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R - Concatenate two dataframes?
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You want "rbind".
b$b <- NA
new <- rbind(a, b)
rbind requires the data frames to have the same columns.
The first line adds column b to data frame b.
Results
> a <- data.frame(a=c(0,1,2), b=c(3,4,5), c=c(6,7,8))
> a
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How to create a loop in bash that is waiting for a webserver to respond?
How to create a loop in bash that is waiting for a webserver to respond?
6 Answers
6
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Is there anything like .NET's NotImplementedException in Java?
Is there anything like .NET's NotImplementedException in Java?
5 Answers
5
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Running multiple commands in one line in shell
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You are using | (pipe) to direct the output of a command into another command. What you are looking for is && operator to execute the next command only if the previous one succeeded:
cp /templates/apple /templates/used &&a...
Can you 'exit' a loop in PHP?
I have a loop that is doing some error checking in my PHP code. Originally it looked something like this...
6 Answers
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Observer Design Pattern vs “Listeners”
It seems to me that the Observer design pattern as described in GOF is really the same thing as Listeners found in various toolkits. Is there a difference between the concepts, or are Listeners and Observers really the same thing.
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What's the equivalent for eclipse's ALT+UP/DOWN (move line) in Visual Studio?
In Eclipse, selecting a line and pressing Alt + ↑ / ↓ will move the line up and down, a quick way to avoid copy&paste.
Is there an equivalent in Visual Studio?
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What is the difference between Spring's GA, RC and M2 releases?
Spring's 3.0 version is now GA release, before that they have launched 3.0 RC1 , RC2 version Also, there was Spring 3.0 M2 version. What's the difference between GA, RC, M versions?
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What is the difference between gsub and sub methods for Ruby Strings
I have been perusing the documentation for String today, and I saw the :sub method, which I'd never noticed before. I've been using :gsub and it appears that they are essentially the same. Can anyone explain the difference to me? Thanks!
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How can I make gdb save the command history?
How can I set up gdb so that it saves the command history? When starting a new gdb session I'd like to use the arrow up keys to access the commands of the previous sessions.
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