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What's the fastest way to merge/join data.frames in R?
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DF1 = data.frame(a = c(1, 1, 2, 2), b = 1:4)
DF2 = data.frame(b = c(1, 2, 3, 3, 4), c = letters[1:5])
merge(DF1, DF2)
b a c
1 1 1 a
2 2 1 b
3 3 2 c
4 3 2 d
5 4 2 e
DF1$c = DF2$c[match(DF1$b, DF2$b)]
DF1$c
[1] a b c e
Levels: a b c d e
> DF1
a b c
1 1 1 a
2 1 2 b
3 2 3 c
4 2 4 e
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Ternary operator is twice as slow as an if-else block?
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376
To answer this question, we'll examine the assembly code produced by the X86 and X64 JITs for ...
How can I discard remote changes and mark a file as “resolved”?
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335
git checkout has the --ours option to check out the version of the file that you had locally (...
Rebasing a branch including all its children
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3 Answers
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How to prevent moment.js from loading locales with webpack?
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306
The code require('./locale/' + name) can use every file in the locale dir. So webpack includes...
Declaration/definition of variables locations in ObjectiveC?
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NolanDC
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answered Sep 28 '12 at 1:38
DrummerBDrummerB
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Deleting all files in a directory with Python
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edited Oct 8 '17 at 7:32
yugr
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answered Jan 3...
What are all the user accounts for IIS/ASP.NET and how do they differ?
...he NETWORK SERVICE account is a built-in identity introduced on Windows 2003. NETWORK SERVICE is a low privileged account under which you can run your application pools and websites. A website running in a Windows 2003 pool can still impersonate the site's anonymous account (IUSR_ or whatever you co...
How to Create Grid/Tile View?
... of jQuery plugin to create masonry layout.
Alternatively, you can use CSS3 columns. But for now jQuery based plugin is the best choice since there is compatibility issue with CSS3 column.
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