Hi Anwesha On Tue, Aug 18, 2009 at 10:48 AM, Anwesha Chakrabarti<c.anwe...@gmail.com> wrote: > I was trying to estimate simultaneous equation system in R using systemfit. > I used the following commands >> library(systemfit) >> data(Kmenta) >> attach(Kmenta) >> eqDemand<-consump~price+income >> eqSupply<-consump~price+farmprice+trend
Please replace "farmprice" by "farmPrice" >> fitsur<-systemfit("SUR",list(demand=eqDemand, supply=eqSupply)) > and got the following error messege > > Error in systemfit("SUR", list(demand = eqDemand, supply = eqSupply)) : > argument 'formula' must be an object of class 'formula' or a list of objects > of class 'formula' The error message is correct. If you do not name the arguments, the first argument must be the formula or the list of formulas. You could estimate the system either by R> fitsur <- systemfit( list( demand=eqDemand, supply=eqSupply ), "SUR" ) or by R> fitsur <- systemfit( method="SUR", formula=list( demand=eqDemand, supply=eqSupply ) ) Please read the documentation/manual of systemfit and the paper about systemfit published in the JSS: http://www.jstatsoft.org/v23/i04/ Best wishes, Arne -- Arne Henningsen http://www.arne-henningsen.name ______________________________________________ R-help@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.