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How does one reorder columns in a data frame?
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Why does the mtcars[c(1,3,2)] subsetting work? I would have expected an error relating to incorrect dimensions or similar... Shouldn't it be mtcars[,c(1,3,2)]?
– landroni
Aug 30 '15 at 13:07...
How to backup a local Git repository?
... - make it work with submodules
# - propose to make backup directory if it does not exists
# - depth feature in git config (eg. only keep 3 backups for a repo - like rotate...)
# - TESTING
# allow calling from other scripts
def git_backup
# constants:
git_dir_name = '.git' # just to...
Why does 0.ToString(“#.##”) return an empty string instead of 0.00 or at least 0?
Why does 0.ToString("#.##") return an empty string? Shouldn't it be 0.00 or at least 0 ?
5 Answers
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Check if a folder exist in a directory and create them using C#
... I check if directory C:/ contains a folder named MP_Upload , and if it does not exist, create the folder automatically?
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Why does this (null || !TryParse) conditional result in “use of unassigned local variable”?
...ither way, y is set. The fact that the analysis is deferred until runtime doesn't change anything.
– Eric Lippert
Apr 30 '13 at 17:52
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Does the join order matter in SQL?
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For INNER joins, no, the order doesn't matter. The queries will return same results, as long as you change your selects from SELECT * to SELECT a.*, b.*, c.*.
For (LEFT, RIGHT or FULL) OUTER joins, yes, the order matters - and (updated) things are much ...
How can I unstage my files again after making a local commit?
... What is described in this answer is actually what git commit --amend does; but with a much more complicated workflow. This does not answer the question OP asked, in spite of giving a good direction (git reset).
– 7heo.tk
May 12 '15 at 11:26
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What does int argc, char *argv[] mean?
...ULL. It's allowed by the standard AFAIK. I've never heard of a system that does this in practice, but it certainly could exist and wouldn't be violating any standards.
– Chuck
Jun 11 '10 at 15:56
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C++, What does the colon after a constructor mean? [duplicate]
I have some C++ code here:
6 Answers
6
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What is std::move(), and when should it be used?
...an: well, it has to be in a state that is safe to destruct, but, AFAIK, it does not have to be usable for anything else.
– Zan Lynx
Oct 4 '11 at 19:15
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