I get this message everytime I log in:     Failure to download extra data files      The following packages requested additional data downloads after   package installation, but the data could not be downloaded or could   not be processed.      ttf-mscorefonts-installer      The download will be attempted again later, or you can try the   download again now.  Running this command requires an active Internet   connection.   When I try to reinstall the package, I get this error:  $ sudo apt-get install --reinstall ttf-mscorefonts-installer             Reading package lists... Done Building dependency tree        Reading state information... Done 0 upgraded, 0 newly installed, 1 reinstalled, 0 to remove and 0 not upgraded. Need to get 0 B/29,5 kB of archives. After this operation, 0 B of additional disk space will be used. Preconfiguring packages ... (Reading database ... 322478 files and directories currently installed.) Preparing to unpack .../ttf-mscorefonts-installer_3.4+nmu1ubuntu2_all.deb ... mscorefonts-eula license has already been accepted Unpacking ttf-mscorefonts-installer (3.4+nmu1ubuntu2) over (3.4+nmu1ubuntu2) ... Processing triggers for fontconfig (2.11.94-0ubuntu1.1) ... Processing triggers for update-notifier-common (3.168.2) ... ttf-mscorefonts-installer: processing... ttf-mscorefonts-installer: downloading http://downloads.sourceforge.net/corefonts/andale32.exe Err:1 http://downloads.sourceforge.net/corefonts/andale32.exe   The HTTP server sent an invalid Content-Range header Bad header data [IP: 78.35.24.46 80] W: Can't drop privileges for downloading as file '/var/lib/update-notifier/package-data-downloads/partial/andale32.exe' couldn't be accessed by user '_apt'. - pkgAcquire::Run (13: Permission denied) E: Failed to fetch http://netcologne.dl.sourceforge.net/project/corefonts/the fonts/final/andale32.exe  The HTTP server sent an invalid Content-Range header Bad header data [IP: 78.35.24.46 80]  E: Download Failed Setting up ttf-mscorefonts-installer (3.4+nmu1ubuntu2) ...   What could I do?  UPDATE  Seems like there is a bug about this topic:
This is an old problem that deserves a bugfix, but it's getting beyond a joke now and I can't seem to work around it.  I keep getting the dreaded failed To download extra data files error in relation to ttf-mscorefonts-installer:    Repeatedly asking it to try again doesn't help, additionally, repeatedly trying-  sudo rm -rf /var/lib/update-notifier/package-data-downloads/partial/* sudo apt-get --purge --reinstall install ttf-mscorefonts-installer   Isn't working either.  I just get at least one 404 error from one of the sourceforge links that stops it working-  Reading package lists... Done Building dependency tree        Reading state information... Done 0 to upgrade, 0 to newly install, 1 reinstalled, 0 to remove and 20 not to upgrade. Need to get 0 B/29.5 kB of archives. After this operation, 0 B of additional disk space will be used. Preconfiguring packages ... (Reading database ... 352049 files and directories currently installed.) Preparing to unpack .../ttf-mscorefonts-installer_3.4+nmu1ubuntu2_all.deb ... mscorefonts-eula license has already been accepted Unpacking ttf-mscorefonts-installer (3.4+nmu1ubuntu2) over (3.4+nmu1ubuntu2) ... Processing triggers for fontconfig (2.11.94-0ubuntu1.1) ... Processing triggers for update-notifier-common (3.168.2) ... ttf-mscorefonts-installer: processing... ttf-mscorefonts-installer: downloading http://downloads.sourceforge.net/corefonts/andale32.exe Get:1 http://downloads.sourceforge.net/corefonts/andale32.exe [198 kB] Fetched 198 kB in 0s (339 kB/s)                                                 W: Can't drop privileges for downloading as file '/var/lib/update-notifier/package-data-downloads/partial/andale32.exe' couldn't be accessed by user '_apt'. - pkgAcquire::Run (13: Permission denied) ttf-mscorefonts-installer: downloading http://downloads.sourceforge.net/corefonts/arial32.exe Get:1 http://downloads.sourceforge.net/corefonts/arial32.exe [554 kB] Fetched 554 kB in 0s (575 kB/s)                                                 W: Can't drop privileges for downloading as file '/var/lib/update-notifier/package-data-downloads/partial/arial32.exe' couldn't be accessed by user '_apt'. - pkgAcquire::Run (13: Permission denied) ttf-mscorefonts-installer: downloading http://downloads.sourceforge.net/corefonts/arialb32.exe Get:1 http://downloads.sourceforge.net/corefonts/arialb32.exe [168 kB] Fetched 168 kB in 0s (306 kB/s)                                                 W: Can't drop privileges for downloading as file '/var/lib/update-notifier/package-data-downloads/partial/arialb32.exe' couldn't be accessed by user '_apt'. - pkgAcquire::Run (13: Permission denied) ttf-mscorefonts-installer: downloading http://downloads.sourceforge.net/corefonts/comic32.exe Err:1 http://downloads.sourceforge.net/corefonts/comic32.exe   404  Not Found W: Can't drop privileges for downloading as file '/var/lib/update-notifier/package-data-downloads/partial/comic32.exe' couldn't be accessed by user '_apt'. - pkgAcquire::Run (13: Permission denied) E: Failed to fetch https://netix.dl.sourceforge.net/project/corefonts/the fonts/final/comic32.exe  404  Not Found  E: Download Failed Setting up ttf-mscorefonts-installer (3.4+nmu1ubuntu2) ...   The specific point at which it fails to download changed - it seems to be a sourceforge reliability problem, but this has now been going on weeks and results in annoying popups as above all the time.  How do we get this fixed and/or how can I work around it for now.
I am trying to create a beamer animation using tikz, but I can't even get basic rotating of a tikz image working as desired.  I have a rectangle specified by  \draw[rounded corners,dotted] (-3.5,0) rectangle (-0.5,2);   I would like to rotate this rectangle about the point (-1,.5) (which is near the bottom right corner of the rectangle).  I've tried:  {\rotatebox[origin=c,x=-1,y=.5]{130}{             \draw[rounded corners,dotted] (-3.5,0) rectangle (-0.5,2);}}   But this produces an error.  If I just use the origin=c option, it compiles, but it rotates the rectangle about the point (0,0).  I've also tried it with just the x=-1,y=.5 (without the origin option), and it fails to compile.  I have searched the documentation, which is where I learned about the options x=xdim and y=ydim.  However, I can't find a single example demonstrating how these options should be used.  Any suggestions would be greatly appreciated.    Also, if there is a better command for rotating things that will be more suitable for use in a beamer animation, please let me know.  Thanks! the root of $N$th transpose matrix For $n=3,$ $L$ matrix is as below:  $$ \left[\begin{matrix} 1&amp;0&amp;0\\ -1&amp;1&amp;0\\ -0.5&amp;-0.5&amp;1\\ \end{matrix}\right] $$  for $n=4$ we have:  $$ \left[\begin{matrix} 1&amp;0&amp;0&amp;0\\ -1&amp;1&amp;0&amp;0\\ -0.5&amp;-0.5&amp;1&amp;0\\ -1/3&amp;-1/3&amp;-1/3&amp;1 \end{matrix} \right] $$  and for $N$th we have: $$ \left[ \begin{matrix} 1&amp;0&amp;0&amp;0&amp;\cdots&amp;0&amp;0\\ -1&amp;1&amp;0&amp;0&amp;\cdots&amp;0&amp;0\\ -0.5&amp;-0.5&amp;1&amp;0&amp;\cdots&amp;0&amp;0\\ \vdots&amp;\vdots&amp;\vdots&amp;\vdots&amp; &amp; \vdots&amp;\vdots\\ -1/(N-2)&amp;-1/(N-2)&amp;-1/(N-2)&amp;-1/(N-2)&amp;\cdots&amp;1&amp;0\\ -1/(N-1)&amp;-1/(N-1)&amp;-1/(N-1)&amp;-1/(N-1)&amp;\cdots&amp;-1/(N-1)&amp;1 \end{matrix} \right] $$  How to get the roots (eigenvalues) of the $N$th order of the $L+L^T$ matrix? is there a specific logic between the roots of this matrix? Render scene with background jpg in python Fairly new to python and blender, so apologies if this is super basic. I've searched around and haven't found an answer.  