I have a mid 2012 MBP. Came with Mountain Lion, upgraded to Mavericks in 2013 and never touched the OS X again. Long story short: I need El Capitan to run some work apps and it can't be newer because an essential piece of hardware won't work on Sierra or later. I installed High Sierra yesterday to confirm and because I didn't install El Capitan at the time, I can't do it now that Sierra/High Sierra are out. Is there a safe source here to download the installer (torrent)?  Thanks in advance.

We have an older iMac (Model A1311, Mid 2011). It has been running Yosemite. We have run into some of the WIFI issues associated with Yosemite.   Is it possible to upgrade to El Capitan but not Sierra?   El Cap has been out longer. Its my wife's computer, its older, and I really don't want to be debugging Sierra until a few  more "dot" releases come out.


Let $A$ be a ring and define $S = A[x_{0}, x_{1}, \ldots , x_{r}]$. Let $X = \text{Proj }S$. I would like to show that $\Gamma(X, \mathcal{O}_{X}(n)) = S_{n}$. This is Proposition II 5.13 in Hartshorne, but I am not comfortable with the proof given there. I am currently trying to follow the proof , which is the corrected version of the proof given in Liu's Algebraic Geometry and Arithmetic Curves. The idea seems simple enough. To specify an element of $\Gamma(X, \mathcal{O}_{X}(n))$ is to specify the restrictions, $$ f_{i} = \frac{g_{i}}{x_{i}^{d_{i}}} \in S(n)_{(x_{i})} \quad \text{with } \deg(g_{i}) = n + d_{i} $$ We can assume WLOG that $g_{i}$ in the above is not divisible by $x_{i}$. We would like these restrictions to agree on overlaps $D_{+}(x_{i}x_{j})$, that is $$ \frac{g_{i}}{x_{i}^{d_{i}}} = \frac{g_{j}}{x_{j}^{d_{j}}}  $$ In terms of the equivalence relation defining localization, this gives us that $$ g_{i}x_{j}^{d_{j}} - g_{j}x_{i}^{d_{i}} = 0 $$ From this I would like to reconstruct a unique element of $S_{n}$. Is someone able to walk me through what is actually going on in the proof above? I'm missing something, and am not sure how we can recover the homogenous polynomial that he does. Even if I could just see this done for the case of $S = A[x_{1}, x_{2}]$ would be enough.

Consider the ring $\Bbb Z[x_0,\cdots,x_n]$ with the grading defined by the degrees of polynomials, then we have $\mathcal O(\mathrm{Proj}\,\Bbb Z[x_0,\cdots,x_n])=\Bbb Z$.  Let $R$ be a nonzero commutative ring and consider the ring $R[x_0,\cdots,x_n]$ with the grading defined by the degrees of polynomials. What kind of ring $R$ makes $\mathcal O(\mathrm{Proj}\,R[x_0,\cdots,x_n])=R$?


How can I log out of one browser? I don't mind whether it's per site or for all Stack Exchange sites, though having both would be nice. I don't mean the “” link in the : that would “log you out on all devices”. I only want to log out of one device, I want to stay logged in elsewhere. I tried the , which claims to “clear all local credentials in your browser”. But that only logged me out of , not out of the Q&A sites. And contrary to the claim it also logged me out of other clients. So how can I log out of one client while staying logged in in other browsers?

While it's great to have the ability to clear all session cookies for all devices, I'd like the ability to log out on one computer only, and not come home to have to relogin on all of my devices. It can really be a pain.   Is there a technical reason we don't have this, or why don't we?


My template makes me use files with file extension ".def". They contain regular tex code. How can I enable syntax highlighting in TeXstudio for these files?

In TeXstudio I want to associate different files with tex coloring scheme. For example, I open .stex file and the syntax is not colored. This .stex file is the same tex file, I just renamed it for some reason.  I've putted .stex extension in my ini file:    Files\Default%20File%20Filter=TeX files (*.tex *.bib *.sty *.cls *.mp  ***.stex**)   But it does nothing.


I just found a good question via Google. There is  answer which links to a self-made project by the user. It has awarded a bounty worth 50 rep by the Community ♦ user.  But how can this user award bounties? How is this possible that, or when does, this bot award bounties?

I accepted an answer to this question:    but the bounty was awarded by Community ♦ to another answer. Why did this happen?


My problem is that when i started install ubuntu server in my server machine(Dell R540), it starts showing me the problem that "there was a problem completing the installation" and it restart with same language prompt again. so I detect the problem and it is not with my hardware machine but it is because of the ISO fie I downloaded from the ubuntu official website. I firstly downloaded the iso from here :   so this iso file is responding with "there was a problem completing the installation" after that I downloaded another ISO from here :   It smoothly worked so the question is why these two are behaving differently.

I've just downloaded a CD image of Ubuntu. I know the installer has a check CD option, but how can I check that the image is good before burning it to CD?


How to tell if a date is between two other dates in angular 2  I need to check a date which is in between the start date and the end date how can i check in angular 2?

Can someone suggest a way to compare the values of two dates greater than, less than, and not in the past using JavaScript? The values will be coming from text boxes.


I have a direct question: How to make "selected" an option of a select using FancySelect plugin?  This is the situation: I have a select with two options and two links. The links should be synchronized with the select. That means that when clicking on a link, it must make "selected" an option of the select.   It is important notice anyway that it is not a normal select, but i am using a JQuery plugin called FancySelect:  And this can be the main reason why normal solutions found elsewhere in StackOverflow did not apply to my specific case. So the point is not how to make "selected" an option of a select, but how to make it "selected" while using the FancySelect plugin.  Here you can understand better:    This is the code i am trying to use, but is not working yet:  $( "#a1" ).click(function() {       $("#selector option:first").attr('selected','selected');  });   Can you tell me please how can i force an option of a select to be "selected"? Thank you very much!

I have a drop-down list with known values. What I'm trying to do is set the drop down list to a particular value that I know exists using jQuery.  Using regular JavaScript, I would do something like:  ddl = document.getElementById("ID of element goes here"); ddl.value = 2; // 2 being the value I want to set it too.   However, I need to do this with jQuery, because I'm using a CSS class for my selector (stupid  client ids...).  Here are a few things I've tried:  $("._statusDDL").val(2); // Doesn't find 2 as a value. $("._statusDDL").children("option").val(2) // Also failed.      How can I do it with jQuery?     Update  So as it turns out, I had it right the first time with:  $("._statusDDL").val(2);   When I put an alert just above it works fine, but when I remove the alert and let it run at full speed, I get the error     Could not set the selected property. Invalid Index   I'm not sure if it's a bug with jQuery or Internet Explorer 6 (I'm guessing Internet Explorer 6), but it's terribly annoying.


I have Ubuntu 15.10 installed. I want to upgrade to 16.04. The option to do this does not show up in software updater. When I ran do-release-upgrade -cd it returns No new release found.   So I downloaded the iso and put it on a usb stick. When I boot up into the installer the option to upgrade 15.10 to 16.04 is blanked out. It will allow me to erase the current installation or install alongside.   Is there anything else I can try before erasing my current installation (thus losing some of my settings).

Recently I have installed an older version of Ubuntu on my old machine. Whenever I try to install any software, I get an error saying it couldn't be found:  $ sudo apt-get install vlc Reading package lists... Done                Building dependency tree        Reading state information... Done     E: Couldn't find package vlc


does anyone has this problem or can solve it, please? I added the references through Mendeley application desktop. Everything is fine except the URL width size. If it is too big it continues across the page size and margin size.  \bibliographystyle{IEEEtran} \bibliography{/home/Thesis.bib}    Thanks

I have an external bib where I put a reference to an external URL.  @misc{myreference,   author = {The Author},   title = {The Title},   howpublished = "\url{http://thisismyurl/2010/3/a-long-url-here}",   year = {year} }   When I compile, the URL (when displayed in Bibliography) exceeds the bounds of the page (set as customs). The URL is composed by different terms concatenated with - symbol. a-long-url-here can be the following:  abc-abc-abca-abc-ab-abc-abc-abc-a-abcabc-ab-abc-abc/   The bib is inserted in the following manner:  \bibliographystyle{IEEEbib} \bibliography{bibliog}   Is there any mechanism to fix this behaviour? I checked  but I don't know how to use it in my situation.  Edit  For the sake of completeness, I use PdfLatex.


Yesterday Blender 2.8 was released and it was exciting for me. But when I move the objects in the viewport, a keyframe gets added, which is quite annoying. Could someone tell me how to turn this off? Thanks in advance (:

I think I must have changed a setting by accident.    Whenever I select an object and do any operation on it (move, rotate, scale, etc), suddenly the boxes in the Transform tab become yellow and the Animate property settings (The diamonds next to the yellow boxes on the right hand side of the photo) become activated.  I don't know what these are and what these do (I don't think they do anything atm), but I know this is not the default behavior.  How can I change this back to default behavior? (i.e. no yellow boxes, no diamonds)


(I see an error I made, but I'd still like to know if there is a specific order.)  I have here $\left(6^{-36}\right)/\left(6^{-16}\right)\cdot\left(6^{16}\right)$.  If I do the division first, it's $-36$ minus $-16$, making an addition of plus $16$ for $6^{-20}$.  This times the $6^{16}$ equals $6^{-4}$.  But if I do the multiplication first, the powers of $16$ and $-16$ cancel out, leaving me with $6^{-36}$, which is a radically different answer.  When it comes to exponents, do I have to strictly go from left to right first, in terms of division/multiplication?

There is a huge debate on the internet on the value of $48\div2(9+3)$. I believe the answer $2$ as I believe it is part of the bracket operation in BEDMAS.  yields the same answer. I also believe that if $48\div2\times(9+3)$ was asked it would be $288$ which Mathway agrees with as well. However,  says it is $288$ either way. A friend of mine (who is better at math) told me that there is no such thing as 'implicit multiplication', only shorthand so that is in fact done after the division (going left to right, not necessarily because division occurs before multiplication. But he didn't explicitly give a reason) What is the answer and why?


I have no interest in saving anything that is still on this device.  When I choose "Erase disk and install ubuntu" I receive the error "?????? "??????" Could anyone help me with this problem?   This PC has a 1Tb HD and 4 Gb of RAM There was previously Windows 7 on the PC, but that is now gone.  I can let you know anything else about the specs if needed. Thank you.

I am trying to install Ubuntu 14.04 on FakeRAID along Win7.  Win 7 has been already installed, and dmraid is running.  During the installation I choose to manually partition, this is the structure:  \dev\mapper\isw_gchdghhd_Volume0 \dev\mapper\isw_gchdghhd_Volume0Op1 - NTFS Win7 loader \dev\mapper\isw_gchdghhd_Volume0Op2 - NTFS Win7 partition \dev\mapper\isw_gchdghhd_Volume0Op3 - swap \dev\mapper\isw_gchdghhd_Volume0Op5 - ext4 mounted as \ \dev\mapper\isw_gchdghhd_Volume0Op6 - ext4 mounted as \home   There is another sequence similar to above marked as "linear".  I choose \dev\mapper\isw_gchdghhd_Volume0 as boot device.  When immediately after the installation begins, an error with question marks pops up, and the installation stops.


