PDL::Math - extended mathematical operations and special functions
use PDL::Math; use PDL::Graphics::TriD; imag3d [SURF2D,bessj0(rvals(zeroes(50,50))/2)];
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.
Signature: (a(); [o]b())
The usual trigonometric function. Works inplace.
acos processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
asin processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
atan processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
The standard hyperbolic function. Works inplace.
cosh processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
sinh processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
tan processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
tanh processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
Round to integer values in floating-point format. Works inplace.
ceil processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
floor processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
Round to integer values in floating-point format.
rint uses the 'round half to even' rounding method (also known as banker's rounding). Half-integers are rounded to the nearest even number. This avoids a slight statistical bias inherent in always rounding half-integers up or away from zero.
If you are looking to round half-integers up (regardless of sign), try floor($x+0.5). If you want to round half-integers away from zero, try ceil(abs($x)+0.5)*($x<=>0). Works inplace.
floor($x+0.5)
ceil(abs($x)+0.5)*($x<=>0)
rint processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
Signature: (a(); b(); [o]c())
Synonym for `**'. Works inplace.
pow processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
acosh processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
asinh processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
atanh processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
The error function. Works inplace.
erf processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
The complement of the error function. Works inplace.
erfc processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
The regular Bessel function of the first kind, J_n Works inplace.
bessj0 processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
bessj1 processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
The regular Bessel function of the second kind, Y_n. Works inplace.
bessy0 processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
bessy1 processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
Signature: (a(); int n(); [o]b())
The regular Bessel function of the first kind, J_n . This takes a second int argument which gives the order of the function required. Works inplace.
bessjn processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
The regular Bessel function of the first kind, Y_n . This takes a second int argument which gives the order of the function required. Works inplace.
bessyn processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
Signature: (a(); [o]b(); int[o]s())
log gamma function
This returns 2 ndarrays -- 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.
lgamma processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
Clears all infs and nans in $a to the corresponding value in $b.
infs
nans
$a
$b
badmask can be run with $x inplace:
$x
badmask($x->inplace,0); $x->inplace->badmask(0);
If bad values are present, these are also cleared.
Signature: (a(); int [o]mask())
Sets $mask true if $a is not a NaN or inf (either positive or negative). Works inplace.
$mask
NaN
inf
Bad values are treated as NaN or inf.
The inverse of the error function. Works inplace.
erfi processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
The value for which the area under the Gaussian probability density function (integrated from minus infinity) is equal to the argument (cf "erfi"). Works inplace.
ndtri processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
Signature: (cr(n); ci(n); [o]rr(m); [o]ri(m))
Complex roots of a complex polynomial, given coefficients in order of decreasing powers.
($rr, $ri) = polyroots($cr, $ci);
polyroots does not process bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
Hasn't been tested on all platforms to ensure Cephes versions are picked up automatically and used correctly.
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.
To install PDL, copy and paste the appropriate command in to your terminal.
cpanm
cpanm PDL
CPAN shell
perl -MCPAN -e shell install PDL
For more information on module installation, please visit the detailed CPAN module installation guide.