When I run the following code I get an Overfull\hbox(... too wide) in paragraph warning.  \documentclass{scrartcl} \usepackage[utf8]{inputenc} \usepackage[english]{babel} \newenvironment{fonttfp}{\fontfamily{cmtt}\selectfont}{\par}  \begin{document} \begin{itemize}   \item[] {\fonttfp Afghanistan\_Albania Algeria\_Andorra Angola\_Antigua and Barbuda\_Argentina Armenia\_Australia Austria\_Azerbaijan} \end{itemize} \end{document}   How can I get it away. When I remove the \fonttfp statement the warning disappears. I've also tried to use sloppypar and the package microtype. Both approaches do not clear the warning.

I asked a question earlier about \verb and overfull hbox :   And regarding the solution there, changed many of my \verbs to \texttt{}s.  I have come up with a new problem now.  An example:  \documentclass {article} \begin{document} \section {Introduction}      The entry point is in \texttt{TRCS.Main()} (\texttt{TRCS\char`\\TRCS.cs}).    The stateless (see \S 3.4.3) forms are started immediately, then another controller   is invoked, namely  \texttt{Workflow}. \end{document}   Compiling this example will show my problem.  \texttt{Workflow} causes an overflow, and a rather significant one.  What should I do to alleviate the problem?  Thanks in advance for your help!


I've seen a lot of contradictory information online when it comes to if $0 \in \mathbb{N}$ and I've been wanting to know if there's a definite answer to this or not. Any help is greatly appreciated.

I know perfectly well the Peano axioms, but if they were sufficient for defining $\mathbb N$, there would be no controversy whether $0$ is a member of $\mathbb N$ or not because $\mathbb N$ is isomorphic to a host of sub- and supersets of $\mathbb Z$.  So it seems that mathematicians, when specifying $\mathbb N$, rarely mean the set of natural numbers according to its definition but rather some particular embedding into sets defined by different axiomatic systems.  Doesn't this sort of misstate then the role of the Peano axioms as the defining characteristics of $\mathbb N$?  It seems like most of the time the Peano axioms are not more than a retrofit to a subset of $\mathbb Z$ or other sets defined by a different axiomatic system with one or several axioms incompatible with the Peano axioms.


Are these attacks considered magical?  Bite. Melee Weapon Attack: +14 to hit, reach 15 ft., one target. Hit: 19 (2d10 + 8) piercing damage.  Claw. Melee Weapon Attack: +14 to hit, reach 10 ft., one target. Hit: 15 (2d6 + 8) slashing damage.  Tail. Melee Weapon Attack: +14 to hit, reach 20 ft., one target. Hit: 17 (2d8 + 8) bludgeoning damage.  Fire Breath. The dragon exhales fire in an 90-foot line that is 10 feet wide. Each creature in that line must make a DC 21 Dexterity saving throw, taking 56 (16d6) fire damage on a failed save, or half as much damage on a successful one.

Often confusion arises when the  spell is used, an  is worn, or the 's anti-magic ray is employed, whether a given character's ability will still function.   The spell does give you some guidelines on how to adjudicate the effects of the loss of magic but says very little about how to determine what is affected.  In short, how do I tell if an ability is magical?


I've seen  with a nice light streaks illusion, that I believe was captured in the camera itself rather than added in post-processing. Can anyone explain how one can replicate it?

I would like to achieve this effect using my Nikon P510:      Are there any suggestions or tips that would help me do that?


Every time I try to connect to any server, Minecraft gives an error stating:     Failed to login: The authentication servers are currently down for   maintenance   I accidentally renamed the Servers file while deleting old screen shots.  I have been unable to connect to any server for several days following.  Can the servers file cause this error?

Similar to  on the bugs in Minecraft, I would like a complete list of what error codes exist in Minecraft and how they occur, as well as how they can be resolved.


Hi everybody thanks for your help, this is what I've done. The Main goal is to move content of Downloads into Recycle bin if is a folder or whatever it is I can't figure out why I run it and after moving items can't seen them in the Desktop>recycle bin I found the items in c:$Recycle.bin what do you suggest? thanks again #Requires -Version 5.1      param (     [string] $path = "$env:HOMEPATH\Downloads\") $myBool = Test-Path $path      if ($myBool -eq $false)      {     "Path does not exist, Input the path to folder"     }      else { Get-childItem -path "$path" -Recurse  | Select-Object | Move-Item -Destination     'C:\$Recycle.Bin'     }

By default when you delete a file using PowerShell it's permanently deleted.  I would like to actually have the deleted item go to the recycle bin just like I would have happen via a shell delete.  How can you do this in PowerShell on a file object?


I'm taking a second year genetics course as a math major (I was interested in bioinformatics, and I need genetics for that). I'm doing poorly in the course so far (I'm passing, but not with great marks). I was wondering how a bad grad will look on my application to math grad schools.   My current cgpa is about 3.8 so I'm wondering if I should just cancel this course (honestly, bioinformatics isn't even interesting to me anymore) and take a CAN on my transcript than a bad grade that will kill my cgpa. How would that look?   Any and all help is appreciated!

When applying to a PhD program in the US, how does the admissions process work? If an applicant is weak in a particular area, is it possible to offset that by being strong in a different area?  Note that this question originated from this . Please feel free to edit the question to improve it.


i am storing the connection string provided by the user at setup time to a txt file  its a website  by setup i mean first access of the admin to the site  well  its working  but i need some code which can encrypt the password text and store to file so any one having access to the system can not understand the passward,  also please show decrpytion   thank u

How can I encrypt and decrypt a string in C#?


I have a linear transformation $A$.  In basis ${(1,1),(1,2)}$  $A= \begin{bmatrix} -1 & -1\\4 & 6 \end{bmatrix}$  Find $A$ in the standard basis ${(1,0),(0,1)}$  The teacher told us the answer, but i have no idea how to get it:  $A= \begin{bmatrix} 1 & 2\\3 & 4 \end{bmatrix}$

Let $\Bbb R^2$ be a finite-dimensional vector space and $T:\mathbb{R}^2\to \mathbb{R}^2$ a linear operator. Let $[T]_B =  \begin {bmatrix}0 & 0 \\-1 & 1 \end{bmatrix} $ be a matrix representation of $T$ in the basis $B= (1,1),(-1,0)$.   How can I find the matrix $[T]_E$ where $E$ is the standard basis $(1,0),(0,1)$ if the transformation isn't given in the question?  Thanks,  Alan


im a newbie doing windows forms c# so i recently wanted to create something like a cashier payment calculation button, but then i got stucked at the rounding part.  For example, if the total amount is $40.23, how can i make it round up to #40.25 instead of going down to $40.20?  Or maybe $40.26 to $40.25?   the total amount values are get from textboxes and the final after-rounded value will be display in textbox as well.  hope i was not being too unclear about my question.  thanks guys

I want to do this using the Math.Round function


i am mking a program where the computer guesses your number. and it has to guess a random num. but how do i make the random line be lower or higher num than the perviously num guessed?  package compguse; import java.util.*;  public class Compguse {   public static void main(String[] args) {     Scanner scan = new Scanner (System.in);     String a;     String b;           String c;     String ans;     String d;             int input =1;     System.out.println("do u have your number?");     a = scan.nextLine();     while (a.equalsIgnoreCase("yes"))     {     int ran = (int) Math.floor(Math.random()*100)+1;         System.out.println(" is" +ran +" your num?");           a = scan.nextLine();         if(a.equalsIgnoreCase("no"))         {             System.out.println("Was i too high or low?");             b = scan.nextLine();             if(b.equalsIgnoreCase("high"))             {             int ran1 = (int) Math.floor(Math.random() < (int) ran);              }             }            } }

How do I generate a random int value in a specific range? I have tried the following, but those do not work: Attempt 1: randomNum = minimum + (int)(Math.random() * maximum);  Bug: randomNum can be bigger than maximum. Attempt 2: Random rn = new Random(); int n = maximum - minimum + 1; int i = rn.nextInt() % n; randomNum =  minimum + i;  Bug: randomNum can be smaller than minimum.


Now I am use serial to generate table primary key in PostgreSQL 13, but today I found the ID jumps and has big gaps in the ID space. It will waste many IDs. I read the docs and found that PostgreSQL has identity as a SQL standard generated primary key. I found a recommendation to use identity in new version of PostgreSQL but I don't know whether ID is continuous. What should I do get a primary key id without gaps in PostgreSQL 13?  Solution 1: I tried to change serial to identity like this: BEGIN; ALTER TABLE public.article ALTER id DROP DEFAULT; -- drop default  DROP SEQUENCE public.article_id_seq;              -- drop owned sequence  ALTER TABLE public.article  -- ALTER clientid SET DATA TYPE int,              -- not needed: already int    ALTER id ADD GENERATED ALWAYS AS IDENTITY (RESTART 2270886); COMMIT;  Still gaps. Solution 2: I tried to add a redis distribution lock about my apps insert article like this: def save_single(guid, pub_time, title, author, content, source, link):     if content is not None and len(content) > 0:         article = Article()         article_content = ArticleContent()         beta_parser = CnbetaParser()         second_parsed_content = beta_parser.parse_cnbeta_content(content, link)         article_content.article_content = second_parsed_content          cover_image = None         lock_identifier = None         try:                          # cover_image = Utils.get_cover_image_url(self, content, link)             lock_identifier = acquire_lock("article-save", 5, 5)             article.save(title, guid, author, pub_time, article_content, link, source, cover_image)         except Exception as e:             logger.error("save article data error,rss:" + source.sub_url, e)         finally:             if lock_identifier is not None:                 release_lock("article-save", lock_identifier)     else:         logger.error("article content is null,title:" + title)  Still gaps.

I had a mistake with a trigger which resulted in errors in PostgreSQL 9.4.3 on x86_64-unknown-linux-gnu, compiled by gcc (Debian 4.9.2-10) 4.9.2, 64-bit.  Each time during the error, the primary key of SERIAL increased.  After fixing the bug, the table measurements is    measurement_id | measurement_size_in_bytes |             time               ----------------+---------------------------+-------------------------------               1 |                     77777 | 2015-07-14 18:29:56.858703+03               2 |                       888 | 2015-07-14 18:29:56.882552+03               3 |                       888 | 2015-07-14 18:30:15.505957+03               4 |                       888 | 2015-07-14 18:41:01.878106+03              39 |                     77777 | 2015-07-15 12:11:21.21391+03              40 |                     77777 | 2015-07-15 12:11:59.551973+03              41 |                     77777 | 2015-07-15 12:12:05.48982+03              42 |                     77777 | 2015-07-15 12:13:02.402053+03              43 |                     77777 | 2015-07-15 12:13:02.419412+03              44 |                       888 | 2015-07-15 12:13:02.434728+03          ...   where the amount of error statements has been 35 (= 39-4).  This jump in IDs may become a challenge later when I want to integrate this table with a partial index where order matters.   Table  CREATE TABLE measurements     (         measurement_id SERIAL PRIMARY KEY NOT NULL,         measurement_size_in_bytes INTEGER NOT NULL,         time TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT CURRENT_TIMESTAMP,         CONSTRAINT no_duplicate_measurements UNIQUE (time)     );       What are the challenges of keys with gaps?