When xargs redirects the first commands output into the second command's argument and there is no choice about which argument for which element of the output, then there is only one way, for instance:  ls | xargs file  # there are as many arguments as files in the listing,                  # but the user does not have too choose himself   now if there is a need for choice:  ls | xargs file | grep image | xargs mv.....   # here the user has to                                                 # deal  with two arguments of mv, first for source second for destination, suppose your destination argument is set already by yourself and you have to put the output into the source argument.    How do you tell xargs to redirect the standard output of the first command into the argument of your choice of the second command ?

I want to find some files and then move them.  I can find the file with:  $ find /tmp/ -ctime -1 -name x*   I tried to move them to my ~/play directory with:  $ find /tmp/ -ctime -1 -name x* | xargs mv ~/play/   but that didn't work.  Obviously mv needs two arguments. Not sure if (or how) to reference the xargs 'current item' in the mv command?


Two years ago, I cropped a video on Windows 7 using Windows Live Movie Maker.  I cannot remember how I did it, but I know I did because I have the video from two years ago in three different sizes. One is the original that looks small and far away. Then I have  a second copy that looks bigger and closer and a third copy that is the biggest and closest.  I need to do this with another video and cannot figure out how I did it. It's driving me nuts! Can someone please tell me how to do it again?  Thanks.

I want to crop (as in, take a subset of each frame, like when you crop a photo) a video in Windows Live Movie maker. Is there a way to do this, and failing that is there another free tool i can use to do that?


In this video, the outline of the proof is given for the polar value decomposition  We want to write square matrix A as $A = QS$ where $Q$ is an isometry and $S$ is a positive semi-definite matrix. The video handles the case where $S$ is invertible. $A^TA = SQ^TQS = S^2$, so $S=\sqrt{A^TA}$, which is indeed positive semi-definite. To check $Q$ is indeed an isometry, $Q = AS^{-1}$, so $Q^TQ = S^{-1}A^TAS^{-1} = I$. How do we check that Q is an isometry if $S$ is not invertible?

I am on the proof of the polar decomposition w/o using SVD:  Let $A$ be a real $n \times n$ matrix. Show that there exists $Q$: orthogonal, $P$: positive semi-definite symmetric matrix such that $A = QP$.   Consider the product $A^*A$, it is a self-adjoint and positive semi-definite (as we are in $\mathbb{R}$) symmetric matrix, so it has a decomposition $EDE^{-1}$ where $D$ is diagonal and $E$ is orthonormal and contains eigenvectors of $A^*A$. Now let $$   P = \sqrt{A^*A} =  E\sqrt{D}E^{-1}     $$ where $\sqrt{D}$ has diagonal elements being the squareroot of $D$. Notice that $||Px|| = ||Ax||,  $ so we can expect the product $AP^{-1}$ to be orthogonal. Provided that $P^{-1}$ exists (i.e. $P$ is positive definite), we have $||AP^{-1}x||=||x||$, so we do find our desired decomposition by letting $Q = AP^{-1}$.  The problem is that if $A$ is not invertible, then $P$ will also not invertible, regarding the whole proof useless. How should I fix it in this case?


using iOS I sometimes like to call 2 functions at random a button press for example, I would use; So sometimes, the user would get  (1) the other time (2) etc.  if (arc4random() % 2 == 0) {  // Do one thing (1)          } else {         // Do something else(2)          }     }   How would I do this within Eclipse/java? In otherwords, what is the same statement but in a Java language?

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.


I've been using 32 GB SDHC card on my canon EOS 1100D but one day suddenly it showed "card cannot be accessed.Reinsert/change the card or try formatting the card with the camera.". I tried a 16 GB card but it again showed the message. when I used a 4 GB card it worked perfectly with my camera and sorry for my poor english.

I know this is not specifically a photography issue but since many of us with prosumer/professional-level DLSRs use Compact Flash cards, it is bound to happen to others as well.  I have a Sandisk 16GB Ultra card that occasionally had the camera reporting inability to access the card. I had to reinsert the card to continue using it. I was able to read the card and transfer the photo files to my computer drive. Today, the same thing happened again, just that nearing the capacity of the card, it failed one last time and the camera was subsequently unable to read it anymore. Despite reinsertion.  My other CF cards never once exhibited this problem, so it's pretty much isolated to this card.  The card is similarly unrecognisable on my computer CF card reader. I think the filesystem is toast, but I suspect the photo files are still intact. I would like to find ways where I can inspect the raw binary data in the card and hopefully recover the photos?


Is there a way to see available seats before purchasing in Premium Economy Class on British Airways? I have already read the answers/tips in the linked duplicate "Can I see which seats are available on a British Airways flight before I book?" Those solutions work when booking Economy or Business Class, but none of those solutions work when trying to book Premium Economy. Any further suggestions are appreciated.

Some airlines (for example, ) offer a seat availability checker so you can see which seats are currently booked on a flight - there are limitations, since some seats might show as occupied but are actually reserved for priority customers - but it's still useful.  Is there any way of getting this kind of live seat booking data for British Airways before you have booked a flight? This would help me select which of several flights I might pick (for example, where I might be able to select a better seat, or where the plane is lightly loaded).


So I am writing a simple lexer for a subset of the C language in python. I am using re to match and find all my tokens but am having issues with my string literal token matching. To match my string literal I am using: r'(?<=").*(?=") I am doing this non-inclusive because I am wanting to match my double quotes as quote tokens and the content inbetween them as a string literal token. It works fine if a string literal is used only once in a line but if I do "hello"  int i "what is up" I end up matching hello correctly but then matching int i because it is inbetween double quotes also. How can I prevent this. Right now all of my input is read in at once into one line.   EDIT: I found out my possible issue. I was using a greedy expression with .* I switched it to .*? and it is matching correctly. It started matching as hello"  int i "what is up and that is where discovered it was being greedy. My new regex is : r'(?<=").*?(?=") Does anyone see any possible conflicts now?

I have this gigantic ugly string: J0000000: Transaction A0001401 started on 8/22/2008 9:49:29 AM J0000010: Project name: E:\foo.pf J0000011: Job name: MBiek Direct Mail Test J0000020: Document 1 - Completed successfully  I'm trying to extract pieces from it using regex. In this case, I want to grab everything after Project Name up to the part where it says J0000011: (the 11 is going to be a different number every time). Here's the regex I've been playing with: Project name:\s+(.*)\s+J[0-9]{7}:  The problem is that it doesn't stop until it hits the J0000020: at the end. How do I make the regex stop at the first occurrence of J[0-9]{7}?


When I use CMU Serif, letter "f" overlaps with other letters "f" when one follows another. Here is what it looks like:     What do I do to fix it? I don't think that the problem is with my PC. I tried it on different machines. Even Overleaf has the same problem with CMU Serif.

The  package allows to completely suppress ligatures. However, this feature requires pdfTeX 1.30 or newer. That's unfortunate if I'm using LaTeX or XeLaTeX while having to avoid ligatures.  Is there any other way to disable ligatures for a complete document or just an environment?


In the modern version of Pascal's wager argument, we assume an infinite value to ending up in heaven, and hence an infinite expected value for choosing to believe in god.  I do not understand why this should be the case. In general, it is a bad idea to place a bet on a highly unlikely option even if the rewards are great.   For example, if there is a lottery that will give a quadrillion dollars to one in quadrillion people and the cost of a lottery ticket is half a dollar (for a net expected value of 50 cents), you might as well not apply and save 50 cents because this event is so unlikely it might as well be impossible.  Indeed, it is only optimal to choose paths which maximize expected value if you have a large number of trials (a quadrillion in the lottery case). In Pascal's case there is only one trial in your hand.   Why should it be the case that we should still choose to maximize expected value (even though it is infinite)?

Blaise Pascal's famous wager was that even if the existence of God cannot be determined through reason, a rational person should wager as though God exists, because living life accordingly has everything to gain, and nothing to lose.  What logical flaws and/or fallacies (if any) are committed in making this argument?


I'm currently studying DeBranges book about Hilbert Spaces of Entire functions. This questions deals with problem 60 on page 61 (page 71 in the pdf on his website ). Let $s_n,t_n$ be (potentially infinite unbounded) positive sequences such that $s_n<t_n<s_{n+1}<t_{n+1}$ (interlacing property) and let $$f(z)=\prod_{n=1}^\infty\frac{1-z/t_n}{1-z/s_n},\qquad z\neq s_n.$$ Then $f$ defines a meromorphic function with only simple, real poles and zeros on $\mathbb{C}$ which is real for real $z$. I want to show that it is in fact real if, and only if, $z$ is real. I tried working with a few examples and found the following problems: Let's go finite first. If we disregard the poles, then there is an easy counterexample: $$f(z)=(z-1)(z+1)=z^2-1,\qquad \text{then }f(\mathrm{i})=-2\in\mathbb{R}.$$ Okay, the poles are relevant here. In particular $$f(z)=\frac{z^2-1}{z},\qquad \text{then }\Im(f(a+\mathrm{i}b))=\frac{b(a^2+1+b^2)}{a^2+b^2}\neq 0\quad \text{for }b\neq 0.$$ But why? What part of the pole property makes this work, if we multiply by a pole? Is it the interlacing part? Again, but why? I tried computing the Imaginary part of finite products - there it actually works out. By partial fraction decomposition we obtain the following sum $$f_n(z)=h+\sum_{k=1}^n\frac{G_n(s_k)}{F_n'(s_k)(z-s_k)},\qquad\text{where } h\in\mathbb{R},\;G_n(z)=\underbrace{\prod_{k=1}^n (1-z/t_k)}_{\text{numerator}},\;F_n(z)=\underbrace{\prod_{k=1}^n(1-z/s_k)}_{\text{denominator}}$$ by computing the residues. The interlacing property of the zeros and poles guarantees that $G_n/F_n'$ doesn't change sign and thus we get a positive imaginary part for $z\in\mathbb{C}^+$. The problem arises now if we take the limit to infinity, because then the strict inequality might become an equality. So once again I don't see a reason why the imaginary part shouldn't be zero. I would much appreciate any input. My only idea would be to do a partial fraction decomposition on all of $f$, but there I don't see why it should converge at all. Is there some result I don't know which allows me to do the decomposition on all potentially infinite poles?

