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How do I clone a generic list in C#?
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I think List.ConvertAll might do this in faster time, since it can pre-allocate the entire array for the list, versus having to resize all the time.
– MichaelGG
Oct 21 '08 at 17:43
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Should I use a data.frame or a matrix?
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Something not mentioned by @Michal is that not only is a matrix smaller than the equivalent data frame, using matrices can make your code far more efficient than using data frames, often considerably so. That is one reason why internally, a lot of R functions will coerce to matrices data th...
Evaluate expression given as a string
...s("5+5")
[1] "character"
> class(parse(text="5+5"))
[1] "expression"
Calling eval() invokes many behaviours, some are not immediately obvious:
> class(eval(parse(text="5+5")))
[1] "numeric"
> class(eval(parse(text="gray")))
[1] "function"
> class(eval(parse(text="blue")))
Error in eva...
Read lines from a file into a Bash array [duplicate]
... from BinaryZebra's comment
and tested here. The addition of command eval allows for the expression to be kept in the present execution environment while the expressions before are only held for the duration of the eval.
Use $IFS that has no spaces\tabs, just newlines/CR
$ IFS=$'\r\n' GLOBIGNORE=...
How to drop columns by name in a data frame
I have a large data set and I would like to read specific columns or drop all the others.
11 Answers
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CSS selector for first element with class
...lass. One workaround that Lea Verou and I came up with for this (albeit totally independently) is to first apply your desired styles to all your elements with that class:
/*
* Select all .red children of .home, including the first one,
* and give them a border.
*/
.home > .red {
border: ...
How to compare a local git branch with its remote branch?
...rbranch_path> <remotebranch_path>
You can git branch -a to list all branches (local and remote) then choose branch name from list (just remove remotes/ from remote branch name.
Example: git diff master origin/master (where "master" is local master branch and "origin/master" is a remote n...
how to remove shared preference while application uninstall in android
...nd password via SharedPreferences thats works fine, but i need to remove all my used SharedPreferences while my application uninstall. How to do it?
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How to open an elevated cmd using command line for Windows?
... batch file with this and saved it as admincmd.bat in my windows folder so all I have to do is type "admincmd" hit enter and it opens an admin cmd.(I also added another line to the batch file with "exit" so it closes the non admin cmd window)
– Tony Brix
Nov 16...
Generate pdf from HTML in div using Javascript
...lement IDs are still done in jQuery style "#id", but it does not mean that all jQuery selectors are supported.
Therefore replacing '#ignorePDF' with class selectors like '.ignorePDF' did not work for me. Instead you will have to add the same handler for each and every element, which you want to ig...