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GBRAND(1) User Commands GBRAND(1)

NAME

gbrand - Sampling from random distributions

SYNOPSIS

gbrand [options] NAME PARAMETERS...

DESCRIPTION

Generates a grid of i.i.d. samples from a distribution. The name of the distribution and its parameters are specified on the command line. the column index. Indeces start from 1. If more than one function are provided they are printed one after the other. The type of random number generator and the default seed can be set with the environment variables GSL_RNG_TYPE and GSL_RNG_SEED, respectively, as documented in GSL manual.

OPTIONS

-r
specify number of rows (default 1)
-c
specify number of columns (default 1)
-R
set the seed (default 1)
-v
verbose mode
-h
this help

List of valid distributions (with parameters):

beta
a,b = shape parameters
binomial
p = probability, N = number of trials
bivariate-gaussian
sigmax = x std.dev., sigmay = y std.dev., rho = correlation
cauchy
a = scale parameter
chisq
nu = degrees of freedom
dir-2d
none
dir-3d
none
dir-nd
n1 = number of dimensions of hypersphere
erlang
a = scale parameter, b = order
exponential
mu = mean value
exppow
a = scale parameter, b = power (1=exponential, 2=gaussian)
aexppow
m = mode, al = left scale, ar = right scale, bl = left shape, br = right shape
fdist
nu1, nu2 = degrees of freedom parameters
flat
a = lower limit, b = upper limit
gamma
a = order, b = scale
gaussian-tail
a = lower limit, sigma = standard deviation
gaussian
sigma = standard deviation
geometric
p = bernoulli trial probability of success
gumbel1
a = order, b = scale parameter
gumbel2
a = order, b = scale parameter
hypergeometric
n1 = # tagged, n2 = # untagged, t = number of trials
laplace
a = scale parameter
landau
none
levy
c = scale, a = power (1=cauchy, 2=gaussian)
levy-skew
c = scale, a = power (1=cauchy, 2=gaussian), b = skew
logarithmic
p = probability
logistic
a = scale parameter
lognormal
zeta = location parameter, sigma = scale parameter
negative-binomial
p = probability, a = order
pareto
a = power, b = scale parameter
pascal
p = probability, n = order (integer)
poisson
mu = scale parameter
rayleigh-tail
a = lower limit, sigma = scale parameter
rayleigh
sigma = scale parameter
tdist
nu = degrees of freedom
ugaussian-tail
a = lower limit
ugaussian
none
weibull
a = scale parameter, b = exponent
pareto3
a = power, b = exponential parameter, s = scale parameter

EXAMPLES

gbrand -c 2 -r 100 gaussian 2.5
generate two columns of 100 rows each sampling from a Gaussian distribution with mean 0 and standard deviation 2.5
gbrand -R 145 -r 1000 exponential 1
one hundredth exponantial variates with parameters 1, the the seed of the RNG is set to 145
gbrand -r 10 flat 3 4
ten realizations of the r.v. uniformly distributed in [3,4]

AUTHOR

Written by Giulio Bottazzi

REPORTING BUGS

Report bugs to <gbutils@googlegroups.com>

Package home page <http://cafim.sssup.it/~giulio/software/gbutils/index.html>

COPYRIGHT

Copyright © 2001-2018 Giulio Bottazzi This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License (version 2) as published by the Free Software Foundation;

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

February 2019 gbrand 6.0.beta2