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Is there an R function for finding the index of an element in a vector?
In R, I have an element x and a vector v . I want to find the first index of an element in v that is equal to x . I know that one way to do this is: which(x == v)[[1]] , but that seems excessively inefficient. Is there a more direct way to do it?
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Getting the filenames of all files in a folder [duplicate]
... edited Jul 24 '18 at 7:27
Andrei Suvorkov
4,91144 gold badges1515 silver badges3535 bronze badges
answered Apr 17 '11 at 15:31
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List of Big-O for PHP functions
...ght it'd be good idea to have it for reference somewhere. I've gone though and either via benchmark or code-skimming to characterize the array_* functions. I've tried to put the more interesting Big-O near the top. This list is not complete.
Note: All the Big-O where calculated assuming a hash look...
How to concatenate columns in a Postgres SELECT?
I have two string columns a and b in a table foo .
8 Answers
8
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Scala best way of turning a Collection into a Map-by-key?
If I have a collection c of type T and there is a property p on T (of type P , say), what is the best way to do a map-by-extracting-key ?
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Delete all files in directory (but not directory) - one liner solution
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import org.apache.commons.io.FileUtils;
FileUtils.cleanDirectory(directory);
There is this method available in the same file. This will also recursively deletes all sub-folders and files under them.
Docs: org.apache.commons.io.FileUtils.cleanDirectory
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“The remote certificate is invalid according to the validation procedure.” using Gmail SMTP server
...ew MMC.
File --> Add/Remove Snap-In...
Click Add...
Choose Certificates and click Add.
Check the "Computer Account" radio button. Click Next.
Choose the client computer in the next screen. Click Finish.
Click Close.
Click OK.
NOW install the certificate into the Trusted Root Certification Author...
Question mark (?) in XML attributes for Android
Can anyone explain the question mark means in Android XML attributes?
2 Answers
2
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Are there legitimate uses for JavaScript's “with” statement?
...nking. I've seldom found a reason to use this particular language feature, and had never given much thought to how it might cause trouble. Now, I'm curious as to how I might make effective use of with , while avoiding its pitfalls.
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Rails new vs create
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Within Rails' implementation of REST new and create are treated differently.
An HTTP GET to /resources/new is intended to render a form suitable for creating a new resource, which it does by calling the new action within the controller, which creates a new unsaved...