I'd like to render some procedurally generated objects with a background image. In case it makes a difference, I'm using:    I don't need any interaction between the generated object and the background image so I've left a skeleton script I'm using to render below  import os DIR ="/home/path/to/folder" bg_file = os.path.join(DIR, "myimage.jpg") bg_img = bpy.data.images.load(bg_file) bpy.data.scenes['Scene'].render.filepath = os.path.join(DIR, "image") bpy.context.scene.camera = bpy.data.objects['Camera'] bpy.ops.render.render(write_still=True)   I managed to find some scripts that seem to be trying to do what I want online, but none that I could get to work. e.g.  import bpy filepath = "/home/path/to/folder" img = bpy.data.images.load(filepath)  for area in bpy.context.screen.areas:     if area.type == 'VIEW_3D':         space_data = area.spaces.active         bg = space_data.background_images.new()         bg.image = img         break  cam = bpy.data.cameras.new("Camera") cam_ob = bpy.data.objects.new("Camera", cam) bpy.context.scene.camera = cam_ob bpy.context.scene.objects.link(cam_ob) bpy.context.scene.objects.active = bpy.context.scene.objects["Camera"]   Any thoughts/tips would be greatly appreciated! Show that $\frac{1}{x_1^2}+\frac{1}{4\cdot x_2^2}+\ldots+\frac{1}{n^2\cdot x_n^2}\leq\frac{3n-2}{2n-1}$. Let $$x_n=\frac{1}{1^2}+\frac{1}{2^2}+\ldots+\frac{1}{n^2},\;\forall n\geq 1.$$ Show that $$\frac{1}{x_1^2}+\frac{1}{4\cdot x_2^2}+\ldots+\frac{1}{n^2\cdot x_n^2}\leq \frac{3n-2}{2n-1}.$$   I tried to prove it by induction  but I got a contradiction. Debian : Verify disk encryption password for already mounted system Counterexamples to the avoidance lemma for arbitrary ideals Let $A$ be a commutative ring with $1$. Let $I$ and $J_k$, $k=1,\dots,n$ be ideals of $A$ with $I\subseteq \cup _{k=1}^n J_k$. Then I have obtained the following:  (1) If $J_k$, $k=1,\dots,n$, are prime ideals, then there exists some $j$ such that $I\subseteq J_j$.   (2) If $A$ is a principal ideal ring, then there exists some $j$ such that $I\subseteq J_j$.   I want some counterexamples that for all $k=1,\dots,n$, $I$ is not contained in $J_k$. How to get the counterexamples? When can you switch the order of limits? I am  new to Linux. I am using Ubuntu 11.04 and do not know how to compile and execute C++ program in it. I need to know the commands to Compile and Execute a C++ program in Linux. My understanding is that when using a Bayesian approach to estimate parameter values:   The posterior distribution is the combination of the prior distribution and the likelihood distribution. We simulate this by generating a sample from the posterior distribution (e.g., using a Metropolis-Hasting algorithm to generate values, and accept them if they are above a certain threshold of probability to belong to the posterior distribution). Once we have generated this sample, we use it to approximate the posterior distribution, and things like its mean.   But, I feel like I must be misunderstanding something. It sounds like we have a posterior distribution and then sample from it, and then use that sample as an approximation of the posterior distribution. But if we have the posterior distribution to begin with why do we need to sample from it to approximate it? A Jamaican committed marriage fraud about 30 years ago by marrying a US citizen in a marriage where the groom was paid a certain amount of money to marry her. The groom got in legal trouble for an unrelated matter, and the marriage fraud was discovered and the family friend was deported back to Jamaica. She no longer has any paperwork involved with the deportation and she can’t remember any of the details. I do not know if she simply agreed to return to Jamica when the fraud was discovered, or if she made any attempts to mount any type of legal defense in the case. I do know that she was cooperative with the immigration authorities and that they did not have to come looking for her. She would like to come the USA for a two-week visit. The main purpose of the visit is for her to visit a friend (US citizen) who is terminally ill.  I have been looking at 8 U.S.C. 1182 and from my reading of it, it would seem that she would not be admissible to the US because of the previous immigration fraud. My understanding is based on the section that says:     In general.-Any alien who, by fraud or willfully misrepresenting a material fact, seeks to procure (or has sought to procure or has procured) a visa, other documentation, or admission into the United States or other benefit provided under this Act is inadmissible.   What’s not clear to me is if this means that she would be inadmissible permanently or if this would be subject to the 10 year limit.  