Stack Exchange blog is showing me the mobile site and won't let me exit on Chrome 21. Could someone take a look? Thanks. Edit I noticed it was with the special query string, that I can't exit it.

The blog link on the bottom sends me to a mobile version of the blog, while i'm not on a mobile device! :)  Thats it! :)


Using authblk.sty, I need to automatically grep the corresponding author name string. But I don't how to execute this concept. I think etoolbox is helpful for this logic.  corresauthor is the key to capture the author name and put the * symbol on the author name like Keith Lindsey2*.  corresaddress={address text here} specifies the name and address to be printed on the particular call out place.  My tex coding is:  \documentclass{article}  \begin{document}    \title{Hormonal crosstalk for root development: a combined experimental and modeling perspective} \author[1]{Junli Liu} \author[2]{James Rowe} \author[2,**corresauthor,corresaddress={is Professor of Plant Molecular Biology in the School of Biological and Biomedical Science sat Durham University, UK}**]{Keith Lindsey} \affil[1]{Integrative Cell Biology Laboratory, School of Biological and Biomedical Sciences, The Bio physical Sciences Institute, Durham University, Durham, UK} \affil[2]{Integrative Cell Biology Laboratory, School of Biological and Biomedical Sciences, The Bio physical Sciences Institute, Durham University, Durham, UK} \maketitle  \end{document}   My required output is:     Please suggest how to get this output using this concept.

I am using the authblk style file. I want to print the corresponding author and address to the left of the complete list of authors (and in addition to this list - so the list should also contain the corresponding author). Moreover, the corresponding author should be marked by an asterisk in the complete list of authors.  Currently, I am using this code:  \documentclass[twocolumn]{article}  \usepackage[noblocks]{authblk} \makeatletter \def\@correspondence{} \def\correspondence#1{%      \gdef\@correspondence{\textbf{\textit{*Correspondence:}}\newline%        \raggedright  #1}}  \def\@maketitle{%   \newpage   \null   \vskip 50pc% \vbox{\hbox to 0pt{\vbox to 0pt{\vskip -40pc% \begin{minipage}[!b]{10pc} {\@correspondence\par}% \end{minipage} \hspace*{12pt} \begin{minipage}[!b]{31pc}     \let \footnote \thanks     {\@title \par}%     \vskip 1.5em%     {\large %      \lineskip .5em%       \begin{tabular}[t]{l}%         \raggedright\@author       \end{tabular}\par}%    \end{minipage}}}}%   \par   } \makeatother \begin{document}  \title{Journal Title} \author[1*]{Junli Liu} \affil{address one} \correspondence{Junli Liu\newline correspondence author address to be printed here}  \maketitle  \end{document}   What I would like to have instead is something like:  \documentclass[twocolumn]{article}  \usepackage[noblocks]{authblk}   \begin{document}  \title{Journal Title} \author[1,corauthor,coraddress={corresponding address here}]{Junli Liu} \affil{address one}   \maketitle  \end{document}   The output of my current code and my requirements are illustrated here:    How can I modify \author to work as required?


In my book they say that $$f(z) = \csc(\pi z)=\frac{1}{\sin(\pi z)}$$ has simple poles, however doesn't explain why.  I tried do to the following: I know it should have simple poles where $g(z) = \sin(\pi z)$ has zeroes, i.e. $z = k\in\mathbb{Z}$. Then I can check if they are indeed simple poles with the following:$$\lim_{z\to k}(z-k)\csc(\pi z) = \lim_{z\to k}\frac{z-k}{\sin(\pi z)} = \lim_{z\to k}\frac{1}{\pi\cos(\pi z)}=\begin{cases}        \frac{1}{\pi} & k \,\,\text{even} \\       -\frac{1}{\pi} & k \,\, \text{odd}     \end{cases} \neq 0$$ hence a simple poles at $z = k\in\mathbb{Z}$? I am not sure this is correct or if this is the shorter/best way to show this.   Are there other options?

Is there a systematic way to determine the order of a pole of a function? For instance, I want to calculate the residues of $\frac{1}{\sin z}$, for the poles at $k\pi$.   If the poles are simple, and apparently they are, it's easy to see the residues to be $(-1)^k$. However, how can one tell the poles are simple?


I want to change the color of the shell window from a running python script on a Mac.  I tried  >>> os.system('color 1f')   and  >>> os.system('setterm -background white -foreground white -store')   but neither works.  (I am NOT tring to change background color of pieces of text; I want to change the entire background.)  Regarding all the suggested duplicates, I'm not looking for an AppleScript solution. I need to do this from python, for the current Terminal window that is running the given python process.

Is it possible to change the background color of Terminal.app from the shell? If so, how?


I want to buy HDD and External Hard Drive Enclosure. I will connect it to computer via USB. I will write on this HDD system backups, current sound work files backups, sound work files archive. I run Windows 10 Home 64-bit. How sector, block, cluster related to each other?

I have gone through wikipedia and other sites and here's the information I have obtained.  Sector: Smallest Addressable Unit (mostly 512 bytes) Cluster: Smallest Allocation Unit (equals to 1 or more sectors and the number of clusters depends on the file system).  Let's say in the below example:  sector =512 bytes and a cluster =8 sectors=4096 bytes. Now, I am having a hard time figuring out, when I am trying to create a file what does the file system do? Does it consider 4096 bytes as the smallest write/read unit or 512 bytes?  If the answer is 4096 bytes: When the manufacturer of the disk drives has provided 512 bytes as the smallest addressable unit, why does the file system consider cluster as the smallest unit? I mean, what are the advantages in doing so?


I have an xubuntu server with a GUI that I need to keep running at all times.  After xubuntu prompts me install system updates, it sometimes prompts me to reboot the computer. I am using Ksplice Uptrack Manager so the reboots are not necessary.  Is there a way to make ubuntu/xubuntu never show the reboot prompts, so a colleague or I don't click the reboot button accidentally out of instinct?

Software Updater has installed some new software. I'm largely not interested in this fact as I just use this machine as a file server and watch everything on my tablet or Windows machine.  However, every time I connect to the machine, I see this:    This is a window with no close button with the "Restart" button selected by default so literally my next keypress will reboot the machine. This is almost as bad as Windows 8 rebooting whenever it wants to in order to apply updates.   I don't mind it installing updates as and when it wants to but I am only ever going to restart the machine when I want to restart it. How can I stop the Software Updater from nagging me to restart?


I want to get a usage log for a particular application during the last 30 days.  Does Windows have a log I can access for that?

In Windows, is there a log that records what programs were run/called?  While browsing the internet, viewing a static page with no ads, mouse clicks, keypresses, or miscellaneous plugins/addons/scripts running, I just saw a spontaneous CMD.exe console pop open and then immediately close in a flash, fast enough that I wasn't able to see anything in the window -- and with no apparent triggering on my part.  I'm wondering if there is some type of Windows log that shows what programs have been run/called/activated? I'd like to see what was happening behind the scenes when this console window flashed, and hopefully determine it wasn't something rogue.  For reference, I'm running Windows 7 Ultimate x64.


I know that  exists, but it deals only with mirrors for ubuntu sources.  I want a application/script/command which would find the best mirror/server from a given list, which may or may not be related to Ubuntu.  For example  gives a list of Arch Linux mirrors. Similarly many softwares have multiple mirrors. I want to find the best mirror from the given list. I am ready to add the mirrors one by one into some script/app/command.  If possible, the script/app/command should find the mirror which gives highest speed, rather than one that is closest.

I want to update my sources.list file with the fastest server from the command line in a fresh Ubuntu Server install. I know this is trivially easy with the GUI, but there doesn't seem to be a simple way to do it from from the command line?


I have two polygon layers, Land-use and Mesh.  I had this mesh layer in specific geometric way. Anyways, I want the mesh layer to have the landuse value of the maximum area it contains. Lets say that a polygon in the mesh contains three land use types (40% urban, 30% roads, 30% green areas). I want it to assign the value of urban because it has the biggest area.   I tried Spatial Join tool, but it did not give me what I was looking for. I used the (mode) as a Field Map of Join Features which should Use the value with the highest frequency but it did not work.

First, I have a shapefile consisting of square grids and each grid has an ID. Second, I have a shapefile consisting of different zones (with IDs).  A grid ID in the first shapefile can contain many zone IDs from the second shapefile.  I want to know what is the dominant zone ID inside a grid and record that in a table. I only want to know the dominant zone (in terms of the area) and not the rest of the zones intersecting that grid. In the end, I would want a 2-column table with all the grid IDs in the first column and the corresponding dominant zone ID (or the largest zone in terms of area) in the second column.  Here is a sample figure.  By just looking at the figure, I could tell that in Grid ID 1, the dominant zone/area is Zone ID 1.  In Grid ID 2, the dominant zone/area is Zone ID 2.  And in Grid ID 3, the dominant zone/area is Zone ID 3.  I would like to have a table with two columns, with each grid showing only the ID of the dominant area.


Why we are not using Lagrangian instead of Hamiltonian in non-relativistic quantum mechanics?

Undergraduate classical mechanics introduces both Lagrangians and Hamiltonians, while undergrad quantum mechanics seems to only use the Hamiltonian. But particle physics, and more generally quantum field theory seem to only use the Lagrangian, e.g. you hear about the Klein-Gordon Lagrangian, Dirac Lagrangian, Standard Model Lagrangian and so on. Why is there a mismatch here? Why does it seem like only Hamiltonians are used in undergraduate quantum mechanics, but only Lagrangians are used in quantum field theory?


reads     {T}: Draw two cards. Target opponent gains control of Humble Defector. Activate this ability only during your turn.   Anthony controls Humble Defector and . He activates Humble Defector's ability and holds priority. He then sacrifices Humble Defector to activate Butcher of the Horde's ability.  When Humble Defector's ability resolves, does Anthony draw two cards?

Player A taps  targeting Player B; its "deals 1 damage to target player" ability is placed on the stack.  Player B gets priority and responds with , targeting Goblin Fireslinger.  Both players pass priority. Snap resolves, and Goblin Fireslinger is returned to its owner's hand.  Does Player B still take 1 damage from Goblin Fireslinger's activated ability?  I know that if the creature had been killed/sent to the graveyard, the ability would still resolve, but I was told recently that because a player's hand is a private zone it couldn't. If anyone could confirm or deny this for me, it would be most appreciated.


