[R] Adding gamma and 3-parameter log normal distributions to L-moments ratio diagram lmrd()

J. R. M. Hosking JRMHosking at gmail.com
Mon Jul 23 16:02:33 CEST 2012

On 2012-07-22 03:31, otsvetkova wrote:
> How to adapt this piece of code but for: - gamma distribution - 3 parameter
> log normal
> More specifically, where can I find the specification of the parameter
> (lmom) for pelgam() and pelln3()?
> Lmom package info just gives: pelgam(lmom), lelln3(lmom), where lmom is a
> numeric vector containing the L-moments of the distribution or of a data
> sample.
> # Draw an L-moment ratio diagram and add a line for the
> # Weibull distribution
> lmrd()
> weimom<- sapply( seq(0, 0.9, by=0.01),
> function(tau3) lmrwei(pelwei(c(0,1,tau3)), nmom=4) )
> lmrdlines(t(weimom), col='darkgreen', lwd=2)
> source: http://rgm2.lab.nig.ac.jp/RGM2/func.php?rd_id=lmom:lmrdpoints
> Thank you.

lmrd() by default draws lines for the Pearson type III distribution
(which is a 3-parameter form of the gamma distribution) and the
generalized normal distribution (a differently parametrized version
of the 3-parameter lognormal distribution).  Is this what you want?
If not, I don't know what else you want to know about "the
specification of the parameter (lmom)".

J. R. M. Hosking

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