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Diffstat (limited to 'MDK/Common/Math.pm')
| -rw-r--r-- | MDK/Common/Math.pm | 197 |
1 files changed, 0 insertions, 197 deletions
diff --git a/MDK/Common/Math.pm b/MDK/Common/Math.pm deleted file mode 100644 index 5ed9a61..0000000 --- a/MDK/Common/Math.pm +++ /dev/null @@ -1,197 +0,0 @@ -package MDK::Common::Math; - -=head1 NAME - -MDK::Common::Math - miscellaneous math functions - -=head1 SYNOPSIS - - use MDK::Common::Math qw(:all); - -=head1 EXPORTS - -=over - -=item $PI - -the well-known constant - -=item even(INT) - -=item odd(INT) - -is the number even or odd? - -=item sqr(FLOAT) - -C<sqr(3)> gives C<9> - -=item sign(FLOAT) - -returns a value in { -1, 0, 1 } - -=item round(FLOAT) - -C<round(1.2)> gives C<1>, C<round(1.6)> gives C<2> - -=item round_up(FLOAT, INT) - -returns the number rounded up to the modulo: -C<round_up(11,10)> gives C<20> - -=item round_down(FLOAT, INT) - -returns the number rounded down to the modulo: -C<round_down(11,10)> gives C<10> - -=item divide(INT, INT) - -integer division (which is lacking in perl). In array context, also returns the remainder: -C<($a, $b) = divide(10,3)> gives C<$a is 3> and C<$b is 1> - -=item min(LIST) - -=item max(LIST) - -returns the minimum/maximum number in the list - -=item or_(LIST) - -is there a true value in the list? - -=item and_(LIST) - -are all values true in the list? - -=item sum(LIST) - -=item product(LIST) - -returns the sum/product of all the element in the list - -=item factorial(INT) - -C<factorial(4)> gives C<24> (4*3*2) - -=back - -=head1 OTHER - -the following functions are provided, but not exported: - -=over - -=item factorize(INT) - -C<factorize(40)> gives C<([2,3], [5,1])> as S<40 = 2^3 + 5^1> - -=item decimal2fraction(FLOAT) - -C<decimal2fraction(1.3333333333)> gives C<(4, 3)> -($PRECISION is used to decide which precision to use) - -=item poly2(a,b,c) - -Solves the a*x2+b*x+c=0 polynomial: -C<poly2(1,0,-1)> gives C<(1, -1)> - -=item permutations(n,p) - -A(n,p) - -=item combinaisons(n,p) - -C(n,p) - -=back - -=head1 SEE ALSO - -L<MDK::Common> - -=cut - - -use Exporter; -our @ISA = qw(Exporter); -our @EXPORT_OK = qw($PI even odd sqr sign round round_up round_down divide min max or_ and_ sum product factorial); -our %EXPORT_TAGS = (all => [ @EXPORT_OK ]); - - -our $PRECISION = 10; -our $PI = 3.1415926535897932384626433832795028841972; - -sub even { $_[0] % 2 == 0 } -sub odd { $_[0] % 2 == 1 } -sub sqr { $_[0] * $_[0] } -sub sign { $_[0] <=> 0 } -sub round { int($_[0] + 0.5) } -sub round_up { my ($i, $r) = @_; $i = int $i; $i += $r - ($i + $r - 1) % $r - 1 } -sub round_down { my ($i, $r) = @_; $i = int $i; $i -= $i % $r } -sub divide { my $d = int $_[0] / $_[1]; wantarray() ? ($d, $_[0] % $_[1]) : $d } -sub min { my $n = shift; $_ < $n and $n = $_ foreach @_; $n } -sub max { my $n = shift; $_ > $n and $n = $_ foreach @_; $n } -sub or_ { my $n = 0; $n ||= $_ foreach @_; $n } -sub and_ { my $n = 1; $n &&= $_ foreach @_; $n } -sub sum { my $n = 0; $n += $_ foreach @_; $n } -sub product { my $n = 1; $n *= $_ foreach @_; $n } - - -sub factorize { - my ($n) = @_; - my @r; - - $n == 1 and return [ 1, 1 ]; - for (my $k = 2; sqr($k) <= $n; $k++) { - my $i = 0; - for ($i = 0; $n % $k == 0; $i++) { $n /= $k } - $i and push @r, [ $k, $i ]; - } - $n > 1 and push @r, [ $n, 1 ]; - @r; -} - -sub decimal2fraction { # ex: 1.33333333 -> (4, 3) - my $n0 = shift; - my $precision = 10 ** -(shift || $PRECISION); - my ($a, $b) = (int $n0, 1); - my ($c, $d) = (1, 0); - my $n = $n0 - int $n0; - my $k; - until (abs($n0 - $a / $c) < $precision) { - $n = 1 / $n; - $k = int $n; - ($a, $b) = ($a * $k + $b, $a); - ($c, $d) = ($c * $k + $d, $c); - $n -= $k; - } - ($a, $c); -} - -sub poly2 { - my ($a, $b, $c) = @_; - my $d = ($b**2 - 4 * $a * $c) ** 0.5; - (-$b + $d) / 2 / $a, (-$b - $d) / 2 / $a; -} - -# A(n,p) -sub permutations { - my ($n, $p) = @_; - my ($r, $i); - for ($r = 1, $i = 0; $i < $p; $i++) { - $r *= $n - $i; - } - $r; -} - -# C(n,p) -sub combinaisons { - my ($n, $p) = @_; - - permutations($n, $p) / factorial($p); -} - -sub factorial { permutations($_[0], $_[0]) } - - -1; |