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Repeat each row of data.frame the number of times specified in a column
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Here's one solution:
df.expanded <- df[rep(row.names(df), df$freq), 1:2]
Result:
var1 var2
1 a d
2 b e
2.1 b e
3 c f
3.1 c f
3.2 c f
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im...
Getting and removing the first character of a string
I would like to do some 2-dimensional walks using strings of characters by assigning different values to each character. I was planning to 'pop' the first character of a string, use it, and repeat for the rest of the string.
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Working with huge files in VIM
I tried opening a huge (~2GB) file in VIM but it choked. I don't actually need to edit the file, just jump around efficiently.
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How to view UTF-8 Characters in VIM or Gvim
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62
Try to reload the document using:
:e! ++enc=utf8
If that works you should maybe change the f...
Why would a post-build step (xcopy) occasionally exit with code 2 in a TeamCity build?
...ying is a file or a directory. This error will appear as "exited with code 2". When you run the same xcopy at a command prompt, you'll see that xcopy is asking for a response of file or directory.
To resolve this issue with an automated build, you can echo in a pre-defined response with a pipe.
To...
Function Pointers in Java
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126
The Java idiom for function-pointer-like functionality is an an anonymous class implementing an...
List comprehension vs map
...n map needs a lambda:
$ python -mtimeit -s'xs=range(10)' 'map(lambda x: x+2, xs)'
100000 loops, best of 3: 4.24 usec per loop
$ python -mtimeit -s'xs=range(10)' '[x+2 for x in xs]'
100000 loops, best of 3: 2.32 usec per loop
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Benchmarking (python vs. c++ using BLAS) and (numpy)
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jfsjfs
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How to pass optional arguments to a method in C++?
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edited May 25 '18 at 10:44
AustinWBryan
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