Can anyone help provide some clarity on this?  If the ban is not permanent are there any tips to being able to increase her chances of being able to get a visa.  She intends to honestly answer all questions during her application process for a visa. Find unique rows in numpy.array Suppose I have this:   $\frac{6^{666}}{2^{6}}$ (mod $125$)  I saw it is possible to reduce only the numerator's power modulo Euler's phi function. Can someone explain why is that possible?  It is essentially this:   $\frac{6^{666 \space (mod \phi(125))}}{2^{6}}$ (mod $125$) Here are two sentences:        Once he got the passport, he went to the Chinese consulate in Toronto and applied for a visa.   Once he got the passport, he went to the Chinese consulate in Toronto to apply for a visa.      Are the two sentences grammatical, and do they sound natural?  If they are both fine, what's the difference? Why can't I move a window to the top left corner with wmctrl in Unity? I've been playing around with wmctrl to take more control of my windows. I've encountered a weird behaviour where Unity reserves double the space. See this screen shot:    I opened the terminal and moved the window using the top command. It should be at the top left corner (X=0 Y=0). But for some reason there is some margin between the terminal and the Unity bars.  If I understand the man pages correctly it might have something to do with the WA: 65,24.  Can anybody help me to fix this? Opening Chromium on Ubuntu VPS Ubuntu noob here. I recently got a VPS running Ubuntu, and decided to install Chromium, my preferred browser, on it. After installation completed, I got a message stating that I cannot open Chromium with root privileges. How would I go about opening Chromium? How to simulate a rope? I'm trying to simulate a rope (that later might get pulled on the ends*) that interacts with some obstacles. So far I created a plane as the floor and a cube as an obstacle, and activated "collision" in the physics menu for both of them.   *(In the end the goal is simulating a .)  For modelling the rope, I tried using a long cylinder with enough subdivisions, and activate "cloth" in the physics menu. This resulted in the cylinder collapsing like a sleeve of a sweater, but I would like the cross section to remain roughly circular. Is there a way to directly avoid this?   Another approach I tried now was just using a a line made up of vertices and edges (with the idea of later adding modifiers to give it a thickness), but this just fell through all the collision objects as it has no faces. Is there good way to do this? I am trying to run a function from  in ArcMap 10.1; Sink evaluation. But before it can finish it returns an error message, that, frankly, I don't understand at all.  It goes System.runtime.interopservices.comexception (0x80004005): error hresult e_fail .  Can anyone help me solve this? I have tried all I can think of. Run the function from the toolbox instead of dropdown menus, shorten paths, restart ArcMap, reinstall AHT, open new map documents, restart my computer, wait till next day and see if it automagically have fixed itself...   After searching this forum I found a , although it's got no answers. Now I'm all out of ideas, can anyone please help me?!    I'm using ArcMap 10.1 SP1 basic license and Windows 7.    I think I have narrowed it down a bit, still not clear what's wrong though. Sink evaluation uses a series of functions in Arcmap, of which one is Zonal statistics as table. That's the one it gets stuck on. The input raster somehow does not exist, path unknown. I guess this is some intermediary raster.       After consulting the Arc Hydro team, I got the advice not to use grids stored in a gdb (which I didn't). I have also tried to change target locations, thanks to @G.Oxsen. Unfortunately neither of those solved the issue. According to the Arc Hydro team, GPL0 that I asked about earlier is an in-memory grid, so probably no problem there.   I am currently pursuing that it is related to the installation of SP1. Anyone out there using AHT with SP1 and got Sink evaluation working?    