Add some more interval operations

db4
Slava Pestov 2008-07-22 01:27:39 -05:00
parent ad47abfe90
commit af09eae727
5 changed files with 112 additions and 44 deletions

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@ -14,6 +14,8 @@ ARTICLE: "math-intervals-new" "Creating intervals"
{ $subsection [-inf,a) }
{ $subsection [a,inf] }
{ $subsection (a,inf] }
"The set of all real numbers with infinities:"
{ $subsection [-inf,inf] }
"Another constructor:"
{ $subsection points>interval } ;
@ -24,16 +26,23 @@ ARTICLE: "math-intervals-arithmetic" "Interval arithmetic"
{ $subsection interval* }
{ $subsection interval/ }
{ $subsection interval/i }
{ $subsection interval-shift }
{ $subsection interval-mod }
{ $subsection interval-rem }
{ $subsection interval-min }
{ $subsection interval-max }
"Bitwise operations on intervals:"
{ $subsection interval-shift }
{ $subsection interval-bitand }
{ $subsection interval-bitor }
{ $subsection interval-bitxor }
"Unary operations on intervals:"
{ $subsection interval-1+ }
{ $subsection interval-1- }
{ $subsection interval-neg }
{ $subsection interval-bitnot }
{ $subsection interval-recip }
{ $subsection interval-2/ } ;
{ $subsection interval-2/ }
{ $subsection interval-abs } ;
ARTICLE: "math-intervals-sets" "Set-theoretic operations on intervals"
{ $subsection interval-contains? }

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@ -84,9 +84,9 @@ IN: math.intervals.tests
1 0 1 (a,b) interval-contains?
] unit-test
[ f ] [ -1 1 (a,b) -1 1 (a,b) interval/ ] unit-test
[ t ] [ -1 1 (a,b) -1 1 (a,b) interval/ [-inf,inf] = ] unit-test
[ f ] [ -1 1 (a,b) 0 1 (a,b) interval/ ] unit-test
[ t ] [ -1 1 (a,b) 0 1 (a,b) interval/ [-inf,inf] = ] unit-test
"math.ratios.private" vocab [
[ t ] [
@ -156,7 +156,7 @@ IN: math.intervals.tests
interval-contains?
] unit-test
[ f ] [ 1 100 [a,b] -1 1 [a,b] interval/i ] unit-test
[ t ] [ 1 100 [a,b] -1 1 [a,b] interval/i [-inf,inf] = ] unit-test
! Interval random tester
: random-element ( interval -- n )
@ -177,12 +177,43 @@ IN: math.intervals.tests
{ 3 [ (a,b] ] }
} case ;
: random-op ( -- pair )
: random-unary-op ( -- pair )
{
{ bitnot interval-bitnot }
{ abs interval-abs }
{ 2/ interval-2/ }
{ 1+ interval-1+ }
{ 1- interval-1- }
{ neg interval-neg }
}
"math.ratios.private" vocab [
{ recip interval-recip } suffix
] when
random ;
: unary-test ( -- ? )
random-interval random-unary-op ! 2dup . .
0 pick interval-contains? over first \ recip eq? and [
2drop t
] [
[ >r random-element ! dup .
r> first execute ] 2keep
second execute interval-contains?
] if ;
[ t ] [ 80000 [ drop unary-test ] all? ] unit-test
: random-binary-op ( -- pair )
{
{ + interval+ }
{ - interval- }
{ * interval* }
{ /i interval/i }
{ mod interval-mod }
{ rem interval-rem }
{ bitand interval-bitand }
{ bitor interval-bitor }
{ bitxor interval-bitxor }
{ shift interval-shift }
{ min interval-min }
{ max interval-max }
@ -192,8 +223,8 @@ IN: math.intervals.tests
] when
random ;
: interval-test ( -- ? )
random-interval random-interval random-op ! 3dup . . .
: binary-test ( -- ? )
random-interval random-interval random-binary-op ! 3dup . . .
0 pick interval-contains? over first { / /i } member? and [
3drop t
] [
@ -202,7 +233,7 @@ IN: math.intervals.tests
second execute interval-contains?
] if ;
[ t ] [ 40000 [ drop interval-test ] all? ] unit-test
[ t ] [ 80000 [ drop binary-test ] all? ] unit-test
: random-comparison ( -- pair )
{
@ -215,11 +246,7 @@ IN: math.intervals.tests
: comparison-test ( -- ? )
random-interval random-interval random-comparison
[ >r [ random-element ] bi@ r> first execute ] 3keep
second execute dup incomparable eq? [
2drop t
] [
=
] if ;
second execute dup incomparable eq? [ 2drop t ] [ = ] if ;
[ t ] [ 40000 [ drop comparison-test ] all? ] unit-test

