installing numpy for python 3.1.2 on Ubuntu 10.04
Install Numpy for Python3.4.0 on Ubuntu 14.04.01 LTS
Let $a,b$ be positive integers.  When $$k = \frac{a^2 + b^2}{ab+1}$$ is an integer, it is a square.    Proof 1: (Ngô Bảo Châu): Rearrange to get $a^2-akb+b^2-k=0$, as a quadratic in $a$ this has two values: $a$ and $kb - a = (b^2-k)/a$. (The second root is determined in two different ways from the expansion $(x-r_1)(x-r_2) = x^2 - (r_1 + r_2)x + r_1 r_2$.)  Now suppose we have $a,b$ such that $k$ is an integer but not a square, by the investigation about roots we have that the second root is a nonzero integer since $k,b,a$ are integers and $k \not = b^2$, futhermore it is positive which is easily seen from its defining equation.  WLOG assume $a \ge b$ so that the second root is strictly smaller than $a$. This leads to a decent, replacing $a$ with the second root.    Proof 2 (Don Zagier): Apply reduction theory (specifically, Sätze 1 and 2 of Section 13 of my book on quadratic fields) to the quadratic form $x^2 + kxy + y^2$, which is the unique reduced quadratic form in its equivalence class.    Note that Proof 2 is pretty much the same as Proof 1 when written out in explicit detail, but I could not read Zagier's book because I cannot read German.  I would like to know more approaches to this and other alternative proofs of this result if possible! Thanks in advance.  I would also be interested in related problems (especially easier ones of a similar nature) and texts which cover the reduction theory in English. Is there any way to kill a Thread? JSonNet boolean serialization Number of genes required to sustain life Are there estimates of the minimum number of genes required to sustain life?   In what I mean by life here, I don't include viruses. Does one wing of fly contain harmful microbes and the other contain only antibodies? There was  study but the conclusion and it's source's relability seemed a bit off. How come a house flies one wing contain all microbe and the other don't. Geometry with Trigonometry Is there a built-in checksum utility on Windows 7? Is there a built-in checksum/hash utility on Windows 7? What does $\rightarrow$ mean in $p \rightarrow q$ I was looking at an exercise where it asked the following:  $$\begin{array}{ccc} p&amp;q&amp;p\rightarrow q \\ T&amp;T&amp;T \\ &amp;\ldots \end{array}$$  So, for the third column, I just put $T$ which was correct but I didn't understand what $\rightarrow$ meant. I have seen $\implies$ but I haven't the arrow. Are they the same thing?  Thanks a bunch! Missing argument 2 for wpdb::prepare() Issue We are Indian passport holders, with valid visas for Canada. Plan is to take the EgyptAir flight Mumbai to Toronto, via Cairo. Problem is Egypt embassy website says we don't need Transit Visa if transit is up to 12 hours but here transit is 14 hours.    Has anyone with a Indian passport traveled this route? What was your experience at Cairo? Did you need a transit visa? Is there a package of Ubuntu drivers as driver pack solution? I tried to search for it, but I did not find it. If there is, how can I easily get it? using gb4e keeping interlinear glosses together on the same page I am using gb4e for several hundred interlinear glosses in my dissertation. Several of the examples span more than one page, that is, the vernacular and gloss will be on one page, while the free translation appears at the top of the next page.   How can I keep all three elements together on the same page? I often have subexamples (a, b, c) that don't need to stay together. That is, 1a can be on one page, and 1b on the next, as long as vernacular-gloss-free translation for each subpart stay together.  In the MWE below, the free translation is at the top of page 2, while the vernacular and gloss are at the bottom of page 1.  \documentclass[11pt,letterpaper]{article} \usepackage{lipsum} \usepackage{gb4e} \noautomath \begin{document} \lipsum[1-4] \begin{exe}     \ex \gll wuz x̃ũch it-ak xohish-em\\              1\textsc{sg.prn} bread eat-\textsc{inf} want.\textsc{prs}-1\textsc{sg}\\         \glt `I want to eat bread.'  \end{exe} \end{document}   A solution was proposed to a similar question (), but it requires me to manually look for what could be dozens of orphans throughout my dissertation (and doesn't work when applied to my example, since it still strands the FT). I would prefer a more elegant solution that takes care of the problem automatically. I am trying to connect to a Linode (running Ubuntu 12.04 LTS) from my local machine (also running Ubuntu 12.04 LTS)  I have created a private and public key on my local machine and copied my public key to my Linode's authorized_keys file.  