Le 07-07-11 à 10:01, livia a écrit : > > Hi, thank you very much for your reply. The function pgpd() is from > the > package POT, and the 1.544 is the location parameter, 0.4477557 is > the scale > parameter and -0.50113 is the shape parameter, which can be both > negtive or > positive.
The documentation of POT states that the scale parameter must be positive. You seem right about the shape parameter, though; POT uses a different parametrization from the one I'm used to. The problem with > x <- seq(1.6, 3, 0.1) > lines(x,pgpd(x, 1.544,0.4477557,-0.50113), col="red") is that lines() must be used to add to an already existing graphic. For a new plot, use > x <- seq(1.6, 3, 0.1) > plot(x,pgpd(x, 1.544,0.4477557,-0.50113), col="red") which works just fine here. We cannot help you more if you do not give a *reproducible* example of what is going wrong. If you have issues with the pgpd() function, you should contact the maintainer of package POT, as the Posting Guide asks. HTH > > > Vincent Goulet wrote: >> >> Le 07-07-11 à 07:56, livia a écrit : >> >>> >>> Hi, I would like to use the following codes to plot the CDF for >>> pareto >>> distribution. Before doing this, I have plot the emperical one. >>> >>> x <- seq(1.6, 3, 0.1) >>> lines(x,pgpd(x, 1.544,0.4477557,-0.50113), col="red") >>> >>> Could anyone give me some advice whether the above codes are >>> correct? >>> >>> Many thanks. >> >> livia, >> >> You seem to be struggling with the Pareto distribution... The above >> code seems correct, but you do not say where you took the pdpd() >> function from. This makes it harder for us to help you. >> >> In you other message (https://stat.ethz.ch/pipermail/r-help/2007- >> July/ >> 136137.html) you quote a negative scale parameter. The Pareto I know >> has strictly positive shape and scale parameters. >> >> Perhaps can you retry with functions ppareto() or pgenpareto() of >> package actuar. >> >> --- >> Vincent Goulet, Associate Professor >> École d'actuariat >> Université Laval, Québec >> [EMAIL PROTECTED] http://vgoulet.act.ulaval.ca >> >> ______________________________________________ >> [email protected] 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. >> >> > > -- > View this message in context: http://www.nabble.com/CDF-for-pareto- > distribution-tf4061253.html#a11540928 > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > [email protected] 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. ______________________________________________ [email protected] 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.