Hi everyone I find the following exercise of infinite product functions.I'd stuck in this exercise.     Let $\{a_k\}$ and $\{b_k\}$ sequences of positive real numbers such that $b_k<a_k<b_{k+1}$ for all $k$ in $\mathbb N$. Prove that the infinite product $\prod_k (1-z/a_k)(1-z/b_k)^{-1}$ converges uniformly on compacts of $\mathbb C_+:=\{z:\mathbb{Im}z>0\}$ and the function $f(z)=\prod_k (1-z/a_k)(1-z/b_k)^{-1}$ is Herglotz.   Let $K$ a compact set in $\mathbb C_+$ in order to show that the infinite product converges uniformly on $K$ it will suffices to show that $\sum_k  [(1-z/a_k)(1-z/b_k)^{-1}-1]$ converges absolutely and uniformly on $K$.   \begin{align*}[(1-z/a_k)(1-z/b_k)^{-1}-1]=\frac{z}{b_k-z}\left(1-\frac{b_k}{a_k}\right) \tag{1}\end{align*}   Since $d=d(K,\mathbb C_+^c)>0$ this is a lower bound for $|b_k-z|$ and so for the denominator of (1) in norm. The $z$ in the numerator is bounded by some $M>0$ on $K$, since $K$ is compact and the identity function is continuous. Then   \begin{align*}|[(1-z/a_k)(1-z/b_k)^{-1}-1]|\le \frac{M}{d}\left(1-\frac{b_k}{a_k}\right) \tag{2}\end{align*}  But from here I'm stuck. I'd appreciate if someone can help me I didn't know how to use the form in which the numbers $\{a_k\}$ and $\{b_k\}$ are defined.


I'm looking for an adjective that can be used in an exchange like this:     Me: I have a gift for you.   Other: Is it the gift of happiness?   Me: I was thinking of something much more _____.   The blank would be a word that means something directly, explicitly, physically felt, like a kiss. The word "visceral" comes to mind, but that's:      relating to deep inward feelings rather than to the intellect. —      felt in or as if in the internal organs of the body. —     which is not quite what I'm looking for.

As the title states, if sound is audible, light is visible, what is a smell? And what is an object when you touch it?


I am trying to retrieve the following fields Owner.Name, Name, Id from ActionPlanTemplate object and returning a list. However, when the list is returned, I do not get Owner.Name in the ActionPlanTemplate object.  How can I get the Owner.Name in the ActionPlanTemplate list for each object?  When I enter the same query in Query Editor, I get the correct results.  String test = 'SELECT Owner.Name, Name, Id from ActionPlanTemplate';  List<ActionPlanTemplate> apt = database.query(test);  System.debug(apt);   This returns:     (ActionPlanTemplate:{OwnerId=0031W000019AA3qWBF, Name=APT Test, Id=0WS5E0000000044WAA}, ...   EDIT: After reading the recommended solutions, Yes Owner.Name can be called when I refer to it directly as object.Owner.Name, however I am trying to display this component as a value in my lightning data table column.  component.set('v.APcolumns', [         {label: 'Action Plan Template Name', fieldName: 'linkName', type: 'url', typeAttributes:{ label: { fieldName: 'Name'} }, target:'_blank', sortable: 'true'},         {label: 'Template Owner', fieldName: 'Owner.Name', type: 'text'}     ]);   The Action Plan Template name shows up, but not the Owner.Name

I am trying to get the Ultimate Parent Account from my contact up to 3rd level parent. Here is my SOQL code:  SELECT Name,Account.Parent.Name, Account.Parent.Parent.Name, Account.Parent.Parent.Parent.Name FROM Contact   I expect to see this result:  Contact:{Name='Name of COntact',Parent='the parent name', ChildParent='Child Parent Name', GrandParent='Grand Parent Name'}    OR   Contact:{Name='Name of COntact',ParentId='the parent Id', ChildParentId='Child Parent Id', GrandParentId='Grand Parent Id'}   Once I debug my query the result is not what i expected.  Contact:{Name='Name of the Contact', AccountId='Parent Id', Id='Id of the Contact'}   Anyone help?


When I select “Recommend deletion” in the VLQ queue, it will automatically add a comment to the post with my reason, if someone hasn’t already. I’m suggesting that the system automatically upvote the comment on my behalf to indicate that multiple users agree with the comment.

While working with the Low Quality review queue, when selecting a reason why you believe a post should be deleted, you automatically comment on the post with a canned piece of text explaining why you voted one way or another (if it doesn't already exist from another reviewer).  When you select the same reason as another reviewer and the comment already exists, what would we think about having it auto-upvote that comment instead of just doing nothing?    In the example above, another user had chosen to flag the answer for deletion for the same reason I picked, so I would expect my action to upvote their comment.


I want to make chrome tell a website the browser is not chrome, but IE 9 or 10. How is this done?

I am looking for a way to switch my user agent in Chrome.  I have tried  with only limited success. I really want more user agents, and the ability to add new agents with different operating systems.  Are there other ways of changing Chrome's user agent?


How can i prove that $ \forall x \in \mathbb{R} \displaystyle \lim_{n \to \infty} \dfrac{\left \lfloor{x}\right \rfloor+\left \lfloor{2x}\right \rfloor+\cdots+\left \lfloor{nx}\right \rfloor}{n^2} = \dfrac{x}{2} $?  I tried $A_{n}=\dfrac{\left \lfloor{x}\right \rfloor+2\left \lfloor {x}\right \rfloor+\cdots+n \left \lfloor{x}\right \rfloor}{n^2}$,  $B_{n}= \dfrac{\left \lfloor{x}\right \rfloor+\left \lfloor{2x}\right \rfloor+\cdots+\left \lfloor{nx}\right \rfloor}{n^2}$,  $C_{n}= \dfrac{x+2x+\cdots +nx}{n^2}$  So $A_{n} \leq B_{n} \leq C_{n}$  $ \Rightarrow \displaystyle \lim_{n \to \infty}A_{n} \leq \displaystyle \lim_{n \to \infty} B_{n} \leq \displaystyle \lim_{n \to \infty} C_{n} \iff \dfrac{\left \lfloor{x}\right \rfloor}{2} \leq \displaystyle \lim_{n \to \infty} B_{n} \leq \dfrac{x}{2}$  But I dont know if thats all or Im missing something

This question came from the prelim exam I took last month. I have a proof that seems a bit unwieldy to me (posted as an answer), so I'm opening it up to ask if there are other ways of showing this.     Let $x$ be any positive real number, and define a sequence $\{a_n\}$ by   $$ a_n = \frac{ [x] + [2x] + [3x] + \dotsb + [nx] }{n^2} $$   where $[x]$ is the largest integer less than or equal to $x$. Prove that $\displaystyle{\lim_{n \to \infty} a_n = x/2}$.


I have a following script sandbox.sh,  #!/bin/bash set -eu -o pipefail -E  function func1() {   echo "FUNC1"   exit 1 }  function func2() {   local ret   ret=$(func1)   echo $ret   echo "(func2)This line shouldn't be reached:'${?}'" >&2 }  var=$(func1) # The Line echo "main:This line shouldn't be reached:'${var}':'${?}'" >&2   (GNU bash, version 4.4.20(1)-release (x86_64-pc-linux-gnu))  This stops executing expectedly,  $ bash -eu sandbox.sh  $    However, if I modify "The Line" to var=$(func2) to call func1 through func2, it will give me following output  $ bash sandbox.sh  (func2)This line shouldn't be reached:'0' main:This line shouldn't be reached:'FUNC1':'0' $    To me, it seems command substitution behaves differently when it is placed inside a function, but I don't see why bash is designed so. Also it is a quite possible situation where a function's output is used by another and such a difference is confusing.  NOTE: If I rewrite func2 like following,  function func2() {   func1 }   The script stops at The Line. However, programmers quite often want to manipulate output from func1, I believe.

Consider this snippet:  stop () {     echo "${1}" 1>&2     exit 1 }  func () {     if false; then         echo "foo"     else         stop "something went wrong"     fi }   Normally when func is called it will cause the script to terminate, which is the intended behaviour. However, if it's executed in a sub-shell, such as in  result=`func`   it will not exit the script. This means the calling code has to check the exit status of the function every time. Is there a way to avoid this? Is this what set -e is for?


I am studying how exports and module.exports differ in Node. This question was particularly useful: . In short... this is what happens:  //require function  module = {    exports:{} }  (function(exports){     exports = 1; //contents of module })(module.exports)   If you forget about the node, and just write a simple function with the same functionality:  newmodule = {exports:{}}; function reassign(exports){     exports = ()=>{console.log("123")}     //or exports = 1;     //or exports = "Hello"; }  reassign(newmodule.exports) console.log(newmodule.exports) // prints empty object, reassign failed   You can observe that newmodule.exports indeed never gets reassigned. Not sure if I am having a brain freeze, but newmodule.exports was passed by reference. Yet, reassigning is not reflected on the passed object newmodule.exports. Why is that?   Extending the passed object works as expected   function reassign(exports){     exports.somefunc = ()=>{console.log("123")} // works as expected }

The primitive types (number, string, etc.) are passed by value, but objects are unknown, because they can be both passed-by-value (in case we consider that a variable holding an object is in fact a reference to the object) and passed-by-reference (when we consider that the variable to the object holds the object itself).  Although it doesn't really matter at the end, I want to know what is the correct way to present the arguments passing conventions. Is there an excerpt from JavaScript specification, which defines what should be the semantics regarding this?


When I read a statement in a paper that is itself derived from another paper, how should I reference it when I use it in my own article? Should I reference the original article or the second article, or both?

I'm review the literature at the moment. Now I'm reading a paper that mention other studies. How can I reference them without reading the original papers?


I would like to know if there is a way to somehow auto sync a folder on my external hard drive with a folder on my computer.  You see, previously my computer's internal Hard Drive got damaged and all my data erased. So now I am wondering, as if I have only a single folder which is important to me, like really important. It would be very safe for me to know that this one folder is auto syncing with my external hard drive's, which is always plugged into my computer. So in case of my computer's Internal hard drive crash, I would know that my data is all safe on my external hard drive.   Or perhaps there is a more simple way out there using which I will be able to have data auto syncing from my internal computers drive to somewhere I can access from any computer.

I'm working on a massive Java web application which is kept under centralized version control, but the source files are used to build and run the actual server, which then copies all the files I work on into a random temporary directory while it's running.  My problem is that I need to either rebuild this huge application to see any changes to my files, or keep track of all my changes and copy over the files I've changed back to their source location before committing them back to source control.  My question is: is there a command line script I can run that will monitor any changes in the source folder and automatically copy changed files across to temporary folder X?  The idea is to remove the human point of failure in having to manually mitigate the two-locations problem.


