On Wed, Oct 28, 2009 at 9:23 AM, Tom Gottfried <tom.gottfr...@wzw.tum.de> wrote: > ?curve > > regards, > Tom
and I was in the process of writing a curve example when I noticed Tom sent this. Here it is: set.seed(777) x <- runif(100, 0, 100) y <- 10*x + x^2 - .01*x^3 + rnorm(100, 0, 500) fit <- lm(y ~ x + I(x^2) + I(x^3)) B <- coef(fit) plot(x, y) curve(10*x + x^2 - .01*x^3, col = 4, lty = 4, lwd = 2, add = TRUE) curve(B[1] + B[2]*x + B[3]*x^2 + B[4]*x^3, col = 2, lty = 2, lwd = 2, add = TRUE) legend('topleft', c('truth', 'fit'), lty = c(4, 2), col = c(4, 2), lwd = 2) btw, it's not possible to fit a 9th-degree polynomial model with lm based on only '6 or so ordered pairs' (assuming that means 6 data points). A 5th degree polynomial would be a direct interpolater. hth, Kingsford > > Ken Ervin schrieb: >> I have a data set of 6 or so ordered pairs, and I've been able to graph >> them and have decided to use a high-order polynomial regression. I've >> used the following piece of code: >> >> regression <- function(x,y) { >> x <- c(insert_numbers_here) >> y <- c(insert_other_numbers_here) >> fit <- lm(y ~ x + I(x^2) + I(x^3) + I(x^4) + I(x^5) + I(x^6) + I(x^7) >> + I(x^8) + I(x^9)) >> summary(fit) >> >> This gives me the coefficients for the regression very nicely, but I >> would like to plot both the data and the regression curve together. How >> do I plot that regression curve as a function, and can I put it on the >> same set of axes as my data scatter plot? >> >> Thanks in advance for your help! >> >> -KE >> >> ______________________________________________ >> 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. > > ______________________________________________ > 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. > ______________________________________________ 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.