I am trying to reinstall Ubuntu after running into some pretty troublesome issues. I am following the directions  but I can't seem to figure out how to start the UbuntuInstaller like it's telling me to. My current setup involves a dual boot with a USB. Do I need to delete the contents of the USB and start over with how I originally installed it, or should I be doing something different from this?  I'm not sure if this is persistent live or fully installed - it was set up with .
Recently I installed Ubuntu 12.10 x64 Server Edition on my PC. Unfortunately, I attempted to install a lightweight desktop but due to the fact that I have an old graphics card, the PC does not perform so well. I am thinking of re-installing an Ubuntu version but I do not want to lose the contents in my home folder. Is there any way to do that with a Live CD?
Could someone make the proof into a hinted exercise? Let $(c_n)$ be a sequence of positive numbers.  Could someone make the proof of the inequality  $\displaystyle\limsup_{n\to\infty}\sqrt[n]{c_n}\leq\limsup_{n\to\infty}\frac{c_{n+1}}{c_n}$  into a hinted exercise? I seem to have screwed up something that allows you to inset evenly, I think I have tried every combination of settings in inset and pivot center and even is far from even.  I tried uninstalling and re installing blender 2.71 and get the same result.  The image attached is a simple default cube that I tried to inset evenly.  I have also attached the blend file link  help?? Dynamic grid with Atlas generation What can I do if I'm the victim of serial downvoting? While browsing Stack Overflow, I noticed that I lost a lot of reputation:        Is this serial downvoting? Will it be corrected by a rep-recalculation? How often are those done?    Here's a second instance: find a sequence converging to zero but not the element of lp space for every 1<_p<infinity Since the final Black Hole (BH) had 3 solar masses less of mass than the original binary BH, it seems the 2 BHs lost mass, and with it event surface area, entropy, and information. If that came from inside the BHs it seems that it would be a contradiction of what a BH is --'nothing escapes its event horizon'. Some may say that came from the rotational energy of the pair, but the new BH now seems to have less than the two original ones summed. So, did some of that escape the horizons? I'm going to accessing my ubuntu machine remotely from my windows machine through putty. Are there any suggestions for possible ways to get an X server running on my windows machine?  Thanks. Framing a combination of cells in the notebook Constructing a HoTT proof term of 1≠0 As an exercise in HoTT basics, I am trying to construct a term that has the type $Id_{Nat}(S(O),O)\to\bot$. If this were a Coq proof, I'd be done after a single inversion on the premise, as the impossible identity would leave zero cases to consider. I guess I could do something similar here, but I'm not sure how. What would be an HoTT term that has the type? How can we extract specific files from a large tar.gz file? I found  but, when I tried the mentioned command there, I got the error:  $ tar --extract --file={test.tar.gz} {extract11} tar: {test.tar.gz}: Cannot open: No such file or directory tar: Error is not recoverable: exiting now   How do I then extract a file from tar.gz? Why did the Nazgûl not attack a second time at Weathertop? One divided by Infinity? What is the module/method used to get the current time? How to create a link to a URL provided in a bib file with custom text Using biblatex, how can I get a URL from the bib file so that I can use it in the \href command?  I am guessing that the \usefield command is what I am looking for and that in order to use that I would need the \entrydata command. But both are undefined.  \documentclass{article} \usepackage[backend=biber]{biblatex} \usepackage{hyperref}  \usepackage{filecontents} \begin{filecontents*}{sources.bib} @online{biblatex,     url = {http://mirrors.ctan.org/macros/latex/contrib/biblatex/doc/biblatex.pdf},     urldate = {2018-02-02}, } \end{filecontents*}  \addbibresource{sources.bib}  \begin{document}      % This would work, but I don't want to duplicate the URL from the bib file:     \href{http://mirrors.ctan.org/macros/latex/contrib/biblatex/doc/biblatex.pdf}{biblatex documentation}      % Does not work because \citeurl{biblatex} is already a link, not the URL:     %The \href{\citeurl{biblatex}}{biblatex documentation}      % Does not work because \usefield and \entrydata are undefined:     %The \entrydata{biblatex}{\usefield\href{url}{biblatex documentation}}      \printbibliography \end{document} TeX capacity exceeded with glossary package My document contains many thousands of glossary items. When compiling with XeLaTeX, about 1/8 of the way through the document, it reports:  ! TeX capacity exceeded, sorry [main memory size=3000000]. \@glolist@ ...},{13586},{9406},{4539},{12811},{179                                                   51},{5831},{1047},{14948},    The numbers you see above are ones placed in #1 of \newglossaryentry{#1}{#2}. These unique numbers are assigned to each entry for convenience. I have successfully compiled short tests of the document, which only used 1% of the full content. The resulting .glo file is about 1 MB in size.   