Recover Ubuntuone files after 14.04 installation
How to download all files from Ubuntu One?
Why aren't Christoffel symbols tensors? - asked from a fibre bundle perspective Am I on the right track to proving this statement about composite function? Is there a software utility to adjust screen gamma/brightness/contrast? Convert ArrayList to String[] array Group cohomology is one thing I don't seem to get my head around.  I understand $H^0$ as being the "fixed points" but when it comes to anything higher I have no idea what the notions are meant to be capturing...if anything.  For example I can see that 1-cocycles are homomorphisms with a specific property but that property doesn't seem to mean anything to me...and I think it should!  Is there an intuition or example that explains the meaning or is it just something that "stuck" and seems to work in lots of places? How is the optimal probability cut-off in a ROC defined by the R package Epi? The plot below was created by R package Epi::ROC for a binary classification problem. There is an optimal cut off or threshold for the classification probability at which sensitivity and 1-specifitiy are balanced in some optimal way (called ps3 in the plot). My question is how this point is defined mathematically in this case and if there are other ways to define it. What is the value of $\sum\limits_{i=1}^\infty\frac{1}{p_{p_i}}$ where $p_{i}$ is the $i$th prime? What is the value of $\sum\limits_{i=1}^\infty\dfrac{1}{p_{p_i}}$ where $p_n$ is the nth prime (and so $p_{p_n}$ is the $k$th prime, where $k$ is the $n$th prime) ?  Thus $\frac{1}{3}+\frac{1}{5}+\frac{1}{11}+...=$ ??  How do I efficiently decide if $\sum_{i=1}^\infty\dfrac{1}{p_{p_i}}\gt1$ is true without using a computer ?  I assume this infinite sum is an irrational number. Has this already been proven ? Why does old PMOS/NMOS logic needed multiple voltages like  +5, -5, and +12 volts? For example, old Intel 8080 processors, old DRAMs, e.t.c...  I'm interested in the causes on the physical/layout level.  What was the purpose of these additional voltages?  Yes, this question is about stuff which was used 35 years ago. Best answer versus best solution Newcommand + Stepcounter I'm trying to come up with a command which should increase a counter and return a string including the current value of the counter.  Have a look at the following minimal example:  \documentclass{article}  \newcounter{mycounter} \newcommand{\mystepFAILS}{\stepcounter{mycounter}foo\themycounter} \newcommand{\mystepWORKS}{foo\themycounter}  \begin{document}  \section{\mystepFAILS}  \section{\mystepWORKS}  \end{document}   Why does the command with \mystepFAILS throw an error? What is so special about \stepcounter? Any ideas? Proof that every polynomial of odd degree has one real root I want to prove that every real polynomial of odd degree has at least one real root, using  the intermediate value theorem.  Let $P(x) = x^{2n+1} + a_n x^{2n} + . . . + a_0$ for each $a_i \in \mathbb{R}$ and $n \in \mathbb{N}$.  By the fundamental theorem of algebra I know that $P(x)$ has exactly $2n+1$ complex roots, so  $P(x) = (x+r_1)(x+r_2) . . . (x+r_{2n+1})$ for each $r_i \in \mathbb{C}$  I do not know how to complete this but I do know that, at some point, I probably have to show that each root with imaginary part non zero has to come in conjugate pairs, and since $2n+1$ is odd there is at least $1$ root that is imaginary part $0$ and thus real. What's the source of "shipped" in a romantic sense? How do you copy a record in a SQL table but swap out the unique id of the new row? How can I Remove .DS_Store files from a Git repository? How can I remove those annoying Mac OS X .DS_Store files from a Git repository? I think it would be super if, in my LaTeX editor, I could click on the name of package...  \usepackage{blob}   ... and the corresponding style file, blob.sty, would be opened.  Do any LaTeX editors have this feature? I mainly use Aquamacs/AucTeX myself, but am interested in other editors too. I reckon it would be mildly challenging to implement, because blob.sty might be    in the current working directory,  in the system texmf directory, or  in the user's texmf directory. Prove $kf(x)+f'(x)=0 $ when conditions of Rolle's theorem are satisfied . Prove that if $f$ is differentiable on $ [a,b]$ and if $ f(a)=f(b)=0$ then for any real $k$ there is an $ x \in (a,b) $such that $$kf(x)+f'(x)=0 $$  As all the conditions of Rolle's theorem are satisfied one can say that there is at least one  $c \in (a,b) $ such that $f'(c) =0$ How should I proceed furthur ? How can I use this to get to the required equation ? I use wubi to install Ubuntu 10.10 on my ntfs partition. So I want to change the home folder to a folder on the ntfs partition. I could keep the personal configuration, software and so on after reinstalling the Ubuntu.  So I use ntfs-config to manage the disk partition, it's mounted when system is startup. And the permission of all files and directories are 777.  Then I modified the /etc/passwd to set the home folder to the folder on the ntfs partition. I can successfully login the account, however it looks like the .bashrc and .profile are not loaded correctly. I can't use the input method(even can't configure ibus), no sound device. However everything works well after changing the home folder back to /home/.  Could anybody give me a hint to make it work? Thanks. SharePoint Current User View using JavaScript Do small title edits constitute trivial edits? Being a fairly new user something I don't seem to be able to locate is information on whether small edits to the title are considered as trivial edits. I see the usual recommendation when suggesting an edit is:     Avoid trivial, tiny one-letter edits unless absolutely necessary.   I can see the logic in that for most cases, but for example I just read a question with a title containing "Andriod" which would be trivial in one way but also affect the ability of users to locate the question using both the site and external search engines. Would it be frowned upon to suggest an edit for those cases? Centre of $GL_n(\mathbb R)$ How to prove that center of $GL_n(\mathbb R)$ is scalar matrices?  Again what can you say about the center of set of all upper triangular matrices and center of set of all diagonal matrices.