Well I am trying to access a variable declared outside of a function. Then whenever I am changing the variable value inside of the function I see an error message...      UnboundLocalError: Local variable 'x' referenced before assignment   Here is the module...  x = 5  def fun():     print 'x is', x     x = 10     print 'x is now changed to', x  fun()   It seems Python assuming the x declared inside of function is different than the x declared outside of the function. Also when I comment out line 5 the program runs without error.  Is this anything relevant to any rule like Python functions will give priority to the variables declared inside of it and if I want to do something like this program then I have to use global statement to achieve the goal?   Answer: Ok I think I sort out the point. Thanks to @unixer for providing me the link - . Actually when we declare a variable in any scope the variable becomes local to that particular scope and it shadows any similarly named variable outside of its scope unless the variable gets another new assignment to it in local or outer scope. In my case...   When I first assigned value to x outside of the function, x became local variable to that particular scope. And then when I fetched value of x inside of the function fun compiler printed value of x as declared in outer scope of the function. And again when I assigned new value to x(on line 5) compiler assigned new value to x. BUT this time it thought I did a mistake as I am trying to print x (on line 4) before assigning a value to it.   Point 3 is same as...  print 'x is', x x = 5   Compiler will raise same error as it sees I am trying to print value of x before assigning any value to it.

What exactly are the Python scoping rules?  If I have some code:  code1 class Foo:    code2    def spam.....       code3       for code4..:        code5        x()   Where is x found?  Some possible choices include the list below:   In the enclosing source file In the class namespace In the function definition In the for loop index variable Inside the for loop   Also there is the context during execution, when the function spam is passed somewhere else. And maybe  pass a bit differently?  There must be a simple reference or algorithm somewhere.  It's a confusing world for intermediate Python programmers.


I am attempting to reproduce an existing typeset equation. I am unable to find an \overanglebracket command. Two instances illustrate what I hope to accomplish. Comment by @SebGlav leads me to \wedge and the stackengine and scalerel packages. \documentclass[11pt]{article} \usepackage[math-style=french]{unicode-math} \usepackage{stackengine} \usepackage{scalerel} \begin{document}  \[\widehat{AOB}\]  \[\stackon[2pt]{AOB}{\hstretch{3.75}{\wedge}}=θ-\frac{π}{2};\]  \[\stackon[2pt]{KCA}{\hstretch{3.75}{\wedge}}=2\stackon[2pt]{KOA}{\hstretch{3.75}{\wedge}}=2θ.\] \end{document}   and I obtain:   and

Is there any way to get a hat wider than widehat?  Why doesn't  \widehat{abcdefghijklmnopqrstuvwxyz}   really go over all of it?


So, to be brief, I am trying to create a system of roads from a top view of google maps.     I started out making the UV Map of the first segment and getting it in order, and hoping that when I extend the road the UV map would keep intact.   I can create the mesh fine, and as far as that goes, I have no problem. I am able to model it rather close to as seen on google maps, using extrude and rotate / translate.  I had the first section good at one point (of the road) but after that, the textures go weird.  (Since then I have messed about and now nothing works properly, in regards to texture mapping which is when these pictures were taken.)  So, my biggest question, is, how can I add a road texture to this curved road, that will follow the road and the curves?   I would use the bezier curve method for road creation, but unfortunately, when exported to the game I intend to use the road for, the poly-count is tremendously high. 20000+ whereas with this method, 600-ish.   I guess, essentially, what I'm trying to do, is create roads like this:    [![Road/UV Windows][3]][3]  So how would I go about that, as far as texturing?

Ok so I have road and I would like to curve it smoothly without using arrays. I have it subdivided. Any ideas of how should I do it? Check the image below of my road and below that image you will see copy from internet of how I want it to look like:    Internet copy:    P.S. I forgot to say that I would like to do something so the road wouldn't have a lot of subdivision. What I mean is that I want it to be 1 solid road without any pieces that it is made up with. Because each time I upload it to software one of the faces goes invisible.


I have two different editions of Windows 7 installed on two different partitions (on the same physical drive).  One is Windows 7 Professional 32-bit, one is Windows 7 Home Premium 64-bit.  I have both because I use some applications that are compatible/work better on one or the other, so I find myself switching between the two quite often.  My question: is it possible to hibernate from both operating systems to make swapping between them faster?  Rebooting every time I need to switch from 32-bit or 64-bit is cumbersome and I wish I could just hibernate and swap quickly.  Is it possible?

I'd love to be able to hibernate one Windows instance, boot into another, then switch back to the first instance and have it resume my hibernated state.  Is there some sort of hack or software product that would enable that, maybe by renaming the hibernation files based on the the instance I'm booting to?  I understand the technical issues with why it's not supported - I could make changes to the filesystem while I'm running instance two that would cause my hibernated state in instance one, but I'm a big boy and don't need to be protected from myself.


Let $X$ be a vector of sample data, and $W$ is a vector of parameters of a model based on that data, and we want to estimate a vector $W^*$ that is, informally speaking, "as close to $W$ as possible".  Then shouldn't we maximize $P(W^*|X)$? that is, we should choose the parameter estimates W* such that the probability that they are the actual parameters, is maximized.  Why then, in maximum likelihood, do we want to maximize $P(X|W^*)$ instead? I don't see the (intuitive) justification behind it.  (On a more general note, I also don't see why $P(X|W^*)$ is called "likelihood of $W^*$, given $X$", since "likelihood" and "probability" seem to me to be synonymous in the original meanings of the words).

Could anyone explain to me in detail about maximum likelihood estimation (MLE) in layman's terms? I would like to know the underlying concept before going into mathematical derivation or equation.


# Program 1 fibSeries = {} def fib(n):         a,b = 1,1     for i in range(1,n+1):                 if i <= 2:              f = 1         else:              f = a + b             a = b             b = f         fibSeries[i] = f     return f  print (fib(number)) print (fibSeries)  # Program 2 fibSeries={} def fib(n):     for k in range(1,n+1):         if k <= 2: f = 1         else: f = fib(k-1) + fib(k-2)         fibSeries[k] = f     return f  print(fib(number)) print(fibSeries)   I have started dynamic programming and my first program is to find Fibonacci series. I have written the above two programs. My first question is which among these programs comes under dynamic programming? Which among these two programs is a better one? Is there a better way than program 1 to find the nth Fibonacci number faster? Is program 2 better than recursion? And how to find the number of times the function is called in program 2?

I had originally coded the program wrongly. Instead of returning the Fibonacci numbers between a range (ie. startNumber 1, endNumber 20 should = only those numbers between 1 & 20), I have written for the program to display all Fibonacci numbers between a range (ie. startNumber 1, endNumber 20 displays = First 20 Fibonacci numbers). I thought I had a sure-fire code. I also do not see why this is happening.  startNumber = int(raw_input("Enter the start number here ")) endNumber = int(raw_input("Enter the end number here "))  def fib(n):     if n < 2:         return n     return fib(n-2) + fib(n-1)  print map(fib, range(startNumber, endNumber))   Someone pointed out in my Part II (which was closed for being a duplicate - ) that I need to pass the startNumber and endNumber through a generator using a while loop. Can someone please point me in the direction on how to do this? Any help is welcome.    I'm a learning programmer and I've run into a bit of a jumble. I am asked to write a program that will compute and display Fibonacci's Sequence by a user inputted start number and end number (ie. startNumber = 20 endNumber = 100 and it will display only the numbers between that range). The trick is to use it inclusively (which I do not know how to do in Python? - I'm assuming this means to use an inclusive range?).  What I have so far is no actual coding but rather:   Write Fib sequence formula to infinite Display startNumber to endNumber only from Fib sequence.   I have no idea where to start and I am asking for ideas or insight into how to write this. I also have tried to write the Fib sequence forumla but I get lost on that as well.


I find it hard to believe that photons always travel with 3 x 10^8 m/s just from the start. But there must be some acceleration of light. Maybe huge or taking place in picoseconds. So what maybe the acceleration of light or photons?

Photons travel at the fastest speed in our universe, the speed of light.  Do photons have acceleration?


where $f(z) = u(x,y) + iv(x,y)$ where $u$ and $v$ are real functions and $f '(z_0) = \lim_{z\to z_0} \frac{f(z) -f(z_0 )}{z-z_0}$

I want to prove that if $f$ is an analytic function for which $\Im f$ is constant, this implies that $f$ itself is constant.  So to start off, it's not given that the function is entire or anything, ruling out Liouville. Rather, I'm guessing the maximum modulus theorem will prove useful here (?).  If I were to show using that the real part of $f$ was constant, proving the statement would be easy (just take the absolute value and investigate $e^f$), but in this case I'm none the wiser from that. Should I use the same parametrization $e^f$ and apply the Cauchy-Riemann equations somewhere? Any suggestions welcome.


root@kali:~# sudo apt-get upgrade Reading package lists... Done Building dependency tree        Reading state information... Done Calculating upgrade... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. 5 not fully installed or removed. Need to get 0 B/587 kB of archives. After this operation, 0 B of additional disk space will be used. Do you want to continue? [Y/n] Y dpkg: error processing package tk8.6-blt2.5 (--configure):  package is in a very bad inconsistent state; you should  reinstall it before attempting configuration dpkg: dependency problems prevent configuration of python-tk:  python-tk depends on tk8.6-blt2.5 (>= 2.5.3); however:   Package tk8.6-blt2.5 is not configured yet.  dpkg: error processing package python-tk (--configure):  dependency problems - leaving unconfigured dpkg: dependency problems prevent configuration of blt:  blt depends on tk8.6-blt2.5 (= 2.5.3+dfsg-4); however:   Package tk8.6-blt2.5 is not configured yet.  dpkg: error processing package blt (--configure):  dependency problems - leaving unconfigured dpkg: dependency problems prevent configuration of tcpwatch-httpproxy:  tcpwatch-httpproxy depends on python-tk; however:   Package python-tk is not configured yet.  dpkg: error processing package tcpwatch-httpproxy (--configure):  dependency problems - leaving unconfigured dpkg: dependency problems prevent configuration of python-pil.imagetk:amd64:  python-pil.imagetk:amd64 depends on python-tk (>= 2.7.7-2); however:   Package python-tk is not configured yet.  dpkg: error processing package python-pil.imagetk:amd64 (--configure):  dependency problems - leaving unconfigured Errors were encountered while processing:  tk8.6-blt2.5  python-tk  blt  tcpwatch-httpproxy  python-pil.imagetk:amd64 E: Sub-process /usr/bin/dpkg returned an error code (1) root@kali:~#    Why am I getting this error?

on step 6 I get error returned that says -bash apt-key: command not found.  This is the same if I try apt-update


I have contacted my professor about recommendation letter for my applications to PhD programmes. He has provided letters for few of my application.   Right now I am applying to few more universities and have contacted him again to provide few more letters in support of my application. He responded by saying that he is in a different country and his father-in-law is ill. He said he would provide the letters once again when he is back in the country. How should I respond to his email? I feel bad about constantly bothering him about letters of recommendation.

When needing to ask a professor about something important and potentially delicate, what is an appropriate way to phrase the question or write the email?  Examples include:   Requesting a recommendation letter Asking for exceptions to policy (e.g., ignoring a course prerequisite, rescheduling an exam) Asking if you can do research with them, join a group, get into a program Scheduling a meeting, exam, or defense Letting them know about a change of plans Letting them know about a life event affecting your work or studies (e.g., wedding, funeral, sickness, vacation)


I would like to present comprehensive arguments to my stakeholders for migration from SOAP to REST. I have spend several years implementing both the SOAP and the REST protocols on the client side (that is why I write this question) and clearly the REST technology was the better one (from the client side perspective: maintainability, scalability, quality of tools, libraries). I'm aware the server side devs put a lot of effort during years to polish the SOAP implementation.   But because I do not know the server perspective so well I would expect to see here in replies cons and pros of both technologies provided by experienced developers (especially on the server side). I know there is plenty of resources dedicated to this issue, companies spent maybe years arguing before they had found a resolution (Yahoo, etc). Can you select the three top reasons why REST is better then SOAP (in long term perspective)?    ... ... ...   Thank you.  Edit: The problem I have with the possible duplicates is the replies contain rather emotional expressions then factual arguments.

Is REST a better approach to doing Web Services or is SOAP?  Or are they different tools for different problems?   Or is it a nuanced issue - that is, is one slightly better in certain arenas than another, etc?  I would especially appreciate information about those concepts and their relation to the PHP-universe and also modern high-end web-applications.


I have a problem, during write something into a root file:  $ ll /sys/bus/usb/devices/3-2/power/wakeup -rw-r--r-- 1 root root 4096 Feb 16 17:28 /sys/bus/usb/devices/3-2/power/wakeup $ sudo echo disabled > /sys/bus/usb/devices/3-2/power/wakeup bash: /sys/bus/usb/devices/3-2/power/wakeup: Permission denied   even it did not ask me for password.    How can I solve this? Why I can't use sudo directly?

When you attempt to modify a file without having write permissions on it, you get an error:  > touch /tmp/foo && sudo chown root /tmp/foo > echo test > /tmp/foo zsh: permission denied: /tmp/foo   Sudoing doesn't help, because it runs the command as root, but the shell handles redirecting stdout and opens the file as you anyway:  > sudo echo test > /tmp/foo zsh: permission denied: /tmp/foo   Is there an easy way to redirect stdout to a file you don't have permission to write to, besides opening a shell as root and manipulating the file that way?  > sudo su # echo test > /tmp/foo


Moaning Myrtle could go through anything you can name, but makes physical contact with water in her toilet, and can turn on taps. Why's that? What can ghosts touch and what can't they touch?

In the movie production  and book Harry Potter and the Sorcerers Stone, we see ghosts floating through walls, without affecting them (i.e. smashing through them and leaving rubble behind).  In the movie production Harry Potter and the Chamber of Secrets, we see Moaning Myrtle surprise Ron Weasley as he asks why they're brewing Polyjuice Potion in the girls lavatory. After revealing herself, Myrtle does a demented loop-de-loop around the lavatory and then dive into the toilet.  Yet later, both in the book version and in the movie version of The Goblet of Fire, we see Myrtle soundlessly enter the prefects bathtub without displacing water.  Therefore, can ghosts (not poltegeists, who as we know can) interact with the physical world, and have an effect upon their surroundings?


Each sensor from the skeleton has different orientation values and each sensor is rotated individually to match the world coordinate system.  Each sensor from the skeleton has different orientation values and rotated individually to match the world coordinate system.   In the first sentence, “each sensor” is repeated. How can I modify it into a proper sentence? In my second sentence, I used only “and”. Is that correct?

Pouring the water on the flower, Jenny admired the flowers just beginning to open. In the above sentence, the word "flower" is repeated once. Is  repetition of the same word in a single sentence ok or is it necessary to avoid repetition?


Some answers contain characters that look like keyboard keys. They look like      Ctrl + E   What markup do I need to add to make Ctrl and E look like actual keys? That's not mentioned in the formatting help.

How are people showing keyboard "glyphs" on Super User? I looked at the Markdown help page and it didn't show anything regarding this. Here is  (question has been deleted since this was asked, so an archive link is provided instead):


I've been facing this error since a lot of months now though it has been occurring annoyingly very often during last few days.  408 Request Time-out Your browser didn't send a complete request in time.   I'm using Google Chrome on a Windows Server 2008 machine and have a fairly stable internet connection. Never seen this error on any other website.  What actually causes this error and is something wrong on my end?

I'm frequently getting 408 Request Time-out errors  when browsing through Stack Overflow and Meta. I used to get this four or five times a day before, but now it has become very frequent. I've read  in which Kyle Brandt ♦ says:     We send our web logs to SQL so we can query them. It turns out that we have a bug that prevents 408s from being logged to SQL. [...] I will do more extensive research when our 408s are part of queryable logs (should be a week or two [...]).   My internet connection is somewhat stable and I haven't experienced this issue on other sites before. I don't think it's a browser-specific issue as it is reproducible on latest versions of Google Chrome and Firefox (on Ubuntu 13.10). However, it is specific to Stack Overflow and Meta. I'm unable to reproduce this on other SE sites.  Am I the only one facing this issue? Could it be something wrong with the regional CDN or something like that? Could someone please take a look at this issue? ()  This appears when I try to close-vote questions, too:


Is there a way to properly pluralize a quotation, if I must and can't just rearrange the sentence to avoid it (or do not wish to rearrange it for artistic purposes)? Example:  We exchanged many "I love you"s/ 'I love you's/ "I love you" 's.  Or would this simply be left unquoted?

I'm in a strange situation where I need to take two short phrases and make them into plural nouns.  Here's the context:     His was the destabilizing blow in a long bombardment of Why Latin?’s and waste of time’s.   The "Why Latin's" and "waste of time's" are obviously the problem.  Do I italicize them?  Use quotes?  And how do I make them plural?  Do I use apostrophes?


I am looking for a proof for this:      If $S=(a,b)=\{x\in\mathbb R\, :\, a < x < b\}$, then the least upper bound of $ S$ is $b$   My professor was fumbling through an explanation and I got lost.

I was trying to prove it this way. Let $a,b\in\mathbb{R}$ with $a<b$. Let $ I=(a,b)$. As for all $x\in I$,$x<b$, we get $b$ is an upper bound. let $u=\sup I$, then $u\leq b$. If $u=b$ it's done. Otherwise, let's suppose $u<b$. Furthermore, for all $x\in I$, $a<x$ and $x\leq u$, so $a<u$, then $u\in I$...  Can I get somewhere this way?


I just came across this simple inequality which I am finding it difficult to prove.  For any complex number z I need to prove that the following inequality holds $$√2|z|≥|Rez|+|Imz|$$ I would much appreciate if someone could give me a hint to solve this. Thanks

Verify that  $\sqrt{2}\left\| z \right\| \ge \left|\Re(z)\right| + \left|\Im(z)\right|.$  I started off noting that $z=x+iy$ and that $Re(z)=x$ and $Im(z)=y$  Then I know that I have to square both sides, giving me   $$2(x^2 +y^2) \ge x^2+2|xy|+y^2$$  I'm not sure what to do after this.


My android device is lava v2s. I have sufficient space of 5.67 GB on my SD card and even of 263mb but, still, when I want to download any app from Google Play Store, it is saying to free up space. It's really very much disappointing. please try to solve my problem and give me a quick solution.

After one of the latest updates (not sure if it was the last one or a previous one) of the Google Play app, I am having an error trying to update a large app (42MB). It says:     Error Downloading . There is insufficient space on the device.   My device is a Samsung P1000 running Froyo. It's rooted, but the error was there before rooting it.  A quick Google search showed several Samsung users having the same problem (the app in question that was giving me the headache is Smurf's village). Some said that removing the updates to the Android Market (Google Play) app would fix it, but to me it was of no avail.  I also tried the procedure in  to no avail.  Now I am stuck with a prehistoric version of the Market (that works on small apps) and still cannot update Smurf's Village or install big apps. How can I fix this?  EDIT: device has over 2GB of internal SD storage, 27GB of external SD card, so space is not an issue.


I have installed Windows 7 and now I want to install Ubuntu alongside Windows 7.  While doing the installation, after some steps I am not getting the "Install Ubuntu alongside Windows 7" option in the booting process. What should I do now?  When I am watching in YouTube, it is visible as "Install Ubuntu alongside Windows 7" but not while am doing it.  Please tell me how to resolve this problem.

Whenever I startup from the LinuxLive USB, and try to install Ubuntu 12.04, it only gives me two options instead of the usual 3 or 4. My options are "Replace Windows 7 with Ubuntu" and "Something Else". Whenever I go into "Something else", it looks extremely confusing. How do I install it side-by-side while using the "Something else" section? These are my partitions.   /dev/sda /dev/sda1 ntfs (104Mb, System Required Partition) /dev/sda2 ntfs (1000097Mb, Windows 7 Partition)   Or should I try reinstalling my installer on a CD rather than USB and maybe then it will have the "Install alongside" function?


Is anyone aware of a third-part app that provides a quick shortcut to toggle mute/unmute state of the built-in microphone?

What I would like to have is:   By default the microphone should be muted When CapsLock is Down the microphone should unmute When CapsLock is Up the microphone should mute   (Basically convert my Skype to act like a Walkie-talkie with a  functionality)  I  the AppleScript that can change the volume input of the microphone, so the first step was easy, but I didn't find any way to even assign the CapsLock to a script. Note that my CapsLock key is turned off and I would't like to sTART experiencing something like tHIS.  If the CapsLock is very special I wouldn't mind using another key, but I want to achieve the same functionality.  Edit: Probably it is not really possible to do it without using any application, so if there is an app that can do that, it would also work for me.


How is this grammar works?  In resume:  I lead a group of three developers and ...  → Led group of three developers and ...  Is this a past participle or  (it just omits subject)?  Is it just omits subject?  I was led group of three developers and ...  becomes  Led group of three developers and ...    And a example likes this in Google Play:  Added reading progress bar    Is this a telegram style?

I’m specifically thinking about emails I receive all day where someone will write:     Haven’t seen it yet.  Will respond when received.   If it were spoken, we would certainly hear:     I haven’t seen it yet.  I will respond when I receive it.   It’s mostly the dropping of I that I wonder about.  Is there a name for this phenomenon?


Since other threads I've read here ask to wait at least 3 days for the reputation update on a specific tag, I waited three days until 5:00 UTC but saw no change in any of my tags on stackoverflow.  Is the process delegated to do this stuck or is there something I didn't consider?

Tag scores update is supposed to happen at 03:00 UTC every day. Tag scores are updated by a scheduled job that is time consuming and often times out  (see for example the answers for  and ).  In the past month or two, the issue with not updating the scores has gotten much worse. Tag scores are now regularly not updated for 2-3 days in a row. The job fails more often than it runs which obviously lowers usability and appeal of tag badges (which are not awarded when the script fails) and scores to some extent.  I can also guess that if a job fails on consecutive days, it only makes it harder to make it work as it has more and more tags and answers to recount.  This issue happened in the past but not to the extent it's happening now.  Please do not close it as duplicate. I'm creating a separate post as I've been asked to do it by Adam Lear in a comment for the answer for the first of the linked questions. Other posts reporting this issue have accepted answers which makes them difficult to track for the SE team.  UPDATE  I've been writing down whether the scores were updated or not every day in April.  The results are:  Day      1   2   3   4   5   6   7   8   9   10  11  12  13  14  15   Updated  -   -   -   ✓   -   ✓  -   -   -   -   -   ✓   -   -   -   Day      16  17  18  19  20  21  22  23  24  25  26  27  28  29  30 Updated  ✓   -   ✓   -   ✓   -   -   ✓  ✓   -   ✓  -   ✓   -   -   The update succeeded on 10 days, failed on 20. The situation got somewhat better in the second half of the month. Has something been done about it?


Say my character is a 5th level monk with the Extra Attack feature and I am holding a dagger in one hand and a short sword in the other: Can I use the Attack action to swing the Short Sword with my first attack, throw the dagger with the second, and then use Martial Arts to make an Unarmed Attack with my bonus action?

When one uses the Extra Attack class feature, must it be done with only one weapon?  If I had, for example, one throwing axe and sword, couldn't I throw the axe and attack with the sword as part of the same "extra attack action"?


Check this below code:  var = input("enter a number between 1 and 12") def switch_demo(var):     switcher = {                 1: "Jan"                  2: "Feb"                  3: "March"                 4: "April"                  5: "May"                  6: "June"                  7: "July"                  8: "August"                  9: "Sept"                  10: "Oct"                  11: "Nov"                  12: "Dec"     }     print switcher.get(var,"Invalid Month")   I am getting Syntax Error at line 5 How can I solve the error?

I want to write a function in Python that returns different fixed values based on the value of an input index.    In other languages I would use a switch or case statement, but Python does not appear to have a switch statement.  What are the recommended Python solutions in this scenario?


In the following snippet, why does re.match return None? And how do I correctly match the line containing   {pattern}? import re  txt = \ """ begin   {pattern} end """  print(re.match(r'^( *)\{pattern\}', txt, re.MULTILINE))

What is the difference between the search() and match() functions in the ?  I've read the  (), but I never seem to remember it.  I keep having to look it up and re-learn it.  I'm hoping that someone will answer it clearly with examples so that (perhaps) it will stick in my head.  Or at least I'll have a better place to return with my question and it will take less time to re-learn it.


I want to compute the cardinality of the following set: $$A= \{ R\subset \mathbb{N}\times\mathbb{N} : R \text { is  a transitive relation}\}$$  I understand that the cardinality is bounded above by $|P(\mathbb{N}\times \mathbb{N})| = 2^{\aleph_0}= \aleph$, but how to find a lower bound?

I need to compute the cardinality of the set of all total orders on $\Bbb{N}$.  Now, by definition there is an inclusion of this set into $\mathcal{P}(\Bbb{N}\times\Bbb{N})$, and so has cardinality $\le 2^{\aleph_0}$.  Now, finding an injection from $\mathcal{P}(\Bbb{N})$ to the set in question is much harder. I have the solution below, which I don't really understand and don't intuitively see. It feels like the usual $\le$ with some priority to elements of the set injected, but not quite.  Can anyone extrapolate some meaning from this, or provide a nicer solution?  (apologies for the laziness of not rewriting the solution)


When is the profile view count incremented? I tried opening the page from different browsers and in incognito mode. But none of my attempts were counted. How do they realize that its me?

This is related to the 'number of times your profile is visited by others'.  How exactly does it work? For example, in my profile page, profile view count is 171.


As you probably know, the bash shell's stdin is logged to $HISTFILE (i.e. usually ~/.history) and can be accessed with the history builtin, and so on.  But the stdout & stderr are not.  How can set up an automated log of the output of shell commands; in the same manner as the input?

I like to use tools like history, script, and asciinema to record and review xterm (i.e. bash/sh) sessions for typical, general administration reasons, and also, sometimes for comprehensive study/revision; as a learning tool.   I thought of setting the default $SHELL as a direct path to said tools and/or commands, like:   /bin/script transcript.log;  /bin/asciinema rec -w0.5 term_log.json;  But these tools typically rely on having a default $SHELL set (i.e. /bin/bash, /bin/sh, /bin/zsh, etc.). Also, I feel like re-defining system variables (i.e. $SHELL, $TERM, etc.) or trying to get it working with config (*.conf) and dot (~/.bashrc / ~/.bash_profile) files is gona be riddled with all kinds of holes and potential problems. However, every time I decide or realize that I want a transcript of a session, it's after the fact, or I'll be halfway through the interesting part already, or some such scenario.   What's the correct, or best practice to set something like this up to simply log everything (preferably stdin, stdout (and stderr when applicable), etc.) automatically?


I'm trying to configure my web server from scratch and since this is my first time doing everything on my own, I'm unsure what kind of permissions I need to set for each site I have in /var/www.  As of right now, I have the following layout for 2 of my websites that I host:  /var/www/ |-- blog.dev/       |--  public_html/               |-- .htaccess               |-- wp-admin               |-- wp-content               ...  |-- web.dev/       |--  public_html/               |-- .htaccess               |-- index.php   As it is right now, my current workflow is mostly consisted of me ssh-ing into the server and occasionally uploading files via sftp. So, I need my user account to be able to modify everything alongside with apache being able to modify stuff as well when I, for instance, upload a picture via Wordpress blog.  So, I have assigned chmod 775 to both public_html's and placed them in chown www-data:www-data, but am unsure if this is safe. /var/www is still owned by root, my user account is also placed in www-data group. My question is, what could I do to improve the overall setup. This feels extremely awkward and clumsy; It just doesn't feel right the way I did it. What are some more fool proof ways to properly configure the permissions so that I can shield myself from potential compromise.

This is a  about File Permissions on a Linux web server.   I have a Linux web server running Apache2 that hosts several websites. Each website has its own folder in /var/www/.  /var/www/contoso.com/ /var/www/contoso.net/ /var/www/fabrikam.com/   The base directory /var/www/ is owned by root:root. Apache is running as www-data:www-data. The Fabrikam website is maintained by two developers, Alice and Bob. Both Contoso websites are maintained by one developer, Eve. All websites allow users to upload images. If a website is compromised, the impact should be as limited as possible.  I want to know the best way to set up permissions so that Apache can serve the content, the website is secure from attacks, and the developers can still make changes. One of the websites is structured like this:  /var/www/fabrikam.com     /cache     /modules     /styles     /uploads     /index.php   How should the permissions be set on these directories and files? I read somewhere that you should never use 777 permissions on a website, but I don't understand what problems that could cause. During busy periods, the website automatically caches some pages and stores the results in the cache folder. All of the content submitted by website visitors is saved to the uploads folder.


I am an avid user of the Stack Exchange iOS App and have come across a "moral dilemma":  I frequent the "hot questions" tab quite alot (about every spare minute I have) and come across interesting questions with equally as interesting answers, which I naturally want to upvote. Is it ok for me to create an account to upvote that question?  I suspect it might skew page statistics registering to upvote one (and potentially just a few more) questions without participating in any other way.

I have read many questions asked in SEs I have not joined yet; the sidebar advertises new hot questions and the top questions of many SEs are worth reading.  Whenever I read an really awesome answer (or a question) on such a SE site, I wonder whether I should join the SE just in order to upvote the answer (or the question, respectively). I know my behavior will have only a minor impact on SE sites, but I look for a general policy which is, in some way, good for SE if followed by all persons who are in such situation.  Is there any such policy? Or should I just do not care about voting and do whatever feels right at the moment. (In the past I have both joined the SE site and simply ignored the upvote button.)


I'm solving a probability problem and the expected value of a random variable is this series I need some hint to find the sum of it.  $\displaystyle \sum_{n=1}^{\infty}\frac{n}{2^n}$

How can I evaluate $$\sum_{n=1}^\infty\frac{2n}{3^{n+1}}$$? I know the answer thanks to , but I'm more concerned with how I can derive that answer. It cites tests to prove that it is convergent, but my class has never learned these before. So I feel that there must be a simpler method.  In general, how can I evaluate $$\sum_{n=0}^\infty (n+1)x^n?$$


Suppose an event $A$ is independent of event $B$. Event $A$ is also independent of event $C$. We also know that $B$ and $C$ are dependent. Is it true that $A$ is independent of $B\cap C$? I think the answer is yes since if the presence of $A$ doesn't affect either $B$ or $C$, it won't affect their intersection as well. But how do we prove it mathematically?

I'm attempting to acquire an intuitive understanding of why the content in the question of the title is correct, however I am unable to do so. Is there way of thinking about the result that makes sense?


I am working on a game in Java but stumbled on an error when trying to draw a background. I am getting a NullPointerException, however I can't actually find where the null object is/where it's coming from.   The error is:  Exception in thread "Thread-2" java.lang.NullPointerException at GameState.Level1State.draw(Level1State.java:39) at GameState.GameStateManager.draw(GameStateManager.java:34) at main.GamePanel.draw(GamePanel.java:91) at main.GamePanel.run(GamePanel.java:70) at java.lang.Thread.run(Thread.java:745)   and points to these:  Level1State  public void draw(Graphics2D g) {      /* this line! */ bg.draw(g);      //draw tilemap     tileMap.draw(g);  }   GameStateManager  public void draw(Graphics2D g) {     /* this line! */ gameStates.get(currentState).draw(g); }   GamePanel  private void draw() {     /* this line! */ gsm.draw(g); }   GamePanel (I don't think this is relevant but I will include it anyways  //game loop     while(running) {          tick();         /* this line! */ draw();   Any ideas on where the null object is?  Thanks :)

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


In Reddit, there is a section for posts that are heavily down/upvoted, making them "controversial." Why might this be a bad idea?

I really like the new sidebar. With the new top bar eliminating the "Hot Questions" area there, I think this is the perfect place for it. One-click access to time-wasting questions about topics I may or may not have an interest in. Seriously, it's a procrastinator's dream come true. The only suggestion I can add is to extend it. I assume the "hot" algorithm can spit out more than 12 questions, and since we now have a huge amount of room for it(without being restricted to a weird drop-down scrollbox), why not show more? If there's something else planned for that spot, disregard. At a minimum, the title could link to the , as ShaWizDowArd suggested in comments. I've been using SE for a couple years now, and I've never seen that page, so it would add visibility there.    Update: They added a link! Just noticed this, I'm pretty sure it wasn't there yesterday. When you click it, it loads 12 more. At the moment, the link disappears once clicked, so you can see a total of 24 here now. Not a link to the full list, but better:


Imagine I have a very long list of images and I want to rank them in order of how 'good' people think they are.  I don't want to get users to assign scores to images outright (1 - 10 etc) and order by that, I'd like to try something new.  What I was thinking would be an interesting way of doing it is:   Show a user two random images, they pick the better one Collect lots of 'comparisons' Use all the comparisons to come up with some ordering   Turns out this is , for example (using features, not images), this appears to be the way  works.  My question is whether there's a good known way to take this long list of comparisons and build a relative ranking for all the images from them but not to the level of complexity found in the research papers.  I've read a bunch of  and research papers but I was wondering if there was any sample code out there people might recommend?

I'd like to rank a collection of landscape images by making a game whereby site visitors can rate them, in order to find out which images people find the  most appealing.  What would be a good method of doing that?   Hot-or-Not style? I.e. show a single image, ask the user to rank it from 1-10. As I see it, this allows me to average the scores, and I would just need to ensure that I get an even distribution of votes across all the images. Fairly simple to implement. Pick A-or-B? I.e. show two images, ask user to pick the better one. This is appealing as there is no numerical ranking, it's just a comparison. But how would I implement it? My first thought was to do it as a quicksort, with the comparison operations being provided by humans, and once completed, simply repeat the sort ad-infinitum.   How would you do it?  If you need numbers, I'm talking about one million images, on a site with 20,000 daily visits. I'd imagine a small proportion might play the game, for the sake of argument, lets say I can generate 2,000 human sort operations a day! It's a non-profit website, and the terminally curious will find it through my profile :)


It would often be useful if a comment disappeared when the intended recipient read it. Two cases come to mind:    Notes of thanks, currently discouraged as polluting.  Suggesting edits for OP to assess.    An option to have deletion done automatically would keep the site tidier and make it just a little easier to use.

Meanwhile, in August 2009  as reason for comment flagging, and the comment flags show in the 10k tools. And  is on its way. Hence: I don't care for this request myself anymore. An explicit [status-declined] would be fine.    What about being able to set comments to auto-expire? Or, alternatively, set a comment to be removable by the author of the question or answer one comments on?  This way the communities would allow for some personal or funny comments (even like "Thanks") without those comments littering the sites forever. Or, when the original author is allowed to clean up, then comments that have been taken care of by editing the question or answer, could be removed.  Why?  As, , there's no way to send a personal message to other members, I find myself abusing the comments like some "poor man's private messaging system". I try to refrain from things like "Thank you", but sometimes I do want to point out something to someone. After a while (hours, days) I then  to remove them (hoping that no-one actually replied to them with another comment, like "Thanks, fixed it").  Like :    (I don't find this feature request very important (at all), I am quite impressed by what's been given us already, and I doubt there's a way to implement it without making things too confusing. Maybe I'm just trying too hard to keep things tidy and clean. Still, I wanted to share it, just in case someone comes up with something very clever...)


How I can prove that this: $$ \frac{1}{2} < \frac{2}{3} < \frac{3}{4} < \frac{4}{5} < \frac{5}{6}<...<\frac{n+1}{m+1}<...$$ always holds when $n < m$ and $n$ and $m$ are positive integers? I started writing this $\frac{n}{m}<\frac{n+1}{m+1}$ but then I don't know how to proceed.

I'm trying to show that $\dfrac{a}{b} < \dfrac{a + 1}{b + 1}$ given $a < b$ and $b$ is positive.  Ideas?


A permanent magnet produces lines of magnet flux that we call a "magnetic field".  Those lines come from inside the magnet, come out of the N pole, loop outside the magnet, & return back into the S pole to complete a magnetic circuit.  Using ferromagnetic materials, other magnets, &/or test equipment, we feel & measure forces that are caused by a magnet/s when other materials are placed within close enough proximity to the magnet/s (i.e. within their magnetic field/s).  We therefore conclude that the magnetic lines flow in a specific direction & exert definite forces (i.e. magnitudes/strength) on some materials (ferromagnetic & other magnets), depending on where those materials are placed within the magnetic field of a magnet/s.    We label those forces as "H Field" & "B Field". We measure H in terms of Amperes/meter. We measure B in terms of Newtons/meter/Ampere (or Tesla). We also commonly defined B in terms of the force that it exerts on moving electric charges (i.e. the Lorentz force).  An "Ampere" is basic unit of electrical current in the SI system, which = 1 Coulomb per second--which is formally defined to be the constant current which if maintained in two straight parallel conductors of infinite length, of negligible circular cross section, and placed one meter apart in vacuum, would produce between these conductors a force equal to 2 × 10 −7 newton per meter of length.  A "Coulomb" is the standard unit of quantity of electricity in the SI system, which = the quantity of charge transferred across a conductor in which there is a constant current of 1 Ampere/Second.  Consequently, those "magnetic lines" are currents (or flows) of charges that don't appear to need any external source of energy to continue generating their currents.  We also know those magnetic lines exist inside a vacuum, so they are independent of air molecules to flow outside of a magnet.  So now my questions:   Exactly what charged particles are flowing outside (and inside) a permanent magnet that create the magnetic "lines"?   Do those particles come from something inside the magnet or does the magnet do something outside of it to affect unknown particles to make the lines? If there is a current (i.e. a continuous flow of charged particles), then why don't we harness that current like a water wheel (instead of 'using energy' to rapidly move copper wires through magnetic fields--like we do with electricity generators?)  Shouldn't we be able to get the line currents to charge a capacitor (or or other device) & then later discharge the capacitor for the energy that we want?

A permanent magnet produces lines of magnet flux that we call a "magnetic field".  Those lines come from inside the magnet, come out of the N pole, loop outside the magnet, & return back into the S pole to complete a magnetic circuit.  Using ferromagnetic materials, other magnets, &/or test equipment, we feel & measure forces that are caused by a magnet/s when other materials are placed within close enough proximity to the magnet/s (i.e. within their magnetic field/s).  We therefore conclude that the magnetic lines flow in a specific direction & exert definite forces (i.e. magnitudes/strength) on some materials (ferromagnetic & other magnets), depending on where those materials are placed within the magnetic field of a magnet/s.    We label those forces as "H Field" & "B Field". We measure H in terms of Amperes/meter. We measure B in terms of Newtons/meter/Ampere (or Tesla). We also commonly defined B in terms of the force that it exerts on moving electric charges (i.e. the Lorentz force).  An "Ampere" is basic unit of electrical current in the SI system, which = 1 Coulomb per second--which is formally defined to be the constant current which if maintained in two straight parallel conductors of infinite length, of negligible circular cross section, and placed one meter apart in vacuum, would produce between these conductors a force equal to 2 × 10 −7 newton per meter of length.  A "Coulomb" is the standard unit of quantity of electricity in the SI system, which = the quantity of charge transferred across a conductor in which there is a constant current of 1 Ampere/Second.  Consequently, those "magnetic lines" are currents (or flows) of charges that don't appear to need any external source of energy to continue generating their currents.  We also know those magnetic lines exist inside a vacuum, so they are independent of air molecules to flow outside of a magnet.  So now my questions:   Exactly what charged particles are flowing outside (and inside) a permanent magnet that create the magnetic "lines"?   Do those particles come from something inside the magnet or does the magnet do something outside of it to affect unknown particles to make the lines? If there is a current (i.e. a continuous flow of charged particles), then why don't we harness that current like a water wheel (instead of 'using energy' to rapidly move copper wires through magnetic fields--like we do with electricity generators?)  Shouldn't we be able to get the line currents to charge a capacitor (or or other device) & then otherwise discharge the capacitor for the energy that we want?


Definitions here:   Pre-image resistance  Given a hash value h it should be difficult to find any message m such that h = hash(m). Second pre-image resistance  Given an input m1 it should be difficult to find different input m2 such that hash(m1) = hash(m2).    says:     These properties form a hierarchy, in that collision resistance implies second pre-image resistance, which in turns implies pre-image resistance, while the converse is not true in general.   Assuming pre-image resistance is broken, we have a function pre(h) which can easily find m such that h = hash(m). How is it helpful in finding a different m2 such that hash(m1) = hash(m2)? What if pre(m1) always returns m1?  Edit. The definition on Wikipedia is not quite formal. A better explanation is .

I am studying hash functions. I can understand why collision resistance implies second preimage resistance, but I don't get why second preimage resistance should imply first preimage resistance. Could anybody be help me with this argument from Introduction to Modern Cryptography by Katz & Lindell, please?   Collision resistance: This is the strongest notion and the one we have considered so far.  Second pre-image resistance: Informally speaking, a hash function is second pre-image resistant if given $s$ and $x$ it is infeasible for a probabilistic polynomial-time adversary to find $x' \ne x$ such that $H^s(x') = H^s(s)$.  Pre-image resistance: Informally, a hash function is pre-image resistant if given $s$ and $y = H^s(x)$ (but not $x$ itself) for a randomly chosen $x$, it is infeasible for a probabilistic polynomial-time adversary to find a value $x'$ such that $H^s(x') = y$. (Looking ahead to later chapters in the book, this essentially means that $H^s$ is one-way.)   [...] Likewise, any hash function that is second pre-image resistant is also pre-image resistant. This is due to the fact that if it is possible to invert $y$ and find an $x^\prime$ such that $H^s (x^\prime ) = y$ then it is possible to take $x$, compute $y = H^s (x)$ and invert it again obtaining $x^\prime$. Since the domain of $H$ is infinite, it follows that with good probability $x \neq x^\prime$. We conclude that the above three security requirements form a hierarchy with each definition implying the one below it.


I have an external hard drive that I used to install programs on, I have since formatted my c drive and use the external drive as a storage only drive. There are however two remnants left over from the previous install on the external hd.  One is a folder full of Windows update files and the other is a Program files folder. I tried to delete the folder but it would give me the "need permissions" dialogue box and would then tell me I need permissions from user "S- ... #####". I did an ownership change on the folder and sub folders/files but that didn't work. Its still says I need permission from the new owner, even though I am the owner ... it does not make any sense. I cannot format the drive either as I have other files on it.   How can I force these folders to deletion?

I have an external HDD and I kind of messed up the file permissions but when fixing it I thought it is ok bc with my username I can access the files perfectly fine. Now that I use this with two PC (actually ATM I don't have access to my other PC) I can't access these files.  The problem is this directory has hundreds of folders with no permission for "everyone". I would like to give it the default permissions including have all access for the user "everyone". How do I do that via command line for these hundreds of folders?


Consider the equation: $ c_0 + c_1x  + \cdots + c_{n-1} + c_{n} = 0$ where each $c_i \in R$  Given that: $ c_0 + \frac{c_1}{2} + \frac{c_3}{3} + \cdots + \frac{c_{n-1}}{n} + \frac{c_{n}}{n+1} = 0$  Prove that the equation has a root in the interval (0,1).  Hint: Use Rolle's theorem.  I'm stuck with this problem. I would usually attack this kind of problem's using Bolzano, but I don't know how to relate the derivative (as stated in Rolle's theorem) with the roots of the original equation.  Thanks in advance.

