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Selecting only numeric columns from a data frame
...list-apply functions:
nums <- unlist(lapply(x, is.numeric))
Then standard subsetting
x[ , nums]
## don't use sapply, even though it's less code
## nums <- sapply(x, is.numeric)
For a more idiomatic modern R I'd now recommend
x[ , purrr::map_lgl(x, is.numeric)]
Less codey, less ref...
How to specify different Debug/Release output directories in QMake .pro file
I have a Qt project and I would like to output compilation files outside the source tree.
11 Answers
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Rails 4: before_filter vs. before_action
...ore_filter.
However all before_filters syntax are deprecated in Rails 5.0 and will be removed in Rails 5.1
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Is there any free OCR library for Android? [closed]
I'm looking for a Java OCR that runs on Android, however Asprise doesn't seem to be a platform independent OCR. is there any opensource/free Java OCR I can use for android application development?
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URL encoding in Android
How do you encode a URL in Android?
7 Answers
7
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PHP convert XML to JSON
...g to convert xml to json in php. If I do a simple convert using simple xml and json_encode none of the attributes in the xml show.
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Cleanest way to build an SQL string in Java
...thing) - instead of the awful string concat method using millions of "+"'s and quotes which is unreadable at best - there must be a better way.
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Execute stored procedure with an Output parameter?
... Sql Server Management Studio(SSMS),
select execute stored procedure...
and add values for the input parameters as prompted.
SSMS will then generate the code to run the proc in a new query window, and execute it for you. You can study the generated code to see how it is done.
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Mounting multiple volumes on a docker container?
...; gcc -o myapp ./mycode.c; cd tst; ./myapp < ./test.txt' This is my command, I'm trying to compile the mycode.c that is in the first volume, but give that same file an stdin from a different volume. How do I do it?
– momal
Mar 23 '15 at 16:00
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Add to Array jQuery
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+1 for explaining both JavaScript and jQuery's method and their fundamental difference. I came here for $.add() and got just a little bit more.
– Sam
Feb 1 '14 at 0:21
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