quantile-abcd ( seq qs a b c d -- quantile )

Vocabulary

math.statistics

Inputs

seq	an object
qs	an object
a	an object
b	an object
c	an object
d	an object

Outputs

quantile

an object

Definition

USING: arrays grouping kernel math math.functions math.order
sequences ;

IN: math.statistics

:: quantile-abcd ( seq qs a b c d -- quantile )
    seq qs a b quantile-indices :> indices indices
    [ [ floor 0 max ] [ ceiling seq length 1 - min ] bi 2array ]
    map concat :> index-pairs seq index-pairs kth-smallests
    2 group indices [ [ first2 ] dip c d qabcd ] 2map ;