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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 do I browse an old revision of a Subversion repository through the web view?
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I am absolutely stunned this works... (I just checked and it does). I've been told many times it's not possible. Note that the string mentioned must be right after the repo root in the URL, then you can put subdirs of the repo after it.
– rmeador
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How do you import classes in JSP?
... answered Oct 27 '08 at 7:50
SandmanSandman
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Creating an empty file in Ruby: “touch” equivalent?
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FileUtils.touch looks like what it does, and mirrors* the touch command:
require 'fileutils'
FileUtils.touch('file.txt')
* Unlike touch(1) you can't update mtime or atime alone. It's also missing a few other nice options.
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List files in local git repo?
I'm using Sparkleshare, which uses Git to sync files between my laptop and my backup server.
3 Answers
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Show dialog from fragment?
...ow a regular dialog. On these dialogs the user can choose a yes/no answer, and then the fragment should behave accordingly.
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Copy entire contents of a directory to another using php
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It seems that copy only handle single files. Here is a function for copying recursively I found in this note on the copy documentation page:
<?php
function recurse_copy($src,$dst) {
$dir = opendir($src);
@mkdir($dst);
while(false ...
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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swap fragment in an activity via animation
...two fragment in an activity via animation.Suppose PageA is for fragement A and left side on the screen and PageB is for fragment B i.e. on the right side of the screen. Now i want that when i click a button on pageA then PageA will move to the right side of the screen with some transition animation....
NSUserDefaults removeObjectForKey vs. setObject:nil
...m not positive.
To completely remove a value for a key use UserDefaults.standard.removeObject(forKey: "YourDefault")
I tested with the following code:
UserDefaults.standard.set(["a", "b", "c"], forKey: "MyDefaults")
print("Test A: My saved defaults \(UserDefaults.standard.object(forKey: "MyDefaul...