NAME

Math::Cephes::Complex - Perl interface to the cephes complex number routines

SYNOPSIS

use Math::Cephes::Complex qw(cmplx);
my $z1 = cmplx(2,3);          # $z1 = 2 + 3 i
my $z2 = cmplx(3,4);          # $z2 = 3 + 4 i
my $z3 = $z1->radd($z2);      # $z3 = $z1 + $z2

DESCRIPTION

This module is a layer on top of the basic routines in the cephes math library to handle complex numbers. A complex number is created via any of the following syntaxes:

my $f = Math::Cephes::Complex->new(3, 2);   # $f = 3 + 2 i
my $g = new Math::Cephes::Complex(5, 3);    # $g = 5 + 3 i
my $h = cmplx(7, 5);                        # $h = 7 + 5 i

the last one being available by importing cmplx. If no arguments are specified, as in

my $h = cmplx();

then the defaults $z = 0 + 0 i are assumed. The real and imaginary part of a complex number are represented respectively by

$f->{r}; $f->{i};

or, as methods,

$f->r;  $f->i;

and can be set according to

$f->{r} = 4; $f->{i} = 9;

or, again, as methods,

$f->r(4);   $f->i(9);

The complex number can be printed out as

print $f->as_string;

A summary of the usage is as follows.

csin: Complex circular sine
SYNOPSIS:

# void csin();
# cmplx z, w;

$z = cmplx(2, 3);    # $z = 2 + 3 i
$w = $z->csin;
print $w->{r}, '  ', $w->{i};  # prints real and imaginary parts of $w
print $w->as_string;           # prints $w as Re($w) + i Im($w)

DESCRIPTION:

If
    z = x + iy,

then

    w = sin x  cosh y  +  i cos x sinh y.
ccos: Complex circular cosine
SYNOPSIS:

# void ccos();
# cmplx z, w;

$z = cmplx(2, 3);    # $z = 2 + 3 i
$w = $z->ccos;
print $w->{r}, '  ', $w->{i};  # prints real and imaginary parts of $w
print $w->as_string;           # prints $w as Re($w) + i Im($w)

DESCRIPTION:

If
    z = x + iy,

then

    w = cos x  cosh y  -  i sin x sinh y.
ctan: Complex circular tangent
SYNOPSIS:

# void ctan();
# cmplx z, w;

$z = cmplx(2, 3);    # $z = 2 + 3 i
$w = $z->ctan;
print $w->{r}, '  ', $w->{i};  # prints real and imaginary parts of $w
print $w->as_string;           # prints $w as Re($w) + i Im($w)

DESCRIPTION:

If
    z = x + iy,

then

          sin 2x  +  i sinh 2y
    w  =  --------------------.
           cos 2x  +  cosh 2y

On the real axis the denominator is zero at odd multiples
of PI/2.  The denominator is evaluated by its Taylor
series near these points.
ccot: Complex circular cotangent
SYNOPSIS:

# void ccot();
# cmplx z, w;

$z = cmplx(2, 3);    # $z = 2 + 3 i
$w = $z->ccot;
print $w->{r}, '  ', $w->{i};  # prints real and imaginary parts of $w
print $w->as_string;           # prints $w as Re($w) + i Im($w)

DESCRIPTION:

If
    z = x + iy,

then

          sin 2x  -  i sinh 2y
    w  =  --------------------.
           cosh 2y  -  cos 2x

On the real axis, the denominator has zeros at even
multiples of PI/2.  Near these points it is evaluated
by a Taylor series.
casin: Complex circular arc sine
SYNOPSIS:

# void casin();
# cmplx z, w;

$z = cmplx(2, 3);    # $z = 2 + 3 i
$w = $z->casin;
print $w->{r}, '  ', $w->{i};  # prints real and imaginary parts of $w
print $w->as_string;           # prints $w as Re($w) + i Im($w)

DESCRIPTION:

Inverse complex sine:

                              2
w = -i clog( iz + csqrt( 1 - z ) ).
cacos: Complex circular arc cosine
SYNOPSIS:

# void cacos();
# cmplx z, w;

$z = cmplx(2, 3);    # $z = 2 + 3 i
$w = $z->cacos;
print $w->{r}, '  ', $w->{i};  # prints real and imaginary parts of $w
print $w->as_string;           # prints $w as Re($w) + i Im($w)

DESCRIPTION:

w = arccos z  =  PI/2 - arcsin z.
catan: Complex circular arc tangent
SYNOPSIS:

# void catan();
# cmplx z, w;

$z = cmplx(2, 3);    # $z = 2 + 3 i
$w = $z->catan;
print $w->{r}, '  ', $w->{i};  # prints real and imaginary parts of $w
print $w->as_string;           # prints $w as Re($w) + i Im($w)

DESCRIPTION:

If
    z = x + iy,

then
         1       (    2x     )
Re w  =  - arctan(-----------)  +  k PI
         2       (     2    2)
                 (1 - x  - y )

              ( 2         2)
         1    (x  +  (y+1) )
Im w  =  - log(------------)
         4    ( 2         2)
              (x  +  (y-1) )

Where k is an arbitrary integer.
csinh: Complex hyperbolic sine
 SYNOPSIS:

 # void csinh();
 # cmplx z, w;

$z = cmplx(2, 3);    # $z = 2 + 3 i
$w = $z->csinh;
print $w->{r}, '  ', $w->{i};  # prints real and imaginary parts of $w
print $w->as_string;           # prints $w as Re($w) + i Im($w)


 DESCRIPTION:

 csinh z = (cexp(z) - cexp(-z))/2
         = sinh x * cos y  +  i cosh x * sin y .
casinh: Complex inverse hyperbolic sine
 SYNOPSIS:

 # void casinh();
 # cmplx z, w;

$z = cmplx(2, 3);    # $z = 2 + 3 i
$w = $z->casinh;
print $w->{r}, '  ', $w->{i};  # prints real and imaginary parts of $w
print $w->as_string;           # prints $w as Re($w) + i Im($w)

 DESCRIPTION:

 casinh z = -i casin iz .
ccosh: Complex hyperbolic cosine
 SYNOPSIS:

 # void ccosh();
 # cmplx z, w;

$z = cmplx(2, 3);    # $z = 2 + 3 i
$w = $z->ccosh;
print $w->{r}, '  ', $w->{i};  # prints real and imaginary parts of $w
print $w->as_string;           # prints $w as Re($w) + i Im($w)

 DESCRIPTION:

 ccosh(z) = cosh x  cos y + i sinh x sin y .
cacosh: Complex inverse hyperbolic cosine
 SYNOPSIS:

 # void cacosh();
 # cmplx z, w;

$z = cmplx(2, 3);    # $z = 2 + 3 i
$w = $z->cacosh;
print $w->{r}, '  ', $w->{i};  # prints real and imaginary parts of $w
print $w->as_string;           # prints $w as Re($w) + i Im($w)

 DESCRIPTION:

 acosh z = i acos z .
ctanh: Complex hyperbolic tangent
SYNOPSIS:

# void ctanh();
# cmplx z, w;

$z = cmplx(2, 3);    # $z = 2 + 3 i
$w = $z->ctanh;
print $w->{r}, '  ', $w->{i};  # prints real and imaginary parts of $w
print $w->as_string;           # prints $w as Re($w) + i Im($w)

DESCRIPTION:

tanh z = (sinh 2x  +  i sin 2y) / (cosh 2x + cos 2y) .
catanh: Complex inverse hyperbolic tangent
 SYNOPSIS:

 # void catanh();
 # cmplx z, w;

$z = cmplx(2, 3);    # $z = 2 + 3 i
$w = $z->catanh;
print $w->{r}, '  ', $w->{i};  # prints real and imaginary parts of $w
print $w->as_string;           # prints $w as Re($w) + i Im($w)

 DESCRIPTION:

 Inverse tanh, equal to  -i catan (iz);
cpow: Complex power function
 SYNOPSIS:

 # void cpow();
 # cmplx a, z, w;

$a = cmplx(5, 6);    # $z = 5 + 6 i
$z = cmplx(2, 3);    # $z = 2 + 3 i
$w = $a->cpow($z);
print $w->{r}, '  ', $w->{i};  # prints real and imaginary parts of $w
print $w->as_string;           # prints $w as Re($w) + i Im($w)

 DESCRIPTION:

 Raises complex A to the complex Zth power.
 Definition is per AMS55 # 4.2.8,
 analytically equivalent to cpow(a,z) = cexp(z clog(a)).
cmplx: Complex number arithmetic
SYNOPSIS:

# typedef struct {
#     double r;     real part
#     double i;     imaginary part
#    }cmplx;

# cmplx *a, *b, *c;

$a = cmplx(3, 5);   # $a = 3 + 5 i
$b = cmplx(2, 3);   # $b = 2 + 3 i

$c = $a->cadd( $b );  #   c = a + b
$c = $a->csub( $b );  #   c = a - b
$c = $a->cmul( $b );  #   c = a * b
$c = $a->cdiv( $b );  #   c = a / b
$c = $a->cneg;        #   c = -a
$c = $a->cmov;        #   c = a

print $c->{r}, '  ', $c->{i};   # prints real and imaginary parts of $c
print $c->as_string;           # prints $c as Re($c) + i Im($c)


DESCRIPTION:

Addition:
   c.r  =  b.r + a.r
   c.i  =  b.i + a.i

Subtraction:
   c.r  =  b.r - a.r
   c.i  =  b.i - a.i

Multiplication:
   c.r  =  b.r * a.r  -  b.i * a.i
   c.i  =  b.r * a.i  +  b.i * a.r

Division:
   d    =  a.r * a.r  +  a.i * a.i
   c.r  = (b.r * a.r  + b.i * a.i)/d
   c.i  = (b.i * a.r  -  b.r * a.i)/d
cabs: Complex absolute value
SYNOPSIS:

# double a, cabs();
# cmplx z;

$z = cmplx(2, 3);    # $z = 2 + 3 i
$a = cabs( $z );

DESCRIPTION:

If z = x + iy

then

      a = sqrt( x**2 + y**2 ).

Overflow and underflow are avoided by testing the magnitudes
of x and y before squaring.  If either is outside half of
the floating point full scale range, both are rescaled.
csqrt: Complex square root
SYNOPSIS:

# void csqrt();
# cmplx z, w;

$z = cmplx(2, 3);    # $z = 2 + 3 i
$w = $z->csqrt;
print $w->{r}, '  ', $w->{i};  # prints real and imaginary parts of $w
print $w->as_string;           # prints $w as Re($w) + i Im($w)

DESCRIPTION:

If z = x + iy,  r = |z|, then

                      1/2
Im w  =  [ (r - x)/2 ]   ,

Re w  =  y / 2 Im w.

Note that -w is also a square root of z.  The root chosen
is always in the upper half plane.

Because of the potential for cancellation error in r - x,
the result is sharpened by doing a Heron iteration
(see sqrt.c) in complex arithmetic.

BUGS

Please report any to Randy Kobes <randy@theoryx5.uwinnipeg.ca>

SEE ALSO

For the basic interface to the cephes complex number routines, see Math::Cephes. See also Math::Complex for a more extensive interface to complex number routines.

COPYRIGHT

The C code for the Cephes Math Library is Copyright 1984, 1987, 1989, 2002 by Stephen L. Moshier, and is available at http://www.netlib.org/cephes/. Direct inquiries to 30 Frost Street, Cambridge, MA 02140.

The perl interface is copyright 2000, 2002 by Randy Kobes. This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.