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Selecting only numeric columns from a data frame
...e is a list we can use the 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.numer...
Difference between int[] array and int array[]
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They are semantically identical. The int array[] syntax was only added to help C programmers get used to java.
int[] array is much preferable, and less confusing.
sh...
Displaying better error message than “No JSON object could be decoded”
... also up on PYPI: https://pypi.python.org/pypi/rson/0.9 so you can use easy_install or pip to get it.
for the example given by tom:
>>> rson.loads('[1,2,]')
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rson.base.tokenizer.RSONDecodeError: Unexpected trailing comma: line 1, column 6, text ']'
RSON is a designed to be a superset...
Remove all special characters, punctuation and spaces from string
I need to remove all special characters, punctuation and spaces from a string so that I only have letters and numbers.
16 A...
Accessing nested JavaScript objects and arays by string path
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great stuff; using the lodash library, one can also do: _.get(object, nestedPropertyString);
– ian
Aug 13 '15 at 12:49
17
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Build fat static library (device + simulator) using Xcode and SDK 4+
It appears that we can - theoretically - build a single static library that includes both simulator and iPhone and iPad.
10...
Using getopts to process long and short command line options
...or using the bash builtin getopts to mimic long options. That solution actually makes a short option whose character is "-". So you get "--" as the flag. Then anything following that becomes OPTARG, and you test the OPTARG with a nested case.
This is clever, but it comes with caveats:
getopts ca...
How do I create a right click context menu in Java Swing?
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You are probably manually calling setVisible(true) on the menu. That can cause some nasty buggy behavior in the menu.
The show(Component, int x, int x) method handles all of the things you need to happen, (Highlighting things on mouseover and...
How do I compare two strings in Perl?
...rldoc perlop for more information.
( I'm simplifying this a little bit as all but cmp return a value that is both an empty string, and a numerically zero value instead of 0, and a value that is both the string '1' and the numeric value 1. These are the same values you will always get from boolean o...
“Could not load type [Namespace].Global” causing me grief
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If you specify x86 as your build platform, visual studio will automatically assign bin/x86/Debug as your output directory for this project. This is perfectly valid for other project types, except for web applications where ASP.NET expects the assemblies to be output to the Bin folder.
What I ...