I have an issue which could be a bug, but before reporting it, I want to make sure I'm not doing something wrong.  When watching a movie with VLC on fullscreen, approximately in 10 minutes the screen goes blank. This happens despite having the "Inhibit the power management daemon during playback" option checked. This even happens when I go to the Ubuntu's system settings > Brightness and Lock and set the "Turn screen off when inactive for: " to "Never". (actually, no matter what value I set it to, the screen always goes blank after 10 minutes or so).  The only way I managed to disable the screen blanking is using the command line utility xset: xset -dpms and xset s off (it's possible only one of these is necessary).  Now, one thing that could possibly cause this is that I removed both gnome-screensaver and xscreensaver packages, because I'm not using screensaver. I only use the power-management to blank the screen (I assume it's different thing than screensaver, but I might be wrong). When no VLC us running, the screen blanking works normally even without those packages. That is, the screen goes blank after whatever timeout I set in the Brightness and Lock settings. Only when VLC is playng (and possibly only when in fullscreen), this issue occurs.  So my question is: Is this a bug in VLC (or elsewhere in Ubuntu), or should I install back gnome-screensaver and/or xscreensaver to make it work correctly again?  I have Ubuntu 12.04.

I am using Ubuntu 11.10 and my screensaver keeps coming on while I'm watching a movie.  I don't remember this happening in 11.04 and can't remember how to stop it?


Claim. The center of $(G_1\times G_2,\star)$ is $Z(G_1)\times Z(G_2)$, where $Z(G_i)$ is the center of $G_i$, for $i=1,2$.  I'm trying to figure out a proof for this and got myself a little bit confused. My thought process was to show that if the two groups $G_1$ and $G_2$ are Abelian groups that the direct product of these two Abelian groups is also Abelian, then the claim would follow by the result of them being Abelian.   If that is the correct way to approach this proof, what does this then say about the center of the direct product if they happened to not be Abelian groups? Is that possible? Does it mean there only exists a center if it's Abelian?  Sorry if my question is kind of stupid. Just trying to understand the problem and how to proceed.

The exercise for which I am seeking feedback wants me to prove that the center of a direct product is the direct product of the centers. That is, $$Z(G_1 \times \cdots \times G_n)=Z(G_1) \times \cdots \times Z(G_n).$$  $\textbf{Attempt at Solution:}$ We proceed by induction on $n$. First, we prove our desired for $n=2$; this will establish our basis step. Let $(g_{1},g_{2}) \in Z(G_{1} \times G_{2})$. Then $(g_{1},g_{2})(x_{1},x_{2})=(x_{1},x_{2})(g_{1},g_{2})$ for all $(x_{1},x_{2}) \in G_{1} \times G_{2}.$ This implies $g_{1}x_{1}=x_{1}g_{1}$ and $g_{2}x_{2}=x_{2}g_{2}$ for all $x_{1} \in G_{1}$ and for all $x_{2} \in G_{2}$. Hence, $g_{1} \in Z(G_{1})$ and $g_{2} \in Z(G_{2})$. To prove the reverse inclusion, this time let $(g_{1},g_{2}) \in Z(G_{1}) \times Z(G_{2})$ Then, $g_{1}x_{1}=x_{1}g_{1}$ and $g_{2}x_{2}=x_{2}g_{2}$ for all $x_{1} \in G_{1}$ and for all $x_{2} \in G_{2}$; it, of course, follows that $(g_{1},g_{2})(x_{1},x_{2})=(x_{1},x_{2})(g_{1},g_{2})$ for all $(x_{1},x_{2}) \in G_{1} \times G_{2}.$ Indeed, $(g_{1},g_{2}) \in Z(G_{1} \times G_{2})$  For our induction step, assume that desired result holds for some $n$; that is, assume $$Z(G_1 \times \cdots \times G_n)=Z(G_1) \times \cdots \times Z(G_n).$$ We show $$Z(G_1 \times \cdots \times G_n \times G_{n+1})=Z(G_1) \times \cdots \times Z(G_n) \times Z(G_{n+1}).$$ By our basis step, $$Z(G_1 \times \cdots \times G_n \times G_{n+1})=Z(G_1 \times \cdots \times G_n) \times Z(G_{n+1}).$$ Then, using our induction hypothesis, we obtain $$Z(G_1 \times \cdots \times G_n) \times Z(G_{n+1})=Z(G_1) \times \cdots \times Z(G_n) \times Z(G_{n+1}).$$ Hence, our induction step has been established. Finally, by the principle of mathematical induction, we conclude $$Z(G_1 \times \cdots \times G_n)=Z(G_1) \times \cdots \times Z(G_n),$$ for any finite collection of groups $G_{1}, \ldots , G_{n}.$  $\blacksquare$  $\textbf{Question:}$ This may be a stupid question; but, I'll ask anyway! Would it be wrong if I completed the proof by letting $(g_{1},\ldots , g_{n}) \in Z(G_1 \times \cdots \times G_n)$ and showing $(g_{1},\ldots , g_{n}) \in Z(G_1) \times \cdots \times Z(G_n)$? (Then, of course, proceed by proving the reverse inclusion.) Thank you!


What is the difference between the following two sentences?  To study English is hard.  Studying English is hard.

As a native speaker of English, the gerund version of this sentence sounds better:  infinitive:     When used together in chains,   extension methods are an unprecedented   tool to produce extremely concise   code.   gerund:     When used together in chains,   extension methods are an unprecedented   tool for producing extremely concise   code.   But how can I explain to someone learning English how to decide in situations like these whether to use the infinitive or the gerund?


One of the most agreed upon mechanism for evolution is natural selection.Changing environmental conditions necessities development of variations that enable the survival of that particular species.These genetically passed down variation later becomes the adaptive features which further result in development of new species.  But with development of technology we are finding newer ways to cope up with changes in the environment.Do this impact human evolution?

I understand that evolution occurred to form the current hominids from a common ancestor millions of years ago. As evolutionary processes take a long time, is there proof of evolution occurring with humans today?


I'm running ArcGIS 10.3 with an Advanced License on a Windows 7 64x system with 20 GB of RAM and a 4th Gen Intel i7 Quadcore-CPU.  I have a problem with the normally very efficient Union tool. What I'd like to achieve is a simple union of two feature classes in order to fill holes in my main feature class, say "flat areas" (blue). I therefore created a large surrounding polygon "union polygon" (green). The below images explain the situation (overview and zoomed in):     My blue feature class is large (60 MB), but not huge. It was created combining different features, then I ran the dissolve and buffer tools on it.  The problem now is that when I try to unify the two feature classes, ArcCatalog returns "Error 999999: Error executing Function. Invalid topology". I have read  about processing large data and followed as many of the instructions as possible:   No network drive SSD dissolved polgons   So finally my questions:   Does anyone have an idea what could cause the problem? Hardware issue? Any further tipps or recommendations about the Union tool?  Or even better - an alternative in order to fill the holes in the "flat areas" feature class?     Update:  I've meanwhile found this post:  which seems to be about the same problem as I'm experiencing, however there isn't a solution either. I'm currently running the Repair Geometry tool.  Also I've tried to run identity instead of union since that would also work for my task. The same error showed again.

Using ArcGIS 10.1 for Desktop, I'm trying to run the Identity function on two large data sets but it fails every time. I don't think it is a lack of hardware as I can run other processes on the same data sets.   I've already updated software, and added the 64 bit geoprocessing add-in, checked and repaired geometry, and done the fix in  (set ARCTMPDIR env variable to a writable local folder).   Executing: Identity DudleyStamp OA2011 "D:\Case Studies\National2\National.gdb\DudleyStampOA11" ALL "1 Meters" NO_RELATIONSHIPS  Start Time: Wed May 08 21:11:43 2013 Reading Features... Processing Tiles... Assembling Tile Features... ERROR 999999: Error executing function. The table was not found. The table was not found. [DudleyStampOA11] The table was not found.   The table was not found. [DudleyStampOA11]   Invalid Topology [Topoengine error.] Failed to execute (Identity). Failed at Wed May 08 21:45:41 2013 (Elapsed Time: 33 minutes 58 seconds)   Based on comments so far I tried copying data to new file geodatabase, and running the tool from ArcCatalog still get exactly the same error.  I have ordered 16GB of the fastest RAM my computer can take (I current have 4GB). I also have a 6 Core AMD Phenom II X6 1090T, SSD, and AMD Radeon HD 6970 Graphics Card. So I'm not sure what more hardware I can add.  I've also tried increasing the size of the page file which was a suggestion I found on Google with no effect.


First of all, I wanna say that I know how DNS Servers work and also I know about the records in a DNS Zone File!  I'm not an expert but I have some knowledge about them. I'm confused! why?! because I don't know what's the exact difference between hostnames and FQDNs.  I know that some thing like my.example.com. is a FQDN. somebody told me it's a FQDN because of the existance of "dot" at the end of it.  I think the final dot at the end of it reffers to the root dns servers in the world, right?  Is my.example.com a hostname? (note that it's doesn't have any final dots!)  maybe "my" is the hostname?!  Actually i'm confused!   What's the difference between a hostname and a FQDN, guys?!  Sorry, My english isn't very good. excuse me if I made a mistake.  Thanks in advance.

I am new to the world of setting up servers and am baffled by the term hostname and fully qualified domain name (FQDN). For example, if I want to set up a server that hosts files on the local network i.e. a file server, what would I use a hostname such as myfileserver or something else? What if I wanted to set up a web server, mail server, etc. that external users could access?


In the snip, we can see that two groups of equations, aligned individually on the within-group = symbols.    \documentclass{article} \usepackage{mathtools}   \begin{document}   \begin{enumerate} \item     $$\begin{aligned}     \int x^2 \cos x \,dx     &= x^2 \sin x - 2 \int x \sin x \,dx     \\ &= x^2 \sin x - 2 (-x \cos x +\int \cos x \,dx)     \\ &= x^2 \sin x - 2 (-x \cos x + \sin x \,dx + C)     \\ &= x^2 \sin x + 2x \cos x - 2\sin x + C     \end{aligned}$$  \item     $$\begin{aligned}     \int \frac{\ln x}{x^3} \,dx     &= -\frac{1}{2} \frac{\ln x}{x^2} +         \frac{1}{2} \int \frac{1}{x^3} \,dx     \\ &= -\frac{\ln x}{2x^2} +         \frac{1}{2} \cdot -\frac{1}{2x^2} + C     \\ &=  -\frac{\ln x}{2x^2} - \frac{1}{4x^2} + C     \\ &= -\frac{1}{4x^2}(2\ln x + 1) + C     \end{aligned}$$  \end{enumerate}   \end{document}   How to align the two groups of equations on the same equal symbol "="?  Like this:    \documentclass{article}   \usepackage{mathtools} \begin{document} \begin{enumerate} \item     $$\begin{aligned}     \int x^2 \cos x \,dx     &= x^2 \sin x - 2 \int x \sin x \,dx     \\ &= x^2 \sin x - 2 (-x \cos x +\int \cos x \,dx)     \\ &= x^2 \sin x - 2 (-x \cos x + \sin x \,dx + C)     \\ &= x^2 \sin x + 2x \cos x - 2\sin x + C     \\     \\     \int \frac{\ln x}{x^3} \,dx     &= -\frac{1}{2} \frac{\ln x}{x^2} +         \frac{1}{2} \int \frac{1}{x^3} \,dx     \\ &= -\frac{\ln x}{2x^2} +         \frac{1}{2} \cdot -\frac{1}{2x^2} + C     \\ &=  -\frac{\ln x}{2x^2} - \frac{1}{4x^2} + C     \\ &= -\frac{1}{4x^2}(2\ln x + 1) + C     \end{aligned}$$ \end{enumerate} \end{document}   In this approach, the numbers generated by enumerate are missing, so I'm wondering are there better ways.

