and a new line is added even though the doi field is empty. Is there a way to fix this?  Then, I wanted to go a bit further by having a new line for each of the DOI, URL, EPRINT, then something like:  \newline \usebibmacro{doi} \newline \usebibmacro{url} \newline \usebibmacro{eprint}   by replacing \newbibmacro*{doi+eprint+url} by \newbibmacro*{doi}, \newbibmacro*{eprint} and \newbibmacro*{url} (copy-paste process of the last lines of standard.bbx) and by replacing \usebibmacro{doi+eprint+url} by the lines above but unfortunately, it does not work. I'd be happy to hear from you on this.


LaTeX code for text above the $\rightarrow$

Hi I am wondering what code is used to get text above the $\rightarrow$   have tried $ \xrightarrow{P}$ but not running on my LaTeX as I do not know which package to install or how to install it.   currently using \usepackage{mathtools} but it wants to load from a random directory and then LaTeX stops working.


I'm thinking about the scenario of using a set of (potentially untrusted) hosts to store (potentially private) files. Think something like distributed backup where you contribute some disk space and in exchange you get to store N copies of your data in other nodes. The issue is how to combine key management + deduplication and I saw the following approach somewhere which looked really promising:   split up the data in fixed-size chunks (not really a necessity, just makes the balancing of the storage simple) hash the chunk using SHA-512 for example using the hash as key, encrypt the chunk and store it   The idea is that if two people have the same data (like "kernel32.dll" for a particular version / patch level of Windows for example), they will independently come up with the same chunks and the data will be deduplicated without them having to coordinate. At the same time if you don't have access to the data, you can't compute the key (hash) and thus this is usable for private data also.  Do people see any problem with the security of this scheme?


How do i combine 3 regex patterns in JS replace() method on a string?

-ANSWER to this example is 'var pattern = /(\\n)|(\\r)|(\\t)/g;'  -ANSWER to question is, you can put each pattern in parentheses, separate with a pipe symbol and assign the global identifier at the end of the regex.   TA DA!   :)  TRY THIS LINK FOR A HELPFUL REGEX TOOL:    I thought that simple questions like how do you combine regexes would get a simple answer - i don't believe there's a straight answer on the tutorial.  But i recommend reading the manual.  I've read a few suggested answers most seem to focus on the pipe OR operator, but i want to combine regexes. Shamefully newbie at regexes. Anyway, I want to remove special characters from tab, space and return. Here's what I have:              var pattern1 = /(\\n)/g;             var pattern2 = /(\\t)/g;             var pattern3 = /(\\r)/g;              $heading = $heading.replace(pattern1, "");             $heading = $heading.replace(pattern2, "");             $heading = $heading.replace(pattern3, "");   This works, however it is repeating and I can't find any info on how to create one regex pattern that will look for all and remove them.


quit iOS application if not able to download database

I want to quit the application if it is not able to download the database from the server. I try to download the database using NSURLSession. if it doesn't then show the alert view.   when user clicks on ok button in the alert, then i want to quit the application. As there is no database, it will crash to proceed. To avoid the crash i want to quit from the app programatically.  I want to achieve something like android's finish().  I have one util.h and util.m which does all download show alert box job. It extends NSObject. It is just like an utility not a controller.  Util.h  #import <Foundation/Foundation.h>   @interface Util : NSObject {   NSURLSession *session; //NSDictionary *plistDictionary; NSURLSessionTask *task1; NSURLSessionTask *task2; NSURLSessionTask *task3; UIAlertView *alertViewSpin; NSMutableData *receivedData;  }   I have seen in one of the SO post..   [self dismissViewControllerAnimated:YES completion:nil];  [self.navigationController popViewControllerAnimated: YES];   But did not help. How can I do this?


Which SE site is appropriate for questions about the use of airguns?

Googling I mainly get hits on Travel, relating to transporting airguns. But I want to ask about their operation and usage and maintenance. Anyone know where would be best?   (I know there are also many local legal restrictions but that's not my main query here)


Why am I getting a NullPointerException?? I instantiate the node object in the Board.setStartPosition. Then I call it from my driver using b.getStartPosition(). I have simplified my code to only leave relavant information.  Driver.java  Static Board b;  public static void main(String[] args){      b = new Board(3,3);      b.setStartPosition(1, 1);      b.createPath(b.getStartPosition()); }   Board.java  public class Board {     private int length;     private int width;     private Node[][] board;     private ArrayList<Node> openList;     private ArrayList<Node> closedList;     private Node startPosition;     private Node endPosition;      Board(int length, int width){         board = new Node[length][width];          Random rand = new Random();          for(int row=0; row < board.length; row++){             for(int col=0; col < board[row].length; col++){                  int randomNum = rand.nextInt(10);                  if(randomNum == 0){                     board[row][col] = new Node('X',row,col);                 }                 else{                     board[row][col] = new Node('O',row,col);                 }             }         }     }      public Node getStartPosition() {         return this.startPosition;     }      public void setStartPosition(int x, int y) {         board[x][y].setStatus('S');         board[x][y].setParent(null);         startPosition = new Node('S', x, y);         startPosition.setG(0);     }      public void createPath(Node n){          //Continue until we cant find a path or we exhaust our searches          //THIS IS WHERE I GET A NULLPOINTER. IT SEEMS TO THINK THAT MY NODE         //n is null, eventhough when i pass it, i pass it by getting the startposition node         //Add startPosition to closed list         closedList.add(n);          //Add things around start square to openList if applicable         addToOpenList(n);            }  }


