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How to create directories recursively in ruby?
I want to store a file as /a/b/c/d.txt, but I do not know if any of these directories exist and need to recursively create them if necessary.
How can one do this in ruby?
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How are GCC and g++ bootstrapped?
This has been bugging me for a while. How do GCC and g++ compile themselves?
1 Answer
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CFLAGS vs CPPFLAGS
I understand that CFLAGS (or CXXFLAGS for C++) are for the compiler, whereas CPPFLAGS is used by the preprocessor.
4 Answer...
Get type of all variables
In R, I'd like to retrieve a list of global variables at the end of my script and iterate over them. Here is my code
6 Answ...
Select multiple columns in data.table by their numeric indices
How can we select multiple columns using a vector of their numeric indices (position) in data.table ?
5 Answers
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Confusion between factor levels and factor labels
There seems to be a difference between levels and labels of a factor in R.
Up to now, I always thought that levels were the 'real' name of factor levels, and labels were the names used for output (such as tables and plots). Obviously, this is not the case, as the following example shows:
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How do you 'redo' changes after 'undo' with Emacs?
This article says that "Emacs has redo because you can reverse direction while undoing, thereby undoing the undo".
9 Answe...
Add legend to ggplot2 line plot
...plot three lines in the same graph and want to add a legend with the three colors used. This is the code used
3 Answers
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Find the max of two or more columns with pandas
I have a dataframe with columns A , B . I need to create a column C such that for every record / row:
2 Answers
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Creating C macro with ## and __LINE__ (token concatenation with positioning macro)
I want to create a C macro that creates a function with a name based
on the line number.
I thought I could do something like (the real function would have statements within the braces):
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