Thank you. I guess using predict() is probably closest to the R philosophy.
All the best, Primož 2009/10/9 Henrique Dallazuanna <www...@gmail.com>: > Try with predict: > > plot(x, y) > lines(0:10, predict(yfit, list(x = 0:10))) > > 2009/10/9 Primoz PETERLIN <primozz.peter...@gmail.com>: >> Dear all, >> >> Here I come with another stupid question. Suppose I want to use nls() >> to fit a series of data (here modelled by generated points), then plot >> the points and the fitting curve. I figured out some way of doing it: >> >> x <- runif(1:20, 0, 10) >> y <- 0.1*x^2 - rep(3, length(x)) + rnorm(length(x), sd = 0.5) >> >> yfit <- nls(y ~ a*x^2 + b*x + c, >> start = list(a = 1, b = 1, c = 1), >> trace = TRUE) >> >> plot(x, y) >> curve(coef(yfit)[1]*x^2 + coef(yfit)[2]*x + coef(yfit)[3], 0, 10, >> add = TRUE) >> >> However, this code is rather fortranesque, and most likely there >> exists a much more elegant way in R/S, something like abline() which >> exists for straight lines. Since both the formula and the coefficients >> are available as a result of nls() (here as formula(yfit) and >> coef(yfit)), I thought there ought to be a way something along the >> following lines: >> >> f <- substitute(formula(yfit), as.list(coef(yfit))) >> curve(f, ...) >> >> However, this snippet of code doesn't work. Am I thinking into the >> correct direction at all? >> >> Thanks in advance. >> >> All the best, >> Primož >> >> -- >> Primož Peterlin, Inštitut za biofiziko, Med. fakulteta, Univerza v >> Ljubljani >> Lipičeva 2, SI-1000 Ljubljana, Slovenija. primoz.peter...@mf.uni-lj.si >> Tel +386-1-5437612, fax +386-1-4315127, >> http://biofiz.mf.uni-lj.si/~peterlin/ >> F8021D69 OpenPGP fingerprint: CB 6F F1 EE D9 67 E0 2F 0B 59 AF 0D 79 56 19 >> 0F >> >> ______________________________________________ >> 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. >> > > > > -- > Henrique Dallazuanna > Curitiba-Paraná-Brasil > 25° 25' 40" S 49° 16' 22" O > -- Primož Peterlin, Inštitut za biofiziko, Med. fakulteta, Univerza v Ljubljani Lipičeva 2, SI-1000 Ljubljana, Slovenija. primoz.peter...@mf.uni-lj.si Tel +386-1-5437612, fax +386-1-4315127, http://biofiz.mf.uni-lj.si/~peterlin/ F8021D69 OpenPGP fingerprint: CB 6F F1 EE D9 67 E0 2F 0B 59 AF 0D 79 56 19 0F ______________________________________________ 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.
