use reject instead of [ ... not ] filter.

[factor.git] / basis / math / matrices / elimination / elimination.factor

diff --git a/basis/math/matrices/elimination/elimination.factor b/basis/math/matrices/elimination/elimination.factor
old mode 100755 (executable)
new mode 100644 (file)
index 8411447..168274a
--- a/basis/math/matrices/elimination/elimination.factor
+++ b/basis/math/matrices/elimination/elimination.factor
@@ -1,17 +1,17 @@
-! Copyright (C) 2006, 2008 Slava Pestov.
+! Copyright (C) 2006, 2010 Slava Pestov.
 ! See http://factorcode.org/license.txt for BSD license.
-USING: kernel math math.vectors math.matrices namespaces
-sequences ;
+USING: kernel locals math math.vectors math.matrices
+namespaces sequences fry sorting ;
 IN: math.matrices.elimination
 
 SYMBOL: matrix
 
 : with-matrix ( matrix quot -- )
-    [ swap matrix set call matrix get ] with-scope ; inline
+    matrix swap [ matrix get ] compose with-variable ; inline
 
 : nth-row ( row# -- seq ) matrix get nth ;
 
-: change-row ( row# quot: ( seq -- seq ) -- )
+: change-row ( ..a row# quot: ( ..a seq -- ..b seq ) -- ..b )
     matrix get swap change-nth ; inline
 
 : exchange-rows ( row# row# -- ) matrix get exchange ;
@@ -42,7 +42,7 @@ SYMBOL: matrix
     [ [ clear-scale ] 2keep [ n*v ] dip v+ ] change-row ;
 
 : rows-from ( row# -- slice )
-    rows dup <slice> ;
+    rows dup iota <slice> ;
 
 : clear-col ( col# row# rows -- )
     [ nth-row ] dip [ [ 2dup ] dip (clear-col) ] each 2drop ;
@@ -70,7 +70,7 @@ SYMBOL: matrix
     [ 0 0 (echelon) ] with-matrix ;
 
 : nonzero-rows ( matrix -- matrix' )
-    [ [ zero? ] all? not ] filter ;
+    [ [ zero? ] all? ] reject ;
 
 : null/rank ( matrix -- null rank )
     echelon dup length swap nonzero-rows length [ - ] keep ;
@@ -79,18 +79,17 @@ SYMBOL: matrix
 
 : reduced ( matrix' -- matrix'' )
     [
-        rows <reversed> [
+        rows iota <reversed> [
             dup nth-row leading drop
-            dup [ swap dup clear-col ] [ 2drop ] if
+            dup [ swap dup iota clear-col ] [ 2drop ] if
         ] each
     ] with-matrix ;
 
-: basis-vector ( row col# -- )
-    [ clone ] dip
-    [ swap nth neg recip ] 2keep
-    [ 0 spin set-nth ] 2keep
-    [ n*v ] dip
-    matrix get set-nth ;
+:: basis-vector ( row col# -- )
+    row clone :> row'
+    col# row' nth neg recip :> a
+    0 col# row' set-nth
+    a row n*v col# matrix get set-nth ;
 
 : nullspace ( matrix -- seq )
     echelon reduced dup empty? [