math.extras: adding nonzero.

2012-06-19 14:23:00 -07:00 · 2012-06-19 14:23:00 -07:00 · 314dc05ab0
parent 03cd8c288d
commit 314dc05ab0
2 changed files with 6 additions and 0 deletions
--- a/extra/math/extras/extras-tests.factor
+++ b/extra/math/extras/extras-tests.factor
@ -20,3 +20,6 @@ IN: math.extras.test
 [ 10 [1,b] 2 exponential-moving-average ] unit-test

 { { 2 5 5 4 3 } } [ { 1 2 5 6 1 4 3 } 3 moving-median ] unit-test
+
+{ { } } [ { 0 0 } nonzero ] unit-test
+{ { 1 2 3 } } [ { 0 1 0 2 0 3 0 } nonzero ] unit-test
--- a/extra/math/extras/extras.factor
+++ b/extra/math/extras/extras.factor
@ -94,3 +94,6 @@ PRIVATE>

 : moving-median ( u n -- v )
    <clumps> [ median ] map ;
+
+: nonzero ( seq -- seq' )
+    [ zero? not ] filter ;