math.statistics: adding interquartile-range, midhinge, and fivenum.

diff --git a/basis/math/statistics/statistics-tests.factor b/basis/math/statistics/statistics-tests.factor
index 5c323f0b2a0c2bcadfa44f3d33911a8e3e6142ba..dd023412321623040e538c57a3d349e67986c2c7 100644 (file)
--- a/basis/math/statistics/statistics-tests.factor
+++ b/basis/math/statistics/statistics-tests.factor
@@ -48,7 +48,6 @@ FROM: math.ranges => [a,b] ;
 { 3 } [ { 1 2 3 4 5 } lower-median ] unit-test
 { 3 } [ { 1 2 3 4 5 } upper-median ] unit-test
 
-
 { 1 } [ { 1 } lower-median ] unit-test
 { 1 } [ { 1 } upper-median ] unit-test
 { 1 } [ { 1 } median ] unit-test
@@ -162,6 +161,10 @@ FROM: math.ranges => [a,b] ;
     { 18.9375 40.0 42.8125 } .00001 v~
 ] unit-test
 
+{ 75 } [
+    { 7 7 31 31 47 75 87 115 116 119 119 155 177 } midhinge
+] unit-test
+
 { 0x1.02eb63cff3f8p0 } [ { 1 2 3 } entropy ] unit-test
 
 { 1.0 } [ 0.5 binary-entropy ] unit-test

diff --git a/basis/math/statistics/statistics.factor b/basis/math/statistics/statistics.factor
index 32e0ce184ed0ceeb75d19afd9097d666826b269c..4950dd983cb5750762c7634cc8155274f719f1ac 100644 (file)
--- a/basis/math/statistics/statistics.factor
+++ b/basis/math/statistics/statistics.factor
@@ -201,6 +201,15 @@ PRIVATE>
 : quartile ( seq -- seq' )
     { 1/4 1/2 3/4 } quantile5 ;
 
+: interquartile ( seq -- q1 q3 )
+    quartile [ first ] [ last ] bi ;
+
+: interquartile-range ( seq -- n )
+    interquartile - ;
+
+: midhinge ( seq -- n )
+    interquartile + 2 / ;
+
 : trimean ( seq -- x )
     quartile first3 [ 2 * ] dip + + 4 / ;
 
@@ -231,6 +240,9 @@ PRIVATE>
 : range ( seq -- x )
     minmax swap - ;
 
+: fivenum ( seq -- seq' )
+    [ quartile ] [ minmax ] bi [ prefix ] [ suffix ] bi* ;
+
 : var-ddof ( seq n -- x )
     2dup [ length ] dip - 0 <= [
         2drop 0