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dplyr summarise: Equivalent of “.drop=FALSE” to keep groups with zero length in output
...e to go with @Moody_Mudskipper's answer: Using .drop=FALSE can give potentially unexpected results when one or more grouping variables are not coded as factors. See examples below:
library(dplyr)
data(iris)
# Add an additional level to Species
iris$Species = factor(iris$Species, levels=c(levels(ir...
How to use bootstrap-theme.css with bootstrap 3?
...bootstrap-theme.css file:
"Load the optional Bootstrap theme for a visually enhanced experience."
The above quote is found here http://getbootstrap.com/getting-started/#examples on a thumbnail that links to this example page http://getbootstrap.com/examples/theme/. The idea is that bootstrap-t...
What is an NP-complete in computer science?
...ng machine but also including a non-deterministic "choice" function). Basically, a solution has to be testable in poly time. If that's the case, and a known NP problem can be solved using the given problem with modified input (an NP problem can be reduced to the given problem) then the problem is NP...
How to do Mercurial's 'hg remove' for all missing files?
...
This will add all new files that are not ignored, and remove all locally missing files
hg addremove
Either of these will remove all locally missing files(They are the same command)
hg remove --after
hg remove -A
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Passing arguments to “make run”
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What's a macro? Isn't that what people call environment variables? What's the difference between a macro and an environment variable?
– KcFnMi
Aug 12 at 23:05
...
File being used by another process after using File.Create()
...pens a FileStream on the file. So your file is already open. You don't really need the file.Create method at all:
string filePath = @"c:\somefilename.txt";
using (StreamWriter sw = new StreamWriter(filePath, true))
{
//write to the file
}
The boolean in the StreamWriter constructor will cau...
Design Pattern for Undo Engine
...this. Every user-action that's undoable gets its own command instance with all the information to execute the action and roll it back. You can then maintain a list of all the commands that have been executed and you can roll them back one by one.
...
How do I get the backtrace for all the threads in GDB?
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Generally, the backtrace is used to get the stack of the current thread, but if there is a necessity to get the stack trace of all the threads, use the following command.
thread apply all bt
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Select all contents of textbox when it receives focus (Vanilla JS or jQuery)
What is a Vanilla JS or jQuery solution that will select all of the contents of a textbox when the textbox receives focus?
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What's the difference between “Layers” and “Tiers”?
...on a single
computer or even in a single process
on a single computer. All we are doing
is discussing a way of organizing a
code into a set of layers defined by
specific function.
Physical tiers however, are only about
where the code runs. Specifically,
tiers are places where laye...