Added dual versions of a few more words to math.dual.

extra/math/derivatives/derivatives.factor

@@ -1,8 +1,15 @@
 ! Copyright (C) 2009 Jason W. Merrill.
 ! See http://factorcode.org/license.txt for BSD license.
-USING: kernel math math.functions math.derivatives.syntax ;
+USING: kernel math math.functions math.derivatives.syntax 
+    math.order math.parser summary accessors make combinators ;
 IN: math.derivatives
 
+ERROR: undefined-derivative point word ;
+M: undefined-derivative summary
+    [ dup "Derivative of " % word>> name>> % 
+    " is undefined at " % point>> # "." % ]
+    "" make ;
+
 DERIVATIVE: + [ 2drop ] [ 2drop ]
 DERIVATIVE: - [ 2drop ] [ 2drop neg ]
 DERIVATIVE: * [ nip * ] [ drop * ]
@@ -12,6 +19,15 @@ DERIVATIVE: / [ nip / ] [ sq / neg * ]
 DERIVATIVE: ^ [ [ 1 - ^ ] keep * * ] 
     [ [ dup zero? ] 2dip [ 3drop 0 ] [ [ ^ ] keep log * * ] if ]
 
+DERIVATIVE: abs 
+    [ 0 <=> 
+        { 
+            { +lt+ [ neg ] } 
+            { +eq+ [ 0 \ abs undefined-derivative ] } 
+            { +gt+ [ ] } 
+        } case
+    ]
+
 DERIVATIVE: sqrt [ sqrt 2 * / ]
 
 DERIVATIVE: exp [ exp * ]
@@ -31,4 +47,7 @@ DERIVATIVE: atan [ sq 1 + / ]
 
 DERIVATIVE: asinh [ sq 1 + sqrt / ]
 DERIVATIVE: acosh [ [ 1 + sqrt ] [ 1 - sqrt ] bi * / ]
-DERIVATIVE: atanh [ sq neg 1 + / ]
+DERIVATIVE: atanh [ sq neg 1 + / ]
+
+DERIVATIVE: neg [ drop neg ]
+DERIVATIVE: recip [ sq recip neg * ]

extra/math/dual/dual-docs.factor

@@ -46,6 +46,48 @@ HELP: d^
 }
 { $description "Raise a dual number to a (possibly dual) power" } ;
 
+HELP: dabs
+{ $values
+     { "x" dual }
+     { "|x|" dual }
+}
+{ $description "Absolute value of a dual number." } ;
+
+HELP: dacosh
+{ $values
+     { "x" dual }
+     { "y" dual }
+}
+{ $description "Inverse hyberbolic cosine of a dual number." } ;
+
+HELP: dasinh
+{ $values
+     { "x" dual }
+     { "y" dual }
+}
+{ $description "Inverse hyberbolic sine of a dual number." } ;
+
+HELP: datanh
+{ $values
+     { "x" dual }
+     { "y" dual }
+}
+{ $description "Inverse hyberbolic tangent of a dual number." } ;
+
+HELP: dneg
+{ $values
+     { "x" dual }
+     { "-x" dual }
+}
+{ $description "Negative of a dual number." } ;
+
+HELP: drecip
+{ $values
+     { "x" dual }
+     { "1/x" dual }
+}
+{ $description "Reciprocal of a dual number." } ;
+
 HELP: define-dual-method
 { $values
     { "word" word }

extra/math/dual/dual-tests.factor

@@ -11,4 +11,6 @@ IN: math.dual.tests
 [ 2 1 ] [ 2 3 <dual> 1 -1 <dual> d* unpack-dual ] unit-test
 [ 1/2 -1/4 ] [ 2 1 <dual> 1 swap d/ unpack-dual ] unit-test
 [ 2 ] [ 1 1 <dual> 2 d^ epsilon-part>> ] unit-test
-[ 2.0 .25 ] [ 4 1 <dual> sqrt unpack-dual ] unit-test
+[ 2.0 .25 ] [ 4 1 <dual> sqrt unpack-dual ] unit-test
+[ 2 -1 ] [ -2 1 <dual> dabs unpack-dual ] unit-test
+[ -2 -1 ] [ 2 1 <dual> dneg unpack-dual ] unit-test

extra/math/dual/dual.factor

@@ -51,9 +51,9 @@ MACRO: chain-rule ( word -- e )
 PRIVATE>
 
 MACRO: dual-op ( word -- )
-    [ '[ _ ordinary-op ] ] 
+    [ '[ _ ordinary-op ] ]
-    [ input-length '[ _ nkeep ] ] 
+    [ input-length '[ _ nkeep ] ]
-    [ '[ _ chain-rule ] ] 
+    [ '[ _ chain-rule ] ]
     tri
     '[ _ @ @ <dual> ] ;
 
@@ -64,17 +64,29 @@ MACRO: dual-op ( word -- )
 [ { sqrt exp log sin cos tan sinh cosh tanh acos asin atan }
     [ define-dual-method ] each ] with-compilation-unit
 
-! Inverse methods { asinh, acosh, atanh } are not generic, so 
+! Inverse methods { asinh, acosh, atanh } are not generic, so
 ! there is no way to specialize them for dual numbers.  However,
 ! they are defined in terms of functions that can operate on
 ! dual numbers and arithmetic methods, so if it becomes
 ! possible to make arithmetic operators work directly on dual
 ! numbers, we will get these for free.
 
-! Arithmetic methods are not generic (yet?), so we have to 
+! Arithmetic words are not generic (yet?), so we have to 
 ! define special versions of them to operate on dual numbers.
 : d+ ( x y -- x+y ) \ + dual-op ;
-: d- ( x y -- x-y ) \ - dual-op ; 
+: d- ( x y -- x-y ) \ - dual-op ;
 : d* ( x y -- x*y ) \ * dual-op ;
 : d/ ( x y -- x/y ) \ / dual-op ;
-: d^ ( x y -- x^y ) \ ^ dual-op ;
+: d^ ( x y -- x^y ) \ ^ dual-op ;
+
+: dabs ( x -- |x| ) \ abs dual-op ;
+
+! The following words are also not generic, but are defined in
+! terms of words that can operate on dual numbers and
+! arithmetic.  If it becomes possible to implement arithmetic on
+! dual numbers directly, these functions can be deleted.
+: dneg ( x -- -x ) \ neg dual-op ;
+: drecip ( x -- 1/x ) \ recip dual-op ;
+: dasinh ( x -- y ) \ asinh dual-op ;
+: dacosh ( x -- y ) \ acosh dual-op ;
+: datanh ( x -- y ) \ atanh dual-op ;