Hi: On Thu, Dec 23, 2010 at 4:37 PM, Tautz, Art ENV:EX <art.ta...@gov.bc.ca>wrote:
> Dear list > > I am sorry to have to ask this question, but I have not been able to > find a solution to what seems a simple problem. I have created a > lattice plot of > a number of regression points and lines using a function containing > panel.xyplot and panel.lmline. The result is what is expected , but I > cannot figure out how to obtain the coefficients of each of the > regression lines. Any help would be appreciated. > Here's one (albeit roundabout) way to get the coefficients using the lsfit() function, assuming that we're discussing simple linear regression; you need to adapt it a bit if you want multiple regression. dd <- data.frame(gp = factor(rep(LETTERS[1:10], each = 50)), x = rnorm(500, 10, 5), y = rep(1:10, each = 50) + 2 * rnorm(500, 10, 5) + rnorm(500, 0, 0.5)) sl <- split(dd[, -1], dd$gp) do.call(rbind, lapply(sl, function(d) lsfit(d$x, d$y)$coef)) or more simply, using package plyr, library(plyr) ddply(dd, .(gp), function(d) lsfit(d$x, d$y)$coef) HTH, Dennis > > Art Tautz > Science Advisor > 2202 Main Mall UBC > Ministry of Environment > University of British Columbia > Vancouver BC Canada V6T 1Z4 > Phone 604-222-6763 > > > > [[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. > [[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.