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RT_weibrnd
(rtools/RT_weibrnd.m)
Function Synopsis
out = RT_weibrnd(aval,mu,mrows,ncols)
Help text
function out = RT_weibrnd(a,mu,mrows,ncols)
Returns variates from the Weibull probability density with shape parameter A
and mean MU.
Note that this is not the `usual' form for the Weibull, which uses a
non-linear scale parameter (b). For simulation, explicit definition
in terms of the mean MU is more meaningful. For theoretical
manipulation of equations, you're better off using b though.
The conversion from b is MU = a^(-b) * gamma(1 + b) which is performed in
RT_weibest.m
A Weibull distribution in Amplitude, is also a Weibull distribution
in Intensity. This `power law invariance' is useful for simulation, but
it causes confusion over whether the `usual' shape parameter (c) refers
to Amplitude _or_ Intensity in radar texts. It most often refers to Amplitude,
but this toolbox uses Intensity as the natural measure, so check your
conventions.
The form used is such that the mean value is MU and larger
A is closer to a Gaussian distribution. A = 1 is equivalent to an
exponential distribution.
Uses a power transform of the Exponential distribution (via RT_exprnd.m)
If aval ~< 0.1 zeroes may be output (the dynamic range of floating point
is not large enough). However, this value should never arise in practice.
Source:
[1] L. Devroye, `Non-Uniform Random Variate Generation',
Springer-Verlag, 1986.
[2] Direct evaluation of PDF
Part of the Matlab Radar Toolbox v0.11 by Glen Davidson at www.radarworks.com
Please acknowledge use of this toolbox in any publication or software.
This header must be retained in any derivative work
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