Could this be the result of some error on my part or am I giving TeX too much work to do?  Update:  I have followed the instructions below (edited texmf.cnf and running  fmtutil-sys --all. This has allowed me to compile an additional portion of the book, but no matter the settings I add, I can't go beyond 5/8 of the way through.  A compile with extra_mem_top.xelatex = 30000000 and extra_mem_top.xelatex = 50000000 both result in:  TeX capacity exceeded, sorry [pool size=3186676].   Update:  I have done the following:  $ kpsewhich texmf.cnf /usr/local/texlive/2011/texmf.cnf $ nano /usr/local/texlive/2011/texmf.cnf   To the texmf.cnf file, following instructions at , I added:  main_memory = 230000000 extra_mem_top = 10000000 extra_mem_bot = 10000000 save_size = 150000 stack_size = 150000  main_memory.xelatex = 30000000 extra_mem_top.xelatex = 30000000   After this, I tried: - fmtutil-sys --all, then compiling xelatex file.tex. - fmtutil --all, then compiling xelatex file.tex. - fmtutil-sys --byfmt xelatex, then compiling with xelatex file.tex. - texhash, then compiling with xelatex file.tex.  All of these resulted in no changes in results. I still get:  TeX capacity exceeded, sorry [pool size=3186676]. Tokenizing strings in C I have been trying to tokenize a string using SPACE as delimiter but it doesn't work. Does any one have suggestion on why it doesn't work?  Edit: tokenizing using:  strtok(string, " ");   The code is like the following  pch = strtok (str," "); while (pch != NULL) {   printf ("%s\n",pch);   pch = strtok (NULL, " "); } Our Epson dot matrix printer is not printing on the following DOS command.:  Type text.txt&gt;prn   But it does print perfectly on:  open TEXT.txt&gt;File&gt;Print    What is the issue here? How to find python installation directory on Ubuntu I have just migrated from Windows environment. I have installed Python 3.2 in a separate directory. How can I get the python installation path in Ubuntu shell?  Is there any way I can let the shell know/choose at runtime which python version is to be used for further code execution?  Are there any environment variables and search path kind of things in Ubuntu Linux as well? Python inheritance - how to disable a function In C++ you can disable a function in parent's class by declaring it as private in the child class. How can this be done in Python? I.E. How can I hide parent's function from child's public interface? Pull down resistor on logic gate input I would like to use a pull-down resistor on the input of a NOT logic gate. I am using a 5V microcontroller, and I want to ensure that the input of the gate will never be floating (eg. microcontroller damage).  General information:  The logic gate I am using is a HD74LS04 inverter whose datasheet can be found . I am testing the output by placing my positive multi-meter lead on R4 and the negative lead on GND. With the digital pin floating, the output of 1Y is 4.33V. This is the expected behavior.  The logic gate requires a minimum of 2.0V for Vih. If I understand this circuit correctly, I expect the voltage at pin 1A to be 3.76V since R2 and R3 will form a voltage divider. This value seems plenty to signify a 'high' in the logic gate.  R2 exists to protect the digital pin. Ideally, I would have liked R2 to be 1KΩ. Increasing the value of R2 means I have to increase the value of R3 to maintain the same voltage divider. During testing I found that if R3 was any value over 3.3KΩ, the pin 1A would not get pulled down all the way if I left the digital pin floating.   Tests: If I disconnect everything except GND and Vcc and place the positive lead of my multi-meter on pin 1A (now floating) and the negative lead to GND, I read 1.49V. Placing a pull-down resistor (R3) on pin 1A to GND with a value of 100Ω changes the reading to 0.02V. Increasing the resistor's value to 330Ω increases the reading to 0.07V. At the value I need, 3.3KΩ, the reading increases to 0.60V. Finally, changing the resistor's value to 1MΩ increases the reading to 1.47V and actually changes the output of pin 1Y to low.  The test that uses the 3.3KΩ resistor is concerning. The reading I took (0.60V) seems to be approaching the Vil maximum of the logic gate which is 0.80V.   Questions:  This must be a trivial question, but why does an R3 value of 3.3KΩ not pull pin 1A all the way to GND? Is there a formula for determining the correct pull-down resistor value? Other answers I found on here simply state 10KΩ as a 'good' value for a pull-up resistor. I'm not sure where that value comes from or if it is applicable to a pull-down resistor.         &ndash; Schematic created using   Edit: Although Ignacio's answer technically answers the question, I thought I would share some information I found for others who may come across this question.  User 'Papabravo' on the  states that the calculation for a pull down resistor can be calculated by taking the Vil (0.8V) and dividing it by the "standard TTL load" of 1.6mA. As Ignacio pointed out, my specific logic gate can source up to 0.4mA, so the calculation would be 0.8/0.0004A which equals 2KΩ. For safety, I performed the calculation at 0.5V in order to give myself some headroom.  Other Resources: