It didn't work because you left out the ... on the inside. it should be panel.contourplot(..., lty=1, lwd = 3)
As Bert pointed out, you don't need to specify the panel function unless you are doing something complex. > On Nov 17, 2021, at 13:06, Bert Gunter <bgunter.4...@gmail.com> wrote: > >>> panel.contourplot(lty=1, lwd = 3) ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.