Math(3)

NAME
PDL::Math - extended mathematical operations and special functions

SYNOPSIS
 use PDL::Math;

 use PDL::Graphics::TriD;
 imag3d [SURF2D,bessj0(rvals(zeroes(50,50))/2)];

DESCRIPTION
This module extends PDL with more advanced mathematical functions than provided by standard Perl.

All the functions have one input pdl, and one output, unless otherwise stated.

Many of the functions are linked from the system maths library or the Cephes maths library (determined when PDL is compiled); a few are implemented entirely in PDL.

FUNCTIONS

  acos
  Signature: (a(); [o]b())

The usual trigonometric function. Works inplace.

  asin
  Signature: (a(); [o]b())

The usual trigonometric function. Works inplace.

  atan
  Signature: (a(); [o]b())

The usual trigonometric function. Works inplace.

  cosh
  Signature: (a(); [o]b())

The standard hyperbolic function. Works inplace.

  sinh
  Signature: (a(); [o]b())

The standard hyperbolic function. Works inplace.

  tan
  Signature: (a(); [o]b())

The usual trigonometric function. Works inplace.

  tanh
  Signature: (a(); [o]b())

The standard hyperbolic function. Works inplace.

  ceil
  Signature: (a(); [o]b())

Round to integral values in floating-point format. Works inplace.

  floor
  Signature: (a(); [o]b())

Round to integral values in floating-point format. Works inplace.

  rint
  Signature: (a(); [o]b())

Round to integral values in floating-point format. Works inplace.

  pow
  Signature: (a(); b(); [o]c())

Synonym for `**'. Works inplace.

  acosh
  Signature: (a(); [o]b())

The standard hyperbolic function. Works inplace.

  asinh
  Signature: (a(); [o]b())

The standard hyperbolic function. Works inplace.

  atanh
  Signature: (a(); [o]b())

The standard hyperbolic function. Works inplace.

  erf
  Signature: (a(); [o]b())

The error function. Works inplace.

  erfc
  Signature: (a(); [o]b())

The complement of the error function. Works inplace.

  bessj0
  Signature: (a(); [o]b())

The standard Bessel function. Works inplace.

  bessj1
  Signature: (a(); [o]b())

The standard Bessel function. Works inplace.

  bessy0
  Signature: (a(); [o]b())

The standard Bessel function. Works inplace.

  bessy1
  Signature: (a(); [o]b())

The standard Bessel function. Works inplace.

  bessjn
  Signature: (a(); int n(); [o]b())

The standard Bessel function. This has a second integer argument which gives the order of the function required.
 Works inplace.

  bessyn
  Signature: (a(); int n(); [o]b())

The standard Bessel function. This has a second integer argument which gives the order of the function required.
 Works inplace.

  lgamma
  Signature: (a(); [o]b(); int[o]s())

log gamma function

This returns 2 piddles -- the first set gives the log(gamma) values, while the second set, of integer values, gives the sign of the gamma function. This is useful for determining factorials, amongst other things.

  badmask
  Signature: (a(); b(); [o]c())

Clears all "infs" and "nans" in $a to the corresponding value in $b.

badmask can be run with $a inplace:

  badmask($a->inplace,0);
  $a->inplace->badmask(0);

  isfinite
  Signature: (a(); int [o]mask())

Sets $mask true if $a is not a "NaN" or "inf" (either positive or negative). Works inplace.

  erfi
  Signature: (a(); [o]b())

The inverse of the error function. Works inplace.

  ndtri
  Signature: (a(); [o]b())

The value for which the area under the Gaussian probability density function (integrated from minus infinity) is equal to the argument (cf erfi). Works inplace.

  polyroots
  Signature: (cr(n); ci(n); [o]rr(m); [o]ri(m))

Complex roots of a complex polynomial, given coefficients in order of decreasing powers.

 ($rr, $ri) = polyroots($cr, $ci);

BUGS
Hasn't been tested on all platforms to ensure Cephes versions are picked up automatically and used correctly.

AUTHOR
Copyright (C) R.J.R. Williams 1997 (rjrw@ast.leeds.ac.uk), Karl Glazebrook (kgb@aaoepp.aao.gov.au) and Tuomas J. Lukka (Tuomas.Lukka@helsinki.fi). Portions (C) Craig DeForest 2002 (deforest@boulder.swri.edu).

All rights reserved. There is no warranty. You are allowed to redistribute this software / documentation under certain conditions. For details, see the file COPYING in the PDL distribution. If this file is separated from the PDL distribution, the PDL copyright notice should be included in the file.