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いろいろ勉強用備忘録的な感じ

pythonとhaskell, perl6で加重平均

python
最後はnumpyの内積(ドット積)を使っている(ずるい?)

>>> weight = [ 0.22, 0.14, 0.04, 0.12, 0.22, 0.26 ]
>>> record = [ 64, 51, 132, 24, 19, 11 ]
>>> sum( a * x for (a, x) in zip(weight, record) )
36.42
>>> sum(map(lambda a, x: a * x, weight, record))
36.42
>>> import operator as op
>>> sum(map(op.mul, weight, record))
36.42
>>> import numpy as np
>>> np.dot(weight, record)
36.420000000000002

haskell

Prelude> let weight = [ 0.22, 0.14, 0.04, 0.12, 0.22, 0.26 ]
Prelude> let record = [ 64, 51, 132, 24, 19, 11 ]
Prelude> sum $ zipWith (*) weight record
36.42


perl6も面白い。

> my @weight = 0.22, 0.14, 0.04, 0.12, 0.22, 0.26
[0.22 0.14 0.04 0.12 0.22 0.26]
> my @record = 64, 51, 132, 24, 19, 11
[64 51 132 24 19 11]
> [+] @weight >>*<< @record
36.42