steve
/
factor
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

math.extras: Faster gini. Leaving this as a separate patch for comparison.

db4
Doug Coleman 2012-09-25 17:52:27 -07:00
parent 59e97e1587
commit d5e26ee76d
1 changed files with 6 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
extra/math/extras/extras.factor
View File

@ -4,7 +4,7 @@
USING: combinators.short-circuit grouping kernel locals math USING: combinators.short-circuit grouping kernel locals math
math.combinatorics math.constants math.functions math.order math.combinatorics math.constants math.functions math.order
math.primes math.ranges math.statistics math.vectors memoize math.primes math.ranges math.statistics math.vectors memoize
sequences sequences.extras sorting assocs ; sequences sequences.extras sorting assocs fry ;
IN: math.extras IN: math.extras
@ -160,9 +160,11 @@ PRIVATE>
:: (gini) ( seq -- x ) :: (gini) ( seq -- x )
seq natural-sort :> sorted seq natural-sort :> sorted
seq length :> len seq length :> len
len [1,b] sorted zip 0 [ * + ] assoc-reduce :> sum0 0 0 sorted [
2 sum0 * sorted sum len * / :> G '[ _ + ] dip dupd +
G 1 - 1 len / - ; inline ] each :> ( a b )
b len a * / :> B
1 len recip + 2 B * - ;
PRIVATE> PRIVATE>