Distr(3pm) | User Contributed Perl Documentation | Distr(3pm) |
PDL::Stats::Distr -- parameter estimations and probability density functions for distributions.
Parameter estimate is maximum likelihood estimate when there is closed form estimate, otherwise it is method of moments estimate.
use PDL::LiteF; use PDL::Stats::Distr; # do a frequency (probability) plot with fitted normal curve my $data = grandom(100)->abs; my ($xvals, $hist) = $data->hist; # turn frequency into probability $hist /= $data->nelem; # get maximum likelihood estimates of normal curve parameters my ($m, $v) = $data->mle_gaussian(); # fitted normal curve probabilities my $p = $xvals->pdf_gaussian($m, $v); use PDL::Graphics::PGPLOT::Window; my $win = pgwin( Dev=>"/xs" ); $win->bin( $hist ); $win->hold; $win->line( $p, {COLOR=>2} ); $win->close;
Or, play with different distributions with plot_distr :)
$data->plot_distr( 'gaussian', 'lognormal' );
Signature: (a(n); float+ [o]alpha(); float+ [o]beta())
my ($a, $b) = $data->mme_beta();
beta distribution. pdf: f(x; a,b) = 1/B(a,b) x^(a-1) (1-x)^(b-1)
mme_beta processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
Signature: (x(); a(); b(); float+ [o]p())
probability density function for beta distribution. x defined on [0,1].
pdf_beta processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
Signature: (a(n); int [o]n_(); float+ [o]p())
my ($n, $p) = $data->mme_binomial;
binomial distribution. pmf: f(k; n,p) = (n k) p^k (1-p)^(n-k) for k = 0,1,2..n
mme_binomial 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: (ushort x(); ushort n(); p(); float+ [o]out())
probability mass function for binomial distribution.
pmf_binomial 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(n); float+ [o]l())
my $lamda = $data->mle_exp;
exponential distribution. mle same as method of moments estimate.
mle_exp processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
Signature: (x(); l(); float+ [o]p())
probability density function for exponential distribution.
pdf_exp processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
Signature: (a(n); float+ [o]shape(); float+ [o]scale())
my ($shape, $scale) = $data->mme_gamma();
two-parameter gamma distribution
mme_gamma processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
Signature: (x(); a(); t(); float+ [o]p())
probability density function for two-parameter gamma distribution.
pdf_gamma processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
Signature: (a(n); float+ [o]m(); float+ [o]v())
my ($m, $v) = $data->mle_gaussian();
gaussian aka normal distribution. same results as $data->average and $data->var. mle same as method of moments estimate.
mle_gaussian processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
Signature: (x(); m(); v(); float+ [o]p())
probability density function for gaussian distribution.
pdf_gaussian processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
Signature: (a(n); float+ [o]p())
geometric distribution. mle same as method of moments estimate.
mle_geo processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
Signature: (ushort x(); p(); float+ [o]out())
probability mass function for geometric distribution. x >= 0.
pmf_geo processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
Signature: (a(n); float+ [o]p())
shifted geometric distribution. mle same as method of moments estimate.
mle_geosh processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
Signature: (ushort x(); p(); float+ [o]out())
probability mass function for shifted geometric distribution. x >= 1.
pmf_geosh processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
Signature: (a(n); float+ [o]m(); float+ [o]v())
my ($m, $v) = $data->mle_lognormal();
lognormal distribution. maximum likelihood estimation.
mle_lognormal processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
Signature: (a(n); float+ [o]m(); float+ [o]v())
my ($m, $v) = $data->mme_lognormal();
lognormal distribution. method of moments estimation.
mme_lognormal processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
Signature: (x(); m(); v(); float+ [o]p())
probability density function for lognormal distribution. x > 0. v > 0.
pdf_lognormal processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
Signature: (a(n); float+ [o]r(); float+ [o]p())
my ($r, $p) = $data->mme_nbd();
negative binomial distribution. pmf: f(x; r,p) = (x+r-1 r-1) p^r (1-p)^x for x=0,1,2...
mme_nbd processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
Signature: (ushort x(); r(); p(); float+ [o]out())
probability mass function for negative binomial distribution.
pmf_nbd processes bad values. It will set the bad-value flag of all output ndarrays if the flag is set for any of the input ndarrays.
Signature: (a(n); float+ [o]k(); float+ [o]xm())
my ($k, $xm) = $data->mme_pareto();
pareto distribution. pdf: f(x; k,xm) = k xm^k / x^(k+1) for x >= xm > 0.
mme_pareto 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: (x(); k(); xm(); float+ [o]p())
probability density function for pareto distribution. x >= xm > 0.
pdf_pareto 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(n); float+ [o]l())
my $lamda = $data->mle_poisson();
poisson distribution. pmf: f(x;l) = e^(-l) * l^x / x!
mle_poisson 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: (x(); l(); float+ [o]p())
Probability mass function for poisson distribution. Uses Stirling's formula for x > 85.
pmf_poisson 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: (x(); l(); [o]p())
Probability mass function for poisson distribution. Uses Stirling's formula for all values of the input. See http://en.wikipedia.org/wiki/Stirling's_approximation for more info.
pmf_poisson_stirling 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: ushort x(); l(); float+ [o]p()
Probability mass function for poisson distribution. Input is limited to x < 170 to avoid gsl_sf_fact() overflow.
Plots data distribution. When given specific distribution(s) to fit, returns % ref to sum log likelihood and parameter values under fitted distribution(s). See FUNCTIONS above for available distributions.
Default options (case insensitive):
MAXBN => 20, # see PDL::Graphics::PGPLOT::Window for next options WIN => undef, # pgwin object. not closed here if passed # allows comparing multiple distr in same plot # set env before passing WIN DEV => '/xs' , # open and close dev for plotting if no WIN # defaults to '/png' in Windows COLOR => 1, # color for data distr
Usage:
# yes it threads :) my $data = grandom( 500, 3 )->abs; # ll on plot is sum across 3 data curves my ($ll, $pars) = $data->plot_distr( 'gaussian', 'lognormal', {DEV=>'/png'} ); # pars are from normalized data (ie data / bin_size) print "$_\t@{$pars->{$_}}\n" for (sort keys %$pars); print "$_\t$ll->{$_}\n" for (sort keys %$ll);
GSL - GNU Scientific Library
PDL::Graphics::PGPLOT
PDL::GSL::CDF
Copyright (C) 2009 Maggie J. Xiong <maggiexyz users.sourceforge.net>, David Mertens
All rights reserved. There is no warranty. You are allowed to redistribute this software / documentation as described in the file COPYING in the PDL distribution.
2022-12-17 | perl v5.36.0 |