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Repeat each row of data.frame the number of times specified in a column
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Here's one solution:
df.expanded <- df[rep(row.names(df), df$freq), 1:2]
Result:
var1 var2
1 a d
2 b e
2.1 b e
3 c f
3.1 c f
3.2 c f
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How to get the current time in Python
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42 Answers
42
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Xcode 4.5 Storyboard 'Exit'
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72
This is called an "Unwind Segue". Unfortunately there's no documentation for this so far except ...
What is a good regular expression to match a URL? [duplicate]
...e URL starts with HTTP/HTTPS:
https?:\/\/(www\.)?[-a-zA-Z0-9@:%._\+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}\b([-a-zA-Z0-9()@:%_\+.~#?&//=]*)
If you do not require HTTP protocol:
[-a-zA-Z0-9@:%._\+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}\b([-a-zA-Z0-9()@:%_\+.~#?&//=]*)
To try this out see http://regexr....
How to stop /#/ in browser with react-router?
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For the versions 1, 2 and 3 of react-router, the correct way to set the route to URL mapping scheme is by passing a history implementation into the history parameter of <Router>. From the histories documentation:
In a nutshell, a histo...
Multiple cases in switch statement
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326
There is no syntax in C++ nor C# for the second method you mentioned.
There's nothing wrong w...
How to get duplicate items from a list using LINQ? [duplicate]
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240
var duplicates = lst.GroupBy(s => s)
.SelectMany(grp => grp.Skip(1));
Note that th...
How to call a method after bean initialization is complete?
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edited Apr 12 '13 at 9:38
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Convert XML String to Object
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280
You need to use the xsd.exe tool which gets installed with the Windows SDK into a directory so...
How to access the ith column of a NumPy multidimensional array?
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724
>>> test[:,0]
array([1, 3, 5])
Similarly,
>>> test[1,:]
array([3, 4])
l...