I keep running up against the same error when I try to plot a line from a nls model. The data is fisheries length/weight data. Code follows:
require(graphics) pow = nls(Weight~alpha*Length^beta, data=wae, start=list(alpha=0.0000001, beta=3.0), trace=TRUE) predict(pow) plot(Weight~Length, data = wae, pch=19, xlab="Length (mm)", ylab="Weight (g)", xlim = c(150,1000), ylim = c(0, 10050)) mod = seq(150, 1000) lines(mod, predict(pow, list(Weight = mod))) The error I get after I submit the final line is: Error in xy.coords(x, y) : 'x' and 'y' lengths differ Like my last post, I'm certain there's something simple I'm overlooking. I've been able to get this to work on other data sets, but _how_ I've been able to get this to work, I'm unsure. Thanks for your help, SR Steven H. Ranney Graduate Research Assistant (Ph.D) USGS Montana Cooperative Fishery Research Unit Montana State University PO Box 173460 Bozeman, MT 59717-3460 phone: (406) 994-6643 fax: (406) 994-7479 [[alternative HTML version deleted]] ______________________________________________ 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.