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Group by multiple columns in dplyr, using string vector input
I'm trying to transfer my understanding of plyr into dplyr, but I can't figure out how to group by multiple columns.
9 Answ...
A fast method to round a double to a 32-bit int explained
When reading Lua's source code, I noticed that Lua uses a macro to round a double to a 32-bit int . I extracted the macro , and it looks like this:
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Parallelize Bash script with maximum number of processes
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Depending on what you want to do xargs also can help (here: converting documents with pdf2ps):
cpus=$( ls -d /sys/devices/system/cpu/cpu[[:digit:]]* | wc -w )
find . -name \*.pdf | xargs --max-args=1 --max-procs=$cpus pdf2ps
From the docs:
--max-...
How to install packages using pip according to the requirements.txt file from a local directory?
...ind-links URLs instead).
-f, --find-links <URL> - If a URL or path to an html file, then parse for links to archives.
If a local path or file:// URL that's a directory, then look for archives in the directory listing.
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How do I hide an element when printing a web page?
I have a link on my webpage to print the webpage. However, the link is also visible in the printout itself.
10 Answers
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How to install plugins to Sublime Text 2 editor?
How to install plugins to the Sublime Text editor?
8 Answers
8
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System.currentTimeMillis vs System.nanoTime
What I would like to know is whether I should use System.currentTimeMillis() or System.nanoTime() when updating my object's positions in my game? Their change in movement is directly proportional to the elapsed time since the last call and I want to be as precise as possible.
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Boolean Field in Oracle
Yesterday I wanted to add a boolean field to an Oracle table. However, there isn't actually a boolean data type in Oracle. Does anyone here know the best way to simulate a boolean? Googling the subject discovered several approaches
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Plot two graphs in same plot in R
I would like to plot y1 and y2 in the same plot.
16 Answers
16
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How to force IntelliJ IDEA to reload dependencies from build.sbt after they changed?
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You can force SBT to reload changes:
Open SBT toolwindow (on the right side of IDE) and press refresh button.
If you use auto-import feature you need to save your file to force auto-refresh.
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