[R] Plotting a smooth curve from predict

Wilson, Andrew eiaaw at exchange.lancs.ac.uk
Tue Jul 31 12:21:57 CEST 2007

Probably a very simple query:

When I try to plot a curve from a fitted polynomial, it comes out rather
jagged, not smooth like fitted curves in other stats software.  Is there
a way of getting a smooth curve in R?

What I'm doing at the moment (for the sake of example) is:

> x <- c(1,2,3,4,5,6,7,8,9,10)

> y <- c(10,9,8,7,6,6.5,7,8,9,10)

> b <- data.frame(cbind(x,y))

> w <- gls(y ~ I(x)+I(x^2),correlation=corARMA(p=1),method="ML",data=b)

> plot(predict(w),type="l")

Many thanks,

Andrew Wilson

More information about the R-help mailing list