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Selecting only numeric columns from a data frame
...de
## 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 reflecting R's particular quirks, and more straightforward, and robust to use on database-back-ended tibbles:
dplyr::select_if(x, is.numeric)
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Node.js on multi-core machines
... entire box; I crashed the kernel on a CentOS5 box by stress-testing Node (now THAT really isn't supposed to happen). I've come around a bit, and I see a bright future for Node, potentially including dedicated LB-type roles. Just not yet.
– Dave Dopson
Jan 16...
Suppress or Customize Intro Message in Fish Shell
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I think this worked once, but it doesn't anymore; now it seems you need to set the variable to an empty string.
– mjs
Jun 13 '17 at 7:34
add a comment...
With Spring can I make an optional path variable?
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It's not well known that you can also inject a Map of the path variables using the @PathVariable annotation. I'm not sure if this feature is available in Spring 3.0 or if it was added later, but here is another way to solve the example:
@R...
Delete specified file from document directory
...bute NSFileImmutable YES. Or something like that. Sorry can't show sources now. But the problem was trivial.
– Vadim
Apr 8 '13 at 14:22
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How to make good reproducible pandas examples
...=25, freq='D'), 4 ),
'price':(np.random.randn(100).cumsum() + 10) })
Now we have a sample dataset with 100 lines (25 dates per ticker), but we have only used 4 lines to do it, making it easy for everyone else to reproduce without copying and pasting 100 lines of code. You can then display sub...
What is the difference between JSON and Object Literal Notation?
...literals, number literals or identifier names as keys (since ES6, keys can now also be computed, which introduces yet another syntax).
The values can be any valid JavaScript expression, including function definitions and undefined.
Duplicate keys produce defined, specified results (in loose mode, th...
What is the performance of Objects/Arrays in JavaScript? (specifically for Google V8)
...;
var lastLongI = 1;
for(var i=0;i<10000;i++)
{
var before = Date.now();
for(var j=0;j<arrayCount;j++)
dynamicArrays[j][i] = i;
var span = Date.now() - before;
if (span > 10)
{
console.log(i + ": " + span + "ms" + " " + (i / lastLongI));
lastLongI =...
What is a “thread” (really)?
...ctions.
Suppose you're reading a book, and you want to take a break right now, but you want to be able to come back and resume reading from the exact point where you stopped. One way to achieve that is by jotting down the page number, line number, and word number. So your execution context for read...
iOS Detect 3G or WiFi
...hability files as they had errors for iOS5 in it - but I am so happy right now. Unfortunately I can only give you 1 up vote:-)
– jwknz
Oct 29 '11 at 20:19
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