Uninstalling SP1 did not change anything, unfortunately. Still working on this, but with less intensity. Seems like I'll have to find workarounds...    By reducing the number of sinks in need of processing I managed to get Sink evaluation running. Having the files not stored in a gdb seem to help as well, as mentioned earlier, and using integer grids.  Changing the "Maximum number of unique values to render" in ArcMap Options (Customize menu), tab Raster --> Raster dataset is another tip that I got (from the Arc Hydro Team). Restarting ArcMap after running every one or two functions also helps keeping things stable. In R, what does qqnorm actually do? qqnorm(x) plot(qnorm(seq(80)/81),sort(x))   Finding that the plots produced by the commands above are slightly different from each other, I tried this:  qqnorm(qnorm(seq(80)/81))   I got a slightly less than perfect line.  I'd have tried regressing the result of qnorm(seq(80)/81) on the variable that was plotted on the $x$-axis and plotting residuals against the predictor, expecting to see some graceful curve, but for the fact that I don't know what to use as the predictor.  Possibly such a residual plot would reveal more than just the graceful S-shaped thing I'd anticipate.  So my question is this: if the thing on the $x$-axis in the plot produced by qqnorm is not what I get from qnorm(seq(80)/81) (and what I did shows that indeed it is not), then what is it? How do I complete the square from the point I have left off at, and is this correct so far?   I have a normal prior for $\beta$ of the form $p(\beta|\sigma^2)\sim \mathcal{N}(0,\sigma^2V)$, to get:  $p(\beta|\sigma^2)=(2\pi\sigma^2V)^\frac{p}{2}\exp[-\frac{1}{2\sigma^2}\beta^T\beta]$  where $\beta^T\beta$ is   $\sum\limits_{i=1}^p \beta_i^2$.  My likelihood has a normal distribtuion for the data points y of the form $p(y|\beta,\sigma^2)\sim\mathcal{N}(B\beta,\sigma^2I)  $  $p(y|\beta,\sigma^2)=(2\pi \sigma^2V)^\frac{n}{2}\exp[-\frac{1}{2\sigma^2}({\bf y}-{\bf B}{\bf \beta})^T({\bf y}-{\bf B}{\bf \beta})]$  (Note that $\beta$ is a matrix/vector too, \bf does not work.)  To get my posterior for $\beta$ I combined the above, took the exponential parts only, and then expanded to get:  $\exp[-\frac{1}{2\sigma^2}({\bf y}^T{\bf y}-{\bf y}^T{\bf B}\beta-\beta{\bf B}^T{\bf y}-\beta^T{\bf B}^T{\bf B}\beta)]\exp[-\frac{1}{2\sigma^2}({\bf \beta}^T{\bf B})]$.  I dropped the $({\bf y}^T{\bf y})$ term, as is not a function of $\beta$.  Putting into one expression without the exponential:  $-\frac{1}{2\sigma^2}(-{\bf y}^T{\bf B}\beta-\beta{\bf B}^T{\bf y}-\beta^T{\bf B}^T{\bf B}\beta+{\bf \beta}^T{\bf B})$.  I know I need to combine the similar terms and get into the form of the multivariate normal distribution, which is what I am aiming for, but I am unsure how to do this? I probably have to add an extra term to the expression to get it into the correct form?  Note: This is not homework, it's a project, but my Bayesian working knowledge is not good at all and so I need to understand the working out. I intend to integrate out the $\beta$ and then the $\sigma^2$ after getting into the multivariate form. Don't delete comments with link to duplicate if they are modified A user just posted his question a second time here on meta after the first was closed as a duplicate. I wrote a comment on the second post, explaining that the answer to his question is in the linked duplicate and that he shouldn't circumvent the closure process by asking a second identical question.  When the second post was closed as a duplicate my comment was automatically deleted. As far as I understand this is a heuristic that removes obsolete comments, which it considers every comment that contains a link to one of the duplicates.  This heuristic is too aggressive and removes comments that go beyond "Duplicate here: link". I suggest that it should be changed to only remove the default duplicate comment, and not any comment that was edited by the owner nor any free-form comment that happens to include a link to the duplicate.  This also triggers for any comment that contains the word "duplicate" and link to any question, not only the question being chosen as duplicate, which makes this much worse.