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Summarizing multiple columns with dplyr? [duplicate]
...ta frame with different variables and one grouping variable. Now I want to calculate the mean for each column within each group, using dplyr in R.
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How to align absolutely positioned element to center?
I am trying to stack two canvas together and make it a double layers canvas.
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sizeof single struct member in C
I am trying to declare a struct that is dependent upon another struct.
I want to use sizeof to be safe/pedantic.
9 Answer...
PowerShell: Setting an environment variable for a single command only
On Linux, I can do:
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How to remove the first Item from a list?
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Class method differences in Python: bound, unbound and static
What is the difference between the following class methods?
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Installing Ruby Gem in Windows
I'm new to ruby. I tried to install GEM on my PC by following the steps given in the site http://rubygems.org/pages/download .
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What's the difference between HEAD^ and HEAD~ in Git?
When I specify an ancestor commit object in Git, I'm confused between HEAD^ and HEAD~ .
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Do zombies exist … in .NET?
I was having a discussion with a teammate about locking in .NET. He's a really bright guy with an extensive background in both lower-level and higher-level programming, but his experience with lower level programming far exceeds mine. Anyway, He argued that .NET locking should be avoided on critic...
What is the __del__ method, How to call it?
I am reading a code. There is a class in which __del__ method is defined. I figured out that this method is used to destroy an instance of the class. However, I cannot find a place where this method is used. The main reason for that is that I do not know how this method is used, probably not like ...