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How to calculate the number of occurrence of a given character in each row of a column of strings?
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The stringr package provides the str_count function which seems to do what you're interested in
# Load your example data
q.data<-data.frame(number=1:3, string=c("greatgreat", "magic", "not"), stringsAsFactors = F)
library(stringr)
# Co...
Cannot truncate table because it is being referenced by a FOREIGN KEY constraint?
Using MSSQL2005, can I truncate a table with a foreign key constraint if I first truncate the child table (the table with the primary key of the FK relationship)?
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How do I set the default locale in the JVM?
... edited Jan 24 '14 at 21:49
eckes
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answered Jan 10 '12 at 19:17
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Finding duplicates in O(n) time and O(1) space
...en one of those entries will be at position A[x].
Note that it may not look O(n) at first blush, but it is - although it has a nested loop, it still runs in O(N) time. A swap only occurs if there is an i such that A[i] != i, and each swap sets at least one element such that A[i] == i, where that w...
Using column alias in WHERE clause of MySQL query produces an error
...umentation
As pointed in the comments, using HAVING instead may do the work. Make sure to give a read at this WHERE vs HAVING though.
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Why does auto a=1; compile in C?
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auto is an old C keyword that means "local scope". auto a is the same as auto int a, and because local scope is the default for a variable declared inside a function, it's also the same as int a in this example.
This keyword is actually a le...
How do I invert BooleanToVisibilityConverter?
...WPF to bind the Visibility property of a control to a Boolean . This works fine, but I'd like one of the controls to hide if the boolean is true , and show if it's false .
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What is the rationale behind having companion objects in Scala?
...he companion object basically provides a place where one can put "static-like" methods. Furthermore, a companion object, or companion module, has full access to the class members, including private ones.
Companion objects are great for encapsulating things like factory methods. Instead of having to...
How do I attach events to dynamic HTML elements with jQuery? [duplicate]
...ument.
See http://api.jquery.com/on/
So instead of...
$(".myclass").click( function() {
// do something
});
You can write...
$('body').on('click', 'a.myclass', function() {
// do something
});
This will work for all a tags with 'myclass' in the body, whether already present or dynami...
Is there a label/goto in Python?
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unwindunwind
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