I have a problem regarding alignment for my equations.  This dummy program shows the problem:  \documentclass{article} \usepackage{amsmath} \begin{document}  \begin{enumerate}     \item First do this     \begin{align}     c^2 &= a^2 + b^2     \end{align}      \item Then do this      \begin{align}     variable &= c^2     \end{align} \end{enumerate}  \end{document}     I would like the = to be aligned under each other, but still be able to list them inside the enumerate.  Any suggestions?


I know that perfect security means absolutely no information about the plaintext is leaked to the adversary while computational secrecy is okay with a tiny amount of leak.  But, what is the difference between Computationally indistinguishably and Perfect Indistinguishably?

What is the difference between the two notions of computational and statistical indistinguishability?


I have a question regarding vectors:      Find the equation of the plane perpendicular to the vector $\vec{n}\space=(2,3,6)$ and which goes through the point $ A(1,5,3)$. (A cartesian and parametric equation).   Also find the distance between the beginning of axis and this plane.    I'm not really sure where to start. Any help would be appreciated.

I have a question regarding Vectors; Find the equation of the plane perpendicular to the vector $\vec{n}\space=(2,3,6)$ and which goes through the point $ A(1,5,3)$. (A cartesian and parametric equation). Also find the distance between the beginning of axis and this plane.   I'm not really sure where to start. Any help would be appreciated.


This is the problem I'm working on. If $f$ is differentiable on $(a,b)$ and $c \in (a,b)$, then $f′$ is continuous at $c$. I believe it to be true, but I'm having a hard time proving it. I don't see how a function's derivative can both be defined at a point inside an open interval and be discontinuous at that same point.

Suppose $f$ is continuous on $[a,b]$ and differentiable on (a,b). Does it follow that $f'$ is continuous on $(a,b)$?


I got pinged with :     There aren't any images.   Upon closer inspection, I realized that not only are my answer's images gone, but the other answer also. This got me looking and I found these posts (none of which were helpful) and this question is not a duplicate of any of them:      or     In that last question there is a :     It does work for these images, if you're referring to those embedded in the example question you linked. If it doesn't, then the image was deleted because it was inactive for 6 months.   That makes it sound as if nobody looked at a particular question for six months, all the images would get deleted!  Are images uploaded through SE's image hosting tool subject to such deletion rules? (I sure hope not!)  If this is not the case why are the images from  answers now gone?

Just now when trying to upload an image with the image uploader I'm greeted intermittently with the following error:  Failed to upload image; imgur is rejecting the request  That error comes from the POST on https://meta.stackexchange.com/upload/image?https=true I initially was on an non-encrypted HTTP connection. Switching to HTTPS seemed to resolve the issue. In this same time-frame I also  that are hosted on i.stack.imgur.com are not served or only after refreshing a couple of times. I have verified in chat that it is  and I rule out caching. Can this be looked at and if possible fixed?


As suggested by the title, I am looking for a term to describe the well-known (?) phenomenon, that some people often start quite lengthy conversations with someone standing in a doorway about to leave. I am sure I came across such a term some time ago, but cannot find it now.  Thanks in advance!

There is a Hungarian expression, küszöbgörcs, which literally means "threshold-cramp", and is used to describe that long conversation you have in the entryway, with all the guests awkwardly holding their coats and purses, and every so often somebody says something like "Ok, we really have to leave now, but just one more thing...", and then the conversation is good for another half an hour at least.  I've searched in vain for an equivalent idiom in English, yet I feel sure it must exist: I know English speakers are equally susceptible to this malady, it's not a uniquely Hungarian thing. I will sometimes use literal translations, like the aforementioned threshold-cramp (or doorway-spasm), but then I need to explain it, and that's less than satisfactory. (Plus it leads to more threshold cramping.)


I have an unknown (let's assume uname -a returns nothing) Linux distribution I have root access to.   How can I verify, looking at file structure, that it is based on Debian?

I'm working on a simple bash script that should be able to run on Ubuntu and CentOS distributions (support for Debian and Fedora/RHEL would be a plus) and I need to know the name and version of the distribution the script is running (in order to trigger specific actions, for instance the creation of repositories). So far what I've got is this:  OS=$(awk '/DISTRIB_ID=/' /etc/*-release | sed 's/DISTRIB_ID=//' | tr '[:upper:]' '[:lower:]') ARCH=$(uname -m | sed 's/x86_//;s/i[3-6]86/32/') VERSION=$(awk '/DISTRIB_RELEASE=/' /etc/*-release | sed 's/DISTRIB_RELEASE=//' | sed 's/[.]0/./')  if [ -z "$OS" ]; then     OS=$(awk '{print $1}' /etc/*-release | tr '[:upper:]' '[:lower:]') fi  if [ -z "$VERSION" ]; then     VERSION=$(awk '{print $3}' /etc/*-release) fi  echo $OS echo $ARCH echo $VERSION   This seems to work, returning ubuntu or centos (I haven't tried others) as the release name. However, I have a feeling that there must be an easier, more reliable way of finding this out -- is that true?  It doesn't work for RedHat. /etc/redhat-release contains : Redhat Linux Entreprise release 5.5  So, the version is not the third word, you'd better use :  OS_MAJOR_VERSION=`sed -rn 's/.*([0-9])\.[0-9].*/\1/p' /etc/redhat-release` OS_MINOR_VERSION=`sed -rn 's/.*[0-9].([0-9]).*/\1/p' /etc/redhat-release` echo "RedHat/CentOS $OS_MAJOR_VERSION.$OS_MINOR_VERSION"


I just have got a Macbook Pro Retina 2014. The charger is new and 85 Watt. I have two issues. When I first connected the charger, there was 54% charge on the laptop and for only 1 second the green light of the magsafe turned on. I have seen no more light [orange/green] after that ever.  And, the pc is not receiving any charge when the power cable is connected.  I have different brightness set for battery/power. When I connect the adapter, the brightness changes, the charging sign in the battery shows. But, no change in percentage and It says, "Battery Is Not Charging".  I have tried all the other answers to the similar questions including SMC reset but nothing worked. It seems to me the connection is okay [as brightness changes]. But somehow laptop doesnt take the charge. Not sure what to do. And, do not know why the green light turned only once and never again in the MagSafe.

I see that the question "why is my MacBook not charging?" gets asked a lot. The problem is, there are multiple reasons. Possible points of failure are: charger, cable, magsafe connector, DC input board, logic board, battery. (Have I missed any?). What is the best sequence for a user to follow, to diagnose the problem? By way of example, here are the first steps that I usually try:  Make sure the charger is working. Either use your charger on a different Mac, or test a spare charger with your Mac.  Check the connection. There might be gunk in your port that's stopping the connector from lying flat.  Try resetting the SMC and PRAM.  If the computer boots, run Coconut Battery to determine battery status.   This is where I get a bit stuck. For example, I have a machine here that boots fine when plugged in, but not from battery. Disconnecting the MagSafe causes the machine to switch off. Sounds like it's a dead battery, except that Coconut reports the battery as detected, in good condition, but not charging. What steps should I take next? Specifically, I'm asking for a generic algorithm to help determine the source of the fault (preferably without swapping out lots of components one by one)?


I use the code below to get JSON data (img, name), and everything works fine, but I get a lot of report in Google Console under ANRs & Crashes :   java.lang.NullPointerException:    at maa.app.Fragments.fragmentAnime$3.onSuccess (fragmentAnime.java:75)   at maa.app.Fragments.fragmentAnime$6.a (fragmentAnime.java:52)   at maa.app.Fragments.fragmentAnime$6.onResponse (fragmentAnime.java:2)   at com.android.volley.request.StringRequest.c (StringRequest.java:4)   at com.android.volley.request.StringRequest.a (StringRequest.java:2)   at com.android.volley.ExecutorDelivery$ResponseDeliveryRunnable.run (ExecutorDelivery.java:30)   at android.os.Handler.handleCallback (Handler.java:789)   at android.os.Handler.dispatchMessage (Handler.java:98)   at android.os.Looper.loop (Looper.java:164)   at android.app.ActivityThread.main (ActivityThread.java:6942)   at java.lang.reflect.Method.invoke (Method.java)   at com.android.internal.os.Zygote$MethodAndArgsCaller.run (Zygote.java:327)   at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:1374)   myApplication :  public class MApplication extends MultiDexApplication {     public static RequestQueue requestQueue;     @Override     public void onCreate() {         super.onCreate();         requestQueue = Volley.newRequestQueue(getApplicationContext());     }   Fragment :   StringRequest stringRequest = new StringRequest(Request.Method.GET,                     URL_DATA,                     s -> {                         List<Post> listItems = new ArrayList<>();                         try {                             JSONObject jsonObject = new JSONObject(s);                             JSONArray array = jsonObject.getJSONArray("bgs");                             for (int i = 0; i < array.length(); i++) {                                 JSONObject o = array.getJSONObject(i);                                 Post item = new Post(                                         o.optString("img"),                                         o.optString("name")                                 );                                 listItems.add(item);                             }                             callback.onSuccess(listItems);                         } catch (JSONException e) {                             slowInternetConnection();                         }                     },                     callback::onError) {             };             if (getActivity() != null && isAdded()) {                 stringRequest.setShouldCache(false);                 requestQueue.getCache().clear();                 requestQueue.add(stringRequest);             }   can anyone help me to get resolve this issue?

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


I'm having trouble to install updates, because it pop-up a window requiring to authenticate. and the problem is, I don't know it.  Thanks!

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


What is the difference between ten minute walk and ten minutes' walk, are they the same?

Recently, while skimming through an article I came across a sentence which is as follows.  The five minute walk will connect you with life.  My rationale says it should have been "five minutes" and not "five minute". Kindly advise where am I going wrong?


Find all pairs of positive integers $(m,n)$ such that $2^{m+1}+3^{n+1}$ is a perfect square    My attempt so far Any perfect square is $0,1$ in mod 4, so $n+1$ must be even : $$2^{m+1}+3^{2r}=k^2$$ Rearranging and factoring $$2^{m+1}=(k+3^r)(k-3^r)$$ That gives two equations $$2^a=k+3^r\\2^b=k-3^r\\a+b=m+1;a>b$$ However I am not able to conclude, subtracting/adding...  these equations is not giving me anything useful. Any help is appreciated... Thanks!

