Hi all, I am encountering the same problem when I use nls to estimate the Bass diffusion model. I used similar code in the previous replies and it works with the data in this original post. However, I got an error when I use my own data.
Error in nls(formula = Bass.Model, start = c(p = 0.03, q = 0.4, m = max(CuSale)), : step factor 0.000488281 reduced below 'minFactor' of 0.000976563 Here is my code: Laptop_sale <- c(1405, 1863,2027,2669,2938,5275,6595,6943,8621,10905,12420,22400,32380,31600,34900,43163,47838,47592) CuSale <- Laptop_sale time <- seq_along(Laptop_sale) Bass.Model <- Laptop_sale ~ m * ((p + q)^2/p) * (exp(-(p + q) * time)/((q / p) * exp(-(p + q) * time) + 1)^2) Bass.Fit <- nls(formula = Bass.Model, start = c(p = 0.03, q = 0.4, m = max(CuSale)), trace = TRUE) Can someone help me to figure out what the problem is? Thank you very much. -- View this message in context: http://r.789695.n4.nabble.com/Problems-with-nls-tp3600409p4650971.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.
