Try this after displaying the xyplot: # this fit.curve returns the whole nls object, not the coefs fit.curve<-function(tab) { nls(y1 ~ 100/(1+exp(((-log(81))/a)*(x1-b))), start=list(a=min(tab$x1[tab$y1>76],na.rm=T)-max(tab$x1[tab$y1<15],na.rm=T),b=tab$x1[abs(tab$y1-50)==min(abs(tab$y1-50),na.rm=T)][!is.na(tab$x1[abs(tab$y1-50)==min(abs(tab$y1-50),na.rm=T)])]),data=tab) }
trellis.focus("panel", 1, 1) f <- function(x) panel.lines(x$x1, fitted(fit.curve(x)), col = 1) junk <- by(df, df$factor1, f) trellis.unfocus() On 8/16/06, GOUACHE David <[EMAIL PROTECTED]> wrote: > Hello RHelpers, > > This may already have been answered, but despite days of scouring through the > archives I haven't found it. > My goal is to add multiple fitted curves to a plot. > An example data set (a data frame named df in following code) is: > > x1 y1 factor1 > 4 1298.25 0.00000000 1 > 5 1393.25 0.00000000 1 > 6 1471.50 0.04597701 1 > 7 1586.70 2.56908046 1 > 8 1692.10 11.14080460 1 > 9 1832.55 45.50459770 1 > 10 1928.30 65.56000000 1 > 11 2092.40 100.00000000 1 > 31 1202.90 0.00000000 2 > 41 1298.25 0.00000000 2 > 51 1393.25 0.37885057 2 > 61 1471.50 0.76839080 2 > 71 1586.70 7.75206897 2 > 81 1692.10 50.19448276 2 > 91 1832.55 94.08045977 2 > 101 1928.30 100.00000000 2 > 111 2092.40 100.00000000 2 > 14 1028.50 0.11111111 3 > 22 1106.40 0.04938272 3 > 32 1202.90 0.03448276 3 > 42 1298.25 0.34482759 3 > 52 1393.25 1.43850575 3 > 62 1471.50 1.96850575 3 > 72 1586.70 36.80597701 3 > 82 1692.10 92.83390805 3 > 92 1832.55 100.00000000 3 > 15 1028.50 0.09638554 4 > 23 1106.40 0.39988506 4 > 33 1202.90 0.49321839 4 > 43 1298.25 1.66045977 4 > 53 1393.25 7.51137931 4 > 63 1471.50 42.02724138 4 > 73 1586.70 99.12068966 4 > 83 1692.10 100.00000000 4 > > I plot this with xyplot: > > trellis.par.set("background","white") > trellis.par.set(list(superpose.symbol=list(pch=c(15:17,21,25)))) > xyplot(y1 ~ x1, data=df, groups=factor1, > type = "p", > auto.key = > list(space = "right", points = TRUE, lines = FALSE)) > > For each level of factor1 I fit a growth curve: > > fit.curve<-function(tab) > { > res.fit<-nls(y1 ~ 100/(1+exp(((-log(81))/a)*(x1-b))), > start=list(a=min(tab$x1[tab$y1>76],na.rm=T)-max(tab$x1[tab$y1<15],na.rm=T),b=tab$x1[abs(tab$y1-50)==min(abs(tab$y1-50),na.rm=T)][!is.na(tab$x1[abs(tab$y1-50)==min(abs(tab$y1-50),na.rm=T)])]),data=tab) > coef(res.fit) > } > by(df,list(df$factor1),fit.curve) > > I would like to add the 4 curves corresponding to these 4 fits to my graphic. > The elegant way would be a custom panel function I suppose, but I haven't > been able to write one up... > Could someone help me out on this please? > > In advance thanks very much!!! > > David Gouache > Arvalis - Institut du Végétal > Station de La Minière > 78280 Guyancourt > Tel: 01.30.12.96.22 / Port: 06.86.08.94.32 > > ______________________________________________ > R-help@stat.math.ethz.ch 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@stat.math.ethz.ch 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.