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cartesian product in pandas
...f1, df2,on='key')[['col1', 'col2', 'col3']]
Output:
col1 col2 col3
0 1 3 5
1 1 3 6
2 2 4 5
3 2 4 6
See here for the documentation: http://pandas.pydata.org/pandas-docs/stable/merging.html#brief-primer-on-merge-methods-relational-algebra
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How to sort an array in descending order in Ruby
...Here's what I found out:
#!/usr/bin/ruby
require 'benchmark'
ary = []
1000.times {
ary << {:bar => rand(1000)}
}
n = 500
Benchmark.bm(20) do |x|
x.report("sort") { n.times { ary.sort{ |a,b| b[:bar] <=> a[:bar] } } }
x.report("sort reverse") { n.times {...
Difference between numpy.array shape (R, 1) and (R,)
...required. For example, given a matrix M , if we want to do numpy.dot(M[:,0], numpy.ones((1, R))) where R is the number of rows (of course, the same issue also occurs column-wise). We will get matrices are not aligned error since M[:,0] is in shape (R,) but numpy.ones((1, R)) is in shape...
Convert light frequency to RGB?
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answered Sep 24 '09 at 15:47
Stephen MesaStephen Mesa
4,31333 gold badges2121 silver badges1616 bronze badges
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Convert pandas dataframe to NumPy array
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409
To convert a pandas dataframe (df) to a numpy ndarray, use this code:
df.values
array([[nan, ...
jQuery animate backgroundColor
... g.elem.style[e] = "rgb(" + [Math.max(Math.min(parseInt((g.pos * (g.end[0] - g.start[0])) + g.start[0]), 255), 0), Math.max(Math.min(parseInt((g.pos * (g.end[1] - g.start[1])) + g.start[1]), 255), 0), Math.max(Math.min(parseInt((g.pos * (g.end[2] - g.start[2])) + g.start[2]), 255), 0)].join(",") ...
RegEx for matching UK Postcodes
...nition given.
The RegEx supplied by the UK Government was:
([Gg][Ii][Rr] 0[Aa]{2})|((([A-Za-z][0-9]{1,2})|(([A-Za-z][A-Ha-hJ-Yj-y][0-9]{1,2})|(([A-Za-z][0-9][A-Za-z])|([A-Za-z][A-Ha-hJ-Yj-y][0-9][A-Za-z]?))))\s?[0-9][A-Za-z]{2})
As pointed out on the Wikipedia discussion, this will allow some no...
how does multiplication differ for NumPy Matrix vs Array classes?
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Neil G
27.5k3030 gold badges127127 silver badges228228 bronze badges
answered Oct 8 '10 at 16:49
Joe KingtonJoe Ki...
How to increase the gap between text and underlining in CSS
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370
No, but you could go with something like border-bottom: 1px solid #000 and padding-bottom: 3px.
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