大约有 40,000 项符合查询结果（耗时：0.0482秒） [XML]
Geometric Mean: is there a built-in?
...ositive values.
gm_mean = function(x, na.rm=TRUE){
exp(sum(log(x[x > 0]), na.rm=na.rm) / length(x))
}
Thanks to @ben-bolker for noting the na.rm pass-through and @Gregor for making sure it works correctly.
I think some of the comments are related to a false-equivalency of NA values in the d...
How dangerous is it to compare floating point values?
...nt the actual result. An easy example where you can see this is adding x = 0x1fffffe and y = 1 as floats. Here, x has 24 bits of precision in the mantissa (ok) and y has just 1 bit, but when you add them, their bits are not in overlapping places, and the result would need 25 bits of precision. Inste...
Get free disk space
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edited Sep 20 '11 at 15:25
Superman
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How to remove the querystring and get only the url?
...
+100
You can use strtok to get string before first occurence of ?
$url = strtok($_SERVER["REQUEST_URI"], '?');
strtok() represents the ...
Android: How to change CheckBox size?
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answered Jan 28 '10 at 7:36
moraesmoraes
11.8k77 gold badges4141 silver badges5858 bronze badges
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Why is printing to stdout so slow? Can it be sped up?
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I ran your file writing test on my machine, and with buffering, it also 0.05s here for 100,000 lines.
However, with the above modifications to write unbuffered, it takes 40 seconds to write only 1,000 lines to disk. I gave up waiting for 100,000 lines to write, but extrapolating from the previou...
How to write a cron that will run a script every day at midnight?
...how to use it on Ubuntu. Your crontab line will look something like this:
00 00 * * * ruby path/to/your/script.rb
(00 00 indicates midnight--0 minutes and 0 hours--and the *s mean every day of every month.)
Syntax:
mm hh dd mt wd command
mm minute 0-59
hh hour 0-23
dd day of month 1-...
How do I add 1 day to an NSDate?
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720
Swift 5.0 :
var dayComponent = DateComponents()
dayComponent.day = 1 // For removing...
Zooming MKMapView to fit annotation pins?
...MKMapView and have added a number of annotation pins to the map about a 5-10 kilometre area. When I run the application my map starts zoomed out to show the whole world, what is the best way to zoom the map so the pins fit the view?
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How to write asynchronous functions for Node.js
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edited Aug 1 '11 at 14:30
answered Aug 1 '11 at 13:20
Ray...