Using R to fit a Sigmoidal Curve

Question

I have read a post ( Sigmoidal Curve Fit in R ). It was labeled duplicated, but I can\'t see anything related with the posts. And the answer given for the posts was not enou

Answer 1

The code I used to fit your data:

 df <- data.frame(x=c(3.9637878,3.486667,3.0095444,2.5324231,2.0553019,1.5781806,1.1010594,0.6242821),                     
                  y=c(6491.314,6190.092,2664.021,2686.414,724.707,791.243,1809.586,541.243))

library(drc)
fm <- drm(y ~ x, data = df, fct = G.3())

plot(fm)
summary(fm)

The way it looks after fitting: