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R - Concatenate two dataframes?
...ine adds column b to data frame b.
Results
> a <- data.frame(a=c(0,1,2), b=c(3,4,5), c=c(6,7,8))
> a
a b c
1 0 3 6
2 1 4 7
3 2 5 8
> b <- data.frame(a=c(9,10,11), c=c(12,13,14))
> b
a c
1 9 12
2 10 13
3 11 14
> b$b <- NA
> b
a c b
1 9 12 NA
2 10 13 NA
3 11 1...
Why is rbindlist “better” than rbind?
...
156
rbindlist is an optimized version of do.call(rbind, list(...)), which is known for being slow ...
What is the difference between ~> and >= when specifying rubygem in Gemfile?
...
166
That's a pessimistic version constraint. RubyGems will increment the last digit in the version...
python tuple to dict
For the tuple, t = ((1, 'a'),(2, 'b'))
dict(t) returns {1: 'a', 2: 'b'}
6 Answers
...
bool operator ++ and --
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91
It comes from the history of using integer values as booleans.
If x is an int, but I am using it...
What's the difference between eval, exec, and compile?
...ed as an expression, so it really does not return anything).
In versions 1.0 - 2.7, exec was a statement, because CPython needed to produce a different kind of code object for functions that used exec for its side effects inside the function.
In Python 3, exec is a function; its use has no effec...
how do I work around log4net keeping changing publickeytoken
...ct which uses a couple of frameworks which is dependent on log4net version 1.2.10.0. Today I tried to include a new framework which is dependent on log4net version 1.2.11.0, I've been stuck ever since:
...
Ruby max integer
...ize
machine_bits = machine_bytes * 8
machine_max_signed = 2**(machine_bits-1) - 1
machine_max_unsigned = 2**machine_bits - 1
If you are looking for the size of Fixnum objects (integers small enough to store in a single machine word), you can call 0.size to get the number of bytes. I would guess ...
Regular expression search replace in Sublime Text 2
...
Usually a back-reference is either $1 or \1 (backslash one) for the first capture group (the first match of a pattern in parentheses), and indeed Sublime supports both syntaxes. So try:
my name used to be \1
or
my name used to be $1
Also note that your or...
How can I create a correlation matrix in R?
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104
An example,
d &lt- data.frame(x1=rnorm(10),
x2=rnorm(10),
...