From aed6825b4a22bb71599e568265096a78f8517858 Mon Sep 17 00:00:00 2001
From: John Benediktsson <mrjbq7@gmail.com>
Date: Mon, 30 Jul 2012 16:15:00 -0700
Subject: [PATCH] math.vectors: implement v^, v^n, n^v.

---
 basis/math/vectors/vectors-docs.factor  | 23 +++++++++++++++++++----
 basis/math/vectors/vectors-tests.factor |  4 ++++
 basis/math/vectors/vectors.factor       |  9 +++++++++
 3 files changed, 32 insertions(+), 4 deletions(-)

diff --git a/basis/math/vectors/vectors-docs.factor b/basis/math/vectors/vectors-docs.factor
index 05477952f6..0e0d05f5e9 100644
--- a/basis/math/vectors/vectors-docs.factor
+++ b/basis/math/vectors/vectors-docs.factor
@@ -9,6 +9,7 @@ ARTICLE: "math-vectors-arithmetic" "Vector arithmetic"
     v+-
     v*
     v/
+    v^
 }
 "Vector unary operations:"
 { $subsections
@@ -30,6 +31,8 @@ ARTICLE: "math-vectors-arithmetic" "Vector arithmetic"
     n+v
     v-n
     n-v
+    v^n
+    n^v
 }
 "Saturated arithmetic (only on " { $link "specialized-arrays" } "):"
 { $subsections
@@ -212,7 +215,7 @@ HELP: vtruncate
 
 HELP: n+v
 { $values { "n" "a number" } { "v" "a sequence of numbers" } { "w" "a sequence of numbers" } }
-{ $description "Adds " { $snippet "n" } " to each element of " { $snippet "u" } "." } ;
+{ $description "Adds " { $snippet "n" } " to each element of " { $snippet "v" } "." } ;
 
 HELP: v+n
 { $values { "u" "a sequence of numbers" } { "n" "a number" } { "w" "a sequence of numbers" } }
@@ -220,7 +223,7 @@ HELP: v+n
 
 HELP: n-v
 { $values { "n" "a number" } { "v" "a sequence of numbers" } { "w" "a sequence of numbers" } }
-{ $description "Subtracts each element of " { $snippet "u" } " from " { $snippet "n" } "." } ;
+{ $description "Subtracts each element of " { $snippet "v" } " from " { $snippet "n" } "." } ;
 
 HELP: v-n
 { $values { "u" "a sequence of numbers" } { "n" "a number" } { "w" "a sequence of numbers" } }
@@ -228,7 +231,7 @@ HELP: v-n
 
 HELP: n*v
 { $values { "n" "a number" } { "v" "a sequence of numbers" } { "w" "a sequence of numbers" } }
-{ $description "Multiplies each element of " { $snippet "u" } " by " { $snippet "n" } "." } ;
+{ $description "Multiplies each element of " { $snippet "v" } " by " { $snippet "n" } "." } ;
 
 HELP: v*n
 { $values { "u" "a sequence of numbers" } { "n" "a number" } { "w" "a sequence of numbers" } }
@@ -236,7 +239,7 @@ HELP: v*n
 
 HELP: n/v
 { $values { "n" "a number" } { "v" "a sequence of numbers" } { "w" "a sequence of numbers" } }
-{ $description "Divides " { $snippet "n" } " by each element of " { $snippet "u" } "." }
+{ $description "Divides " { $snippet "n" } " by each element of " { $snippet "v" } "." }
 { $errors "May throw an error if a division by zero occurs; see " { $link "division-by-zero" } "." } ;
 
 HELP: v/n
@@ -244,6 +247,14 @@ HELP: v/n
 { $description "Divides each element of " { $snippet "u" } " by " { $snippet "n" } "." }
 { $errors "May throw an error if a division by zero occurs; see " { $link "division-by-zero" } "." } ;
 
+HELP: n^v
+{ $values { "n" "a number" } { "v" "a sequence of numbers" } { "w" "a sequence of numbers" } }
+{ $description "Raises " { $snippet "n" } " to the power of each element of " { $snippet "v" } "." } ;
+
+HELP: v^n
+{ $values { "u" "a sequence of numbers" } { "n" "a number" } { "w" "a sequence of numbers" } }
+{ $description "Raises each element of " { $snippet "u" } " to the power of " { $snippet "n" } "." } ;
+
 HELP: v+
 { $values { "u" "a sequence of numbers" } { "v" "a sequence of numbers" } { "w" "a sequence of numbers" } }
 { $description "Adds " { $snippet "u" } " and " { $snippet "v" } " component-wise." } ;
@@ -276,6 +287,10 @@ HELP: v/
 { $description "Divides " { $snippet "u" } " by " { $snippet "v" } " component-wise." }
 { $errors "May throw an error if a division by zero occurs; see " { $link "division-by-zero" } "." } ;
 
+HELP: v^
+{ $values { "u" "a sequence of numbers" } { "v" "a sequence of numbers" } { "w" "a sequence of numbers" } }
+{ $description "Raises " { $snippet "u" } " to the power of " { $snippet "v" } " component-wise." } ;
+
 HELP: vmax
 { $values { "u" "a sequence of real numbers" } { "v" "a sequence of real numbers" } { "w" "a sequence of real numbers" } }
 { $description "Creates a sequence where each element is the maximum of the corresponding elements from " { $snippet "u" } " and " { $snippet "v" } "." }
diff --git a/basis/math/vectors/vectors-tests.factor b/basis/math/vectors/vectors-tests.factor
index 826bbfb68c..cfc99459b2 100644
--- a/basis/math/vectors/vectors-tests.factor
+++ b/basis/math/vectors/vectors-tests.factor
@@ -8,6 +8,10 @@ SPECIALIZED-ARRAY: int
 [ { 1 2 3 } ] [ { 2 4 6 } 2 v/n ] unit-test
 [ { 1/1 1/2 1/3 } ] [ 1 { 1 2 3 } n/v ] unit-test
 
+{ { 1 4 27 } } [ { 1 2 3 } { 1 2 3 } v^ ] unit-test
+{ { 1 4 9 } } [ { 1 2 3 } 2 v^n ] unit-test
+{ { 2 4 8 } } [ 2 { 1 2 3 } n^v ] unit-test
+
 [ 5 ] [ { 1 2 } norm-sq ] unit-test
 [ 13 ] [ { 2 3 } norm-sq ] unit-test
 
diff --git a/basis/math/vectors/vectors.factor b/basis/math/vectors/vectors.factor
index 93db261545..7dbea0cbfa 100644
--- a/basis/math/vectors/vectors.factor
+++ b/basis/math/vectors/vectors.factor
@@ -57,6 +57,15 @@ M: object v*hs+ [ * ] 2map (h+) ; inline
 GENERIC: v/ ( u v -- w )
 M: object v/ [ / ] 2map ; inline
 
+GENERIC: v^ ( u v -- w )
+M: object v^ [ ^ ] 2map ; inline
+
+GENERIC: v^n ( u n -- w )
+M: object v^n [ ^ ] curry map ; inline
+
+GENERIC: n^v ( n v -- w )
+M: object n^v [ ^ ] with map ; inline
+
 GENERIC: vavg ( u v -- w )
 M: object vavg [ + 2 / ] 2map ; inline