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@ -36,6 +36,8 @@ C: <interval> interval
: (a,inf] ( a -- interval ) 1./0. (a,b] ; inline
: [-inf,inf] ( -- interval ) -1./0. 1./0. [a,b] ; foldable
: compare-endpoints ( p1 p2 quot -- ? )
>r over first over first r> call [
2drop t
@ -154,7 +156,7 @@ C: <interval> interval
: interval-shift-safe ( i1 i2 -- i3 )
dup to>> first 100 > [
2drop f
2drop [-inf,inf]
] [
interval-shift
] if ;
@ -172,7 +174,7 @@ C: <interval> interval
: interval-division-op ( i1 i2 quot -- i3 )
>r 0 over interval-closure interval-contains?
[ 2drop f ] r> if ; inline
[ 2drop [-inf,inf] ] r> if ; inline
: interval/ ( i1 i2 -- i3 )
[ [ / ] interval-op ] interval-division-op ;
@ -187,6 +189,25 @@ C: <interval> interval
[ [ /i ] interval-op ] interval-integer-op
] interval-division-op interval-closure ;
: interval/f ( i1 i2 -- i3 )
[ [ /f ] interval-op ] interval-division-op ;
: interval-abs ( i1 -- i2 )
interval>points [ first2 [ abs ] dip 2array ] bi@ 2array
points>interval ;
: interval-mod ( i1 i2 -- i3 )
#! Inaccurate.
[
nip interval-abs to>> first [ neg ] keep (a,b)
] interval-division-op ;
: interval-rem ( i1 i2 -- i3 )
#! Inaccurate.
[
nip interval-abs to>> first 0 swap [a,b)
] interval-division-op ;
: interval-recip ( i1 -- i2 ) 1 [a,a] swap interval/ ;
: interval-2/ ( i1 -- i2 ) -1 [a,a] interval-shift ;
@ -194,16 +215,16 @@ C: <interval> interval
SYMBOL: incomparable
: left-endpoint-< ( i1 i2 -- ? )
[ swap interval-subset? ] 2keep
[ nip interval-singleton? ] 2keep
[ from>> ] bi@ =
and and ;
[ swap interval-subset? ]
[ nip interval-singleton? ]
[ [ from>> ] bi@ = ]
2tri and and ;
: right-endpoint-< ( i1 i2 -- ? )
[ interval-subset? ] 2keep
[ drop interval-singleton? ] 2keep
[ to>> ] bi@ =
and and ;
[ interval-subset? ]
[ drop interval-singleton? ]
[ [ to>> ] bi@ = ]
2tri and and ;
: (interval<) ( i1 i2 -- i1 i2 ? )
over from>> over from>> endpoint< ;
@ -235,6 +256,27 @@ SYMBOL: incomparable
: interval>= ( i1 i2 -- ? )
swap interval<= ;
: interval-bitand ( i1 i2 -- i3 )
dup 1 [a,a] interval>= [
1 [a,a] interval- interval-rem
] [
2drop [-inf,inf]
] if ;
: interval-bitor ( i1 i2 -- i3 )
#! Inaccurate.
2dup [ 0 [a,a] interval>= ] both?
[ to>> first 0 swap [a,b] interval-intersect ]
[ 2drop [-inf,inf] ]
if ;
: interval-bitxor ( i1 i2 -- i3 )
#! Inaccurate.
2dup [ 0 [a,a] interval>= ] both?
[ nip to>> first 0 swap [a,b] ]
[ 2drop [-inf,inf] ]
if ;
: assume< ( i1 i2 -- i3 )
to>> first [-inf,a) interval-intersect ;

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@ -130,38 +130,27 @@ HELP: /
{ $see-also "division-by-zero" } ;
HELP: /i
{ $values { "x" real } { "y" real } { "z" real } }
{ $values { "x" real } { "y" real } { "z" integer } }
{ $description
"Divides " { $snippet "x" } " by " { $snippet "y" } ", truncating the result to an integer."
{ $list
"Integer division of fixnums may overflow and yield a bignum."
"Integer division of bignums always yields a bignum."
"Integer division of floats always yields a float."
"Integer division of ratios and complex numbers proceeds using the relevant mathematical rules."
}
}
{ $see-also "division-by-zero" } ;
HELP: /f
{ $values { "x" real } { "y" real } { "z" real } }
{ $values { "x" real } { "y" real } { "z" float } }
{ $description
"Divides " { $snippet "x" } " by " { $snippet "y" } ", representing the result as a floating point number."
{ $list
"Integer division of fixnums may overflow and yield a bignum."
"Integer division of bignums always yields a bignum."
"Integer division of floats always yields a float."
"Integer division of ratios and complex numbers proceeds using the relevant mathematical rules."
}
}
{ $see-also "division-by-zero" } ;
HELP: mod
{ $values { "x" integer } { "y" integer } { "z" integer } }
{ $values { "x" rational } { "y" rational } { "z" rational } }
{ $description
"Computes the remainder of dividing " { $snippet "x" } " by " { $snippet "y" } ", with the remainder being negative if " { $snippet "x" } " is negative."
{ $list
"Modulus of fixnums always yields a fixnum."
"Modulus of bignums always yields a bignum."
"Modulus of bignums always yields a bignum."
{ "Modulus of rationals always yields a rational. In this case, the remainder is computed using the formula " { $snippet "x - (x mod y) * y" } "." }
}
}
{ $see-also "division-by-zero" rem } ;
@ -254,12 +243,13 @@ HELP: recip
{ $errors "Throws an error if " { $snippet "x" } " is the integer 0." } ;
HELP: rem
{ $values { "x" integer } { "y" integer } { "z" integer } }
{ $values { "x" rational } { "y" rational } { "z" rational } }
{ $description
"Computes the remainder of dividing " { $snippet "x" } " by " { $snippet "y" } ", with the remainder always positive."
{ $list
"Modulus of fixnums always yields a fixnum."
"Modulus of bignums always yields a bignum."
"Given fixnums, always yields a fixnum."
"Given bignums, always yields a bignum."
"Given rationals, always yields a rational."
}
}
{ $see-also "division-by-zero" mod } ;

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@ -66,7 +66,7 @@ PRIVATE>
: ?1+ [ 1+ ] [ 0 ] if* ; inline
: rem ( x y -- z ) tuck mod over + swap mod ; foldable
: rem ( x y -- z ) abs tuck mod over + swap mod ; foldable
: 2^ ( n -- 2^n ) 1 swap shift ; inline