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Performance of foreach, array_map with lambda and array_map with static function
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Thanks for the benchmarks. However, I would like to know why there is such difference. Is it because of a function call overhead?
– Pavel S.
Jan 25 '14 at 13:06
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Selecting only numeric columns from a data frame
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## 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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What's the opposite of chr() in Ruby?
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Now that Ruby 1.9 has changed the meaning of 'A'[0], this is the more portable method.
– AShelly
Nov 22 '08 at 1:11
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What online brokers offer APIs? [closed]
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Looks like E*Trade has an API now.
For access to historical data, I've found EODData to have reasonable prices for their data dumps. For side projects, I can't afford (rather don't want to afford) a huge subscription fee just for some data to tinker wi...
Close file without quitting VIM application?
...artin, to completely delete the buffer, use :bw
– sebnow
Dec 2 '10 at 11:14
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What is the performance of Objects/Arrays in JavaScript? (specifically for Google V8)
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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 =...
classical inheritance vs prototypal inheritance in javascript
...rld entity (i.e. they represent real word things in the program). This is known as abstraction.
Abstraction: The representation of real world things in computer programs.
Theoretically an abstraction is defined as "a general concept formed by extracting common features from specific examples". How...
Android : difference between invisible and gone?
...e idea with some pictures.
Assume that you have three buttons, like below
Now if you set visibility of Button Two as invisible (View.INVISIBLE), then output will be
And when you set visibility of Button Two as gone (View.GONE) then output will be
Hope this will clear your doubts.
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Why is an int in OCaml only 31 bits?
Haven't seen this "feature" anywhere else. I know that the 32nd bit is used for garbage collection. But why is it that way only for ints and not for the other basic types?
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Can you detect “dragging” in jQuery?
...n threshold on mouseup jsfiddle.net/W7tvD/1649 Works like a charm for me now, thanks!
– halfbit
Feb 26 '16 at 12:30
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