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How to sort a dataframe by multiple column(s)
...ple(order) code:
R> dd[with(dd, order(-z, b)), ]
b x y z
4 Low C 9 2
2 Med D 3 1
1 Hi A 8 1
3 Hi A 9 1
Edit some 2+ years later: It was just asked how to do this by column index. The answer is to simply pass the desired sorting column(s) to the order() function:
R> dd[order(-dd[,4],...
How do I fit an image (img) inside a div and keep the aspect ratio?
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Select random row from a sqlite table
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216
Have a look at Selecting a Random Row from an SQLite Table
SELECT * FROM table ORDER BY RANDO...
“Missing compiler required member” error being thrown multiple times with almost no changes to code
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Concatenating two lists - difference between '+=' and extend()
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The only difference on a bytecode level is that the .extend way involves a function call, whic...
How to remove single character from a String
...ccessing individual characters of a String in Java, we have String.charAt(2) . Is there any inbuilt function to remove an individual character of a String in java?
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Why isn't sizeof for a struct equal to the sum of sizeof of each member?
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What is a magic number, and why is it bad? [closed]
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answered Sep 6 '08 at 22:46
Marcio AguiarMarcio Aguiar
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Automatically expanding an R factor into a collection of 1/0 indicator variables for every factor le
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edited Jan 13 '16 at 20:13
Jaap
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answe...