I am trying to understand NLM package, so I generated this data set consisting y and x using
y= a + b*x +c*x^2 + N(0,10), with a=3.5,b=4.5,c=5.5 Given y and x, I am trying to use NLM to have estimates of parameters a, b and c that minimize the least square error my code looks like f<- function(y,x,a,b,c) {sum((y-(a+b*x+c*x^2))^2)} nlm(f, y, x, a=3, b=4,c=5) But it comes up with rediculous result. My understanding of this NLM must be wrong. Please help! Andy ______________________________________________ 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.