If $x$ and $y$ are positive integers, then when is $2^x+3^y$ a perfect square?   I tried this question a lot but failed. I tried dividing cases into when $x,y$ are even/odd, but still have no idea what to do when they are both odd. I tried looking into when is  $2^x+3^y$ is of the form $6k+1$ and so on .. but couldn't succeed. Can anyone help?


Just a bit of background on the question: When proving:  $$\cos\frac{\pi}{15}\cdot \cos\frac{2\pi}{15} \cdot \cos\frac{3\pi}{15}\cdot \cos\frac{4\pi}{15} \cdot \cos\frac{5\pi}{15} \cdot \cos\frac{6\pi}{15}\cdot \cos\frac{7\pi}{15} = \frac{1}{128}$$  The following formula was used:     $$\cos A \cdot \cos 2A \cdot \cos 2^2A \cdot \cos 2^3A\cdot \cdots \cdot \cos2^{n-1}A = \frac{\sin 2^n A}{2^n \sin A}$$   I'm just interested to see how this is derived. The question assumes that this formula is memorised and known beforehand, but it looked interesting to me since I'd actually never come across it before.  If anyone's interested, I'll link full proof for the question   Cheers in advance!

$$\cos A \cdot \cos 2A  \cdot \cos 2^{2}A  \cdot \cos 2^{3}A  ... \cos 2^{n-1}A = \frac { \sin 2^n A}{ 2^n \sin  A } $$  I am very much inquisitive to see how this trigonometrical identity can be proved.  PS:I am not much of interested about an inductive proof.


I am trying to solve a problem which asks to find the smallest prime palindrome, which comes after a given number which means that if the input is 24, the output would be 101 as it is the smallest number after 24 which is both prime and a palindrome.  Now my code works perfectly for small values but the moment I plug in something like 543212 as input, I end up with a StackOverFlowError on line 20, followed by multiple instances of StackOverFlowErrors on line 24. Here is my code :  package nisarg; import java.util.Scanner;  public class Chef_prime_palindromes {     public static void main(String[] args) {         Scanner input = new Scanner(System.in);         long num = input.nextLong();         isPalindrome(num + 1);     }      public static boolean isPrime(long num) {         long i;         for (i = 2; i < num; i++) {             if (num % i == 0) {                 return false;             }         }         return true;     }      public static void isPalindrome(long num) {         String word = Long.toString(num);         int i;         for (i = 0; i < word.length() / 2; i++) {             if (word.charAt(i) != word.charAt(word.length() - i - 1)) {                 isPalindrome(num + 1);             }         }         if (i == word.length() / 2) {             if (isPrime(num)) {                 System.out.println(num);                 System.exit(0);             } else {                 isPalindrome(num + 1);             }         }     } }

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


I need to compare the memory consumption of the same algorithms when executed in C, C++ and Java. After doing some reading I figured out that measuring maximum resident set size is the best indicator of memory consumption. For C/C++ I am able to use getrusage() to get the data, but for Java I am not able to find any equivalent.

I need to check CPU and memory usage for the server in java, anyone know how it could be done?


There's a professor of mine who's USB hard drive was stolen from her desk plugged into her laptop.  So I was wondering if there is any way or any "log file" in windows which stores the date and time of all USB drives last "plugged in/plugged out" so that I can find at what time exactly the hard drive was plugged out and stolen.  Please tell me if it is even possible from "windows event viewer", "Device manager" or "Registry Editor" etc?   I tried a software  from Nirsoft but it only showed the last time when the USB drive was plugged in.

I am currently trying to find a way to log all of the connections and disconnections of USB devices from all of the Windows machines on our network. This information needs to automatically be logged to a file on the machine, this file can then be read by nxlog and then get shipped to our centralised logging platform for processing. I was hoping that this information would be logged by Windows logs automatically, but I found that while some information about USB removable storage appears to get logged to Event Viewer, this is quite limited information and doesn't pick up when USB keyboards and mice are connected and disconnected.  After some digging I found that nirsoft had written a small exe which does a lot of the hard work,  can be run without installation and logs every time a USB device connects and disconnects to the machine. The issue with this is that I cannot see a way to run this as a service, nor do I see any way to have it automatically log the information it outputs to a log file, although you can select log entries and manually select them to be saved to a log file.  I could use Group Policy to create a local copy of the exe file, and then somehow force this exe to run during startup, but the main issue of not being able to get the logs automatically written to file would still need to be overcome. I would also need to be able to ensure that the user isn't able to close the program, which is possible when I launch it myself, ideally having it hidden and not showing a tray icon would be the best way for it to be set up (but when I have tried using the hidden setting, it seems to me that it can either be shown in the main window, or just displaying the systray icon). I looked on the website, but I don't see any way to invoke the program with options to tell it to do this. I also emailed nirsoft last week to see if they had any advice, but I am still waiting for a response.  Has anyone got any alternative ways to do this at all? Any suggestions or help welcome! Thanks


It's very important for a research professional (such as a Statistician) who needs to work on multidisciplinary fields to attend international conferences and see what's going around in the field of research. However, sometimes information contained in the websites about the upcoming conferences are too subject specific (e.g. there's so many related to computer science).   Is there any website that 'gathers information' (rather than just providing information from the user submitted ones) on all conferences irrespective of particular subject areas?  If there is any website about conferences that is related to Statistics and the fields which has its use, it'll do for me as well. Thank you for your reading.

What is the best way to search for conferences all over world? I need to participate in one in the near future.


i'm new here and i'm struggling to prove that for R,S fields and f : R → S kernel(f) = {0} Definition of kernel is : kern(f)= { r ∈ R | f(r) = 0 } I started the proof but stuck at the start : ∀a ∈ R-{0} => f(a) ≠ 0 Thank you for your help !

Let $\phi\colon R \to R'$ be a ring homomorphism. Prove that if $R$ is a field then either $\phi$ is an isomorphism or $\phi(r) = 0$ for all $r \in R$.   I am stuck on this problem and don't know where to begin. I feel like I'm very weak in writing proofs.


I am trying to import several CSV-files using Python. However, my code does not work. Furthermore, the coordinates are in DMS-format and I am unsure on how to implement that to my code. import os.path, glob layers=[] for file in glob.glob('/Users/NAME/Desktop/gis/weights/*'):     uri="file:///"+file+"?type=csv&xField=LON&yField=LAT&spatialIndex=no&subsetIndex=no&watchFile=no&crs=epsg:4326"     vlayer = QgsVectorLayer(uri, os.path.basename(file), "delimitedtext")     vlayer.addAttributeAlias(0,'x')     vlayer.addAttributeAlias(1,'y')     layers.append(vlayer) QgsMapLayerRegistry.instance().addMapLayers(layers)  When running my code I get the following error-messages: Traceback (most recent call last):  File "/Applications/QGIS3.10.app/Contents/Frameworks/Python.framework/Versions/Current/lib/python3.7/code.py", line 90, in runcode exec(code, self.locals) File "<input>", line 1, in <module>  File "<string>", line 10, in <module> NameError: name 'QgsMapLayerRegistry' is not defined   Below is a sample of the data in the CSV-file.

Is QgsMapLayerRegistry going to be availabe in pyqgis with QGIS3  When I typed it into the QGIS python console (2.99), python seems to recognize it because it auto-completes qgis.core.QgsMapLayerRegistry, but then gives an error that it's not there:  Traceback (most recent call last):   File "/usr/lib/python3.5/code.py", line 91, in runcode     exec(code, self.locals)   File "<input>", line 1, in <module> AttributeError: module 'qgis.core' has no attribute 'QgsMapLayerRegistry'   I tried this with two versions of QGIS 2.99 (one in 01/07 and on in 06/17). Both versions give the same error. import doesn't work either:  >>>from qgis.core import QgsMapLayerRegistry Traceback (most recent call last):   File "/usr/lib/python3.5/code.py", line 91, in runcode     exec(code, self.locals)   File "<input>", line 1, in <module> ImportError: cannot import name 'QgsMapLayerRegistry'   Is QgsMapLayerRegistry removed in QGIS3?


How can I tell what are the maximum attribute values that are expected from the different item levels? Is there a Diablo III items prefixes and suffixes list?

Someone found this quiver with surprisingly high values, although I'm unable to find a level 30 rare quiver on     Given that the item's internal level (IIL) determines which affixes are possible, I'd like to know whether the IIL affects the minimum/maximum rolls for an attribute, a graph or table would be great.  For example, let's say items are able to get a pure +intellect affix from IIL 20, what's stopping you from rolling 250 at 20?  Is it a bell curve, which has shallower gradients with a higher IIL of the item?  Is it capped, dependant on IIL?  Do the min/max caps step up at certain IILs,though it's the same attribute? For example, IIL 20-40 is capable of 5-120, IIL 41-60 is capable of 20-320, ..., IIL 63 = 40-400


I was trying to save customization templates in QGIS 2.4 and have managed to hide the MENU bar. Now I cannot access Settings->Customization to switch it on again.   I even un-installed and deleted the .qgis2/ folder from my user but it always loads without the menu bar now.  Please suggest a way to get the MENU bar back please.

Making some tests in Windows XP for customizing a user interface in QGIS 1.8 (see ), I have unchecked, among other options, the Settings Menu. This means that, after restarting QGIS, there's no way of recovering the older settings because there is not already a Setting Menu. So, I cannot reload any ini file.  For your information, as a precaution, previously I have saved in a folder both the original ini file, with all the options, and the customized ini file with only some options (of course, not included here the necessary Settings Menu).  Before reinstalling QGIS (version 1,8), I would like to try other smarter options if there's any. Where and what does QGIS look at where this applications starts?


Question :What is the maximum value of $\lvert z\rvert$ when $z$ satisfies the condition $\lvert z+\frac{2}{z}\rvert=2$  My try: By removing modulus, and simplifying as $-2<z+\frac{2}{z}<2$, I am not getting the required answer. Someone please help.

