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Does order of where clauses matter in SQL?
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marc_smarc_s
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Reading InputStream as UTF-8
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edited Apr 16 '15 at 9:47
tobijdc
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answered Feb...
Order data frame rows according to vector with specific order
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Try match:
df <- data.frame(name=letters[1:4], value=c(rep(TRUE, 2), rep(FALSE, 2)))
target <- c("b", "c", "a", "d")
df[match(target, df$name),]
name value
2 b TRUE
3 c FALSE
1 a TRUE
4 d FALSE
It will work as long as your target contains exactly...
How to add an extra column to a NumPy array
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b = np.zeros((N,N+1))
b[:,:-1] = a
And timings:
In [23]: N = 10
In [24]: a = np.random.rand(N,N)
In [25]: %timeit b = np.hstack((a,np.zeros((a.shape[0],1))))
10000 loops, best of 3: 19.6 us per loop
In [27]: %timeit b = np.zeros((a.shape[0],a.shape[1]+1)); b[:,:-1] = a
100000 loops, best of ...
Aligning a float:left div to center?
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answered Apr 2 '11 at 14:12
clairesuzyclairesuzy
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Why does “,,,” == Array(4) in Javascript?
...d operand is converted to a string and the string representation of Array(4) is ,,,:
> Array(4).toString()
",,,"
If you use the array constructor function and pass a number, it sets the length of the array to that number. So you can say you have four empty indexes (same as [,,,]) and the de...
Installing specific laravel version with composer create-project
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From the composer help create-project command
The create-project command creates a new proj...
Sorting data based on second column of a file
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