Hello everyone, I am working with plm package and I have problem with random and within models, which are giving errors which says "empty model". However, the model is not empty. In the source code for plm.fit, where the error originates it says something like (writing from the top of my head...)
X <- model.matrix(formula,data, lhs=1,...) if (ncol(X) == 0) stop("empty model") however if I try to replicate this behaviour with the commands I am inputing into the original function, it gives ncol(X) is 17 or something like that. My code is (I am not sure about sharing permissions for dataset... ): library(sampleSelection) library(foreign) library(censReg) library(plm) library(micEcon) library(ggplot2) data <- read.dta('kpfull1.dta') summary(data) attach(data) # profit share ratio. as profit I take profit in 91 which is the closest year and as share I take number of shares offered for voucher scheme data$profit_share <- p91/tnsvp data$debt_assets <- d91/naba data$naba3 <- naba^3 data$difprofit <- p91-p90 data$agri <- (mind==1)*1 data$hi <- (mind==2)*1 data$li <- (mind==3)*1 data$constr <- (mind==4)*1 data$trans <- (mind==5)*1 data$trade <- (mind==6)*1 data$rd <- (mind==7)*1 data$ser <- (mind==8)*1 data$fin <- (mind==9)*1 data$for1 <- data[,7] detach(data) data1 <- data panel <- pdata.frame(data, c("num","rnd")) testovaci <- plm(tb ~ profit_share + debt_assets + naba + naba3 + for1 + dom + difprofit + agri + hi + li + constr + trans + trade + rd + ser + fin, data = panel, model = "within") summary(testovaci) model.matrix(tb ~ profit_share + debt_assets + naba + naba3 + for1 + dom + difprofit + agri + hi + li + constr + trans + trade + rd + ser + fin, data) model.matrix(tb ~ profit_share + debt_assets + naba + naba3 + for1 + dom + difprofit + agri + hi + li + constr + trans + trade + rd + ser + fin, panel) Thanks, Tomáš Křehlík. -- View this message in context: http://r.789695.n4.nabble.com/Problem-in-plm-package-tp4635926.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.