However, whenever I try to ssh to my Linode I get the error message Permission denied (publickey).    It's not a problem with how ssh is set up on my Linode because I can ssh to it from my Windows machine using key authentication.    In my .ssh directory on my local Ubuntu machine, I have my id_rsa and id_rsa.pub files.  Do I need to create an authorized_keys file on my local machine?    EDIT:  This is what I get when I run ssh -vvv -i id_rsa [youruser]@[yourLinode]:  debug3: authmethod_lookup publickey debug3: remaining preferred: keyboard-interactive,password debug3: authmethod_is_enabled publickey debug1: Next authentication method: publickey debug1: Offering RSA public key: id_rsa debug3: send_pubkey_test debug2: we sent a publickey packet, wait for reply debug1: Authentications that can continue: publickey debug2: we did not send a packet, disable method debug1: No more authentication methods to try. Permission denied (publickey). How to make cmd correctly display arabic script? How do I pipe each command given to the shell? I'd like to edit my .bashrc so that every command executed on the shell is piped to something, for example:   $ sudo apt update   _________________ &lt; sudo apt update &gt;  -----------------     \   ^__^      \  (oo)\_______         (__)\       )\/\             ||----w |             ||     ||   I have managed something rather similar, but not entirely:  $ bash $ exec &gt; &gt;(cowsay) $ echo "Hello AU!" $ exit  _______ &lt; Hello AU! &gt;  -------     \   ^__^      \  (oo)\_______         (__)\       )\/\             ||----w |             ||     ||   It is not the desired result, as it only happens after exiting the current shell.  It's mainly for fun/learning purposes. iOS 7 Locked Bug via Ubuntu 13.10 I wanted to bring up an issue with the latest Ubuntu release that I hope can be solved. Although I will agree with the community that iOS 7 is not the most open platform release, it still is my desire to be able to grab Photos, Music, and Files off my Phone similar to what I would do to any other device.  Every time I connect my device to Ubuntu, I receive the following notification:  The device "Justin's iPhone" is locked. Enter the passcode on the device and click "Try again".   On my iPhone, I select the following   Unfortunately, this is where problems start to arise. It appears that Ubuntu either does not recognize the permissions from my iPhone or the iPhone is not allowing itself to truly be unlocked. As we can see the permissions are   Browsing askubuntu, I encountered the following   After running the code, I receive the following error:  justin@justin-CT15:~$ idevicepair unpair &amp;&amp; idevicepair pairERROR: Device d1fea2c56e51199f901eb34020a1581ea31a2a50 is not paired with this host   If I call the command again, i receive another error:  justin@justin-CT15:~$ idevicepair pair ERROR: Could not pair with the device because a passcode is set. Please enter the passcode on the device and retry.   Ultimately, I am stuck to experiment with solutions that end up not working. I am troubled by the lack of information and support for the iOS 7 platform on Ubuntu's latest release. If anyone has a workable solution or experiment for a workaround, I am happy to try  Thanks for reading and have a wonderful day! Wacom Tablet - Illustrator brush tool I currently got the intuos art wacom tablet so still learning how to use it. I'm currently in illustrator trying to draw out a map and the brush tool is doing something weird and I cannot figure out why. You can see in my image that where there are curves the black slightly spills over and is filling in half the curve with black. Brush setting is set up as a new calligraphic brush and the size is set to pressure, 3pt-3pt. What is the difference between "What are you?" and "Who are you?"? I am often asked "Who are you?" and "What are you?", but I don't know the difference between these two questions.  Please explain it to me. How to completely remove desktop? I wanted to switch to Xfce (I had KDE and GNOME installed), and I did this :    sudo apt-get install xubuntu-desktop sudo apt-get remove kubuntu-desktop sudo apt-get remove ubuntu-desktop sudo apt-get autoremove   but to my surprise, I could still pick gnome, kde plasma, etc during the log in.  So, how do I completely remove KDE and GNOME desktops? Difference between StringBuilder and StringBuffer What is the main difference between StringBuffer and StringBuilder? Is there any performance issues when deciding on any one of these?