factor/extra/math/derivatives/derivatives.factor

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Factor

! Copyright (C) 2009 Jason W. Merrill.
! See http://factorcode.org/license.txt for BSD license.
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 * ] ;
DERIVATIVE: / [ nip / ] [ sq / neg * ] ;
! Conditional checks if the epsilon-part of the exponent is
! 0 to avoid getting float answers for integer powers.
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: e^ [ e^ * ] ;
DERIVATIVE: log [ / ] ;
DERIVATIVE: sin [ cos * ] ;
DERIVATIVE: cos [ sin neg * ] ;
DERIVATIVE: tan [ sec sq * ] ;
DERIVATIVE: sinh [ cosh * ] ;
DERIVATIVE: cosh [ sinh * ] ;
DERIVATIVE: tanh [ sech sq * ] ;
DERIVATIVE: asin [ sq neg 1 + sqrt / ] ;
DERIVATIVE: acos [ sq neg 1 + sqrt neg / ] ;
DERIVATIVE: atan [ sq 1 + / ] ;
DERIVATIVE: asinh [ sq 1 + sqrt / ] ;
DERIVATIVE: acosh [ [ 1 + sqrt ] [ 1 - sqrt ] bi * / ] ;
DERIVATIVE: atanh [ sq neg 1 + / ] ;
DERIVATIVE: neg [ drop neg ] ;
DERIVATIVE: recip [ sq recip neg * ] ;