i.landsat.toar not working and returning error

First time using grass. I need to convert DN to reflectance. Imagery -> Sat. images tools-> i.landsat.toar. But when I add raster name. I get error.  Im using landsat 8 images  WARNING: WARNING: ESUN evaluated from REFLECTANCE_MAXIMUM_BAND Calculating... ERROR: Unable to open header file for raster map <LC81890272015184LGN00_B11@abcdefgh1@   I have try  but it wasnt working.


I'm doing a problem on hackerRank and the problem is:  Problem Statement  Here we have to count the number of valleys does XYZ person visits.  A valley is a sequence of consecutive steps below sea level, starting with a step down from sea level and ending with a step up to sea level.  For One step up it U, and one step down it is D. We will be given the number of steps does XYZ person traveled plus the ups and down in the form of string, i.e,   UUDDUDUDDUU   Sample Input  8 UDDDUDUU   Sample Output  1   Explanation  If we represent _ as sea level, a step up as /, and a step down as \, Gary's hike can be drawn as:  _/\      _    \    /     \/\/   He enters and leaves one valley.  The code I wrote doesn't work   static int countingValleys(int n, String s) {         int count = 0;     int level = 0;     String[] arr = s.split("");     for(int i = 0; i<n;i++){         if(arr[i] == "U"){             level++;         } else{             level--;         }             if(level==0 && arr[i]=="U"){             count++;         }     }     return count; }   But another solution I found does, however no matter how I look at it the logic is the same as mine:  static int countingValleys(int n, String s) {     int v = 0;     // # of valleys     int lvl = 0;   // current level     for(char c : s.toCharArray()){         if(c == 'U') ++lvl;         if(c == 'D') --lvl;          // if we just came UP to sea level         if(lvl == 0 && c == 'U')             ++v;     }     return v; }   So what's the difference I'm missing here that causes mine to not work?  Thanks.


Let $X$ denote the two-element set {$0, 1$} and let $A$ be the set of countable subsets of $X^ω$. Show that $X^ω$ and $A$ have the same cardinality. (This is from Topology by James Munkres) How can I prove this without using the Axiom of Choice? It this trivial that there exists an injective function from $X^ω$ to $A$ but I have no idea how to prove the opposite direction.


unable to recover corrupted 32gb sd card

while doing format my sd card was suddenly removed after that i tried to connected it splits in to two partitions and unable to format that. i tried disk part cmd but it unable to delete partition due to there is no listing of volumes  i also tried easyus partition manager but it also not worked i also tried minitool partition wizard but it also not worked while using disk part it listed there are no volumes. while delete partition it showing that no volume is selected how can i recover my sd card plese give me suggeetions


How do I fix this issue with these harsh dark-shaded polygons?

Whenever I move the camera/light around I get these harsh shading on these polygons. Any ideas?