Let $c_0,c_1,c_2,\ldots ,c_n$ be constants such that :  $$c_0+\frac{c_1}{2}+\ldots+\frac{c_{n-1}}{n}+\frac{c_n}{n+1}=0$$  I have to prove that the equation: $$c_0+c_1x+\ldots+c_nx^n=0$$  Has a real solution between 0 and 1.  Didn't know how to start...I thought that maybe I could use something about derivative...But I'm lost... Any help,much appreciated!!!


Plunker () seems to be a more feature-rich alternative to  (it seems to be especially popular with AngularJS developers, probably because you can "host" multiple files there, which is useful for templates). It's a very good site and certainly useful.  But since we often ended up with incomplete questions, because code was only posted on jsFiddle, we ended up  with jsFiddle links that don't also contain code.  And I simply think that Plunker should share the same fate.  Some examples:

A user may not post a  link if the user doesn't also post some code with it.  I recently learned that .  Why isn't this ban in place with all the other sites similar to JS/PHPFiddle, like , , , ,  etc.?


Can anyone explain why this code not work, pls!! Thanks you so much!  #include <stdio.h>  void changer(char * tp) {     int i=0;     tp[0]='b'; }  int main(void) {     char *st="aaab";     changer(st);     printf("%s",st); }

The following code receives seg fault on line 2:  char *str = "string"; str[0] = 'z';  // could be also written as *str = 'z' printf("%s\n", str);   While this works perfectly well:  char str[] = "string"; str[0] = 'z'; printf("%s\n", str);   Tested with MSVC and GCC.


I was running few commands and suddenly my apt-get command stopped working, reporting command not found error.   Kindly help. I am blocked due to this.  I tried commands from this answer -

I have mistakenly removed the default package APT from my system .  When I run command locate apt-get, I get below output:  /home/jeet/apt-get /home/jeet/Desktop/apt/apt-0.7.25.3ubuntu9.13/cmdline/apt-get.cc /home/jeet/Desktop/apt/apt-0.7.25.3ubuntu9.13/doc/apt-get.8.xml /home/jeet/Desktop/apt/apt-0.7.25.3ubuntu9.13/doc/de/apt-get.de.8 /home/jeet/Desktop/apt/apt-0.7.25.3ubuntu9.13/doc/fr/apt-get.fr.8 /home/jeet/Desktop/apt/apt-0.7.25.3ubuntu9.13/doc/ja/apt-get.ja.8 /home/jeet/Downloads/apt-get /home/jeet/Downloads/apt-get.8.gz /usr/share/bash-completion/completions/apt-get /usr/share/bash-completion/completions/slapt-get   If I run ls | grep apt-get, then I won't get any output.  Can anybody please advice how to recover apt package or install it from start?


I have a page where the fields can be multiple.  At first, my code was working when I only had 1 add and one remove button. When I decided to have a remove button beside every appended field, my jquery function doesn't work anymore.  I've tried adding the 'on', and changing my code to $this.parent().remove() but it's still not working.  Here's my HTML:
    General Information
 Project Head

         <button id="addc" type ="button" class ="btn btn-default">Add</button>
   Here's my code for the append and remove:  $("#ph").append($('

 <input class="phname form-control has-feedback-left" name="phname[' + numberIncr + ']" placeholder="Name" type="text"/>

<input class="phnum form-control has-feedback-right" name="phnum[' + numberIncr + ']" placeholder="Contact Number" />

'));    $("#addc").on('click', function () {        numberIncr++;        var temp = $("#ph").append($('

 <input class="phname form-control has-feedback-left" name="phname[' + numberIncr + ']" placeholder="Name" />

<input class="phnum form-control has-feedback-right" name="phnum[' + numberIncr + ']" placeholder="Contact Number" />
<button id="remc" type ="button" class ="btn btn-default">Remove</button>

'));          $(".phname").each(function(){         $(this).rules( "add", {         required:true,         lettersonly: true,       messages: {         required: 'Enter project head name',         lettersonly:'Alphabetic characters only'       }     });       });        $(".phnum").each(function(){         $(this).rules( "add", {         required: true,         maxlength: 11,         minlength: 11,       messages: {         required: 'Enter project head contact number',         maxlength: 'Invalid contact number',         minlength: 'Invalid contact number'       }     });       });      });    $("#remc").on('click', function () {         var v= document.getElementById("new");         v.remove();   });

I have a bit of code where I am looping through all the select boxes on a page and binding a .hover event to them to do a bit of twiddling with their width on mouse on/off.  This happens on page ready and works just fine.  The problem I have is that any select boxes I add via Ajax or DOM after the initial loop won't have the event bound.  I have found this plugin (), but before I add another 5k to my pages with a plugin, I want to see if anyone knows a way to do this, either with jQuery directly or by another option.


Last night I tried to get some club shots with my 60D (with the 16-35 2.8L lens) at ISO 1600.   I had about ¹⁄₁₅ — ¹⁄₂₀ seconds at f/2.8, all in Av mode.   When I raised the pop-up flash, I hoped that the camera would decrease the time to ¹⁄₆₀ or ¹⁄₂₅₀ to freeze some of the motion, but the timing remained as it there would be no flash. I had to switch to "M" to get the desired result. I know from my 550D that on that camera there is a setting that automatically switches the timing as soon as one raises the flash. To make a long story short, is there a camera fault or did I miss a setting?

About one year ago I bought a Metz 58 AF-2 for my Canon 60D. Because of a lack of free time to experiment with automatic functions, I have used it only in manual mode with other manual flashes, without problem. Those few times I used it in auto-mode (E-TTL 2 w/o HSS)  I noticed some problem but I thought I was incompetent in setting it correctly.  The problem is that when the flash is in mode ETTL 2 or ETTL2 HSS (attached on the camera) the shots, sometimes (apparently randomly) are underexposed.  In my last experiment I've noticed a thing that made me suspect about a real hardware problem. If, on the camera, I set the AV (Aperture priority) mode (e.g. to f3.5)  and the flash is in the mode I just described, with the parabola oriented toward the ceiling, when I half-press the shutter button, the camera sets an exposure time much too long, between 1 and 2 seconds. Instead, I was expecting that, as it has a very powerful flash attached, it could reduce the exposure time to something like 1/300 and increase the output power of the flash.  These extra-long exposure times are set when I lock the ISO on 125. if I set ISO to AUTO, it reduces the exposure time to 1/60, but increases ISO to 1600... In no way does the camera seems to take in account that there is a 58GN flash attached that could improve the shot.  Anyway the camera is aware that there is a good flash attached, as I see it use the flash-focus-beam, and I can control flash parameters by the camera menu. Also the flash fires when I press the shutter button, but photos are underexposed.   Is this behavior normal? How could I solve it?


I have my PC with Ubuntu 19.04 on it, and I have "server" (it's old laptop with Debian 9 installed). However, getting physical access to laptop is complicated task, because it has some problems with screen and keyboard. I'd like to use my laptop to run some python codes, and when I connect (on my PC) to my laptop via SSH and run them, it works fine. However, when I close terminal on my PC, python program, which was running on my laptop, also closes. So, it is cause by closing terminal session. My question is: How to continue running application on that laptop after closing SSH connection? Because the main problem is: I can't just run it directly on my laptop, because it has technical problems (described above).

I sometimes have long running processes that I want to kick off before going home, so I create a SSH session to the server to start the process, but then I want to close my laptop and go home and later, after dinner, I want to check on the process that I started before leaving work. How can I do that with SSH? My understanding is that if you break your SSH connection you will also break your login session on the server, therefore killing the long running process.


Let $p$ be an odd prime and let $g$ be a primitive root $\pmod{p}$.  Show that $−g$ is also a primitive root of $p$ if $p \equiv 1 \pmod{4}$, but that $ord_p(−g) = \frac{p−1}{2}$ if $p \equiv 3 \pmod{4}$.   So far, I have shown as $p \equiv1 \pmod{4}$ I can use Fermat's Little Theorem.     $$g \equiv g^{p} \equiv -(-g)^{p} \pmod{p}$$  Since $p \equiv 1 \pmod{4}$, $x^2 \equiv -1 \pmod{p}$. ($-1$ is a QR of $p$) There $\exists k \in \mathbb{Z}$ such that  $$-1 \equiv g^{2k} \equiv (-g)^{2k} \pmod{p}$$  Thus, $g \equiv (-g)^{2k}(-g)^{p} \pmod{p}$. As $g$ is congruent to $-g^{p}$, $-g$ is a primitive root of $p$.   Is this enough to show the first part of the question, also how do I begin to show the 2nd part?

The question states:     Let $g$ by a primitive root of the odd prime $p$. Show that $-g$ is a primitive root , or not, according as $p \equiv 1 \pmod 4$ or not.   For me, I cannot see any connection between the type of primes and the primitive root. Any Hint is highly appreciated.  Thanks


Create an $f(x)$ that is continuous only at $x = 0$.   In other words, $f(x)$ is discontinuous at every other point. Maybe they are scattered points. However, for $f(x)$ to be continuous at $x = 0$, its limit as $x$ approaches zero must be $f(0)$. But even then, I cannot imagine such a function.  Here is another approach. Consider the function $f(x) = (cx)^n$. If $c$ and $n$ are very large, it acts like two vertical asymptotes squeezing from the sides very near $x = 0$, so that $f(x)$ is continuous only at $x = 0$.  Is my thinking correct? Are there any other ways that we can create such a function?

Possible Duplicate:          I want to know some example of a continuous function which is continuous at exactly one point. We know that $f(x)=\frac{1}{x}$ is continuous everywhere except at $x=0$. But i think this in reverse manner but i dont get any example. So please help me out!


Assume $(a,b) \in \mathbb C^2$. Is there a polynomial $f(x,y)$ which vanishes only at $(a,b)$ ? Thanks.

Why is the zero set in $\mathbb{C}\times\mathbb{C}$ of a polynomial $f(x,y)$ in two complex variables always non-discrete (no zero of $f$ is isolated)?


There are several R packages for Bayesian analysis, i.e., RBugs, JAGS,MCMCPack. Are there any pros and cons for each of these packages?

I was wondering which software statistical package do you guys recommend for performing Bayesian Inference.  For example, I know that you can run openBUGS or winBUGS as standalones or you can also call them from R. But R also has several of its own packages (MCMCPack, BACCO) which can do bayesian analysis.  Does anybody have any suggestions as to which bayesian statistics package in R is best or about other alternatives (Matlab or Mathematica?)  The main features I am looking to compare are performance, ease of use, stability and flexibility