[R] question about non-linear least squares in R

[Yu (Warren) Wang]

Hi, everyone,
    My question is: It's not every time that you can get a converged 
result from the nls function. Is there any solution for me to get a 
reasonable result? For example:

x <- c(-0.06,-0.04,-0.025,-0.015,-0.005,0.005,0.015,0.025,0.04,0.06)

y <- 
c(1866760,1457870,1314960,1250560,1184850,1144920,1158850,1199910,1263850,1452520)

fitOup<- nls(y ~ constant + A*(x-MA)^4 + B*(x-MA)^2, 
start=list(constant=10000000, A=100000000, B=-1000000, MA=0), 
control=nls.control(maxiter=100, minFactor=1/4096), trace=TRUE)

 

 For this one, I cannot get the converged result, how can I reach it? To 
use another funtion or to modify some settings for nls?

Thank you very much!

Yours,

Warren