Sorry for the newbie question, but I have been trying to resolve the problem of citations not showing up with texstudio. Below is a sample of my tex code \documentclass[12pt,a4paper]{article} \usepackage{graphicx} \usepackage[margin=1in]{geometry} \usepackage[table,xcdraw]{xcolor} \usepackage{float} \usepackage[utf8]{inputenc} \usepackage[english]{babel} \usepackage{chemfig} \usepackage[backend=biber,style=mla]{biblatex} \restylefloat{table}   \bibliography{EnzymeLabCitation} %opening \title{Sample Title} \author{Me} \date{}  \begin{document}     This is an example sentence with citation \cite{Polysaccharides}     \printbibliography \end{document}  with the following in the file EnzymeLabCitation.bib @misc{Polysaccharides, month = {mar}, title = {{Polysaccharides}}, url = {https://chem.libretexts.org/@go/page/17529}, year = {2016} } @misc{Starch_Iodine, month = {mar}, title = {{Starch and Iodine}}, url = {https://chem.libretexts.org/@go/page/383}, year = {2020} } @misc{Ololade2021, author = {Ololade, Akinfemiwa and Thiruvengadam, Muniraj}, booktitle = {Startpearls Publishing}, title = {{Amylase}}, url = {https://www.ncbi.nlm.nih.gov/books/NBK557738/}, urldate = {2021-03-21}, year = {2021} } @misc{Amylase, booktitle = {Britannica}, publisher = {Britannica}, title = {{Amylase}}, year = {2020} } @incollection{Kaphalia2019, abstract = {Advanced stages of chronic pancreatitis and pancreatic cancers (PCs) are very serious diseases with very poor prognosis. Therefore, identification of reliable and specific biomarker(s) at early stages of the diseases could be key to their early prevention and therapy. In this chapter, currently used and putative biomarkers of acute and chronic pancreatitis and PC are summarized. Total serum lipase and/or amylase are most widely used biomarkers of acute pancreatitis; lipase assay being more sensitive and specific than that of amylase. Imaging technologies provide key support for the diagnosis of both acute and chronic pancreatitis. Biomarkers of chronic pancreatitis are poorly developed and remain challenging because of impaired secretory components of exocrine pancreas. The focus of future clinical diagnosis of chronic pancreatitis and PC lies in identification of biomarkers using omics and microRNA arrays along with imaging technologies in well-defined experimental models and their validation in patients diagnosed with various stages of chronic pancreatitis and PC.}, author = {Kaphalia, Bhupendra S}, doi = {https://doi.org/10.1016/B978-0-12-814655-2.00019-0}, editor = {Gupta, Ramesh C B T - Biomarkers in Toxicology (Second Edition)}, isbn = {978-0-12-814655-2}, keywords = {Acute pancreatitis,Chronic pancreatitis,Diagnostic biomarkers,Functional biomarkers,Pancreatic cancer}, pages = {341--353}, publisher = {Academic Press}, title = {{Chapter 19 - Early Biomarkers of Acute and Chronic Pancreatitis}}, url = {https://www.sciencedirect.com/science/article/pii/B9780128146552000190}, year = {2019} } @misc{Williams2019,     author = {Williams, John},     booktitle = {Pancreapedia: Exocrine Pancreas Knowledge Base},     doi = {10.3998/panc.2019.02},     title = {{Amylase}},     url = {https://www.pancreapedia.org/molecules/amylase-2},     urldate = {March 21st, 2021},     year = {2019} }  With this, the document simply shows the word Polysaccharides instead of the citation, and the title 'Works Cited' does show up, but not the sources. I have been trying to run it in overleaf, and no luck either. I am quite confused and would appreciate all help (I am using Texstudio as the main text editor).


I have often heard people say "x of his" or "x of mine". But since his and mine point out ownership, isn't using "of" here doubles that ownership? Wouldn't it be more appropriate to say "x of him" or "x of them" etc.?  Example:     I was a good friend of your dad's. He told me all about you`


How can I fix the auto-login to the Cerberus network (EA Online)

Whenever I start up Mass Effect 2 and it tries to auto-login to my EA Online Account, I see this screen.    Then, I have to manually log in, and I see this screen.    Empty login screen. Every time. So I have to input my email address and password again. Every time. Once I do this manually, it works. However, the next time I close and reopen the game, I have to go through this entire process again. The auto-login isn't working for me.  Is there any way to get Mass Effect 2 to remember my new login information?


Find the infinite sum $\sum_{k=1}^{\infty}\sqrt k - 2\sqrt {k + 1} + \sqrt {k + 2} $

I am facing a problem, where I have to find the partial sum of a sequence/sum and with that, the infinite sum of the sequence.  $\sum_{k=1}^{\infty}\sqrt k - 2\sqrt {k + 1} + \sqrt {k + 2} $   The problem here is that I don't know how to proceed. I would be thankful if someone would steer me in the right direction.


Why is 'present perfect' present if it happened in the past? And why is it 'perfect'?


What is an observer in quantum mechanics?

My question is not about (pseudo) philosophical debate; it concerns mathematical operations and experimental facts.  What is an observer? What are the conditions required to be qualified of observer, both mathematically and experimentally?


Would a Cup of Tea Be Hotter If you Add the Milk Before or After Boiling Water?

This is a bit of dispute between work colleagues. An answer would be greatly appreciated.  My argument is as follows:  If you add X amount of milk at a temperature of M to a mug at room temperature R before adding X amount of water at temp W, the result would be a cooler cup of tea than if you'd added the hot water first. This would be due to the milk reducing the overall temperature of the mug in the time that has been in it resulting in the addition of boiling water having less of an effect and resulting in a slightly cooler cup of tea/coffee.   Conversely, if you add the hot water first, due to the mug being heated, the effect of adding the cool milk will be less and therefore the end result will be a hotter cup of tea.  My Colleagues arguement is simply that it would not make a difference but without any form of justification.   If anyone can give real scientific light to this issue it would be greatly appreciated :)


Let's say that you have overridden an object's equals() and hashCode() methods, so that they use the object's fields.  How you do you check if two references are to the same object, ala the stock equals() method?