RSiteSearch("Dagum") Francisco
>From: "Uri Iskin" <[EMAIL PROTECTED]> >To: <r-help@stat.math.ethz.ch> >Subject: [R] help with estimating parameters with nls >Date: Tue, 20 Sep 2005 15:44:07 -0300 > >Dear helpeRs, > >I have a vector containing values of incomes and I would like to estimate >the three parameters of a Dagum distribution. >Dagum himself recommends to use nonlinear least-squares method. >I have read nls, optim (and the posting guide!) and still have not >succeded. > >sipcf is my sorted vector of incomes with 3065 obs. >fda is a vector of the empirical cumulative distribution probabilities: > > fda <- vector(length=length(sipcf)) > > for (I in 1:length(sipcf)){ > > fda[i] <- sum(sipcf <= sipcf[i])/length(sipcf) > > } >fdae is the cdf: > > fdae <- function(x){ > > fda[sum(sipcf<=x)] >} >dagfda is the cdf of Dagum: > > dagfda <- function(x,a,b,p){ >(1+(x^(-a)*b^a))^(-p) >} > >start values I am using: a=1.9 b=0.34 p=1.3 > >I am trying to get the parameters estimates with nls and optim, but all I >get are errors. >Could you help me showing how to get them? >Thank you in advance! > >Uri Iskin > >______________________________________________ >R-help@stat.math.ethz.ch mailing list >https://stat.ethz.ch/mailman/listinfo/r-help >PLEASE do read the posting guide! >http://www.R-project.org/posting-guide.html ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html