If $z$ is a complex no. such that $\displaystyle \left|z+\frac{2}{z}\right| = 2\,$ Then find max. and min. value of $\left|z\right|$.  $\bf{My\; Try:}$ Given $\displaystyle \left|z+\frac{2}{z}\right| = 2\Rightarrow  \left|z+\frac{2}{z}\right|^2 = 2^2=4$.  So $\displaystyle \left(z+\frac{2}{z}\right)\cdot \left(\bar{z}+\frac{2}{\bar{z}}\right) = 4\Rightarrow \left|z\right|^2+2\left(\frac{z}{\bar{z}}+\frac{\bar{z}}{z}\right)+\frac{1}{|z|^2} = 4$.  Now how can I find the max. and min. values of $|z|$?  Help me please.  Thanks


guys. i wanted to install virtualbox on my Ubuntu 18.04 lts,but when i run sudo apt update,i get this : E: Malformed entry 53 in list file /etc/apt/sources.list (Component) E: The list of sources could not be read. Here is that list: # deb cdrom:[Ubuntu 18.04 LTS _Bionic Beaver_ - Release amd64 (20180426)]/ bionic main restricted  # See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to # newer versions of the distribution. deb http://lt.archive.ubuntu.com/ubuntu/ bionic main restricted # deb-src http://lt.archive.ubuntu.com/ubuntu/ bionic main restricted  ## Major bug fix updates produced after the final release of the ## distribution. deb http://lt.archive.ubuntu.com/ubuntu/ bionic-updates main restricted # deb-src http://lt.archive.ubuntu.com/ubuntu/ bionic-updates main restricted  ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu ## team. Also, please note that software in universe WILL NOT receive any ## review or updates from the Ubuntu security team. deb http://lt.archive.ubuntu.com/ubuntu/ bionic universe # deb-src http://lt.archive.ubuntu.com/ubuntu/ bionic universe deb http://lt.archive.ubuntu.com/ubuntu/ bionic-updates universe # deb-src http://lt.archive.ubuntu.com/ubuntu/ bionic-updates universe  ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu  ## team, and may not be under a free licence. Please satisfy yourself as to  ## your rights to use the software. Also, please note that software in  ## multiverse WILL NOT receive any review or updates from the Ubuntu ## security team. deb http://lt.archive.ubuntu.com/ubuntu/ bionic multiverse # deb-src http://lt.archive.ubuntu.com/ubuntu/ bionic multiverse deb http://lt.archive.ubuntu.com/ubuntu/ bionic-updates multiverse # deb-src http://lt.archive.ubuntu.com/ubuntu/ bionic-updates multiverse  ## N.B. software from this repository may not have been tested as ## extensively as that contained in the main release, although it includes ## newer versions of some applications which may provide useful features. ## Also, please note that software in backports WILL NOT receive any review ## or updates from the Ubuntu security team. deb http://lt.archive.ubuntu.com/ubuntu/ bionic-backports main restricted universe multiverse # deb-src http://lt.archive.ubuntu.com/ubuntu/ bionic-backports main restricted universe multiverse  ## Uncomment the following two lines to add software from Canonical's ## 'partner' repository. ## This software is not part of Ubuntu, but is offered by Canonical and the ## respective vendors as a service to Ubuntu users. # deb http://archive.canonical.com/ubuntu bionic partner # deb-src http://archive.canonical.com/ubuntu bionic partner  deb http://security.ubuntu.com/ubuntu bionic-security main restricted # deb-src http://security.ubuntu.com/ubuntu bionic-security main restricted deb http://security.ubuntu.com/ubuntu bionic-security universe # deb-src http://security.ubuntu.com/ubuntu bionic-security universe deb http://security.ubuntu.com/ubuntu bionic-security multiverse deb http://archive.canonical.com/ubuntu bionic multiverse # deb-src http://archive.canonical.com/ubuntu bionic multiverse deb http://archive.canonical.com/ubuntu multiverse # deb-src http://archive.canonical.com/ubuntu multiverse deb http://download.virtualbox.org/virtualbox/debian bionic contrib # deb-src http://download.virtualbox.org/virtualbox/debian bionic contrib # deb-src http://security.ubuntu.com/ubuntu bionic-security multiverse  Sorry,im a newbie in Ubuntu,but as i see the problem is with this one **deb http://archive.canonical.com/ubuntu multiverse** (??) Where can be a problem? thank u !

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


I fell for the tarp. In an attempt to fix an installation issue with Python and Pygame I read something stupid online telling me to delete this file and that file to completely get rid of python on my machine so I could install it. One of the files was Library/Frameworks/Python and the other was System/Library/Frameworks/Python. Obviously when I tried to reinstall Python it wouldn't let me. So now the real dilemma. I'm even more of an idiot because I've never had any kind of backups. I don't have an external to save backups to anyways so I just never did it. Now I find myself unable to do anything with Python anymore and I can't restore from a backup because I'm stupid. So is there any way I can get python reinstalled again without completely restoring my computer and losing everything I have?

I've deleted a system file from my Mac and need to get it back.  System files can include:   hidden files in the root of / - especially unix files in /private  /System files /Library files /Applications files that ship with the core OS   System files are not any app, user files or files that can be regenerated by a known sequence such as cache files, Spotlight index files, etc…    Canonical question and answer for .


I wondered, if $\forall x\, \exists y\, R(x,y)$ is equivalent to $\exists y\, \forall x\, R(x,y)$.  If $R(x, y) = (x < y)$ then the answer would appear to be no.   In the first case, for all $x$, does there exist a $y$ such that $x < y$? Sure, just pick $y = x + 1$.   In the second case, it says there exists a $y$ such that $x < y$ holds for all $x$. But any $x$ that is greater than or equal to $y$ would make this false.  So it seems that the order of the quantifiers matter, but then we have this proof:  ∃x ∀y R(x, y)                                 [Hypothesis]  Let c be a constant such that ∀y R(c, y)     ∀y R(c, y)          Given constant d:         R(c, d)                               [∀ elim]         ∃x R(x, d)                            [∃ intro]      ∀y ∃x R(x, y)                             [∀ intro]  ∀y ∃x R(x, y)                                 [∃ elim]   Here it seems to imply we can swap the order if we start out with an exists quantifier coming first?  In other words is it true that:  $\forall x\, \exists y\, R(x,y) \not\rightarrow \exists y\, \forall x\, R(x,y)$ (how would we actually prove this?)  But:  $\exists y\, \forall x\, R(x,y) \rightarrow \forall x\, \exists y\, R(x,y)$

Does the quantifier order matter in this problem? I don't think it does.  (∃y in R)(∀x in R)(x+y=x) For some real number y and for all real numbers x, x plus y equals x. I assert this to be true. (I won't bother with the proof unless somebody really wants it)  I feel that, although the quantifiers are switched, the sentence is still true. Is this right?  (∀x in R)(∃y in R)(x+y=x) For all real numbers x there is a real number y such that x plus y = x  I also feel that these sentences are also all true, regardless of their order. Am I missing something here?   (∃y in R)(∀x in R)(x+y=0) and (∀x in R)(∃y in R)(x+y=0).   Plus these two sentences (∃y in R)(∀x in R)(xy=1) and (∀x in R)(∃y in R)(xy=1)


Despite there're some related topics to this one, I'm still struggling to figure out how mathematicians came to use antiderivatives ( F(b) - F(a) in a definite integral formula) in order to find out the area under the curve?  I know how to calculate both derivative and antiderivative, but this knowledge comes from learning the rigorous formulas by heart; but what I would like to understand is the train thought that has lead to realization that we need to use antiderivatives while integrating.  For instance, I look at the simple function graph y=2x. I know the algorithm of steps I need to take to find the area, say, between 0 and 2. However, why antiderivative? Why do we work not with the f(0) and f(2), but first find the "parent" function and then work with F(0) and F(2) ?  What kind of reasoning should I follow to bind such things like "infinite number of rectangles" and antiderivative of the function at the given values?  I'm studying Algebra and Calculus on my own, so that's the reason for, perhaps, a stupid question. Still, thanks in advance for any help.

I understand how derivatives work based on the definition, and the fact that my professor explained it step by step until the point where I can derive it myself.  However when it comes to the area under a curve for some reason when you break it up into an infinite amount of rectangles, magically it turns into the anti-derivative. Can someone explain why that is the definition of the integral and how Newton figured this out?


We are creating the records using the Lightning component like below     var createRecordEvent = $A.get("e.force:createRecord");      createRecordEvent.setParams({          "entityApiName": "Contact",          "defaultFieldValues": {             'AccountId':accId,          }});     createRecordEvent.fire();    Is there any way to get the ID of the created record after the event is fired and the record is saved.

Are there a way to add callback after the user created a record and clicked the Save button?  I am using a custom tab and custom components and open the Create a record modal window using e.force:createRecord, but I was not able to find out how to attach callback to the event.  I even found :     Currently force:createRecord event does not accept any callback method or any after save event to handle custom action. Current force:createRecord always redirects to the newly created record. But in case if you want to just close the force:createRecord popup after save and refresh some other related component using the refresh is not possible.    So, is it really impossible? If so, what are current workarounds here?


How to prove that  $$\displaystyle\lim_{n\to\infty}\sum_{k=1}^n\left(\frac{k}{n}\right)^n=\frac{e}{e-1}$$  Thank in advances.

I can show that the following limit exists but I am having difficulties to find it. It is $$\lim_{n\to \infty} \sum_{k=1}^n \frac{k^n}{n^n}$$ Can someone please help me?


My name is Tom and I am turning 18 in 6 months. I want to go to London in the first week of May but on my visa it's written only valid if accompanied by my mother. So my question is that if a get consent letter sign from my mother, can I go to England alone?

I am supposed to be traveling to the UK tomorrow, but my visa is an accompanied visa by my mom. My mom is already in the UK (she had to leave early).  Will I be allowed in the airport to enter if my parent (that I'm accompanied by) is already in the UK (arrived before me and probably will be waiting at the airport)?


The  feature says:  Spell Slots The Warlock table shows how many spell slots you have. The table also shows what the level of those slots is; all of your spell slots are the same level. To cast one of your warlock spells of 1st level or higher, you must expend a spell slot. You regain all expended spell slots when you finish a short or long rest.  If you multiclass from another caster class and take a level in Warlock, do all your other spell slots suddenly start recharging over a short rest?

If you multiclass a Warlock and a Sorcerer, then you have a character with both the Spellcasting and Pact Magic features.  PHB Page 101, Sorcerer, Spellcasting, Spell Slots:     You regain all expended spell slots when you finish a long rest.   PHB Page 107, Warlock, Pact Magic, Spell Slots:     You regain all expended spell slots when you finish a short or long rest.   PHB Page 165, Customization Options, Multiclassing, Class Features:     Pact Magic. If you have both the Spellcasting class feature and the Pact Magic class feature from the warlock class, you can use the spell slots you gain from the Pact Magic feature to cast spells you know or have prepared from classes with the Spellcasting class feature, and you can use the spell slots you gain from the Spellcasting class feature to cast warlock spells you know.   Do the spell slots keep their previous method of recovery (sorcerer slots long rest, warlock slots any rest), or do they all act consistently as I am led to believe from the language of the multiclass section? Do they all recover only from long rests as per the sorcerer feature, or can they all be recovered with a short rest because the warlock feature says so?


I have started learning java. I am learning  Boolean in java. Boolean has two types, true & false. In C there was nothing like this. We have either 0 or 1. So, I want to know how does true and false work? How is it stored in memory? Does it require 1 bit space or more? Is it some type of string? For example,  class Test { public static void main(String[] args) {     System.out.println( 5 > 6 ); }   }  I get :  false   So, what is the size of false? It looks like a string in java.

Can any one tell the bit size of boolean in Java?


