On 2010-04-22 11:09, Muhammad Rahiz wrote:
Hello everyone,I'm trying to draw the non-linear regression curve to look at the distance decay relationship between distance and correlation values. But I'm not able to plot the curve as I'm struggling with the following error ("parameters without starting value in 'data': x") and found no answers online.* *Can anyone help... -- Muhammad* * s1 cm 1 0 0.57223196 2 10 0.33110049 3 20 0.11163181 4 30 0.10242237 5 40 0.09254315 6 50 0.02739370 7 60 0.02567137 8 70 0.02492397 9 80 0.03206637 10 90 0.02487381 11 100 0.01747584 12 110 0.15977533 13 120 0.13317708 new <- data.frame(s1,cm) plot(s1,cm) f <- function(x,a,b){a*exp(-b*x)} fm <- nls(cm~f(x,a,b),data=new,start=c(a=1,b=1)) co <- coef(fm)
Presumably you want f(s1,a,b) in your nls call. -Peter Ehlers
curve(f(x,a=co[1],b=co[2]),add=TRUE,col="blue") ______________________________________________ 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.
-- Peter Ehlers University of Calgary ______________________________________________ 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.
