will downloading ubuntu erase windows? And what will happen to my files (pictures, documents etc.)
How can I install Ubuntu without removing Windows?
Is there a way I can see all the versions that are in the archives that I have configured in sources.list. I can see the last version of each archive withapt-get policy, but how can I see them all?  Is there any way that this can also include PPA and anything in sources.list.d? How to show $(mn)!$ is divisible by $(m!)^n$? How to show $(mn)!$ divides $(m!)^n$, $m$ and $n$ is integers? What is the plural of the abbreviation of "multiplicity automaton", "MA" or "MAs"? The "multiplicity automaton (MA)" is a model in compute science and its plural is "multiplicity automata". Should the plural of the abbreviation be MA or MAs?      is not a duplicate as it is focused on cases like "ATMs" where the expanded form "automated teller machines" has a regular plural ending in "s." Unlike "machines," the word "automata" has an irregular plural that does not end in "s." It's unclear from the linked answers how abbreviations that end in words like this should be pluralized. A high-ranking  mentions "VIPs," but a high-ranking  says     VIPs' is a strange one. It could be argued that the expanded acronym,   when pluralized, should be 'Very Important People' rather than 'Very   Important Persons'. Using this argument, 'VIP' could be used as a   singular or plural noun. "The VIP has arrived." "The VIP have   arrived." I'm not sure anyone else would agree with my logic, though. Metric is continuous function Let $X$ be a metric space , $d$ is the metric , show that $d$ is a continuous function from $X\times X$ to $R$.  I think the definition is all we need , but I just don't know where to start , can anyone help me. Do spell effects move if the object they are cast on moves? let's suppose that I cast a Silent image of a wall on an airship. Let's suppose that I don't move it with concentration.  Does the image of the wall move with the airship or it will progressively go far? The man page for GNU find states:    -exec command ;     [...] The  string `{}'  is  replaced  by the current      file name being processed everywhere it occurs in the      arguments to the command, not just in arguments where      it is alone, as in some  versions  of  find.     Both  of  these  constructions might need to be escaped      (with a `\') or quoted to protect them from expansion      by the shell.     That's from the man to find (GNU findutils) 4.4.2.   Now I tested this with bash and dash, and both don't need to have the {} being masked. Here is a simple test:  find /etc -name "hosts" -exec md5sum {} \;    Is there a shell, for which I really need to mask the braces? Note, that it doesn't depend upon whether the file found contains a blank (invoked from bash):   find ~ -maxdepth 1 -type d -name "U*" -exec ls -d {} \;  /home/stefan/Ubuntu One   This changes if the found file is passed to a subshell:  find ~ -maxdepth 3 -type d -name "U*" -exec bash -c 'ls -d {}' \;  ls: cannot access /home/stefan/Ubuntu: No such file or directory ls: cannot access One: No such file or directory   which can be solved by:  find ~ -maxdepth 3 -type d -name "U*" -exec bash -c 'ls -d "$0"' {} \;   in contrast to:   find ~ -maxdepth 3 -type d -name "U*" -exec bash -c 'ls -d "{}"' \;  /home/stefan/Ubuntu One   but that's not what the man page is talking about, is it? So which shell treats {} in a different way? I use the native Clock app, and my alarm used to just have a normal ringtone. I assume there was some automatic update recently because this morning, in addition to the normal ringtone, there was a robotic voice saying "It is 7:25 AM." Then later I got a notification from the native Calendar app, and in addition to my normal ringtone, the robotic voice announced the text of the notification.  How do I shut this off? It's really annoying and I don't see an option in Settings. Control a property with no socket (color ramp swatch, etc) from a Group Node input? What is code coverage and how do YOU measure it?  I was asked this question regarding our automating testing code coverage. It seems to be that, outside of automated tools, it is more art than science. Are there any real-world examples of how to use code coverage? Mouse cursor flickering and disappearing Dealing with multiple private DNS servers Some doubts about photons Shape of confidence interval for predicted values in linear regression I have noticed that the confidence interval for predicted values in an linear regression tends to be narrow around the mean of the predictor and fat around the minimum and maximum values of the predictor. This can be seen in plots of these 4 linear regressions:    I initially thought this was because most values of the predictors were concentrated around the mean of the predictor. However, I then noticed that the narrow middle of the confidence interval would occur even if many values of were concentrated around the extremes of the predictor, as in the bottom left linear regression, which lots of values of the predictor are concentrated around the minimum of the predictor.  is anyone able to explain why confidence intervals for the predicted values in an linear regression tend to be narrow in the middle and fat at the extremes? Velocity Maxwell-Boltzmann distribution for dummies I have a volume with $N$ molecules; I need to assign to each particle a velocity vector: $$|\mathbf{v}_{i}|=[v_{x}, v_{y}, v_{z}]^{T}$$ for the $i$-th molecule; the velocities must follow the Maxwell-Boltzmann distribution; here is the question: I know the definition of the M.B. distribution, how do I extract the velocities that I have to assign to each molecule? Basically what I want to know is how to calculate $$v_{x}=?$$ $$v_{y}=?$$ $$v_{z}=?$$ for each molecule. Extracting intersection areas in R I have two polygons. One contains fields(X,Y,Z) and the other contains soil types (A,B,C,D). I want to know what  area of every field contains which type of soil. I tried the following:    library(rgdal) library(rgeos) Field&lt;-readOGR("./","Field") Soil&lt;-readOGR("./","Soil") Results&lt;-gIntersects(Soil,Field,byid=TRUE) rownames(Results)&lt;-Field@data$FieldName colnames(Results)&lt;-Soil@data$SoilType  &gt; Results       A     B     C     D Z  TRUE FALSE FALSE FALSE Y FALSE  TRUE  TRUE FALSE X  TRUE  TRUE  TRUE  TRUE   and achieved good results with it telling me which field contains which soil type. However, how do I get the area instead? I saw a commercial on televison for preparing spaghetti without boiling the noodles, just place them in water for about on hour.  Can this be done? Schadenfreude is the joy or pleasure derived from the misfortunes of others. What is the word for joy or pleasure derived from the happiness of others? Pytest is in PATH but not found Why is the net speed of Stack Overflow so fast? This question is about the net speed.  I'm from China, and I find that opening pages on Stack Overflow is very fast, normally within a range of 1 to 4 seconds. This speed is very good for a website outside China; it's even faster than some native websites.  Not every website outside China has such good speed, so I am wondering why and how Stack Overflow manages to be so quick. Sort sections according to alphabetical order Is it possible to tell latex, that it should sort the sections you used in your document according to their alphabetical order in the final pdf document? I.e. I want to have something like this  \begin{document} \section{A} \section{C} \section{B} \end{document}   and in the pdf I get the result as  A B C   Is that possible, and if yes, how? Putting the sections into separate files is not preferred (but possible if scripted) due to having ~300 sections. Edit: I can also rewrite it as   \begin{sortEnvironment}{Title} Content \end{sortEnvironment}   if that makes it easier.