I have a plot that has residuals vertically dashed to the regression line. I also am using the function resid to derive all residuals. I am not entirely sure what good is finding residuals. Someone please explain and show an example.  library("MASS")     # data survey              # data  plot(survey$Height ~ survey$Wr.Hnd, xlab = "Writing Handspan (cm)", ylab = "Height (cm)")  survfit <- lm(Height ~ Wr.Hnd, data = survey) survfit  abline(survfit, lwd = 2) resid(survfit)    # residuals  obsA <- c(survey$Wr.Hnd[197], survey$Height[197]) obsA  obsB <- c(survey$Wr.Hnd[154], survey$Height[154]) obs  mycoefs <- coef(survfit) mycoefs  beta0.hat <- mycoefs[1] beta1.hat <- mycoefs[2]   segments(x0 = c(obsA[1],obsB[1]),           y0 = beta0.hat + beta1.hat * c(obsA[1], obsB[1]),          x1 = c(obsA[1], obsB[1]), y1 = c(obsA[2], obsB[2]), lty = 2)  # residual dashed vertical line

Suppose that we have a model $Y_i = \beta_0 + \beta_1X_{i1} + \beta_2X_{i2} + \dots + \beta_kX_{ik} + \epsilon_i$.  Regression has a number of assumptions, such as that the errors $\epsilon_i$ should be normally distributed with mean zero and constant variance. I have been taught to check these assumptions using a normal QQ plot to test for normality of the residuals $e_i = Y_i - \hat{Y}_i$ and a residuals vs. fitted plot to check that the residuals vary around zero with constant variance.  However, these tests are all on the residuals, not the errors.  From what I understand, the errors are defined as the deviation of each observation from their 'true' mean value. So, we can write $\epsilon_i = Y_i - \mathbb{E}[Y_i]$. These errors cannot be observed by us. *  My question is this: how good of a job do the residuals do in mimicking the errors?   If the assumptions appear to be satisfied on the residuals, does this mean they are satisfied on the errors too? Are there other (better) ways to test the assumptions, like fitting the model to a testing dataset and getting the residuals from there?    * Furthermore, does this not require that the model is specified correctly? That is, that the response really does have a relationship with the predictors $X_1, X_2,$ etc. in the way specified by the model.  If we are missing some predictors (say, $X_{k+1}\ \text{to}\ X_p$), then the expectation $\mathbb{E}[Y_i] = \beta_0 + \beta_1X_{i1} + \beta_2X_{i2} + \dots + \beta_kX_{ik}$ would not even be the true mean, and further analysis on an incorrect model seems pointless.  How do we check whether the model is a correct one?


I have 2 questions:   I am using a texture with a transparent alpha channel. It renders alright, but it displays in the 3D Viewport's texture shading mode all wrong, as you can see below. Is this a glitch or did I do something wrong?        Is there any way I can make the grey area outside the texture a different shader? Everytime I put a UVmap there, thinking nothing would appear on the model, the texture still appears! Is it obligatory to fit everything in that little square?   Any help will be appreciated! Thanks!

I have two planes with the same node setup, but only one of them is transparent in Material Viewport Shading.    The one that works was created by the Import Images as Planes addon. The other plane was created manually and copying the addon's material setup into a new material.  If I set the addon's material to the "bad" plane it works, so the problem is related to the material itself (nor the object, OPGL or my hardware). I'm working on 2.73.  I have no clue about this behavior,  for checking it out.


I can't boot my Windows. Windows boot option is not listed in GRUB boot list.   Boot-repair gave me .

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


Is there a way to write short code in LINQ to check if one array is a subsequence of other and honor an order?  For example (pseudo code):   var masterList = new double[] {0,1,2,3,4}; var lst1 = new double[] {0,1,2,3}; var lst2 = new double[] {0,1,3,4}; var lst3 = new double[] {2,3,4}; var lst4 = new double[] {3,4}; var lst5 = new double[] {4,3};  bool isSubseq1 = lst1.Compare(masterList); // true bool isSubseq2 = lst2.Compare(masterList); // false bool isSubseq3 = lst3.Compare(masterList); // true bool isSubseq4 = lst4.Compare(masterList); // true bool isSubseq5 = lst5.Compare(masterList); // false   edit:  bool isSubseq = !lst5.Except(masterList).Any(); // returns true, but I want to return false   edit2: Example2:  var masterList = new double[] {0,1,2,3,4,4,4,5,6,6,8,8}; var lst1 = new double[] {0,1,2,3}; var lst2 = new double[] {0,3,4}; var lst3 = new double[] {4,4,4}; var lst4 = new double[] {6,6,8,8}; var lst5 = new double[] {5,4,4,4,3}; var lst6 = new double[] {9,9};  bool isSubseq1 = lst1.Compare(masterList); // true bool isSubseq2 = lst2.Compare(masterList); // false bool isSubseq3 = lst3.Compare(masterList); // true bool isSubseq4 = lst4.Compare(masterList); // true bool isSubseq5 = lst5.Compare(masterList); // false bool isSubseq6 = lst6.Compare(masterList); // false   Yeah I could write my own method, but this is not I'm asking for. I will accept nested query.

Any idea on how to check whether that list is a subset of another?  Specifically, I have  List<double> t1 = new List<double> { 1, 3, 5 }; List<double> t2 = new List<double> { 1, 5 };   How to check that t2 is a subset of t1, using LINQ?


First of all, really sorry I remember there should be a term for these two but I am really bad at terms.  Anyways, I am just playing around and at first I thought both of them should be giving the same result which YES it gave the same result but when I try to assign something into one of the index, that's when I found out there are differences, but I can't figure out.  Can someone please give me a hand on explaning the differences and why the result is like this?  e = [[0 for _ in range(3)] for _ in range(3)] e[0][1] = 1 print(e, 'e')  # [[0, 1, 0], [0, 0, 0], [0, 0, 0]] e   d = [[0] * 3] * 3 d[0][1] = 1 print(d, 'd')  # [[0, 1, 0], [0, 1, 0], [0, 1, 0]] d   as seen, e is doing exact what I expected changing only index [0][1] to ` but as for d it's changing all.  Why is this happening though?  Thanks in advance for any help and explanations

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


I'm using a batch file to execute an awk program and feed it filenames.  Question: How do I get it to expand the filenames on the command line?  Syntax:  Command.exe *.rpt > out.txt  Exact:  "C:\Users\user\Utilities\mawk.exe" -f "C:\Users\user\My Projects\AWK\EmailSQLResults.awk" C:\Temp\SQL\*.rpt > "C:\Temp\SQL\EmailResults.txt"  Result:  mawk: cannot open C:\Temp\SQL\*.rpt (Invalid argument)  Windows 10. Standard CMD window. mawk 1.3.4 20140914

Occasionally, the cmd shell's inability to expand wildcard paths can really be an inconvenience. I had to pass 100 files in a directory to a program, and couldn't type *.ext. Instead, I used mingw's 'ls' to dump the list to a file, then replaced newlines with spaces, copied and pasted into cmd. Quite a nightmare.  I suspect the answer will be no, but has anyone dealt with this or come up with any way to make this easier?


So I've tried new Gmail design. I couldn't believe it was that ugly and unpleasant to use.  How to roll back to previous normal Gmail design?  New Gmail design:

So I've tried new Gmail design. I couldn't image it is that ugly and unpleasant to use.  How to roll back to previous normal Gmail design?  New Gmail design:


Here's my code. My problem is that I'm trying to check if my user input variable, titleScanner, is equal to the title (which is specified earlier in the code) or if its equal to "exit". Even when I get my code to print out what titleScanner is equal to (exit when I type exit) the else if code for exit won't run.      void getId() {             Scanner titleScanner = new Scanner(System.in);             System.out.println("Please enter the title of the game in order to obtain the ID Number");             int loopbreak = 0;             while (loopbreak == 0) {                 String titleVerification = titleScanner.nextLine();                 if (titleVerification == title) {                     System.out.println(title + " has ID Number " + id);                     loopbreak = 1;                 } else if (titleVerification == "exit") {                     loopbreak = 1;                 } else {                     System.out.println("Please enter a valid title or type exit to exit");                 }              }          }

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


I have this Boolean operator which adds a Boolean to the active object and adds the second in order to the object property but this wont more than once because the second modifier added wont be dif it would be dif.001 How do i automate this name issue class BoolOp(Operator):     """Quick Booelan Operation"""     bl_idname = "extorctools.boolop"      bl_label = "Bool Op"         bl_options = {'REGISTER', 'UNDO'}          def execute(self, context):         target = bpy.context.active_object         lis = bpy.context.selected_objects         cutter = []         for x in range(len(lis)):             if len(lis) == 1:                 raise Exception("2 Objects must be selected")             elif not lis[x] == target:                 cutter.append(lis[x])                 break         try:             target.modifiers.new(name = f"dif" , type = 'BOOLEAN')             target.modifiers['dif'].object = cutter[0]         except:             pass         return {'FINISHED'}  What i want to be able to do is to do something like this target.modifiers[the.most.recent.modifier.of.type.BOOLEAN].object = cutter[0]

I've found some code that could add a modifier but none can set parameters like Octree.


I am writing a script that is supposed to ask for user's password, do some stuff with it and eventually pass it to sudo. This is roughly how it looks:  echo "input password: " read -s password printf "\n"  echo $password | sudo -S <somecommand> | <what i need>   It all works as it should, but sudo outputs "[sudo] password for user: " whenever I call the script. I would like to cut this, but leave all other output. This is what I've tried for :  grep -v -e "[sudo] password for user: " awk -F"[ ',]+" '/[sudo] password for user:/{print $2}' sed -En "s/[sudo[ password for user: '(.*)',/\1/p"   Obviously, since I am here none of this worked. Does anyone have an idea on how to do this?

I want to write the output of only sudo command to some file i.e. the line which I get on terminal after writing sudo i.e.   [sudo] password for user:   If I use sudo ls > file or sudo ls 2> file then I get the stdout and stderr respectively of the whole command. Also I can't use sudo > file or sudo 2> file, then I will get error that I should use some options or command after sudo. So, is it possible to achieve?


$1 + 3 = 4$ (or $2$ squared) $1+3+5 = 9$ (or $3$ squared) $1+3+5+7 = 16$ (or $4$ squared) $1+3+5+7+9 = 25$ (or $5$ squared) $1+3+5+7+9+11 = 36$ (or $6$ squared)  you can go on like this as far as you want, and as long as you continue to add odd numbers in order like that, your answer is always going to be a perfect square.  But how to prove it?

How to derive this formula?   $$n^2=\sum_{k=1}^n(2k-1).$$


Using Ubuntu 16.04. I like Krusader, but can't figure out how it is possible to change date/time format for the Modified column. I truied to change system regional settings, but Krusader ignores them (while, e.g., Midnight Commander uses system settings). Switching application language (in Help menu) also does not affect the date/time format. I like the 24-hour format, not PM/AM, and I may prefer even to hide time, and leave only date. Is that possible in Krusader?  The other post is of no help, as there is no even such file in mys systems as ~/.kde/env/setlocale.sh

With Kubuntu 14.04, I have got some trouble with the locales. "Something" in KDE override my settings (I say in KDE because if I use gnome, I got no problems).  Here are my settings   $ cat /etc/default/locale  LANG="en_US.UTF-8" LANGUAGE="en" LC_NUMERIC="fr_FR.UTF-8" LC_TIME="fr_FR.UTF-8" LC_MONETARY="fr_FR.UTF-8" LC_PAPER="fr_FR.UTF-8" LC_IDENTIFICATION="fr_FR.UTF-8" LC_NAME="fr_FR.UTF-8" LC_ADDRESS="fr_FR.UTF-8" LC_TELEPHONE="fr_FR.UTF-8" LC_MEASUREMENT="fr_FR.UTF-8"   $ cat /etc/environment PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games"   But I got (the problem are the "en_FR.UTF-8"):  $ locale locale: Cannot set LC_ALL to default locale: No such file or directory LANG=en_US.UTF-8 LANGUAGE=en LC_CTYPE="en_US.UTF-8" LC_NUMERIC=en_FR.UTF-8 LC_TIME=en_FR.UTF-8 LC_COLLATE="en_US.UTF-8" LC_MONETARY=en_FR.UTF-8 LC_MESSAGES="en_US.UTF-8" LC_PAPER=en_FR.UTF-8 LC_NAME=en_FR.UTF-8 LC_ADDRESS=en_FR.UTF-8 LC_TELEPHONE=en_FR.UTF-8 LC_MEASUREMENT=en_FR.UTF-8 LC_IDENTIFICATION=en_FR.UTF-8 LC_ALL=   What do you think of that?  Thanks!


I read in this school book, an algorithm to find the LCM of rationals. It goes in the following manner. $[\frac{a}{b}, \frac{c}{d}]=\frac{[a,c]}{(b,d)}$.  If you inspect as to why the formula is given so you will realise that this formula gives the smallest positive rational which is an integral multiple of both $\frac{a}{b}$ and $\frac{c}{d}$.  For example, $[\frac{1}{2}, \frac{3}{4}]=\frac{3}{2}$. Where, $\frac{3}{2}=3(\frac{1}{2})=2(\frac{3}{4})$.  Now, what is puzzling me is the idea of LCM. Because I was of the opinion that this is a concept only defined on integer, but here they define it for rational numbers. So, is this a universally accepted formula or was it just something the person who wrote this book put in?  I just realised that someone has already asked a question previously questioning the logic behind this formula. Well, that is not my question. I wish to know whether this formula is actually relevant in higher mathematics.

I was reading a text book and came across the following approach to find the LCM and HCF of rational numbers/fractions:   LCM of fractions = LCM of numerators/HCF of denominators HCF of fractions = HCF of numerators/LCM of denominators   Can someone please help me understand why the above formula holds true or how the above is logically deduced?  Thanks in advance!


I am a heavy user of custom tag filters through stackexchange.com.  For all of my custom filters, I am (unsurprisingly) the only follower.  However, custom filters are public, and I can browse/view/follow filters created by others by manually constructing a relevant URI and guessing a filter ID:        etc...  but that's not a very efficient way of searching.  Are there any other ways of browsing custom tag filters, apart from manually constructing an URI? How can I find what custom stackexchange.com tag filters are popular?

The -interest list  and  has decided to use both Stack Overflow for questions and Google groups dicussions for ANTLR users. There seems to be problems with new Stack Overflow users trying to effectively monitor the ANTLR tags. I created a  for just the ANTLR tags, but how do I allow others to follow it? Do I just give the link as I did here? (I would not be surprised if this is a duplicate, I just could not find the original.)


So, it appears about 2 IP addresses are overloading my HTTP server (apache) over UDP and I am unable to stop this using IP Tables. I am using CentOS 5. I managed to block some other IP addresses that were overloading TCP, but can't seem to stop the UDP.  I've narrowed down the offenders to connecting to random ports using UDP connections, but the following entry in iptables isn't working:  -A INPUT -s <offending IP> -p udp -j DROP   Can anyone offer some advice as to what I'm doing wrong?  UPDATE: I noticed that all offending incoming connections were from port 53, so did the following and it seemed to work:  -A INPUT -s <offending IP> -p udp --dport 53 -j REJECT

This is a  about DoS and DDoS mitigation.   I found a massive traffic spike on a website that I host today; I am getting thousands of connections a second and I see I'm using all 100Mbps of my available bandwidth.  Nobody can access my site because all the requests time out, and I can't even log into the server because SSH times out too!  This has happened a couple times before, and each time it's lasted a couple hours and gone away on its own.  Occasionally, my website has another distinct but related problem: my server's load average (which is usually around .25) rockets up to 20 or more and nobody can access my site just the same as the other case.  It also goes away after a few hours.  Restarting my server doesn't help; what can I do to make my site accessible again, and what is happening?  Relatedly, I found once that for a day or two, every time I started my service, it got a connection from a particular IP address and then crashed.  As soon as I started it up again, this happened again and it crashed again.  How is that similar, and what can I do about it?


Question was  Let $$A= \left[\begin{matrix}          a_1 & a_2\\          a_3&a_4\\        \end{matrix}\right]$$ $$P= \left[\begin{matrix}          p_1 & p_2\\          p_3&p_4\\        \end{matrix}\right]$$  Find the matrix $Q$ such that   $$ Q\left[     \begin{array}       \\       p_1\\p_3\\p_2\\p_4     \end{array} \right] = \left[     \begin{array}       \\       1\\0\\0\\1     \end{array} \right]$$ is equivalent to the equation $A^TPA+P=I$  In this question I approached to make $Q$ to $2\times 2$ matrix. but I couldn't get any idea.. I need you genius to help.


I will arrive to Geneva airport from Paris, the specified arrival time is 09:05 in the morning. I heard that the airport terminal and train station are in same floor there, I have to transfer to the train to Interlaken right away and can I make it to the 10:00 train after all the luggage claim and sort of security pat down things? if that 55 minutes are too much pushing how much time will be the best?

My plane departs from Geneva Airport (Geneva International terminal M) at 19:55. I'll be in Zürich and a bit short on time. If I take the train that arrives at "Genève-Aéroport" at 18:51, will I have enough time to find the terminal and check in? I've never been to this airport before.


Is anyone familiar with a technique for removal of whitespace that results from the use of tag libraries such as JSTL?  I know that you can do this , but does anyone have similar experience doing this type of thing within WebSphere App Server?

How can I strip out extra whitespace from jsp pages' output?  Is there a switch I can flip on my web.xml?  Is there a Tomcat specific setting?


Which one is correct?     He engraved photos of himself and his wife on the coins.   Or     He engraved photos of him and his wife on the coins.

(1) Andrew looked at him in the mirror.    (2) Andrew looked at himself in the mirror.   Does (1) include (2)’s possibility? Or does him in (1) only refer to someone other than Andrew?


most books say that contractible implies simply connected is trivial as at time one, every point of the space is shrunk to one point, including the loop. However, there is a problem. In discussing simply connectedness, we use loop homotopy, i.e. we have to ensure the paths in between is also a loop with the same basepoint. But i there no way to guarantee that by contractible condition?   Thanks a lot.

Every contractible space X is simply connected because X is homotopy equivalent to a point.  Is there a direct proof of this fact? There obviously is a (free) homotopy between any loop and the trivial loop at the base point. But how to construct a based homotopy, which is required for a loop to be trivial in the fundamental group?


When users receive a question ban they  in the  tag.  I would like to put forward the hypothesis that this is the way most of the users who post blatantly off-topic questions on meta find meta in the first place.   If this is true then hosting that link anywhere other than on meta would go a long way towards cutting the volume of "I got banned so I asked it here instead" questions that meta sees.  Proposal: the link question banned users see should be hosted on the site the ban relates to itself, not on meta. The text of that message could link to meta still, it's a layer of additional indirection.  Rationale: The people who post these questions clearly don't read the contents of the message, it seems like the thought process runs approximately as "I'm banned, but what a stroke of luck - another Q&A site, I'll just ask there, someone is bound to solve this for me". This would remove the "another Q&A site" aspect and make reading the text the only option.  It's hard to say for certain that this is indeed the cause, questions of this nature get deleted quickly and it's not possible to do more than guess if a user is indeed question banned. (I would give example of these questions, but I can't see them once they're deleted on meta and I think it's fairly obvious what the sort of questions I'm referring to are)  I think this hypothesis could be tested (by a developer) with something like  on the number of closed+deleted off-topic questions after making the change.  I can't quite believe I'm the first one to suggest this, but searching for this mostly just turns up thousands of duplicates of the "Help I'm banned" questions.

Related:    The helpcenter has . It still links to the  for further details. Besides that, the question ban message .  Now that we have the helpcenter, could the following changes be implemented?   Link to the help center instead of the meta post Remove the link to the meta post from the help center, and instead incorporate its contents into the helpcenter itself


I have been testing Sharepoint Foundation 2010 web application, now its time to move site to Live. Customer is asking to reset the web analytics counter to 0. I tried stopping web analytics data processing service and Web Analytics Web service. They both stopped sucessfully and started sucessfully, but data still exists in site collection.   Any ideas on how to complete this task.  Thank You

Is it possible to reset the numbers reported in Web Analytics? We have created some sites and have tested them out but want to see what the actual usage is, excluding our testing information.


If my opponent casts say an Elspeth, can I then Hero's Downfall that Planeswalker before any abilities are used?   I think my question boils down to: are planeswalker abilities sorcery or instant speed?

Say my opponent plays a planeswalker during their first main phase.  I have a  or some other effect that will kill it after it is already in play, but before they use any of its abilities.  I could respond to them using a +1 ability, but I want to kill it before that effect goes on the stack.  In most casual situations, it would basically come down to whether I say "Hero's Downfall" first, or they say "+1" first.  But I can't imagine that's how it's supposed to work.  Is there a time between when the planeswalker hits the battlefield and when they activate its abilities that they must let me respond? It seems to me that situations like this arise frequently, and they are resolved simply by who speaks up first, which is horrible for such a rules-oriented game.


I am trying to use GREP to select multiple-line records from a file.  The records look something like that  ########## Ligand Number :       1 blab bla bla bla blab bla   ########## Ligand Number :       2 blab bla bla bla blab bla   ########## Ligand Number :       3 bla bla bla   <EOF>   I am using Perl RegEx (-P).  To bypass the multiple line limitation in GREP, I use grep -zo. This way, the parser can consume multiple lines and output exactly what I want. generally, it works fine.  However, the problem is that the delimiter here is two empty lines after the end of last record line (three consecutive '\n' characters: one for end line and two for two empty lines).   When I try to use an expression like      grep -Pzo '^########## Ligand Number :\s+\d+.+?\n\n\n' inputFile   it returns nothing. It seems that grep can't tolerate consecutive '\n' characters.  Can anybody give an explanation?  P.S. I bypassed it already by translating the '\n' characters to '\a' first, then translating them back. like this following example:      cat inputFile | tr '\n' '\a' | grep -Po '########## Ligand Number :\s+\d+\a.+?\a\a\a' | tr '\a' '\n'   But I need to understand why couldn't GREP understand the '\n\n\n' pattern.

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