Maithili Shiva
2009-Mar-18 16:07 UTC
[R] Fw: Estimating Parameters of Weibull and Pareto distribution using LMOM package
Dear R helpers I have r file which estimate the parameters of 3 parameter Weibull - (A) - continuous shape parameter (alpha) - continuous scale parameter (beta) - continuous location parameter (gamma) (B) Also, I have a r file which calculates the parameters of Generalized Pareto distribution. - location parameter xi, - scale parameter alpha and - shape parameter k However, If I have to use the same files for estimating parameters of 2 parameter Weibull and 2 parameter Pareto distribution, how do I use it? I am giving the R script I am using to calculate the Generalized Pareto distribution as library(lmom) amounts <- (10023.47, 10171.42,13446.83,10263.49,10219.07, 10025.71, 10318.88, 10034.85,10004.98,10012.72) lmom <- samlmu(amounts); lmom parameters_of_Gen_Pareto <- pelgpa(lmom); parameters_of_Gen_Pareto The parameters estimated are xi alpha k 9993.3131812 81.9540457 -0.8213843 If the location paramter xi = 0, then this becomes two parameter Paretom distribution. However, it is my gut feeling that if xi = 0, other parameter values will also change. Please help me. Regards and thanking in advance Maithili
J. R. M. Hosking
2009-Mar-18 20:25 UTC
[R] Fw: Estimating Parameters of Weibull and Pareto distribution using LMOM package
Maithili Shiva wrote:> Dear R helpers > > I have r file which estimate the parameters of 3 parameter > Weibull - > > (A) - continuous shape parameter (alpha) > - continuous scale parameter (beta) > - continuous location parameter (gamma) > > (B) Also, I have a r file which calculates the parameters > of Generalized Pareto distribution. > > - location parameter xi, > - scale parameter alpha and > - shape parameter k > > > However, If I have to use the same files for estimating > parameters of 2 parameter Weibull and 2 parameter Pareto distribution, how do I use it? > > > I am giving the R script I am using to calculate the Generalized Pareto distribution as > > library(lmom) > > amounts <- (10023.47, 10171.42,13446.83,10263.49,10219.07, 10025.71, 10318.88, 10034.85,10004.98,10012.72) > > lmom <- samlmu(amounts); lmom > > parameters_of_Gen_Pareto <- pelgpa(lmom); > parameters_of_Gen_Pareto > > > The parameters estimated are > > xi alpha k > 9993.3131812 81.9540457 -0.8213843 > > > If the location paramter xi = 0, then this becomes two > parameter Paretom distribution. However, it is my gut > feeling that if xi = 0, other parameter values will also > change.pelgpa allows you to specify the lower bound of the distribution and estimate the other two parameters. Compare > pelgpa(samlmu(amounts)) xi alpha k 9993.3131812 81.9540457 -0.8213843 and > pelgpa(samlmu(amounts),bound=10000) xi alpha k 10000.000000 72.993343 -0.838561 pelwei offers similar options for the Weibull distribution. J. R. M. Hosking> Please help me. > > Regards and thanking in advance > > Maithili > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. >