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Formatting floats without trailing zeros
...rtelli
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How can I check which version of Angular I'm using?
...26
Kabb5
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answered Apr 15 '13 at 14:35
TheHippoTheHippo...
Fastest way to check if a string matches a regexp in ruby?
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answered Mar 16 '17 at 12:30
Wiktor StribiżewWiktor Stribiżew
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Apply a function to every row of a matrix or a data frame
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You simply use the apply() function:
R> M <- matrix(1:6, nrow=3, byrow=TRUE)
R> M
[,1] [,2]
[1,] 1 2
[2,] 3 4
[3,] 5 6
R> apply(M, 1, function(x) 2*x[1]+x[2])
[1] 4 10 16
R>
This takes a matrix and applies a (silly) function to each row. You pass extr...
What are the mathematical/computational principles behind this game?
...nd you have the question:
Can we have a geometry with just 2 points? With 3 points? With 4? With 7?
There are still open questions regarding this problem but we do know this:
If there are geometries with Q points, then Q = n^2 + n + 1 and n is called the order of the geometry.
There are n+1 poin...
What's the fastest way to merge/join data.frames in R?
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DF1 = data.frame(a = c(1, 1, 2, 2), b = 1:4)
DF2 = data.frame(b = c(1, 2, 3, 3, 4), c = letters[1:5])
merge(DF1, DF2)
b a c
1 1 1 a
2 2 1 b
3 3 2 c
4 3 2 d
5 4 2 e
DF1$c = DF2$c[match(DF1$b, DF2$b)]
DF1$c
[1] a b c e
Levels: a b c d e
> DF1
a b c
1 1 1 a
2 1 2 b
3 2 3 c
4 2 4 e
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How to use a decimal range() step value?
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33 Answers
33
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how to convert array values from string to int?
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edited Apr 23 '19 at 10:46
Rahul
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a...
Output data from all columns in a dataframe in pandas [duplicate]
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Erel Segal-Halevi
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answered Nov 5 '12 at 18:13
YarivYariv
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Drop rows with all zeros in pandas data frame
...0,1,0,1]})
> df = df[(df.T != 0).any()]
> df
a b
1 0 1
2 1 0
3 1 1
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