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dplyr summarise: Equivalent of “.drop=FALSE” to keep groups with zero length in output
When using summarise with plyr 's ddply function, empty categories are dropped by default. You can change this behavior by adding .drop = FALSE . However, this doesn't work when using summarise with dplyr . Is there another way to keep empty categories in the result?
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Boolean operators && and ||
According to the R language definition , the difference between & and && (correspondingly | and || ) is that the former is vectorized while the latter is not.
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Is a statically-typed full Lisp variant possible?
Is a statically-typed full Lisp variant possible? Does it even make sense for something like this to exist? I believe one of a Lisp language's virtues is the simplicity of its definition. Would static typing compromise this core principle?
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Python: Checking if a 'Dictionary' is empty doesn't seem to work
I am trying to check if a dictionary is empty but it doesn't behave properly. It just skips it and displays ONLINE without anything except of display the message. Any ideas why ?
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Difference between Pragma and Cache-Control headers?
I read about Pragma header on Wikipedia which says:
3 Answers
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Using -performSelector: vs. just calling the method
I'm still kind of new to Objective-C and I'm wondering what is the difference between the following two statements?
5 Answe...
Remove duplicate values from JS array [duplicate]
I have a very simple JavaScript array that may or may not contain duplicates.
54 Answers
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What's the strangest corner case you've seen in C# or .NET? [closed]
I collect a few corner cases and brain teasers and would always like to hear more. The page only really covers C# language bits and bobs, but I also find core .NET things interesting too. For example, here's one which isn't on the page, but which I find incredible:
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Python executable not finding libpython shared library
I am installing Python 2.7 on CentOS 5. I built and installed Python as follows
9 Answers
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Is it bad practice to have a constructor function return a Promise?
I'm trying to create a constructor for a blogging platform and it has many async operations going on inside. These range from grabbing the posts from directories, parsing them, sending them through template engines, etc.
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