see ?paste main = paste ("Main effect of ", variable)
> par(mfrow = c(n/2, 2)) > for ( i in 1:n) > { > plot(1:J, y[i, 1: J], main = 'Main effect of X_i') > } > ______________________________________________ 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.