Richard and Barbara Males
2011-Mar-08 15:49 UTC
[R] R Commander QQ Plot with triangular distribution
I am attempting to use the R Commander Graphs Quantile-Comparison functionality on a dataset, to compare with a triangular distribution. I have the package triangle. My question is on the syntax of how to specify the parameters of the theoretical distribution in the Parameters field of the dialog box. For example, the theoretical distribution has min of 3000, max of 5000, mode of 4000. When I enter this info as 3000,5000,4000 in the parameters field, I get: qqPlot(EmpiricalData$Value, dist="triangle", 3000,5000,4000) it produces a plot, but I am not sure that this is correct. I have searched for examples, not found anything. Any help much appreciated. R. Males Cincinnati, Ohio, USA
Dear R. Males, This isn't really an R Commander question, since the qqPlot() function is in the car package and is just invoked by the R Commander.>From ?qqPlot: "distribution: root name of comparison distribution - e.g.,"norm" for the normal distribution ... Any distribution for which quantile and density functions exist in R (with prefixes q and d, respectively) may be used." Thus, if there's a qtriangle() and dtriangle(), I suppose that you should be able to get a QQ plot. Further from ?qqPlot: " ... arguments such as df to be passed to the appropriate quantile function." Thus, you should *name* the arguments to be passed to qtriangle() -- perhaps (of course, you should use the correct names) min=3000, max=5000, mode=4000. I hope this helps, John -------------------------------- John Fox Senator William McMaster Professor of Social Statistics Department of Sociology McMaster University Hamilton, Ontario, Canada http://socserv.mcmaster.ca/jfox> -----Original Message----- > From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] > On Behalf Of Richard and Barbara Males > Sent: March-08-11 10:49 AM > To: r-help at r-project.org > Subject: [R] R Commander QQ Plot with triangular distribution > > I am attempting to use the R Commander Graphs Quantile-Comparison > functionality on a dataset, to compare with a triangular distribution. > I have the package triangle. My question is on the syntax of how > to specify the parameters of the theoretical distribution in the > Parameters field of the dialog box. For example, the theoretical > distribution has min of 3000, max of 5000, mode of 4000. When I > enter this info as 3000,5000,4000 in the parameters field, I get: > > qqPlot(EmpiricalData$Value, dist="triangle", 3000,5000,4000) > > it produces a plot, but I am not sure that this is correct. > > I have searched for examples, not found anything. Any help much > appreciated. > > R. Males > Cincinnati, Ohio, USA > > ______________________________________________ > 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.