I have a script I run on erach new machine I own, that installs somethings I need.  For some reason, on a dell Inspiron 3542 with Ubuntu 14.04, the following fails:  $ sudo apt-get install libamd2.2.0 libumfpack5.4.0  libatlas-sse2-dev    with the errors:  Reading package lists... Done Building dependency tree        Reading state information... Done Package libatlas-sse2-dev is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source  E: Unable to locate package libamd2.2.0 E: Couldn't find any package by regex 'libamd2.2.0' E: Unable to locate package libumfpack5.4.0 E: Couldn't find any package by regex 'libumfpack5.4.0' E: Package 'libatlas-sse2-dev' has no installation candidate   BTW,I did try sudo apt-get update first.  With other computers this always worked for me before. How can I fix that?
What does the above Error mean? What is an installation candidate?  I was trying to do  sudo apt-get install munin-memcached     and I get this message:  Reading package lists... Done Building dependency tree        Reading state information... Done Package munin-memcached is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source E: Package munin-memcached has no installation candidate   I googled for the problem and someone said to do a apt-get upgrade but it still did not solve my problem.
Nested amsmath environments with \newenvironment Trying to install CPAN I need a non trivial  examples of group isomorphism that maps $G\to H$ such that   $G/H \cong G$. The collection of all subsets of $\mathbb{Z}$ is uncountable, due to   But how can I prove that the collection of all finite subsets of $\mathbb{Z}$ is countable? How do I get the title of a .pdf document to appear as the page title? How does one find which files are taking up 80% of the space on a Linux webserver? The drive is constantly filling up. You've hunted down all the spare and random files you can. grep'd for coredump files and even removed some of the un-needed backups...  What would be your next move.  The actual server in question has 10GB of website files and the OS shouldn't take any more than 10GB so how do you track down what's filling a 50GB (virtual) drive? I have built a peak detector circuit using op-amps/comparators to amplify the signal from an electret microphone, hold the peak signal and create a sharp logic edge when a peak is detected to be sent to a microcontroller.  I have built the circuit as follows setting up OA1 as a non inverting amplifier with a gain of 1000, but the voltage out from the OA1 remains fixed at about 4.5V no matter how much noise I make into the microphone. The comparator part of the circuit is outputting approximately 2V low and 5V high depending on how I set the potentiometer. All the components appear to be working.         &ndash; Schematic created using AES Mix Column Transformation Section 3.4.3 "The MixColumns Step"(page 39) of , it states     The columns of the state are considered as polynomials over   $\operatorname{GF}(2^8)$ and multiplied modulo $x^4 + 1$ with a fixed polynomial $c(x)$.      The polynomial $c(x)$ is given by   $c(x) = \mathtt{03} \cdot x^3 + \mathtt{01} \cdot x^2 + \mathtt{01} \cdot x + \mathtt{02}$      Let $b(x) \equiv c(x) \cdot a(x) \pmod{x^4 + 1}$. Then         How this polynomial multiplication modulo $x^4+1$ is converted to Matrix Multiplication? Let the function $f(x)$ be differentiable  and $f'(x)$ be continuous in $\left(-\infty,\infty \right)$ with $f'(2)=14$ then evaluate the limit  $$\lim_{x\to 0}\frac{f(2+\sin x)-f(2+x\cos x)}{x-\sin x}$$  My attempt:  $\lim_{x\to 0}\frac{f(2+\sin x)-f(2+x\cos x)}{x-\sin x}$  $\lim_{x\to 0}\left(\frac{f(2+\sin x)-f(2+x\cos x)}{\sin x-x\cos x}\right)$ $\frac{\sin x-x\cos x}{x-\sin x}$$=\left(f'(2)\right)(2)=28$  Is the method used here correct Best Algebraic Geometry text book? (other than Hartshorne) Is it possible to change your spawn point? A non orientable closed surface cannot be embedded into $\mathbb{R}^3$ I'd like to be able to decompose a concave mesh into a set of convex meshes for 2 reasons:   Transparent rendering Physics shapes   Is there an algorithm that takes a set of triangles (concave) as input and outputs a number of sets of triangles (convex)?  I'd like it to not fill in the holes between parts of the original mesh.  I've already come across a small idea: find all the concave edges, and split the meshes along the edge loops.  Am I on the right track?  How could I implement this? How can I return to the start of a line in a console? How can I return to the start of a line and overwrite what has already been output on the console? The following does not appear to work:  System.out.print(mystuff+'\r'); How can I combine multiple rows into a comma-delimited list in Oracle? I have a simple query:  select * from countries   with the following results:  country_name ------------ Albania Andorra Antigua .....   I would like to return the results in one row, so like this:  Albania, Andorra, Antigua, ...   Of course, I can write a PL/SQL function to do the job (I already did in Oracle 10g), but is there a nicer, preferably non-Oracle-specific solution (or may be a built-in function) for this task?  I would generally use it to avoid multiple rows in a sub-query, so if a person has more then one citizenship, I do not want her/him to be a duplicate in the list.  My question is based on the similar question on .  UPDATE: My function looks like this:  CREATE OR REPLACE FUNCTION APPEND_FIELD (sqlstr in varchar2, sep in varchar2 ) return varchar2 is ret varchar2(4000) := ''; TYPE cur_typ IS REF CURSOR; rec cur_typ; field varchar2(4000); begin      OPEN rec FOR sqlstr;      LOOP          FETCH rec INTO field;          EXIT WHEN rec%NOTFOUND;          ret := ret || field || sep;      END LOOP;      if length(ret) = 0 then           RETURN '';      else           RETURN substr(ret,1,length(ret)-length(sep));      end if; end; Why the name 'Rogue One'? So far, is there any suggestion, or speculation as to the reason for the name 'Rogue One' for the next Star Wars film?   To me, the name seems very close to the Rogue Squadron, most known from Hoth (their leader Luke Skywalker), especially the number following Rogue like a callsign.   However as far as I know, they were formed after the first Death Star destruction. So why Rogue One? On equations $m^2+1=5^n$ I am looking for integer solutions of Diophantine equation $m^2+1=5^n$. I found that $m=0,n=0$ and $m=2,n=1$. I could not find any other solutions. I try to prove this but I could not. Could anyone help me to solve this equation? This is a  about Apache's mod_rewrite.   Changing a request URL or redirecting users to a different URL than the one they originally requested is done using mod_rewrite. This includes such things as:   Changing HTTP to HTTPS (or the other way around) Changing a request to a page which no longer exist to a new replacement. Modifying a URL format (such as ?id=3433 to /id/3433 ) Presenting a different page based on the browser, based on the referrer, based on anything possible under the moon and sun. Anything you want to mess around with URL   Everything You Ever Wanted to Know about Mod_Rewrite Rules but Were Afraid to Ask!  How can I become an expert at writing mod_rewrite rules?   What is the fundamental format and structure of mod_rewrite rules? What form/flavor of regular expressions do I need to have a solid grasp of? What are the most common mistakes/pitfalls when writing rewrite rules? What is a good method for testing and verifying mod_rewrite rules? Are there SEO or performance implications of mod_rewrite rules I should be aware of? Are there common situations where mod_rewrite might seem like the right tool for the job but isn't? What are some common examples?   A place to test your rules  The  web site is a great place to play around with your rules and test them. It even shows the debug output so you can see what matched and what did not. Determine which app is drawing on top of other apps? What is DOCTYPE and why do I want to use it? What are the different DOCTYPEs I can use? What is the difference between standards and quirks mode, and what are some quirks I may run into with differently set DOCTYPEs?   Lastly, what is the proper DOCTYPE that I should be using?