kindly help correct this program as given below i run and run is given me some error and i want to estimate robust MM rm(list=ls()) require(stats) require(robustbase) x1<-as.matrix(c(5.548,4.896,1.964,3.586,3.824,3.111,3.607,3.557,2.989)) y<-as.matrix(c(2.590,3.770,1.270,1.445,3.290,0.930,1.600,1.250,3.450)) x2<-as.matrix(c(0.137,2.499,0.419,1.699,0.605,0.677,0.159,1.699,0.340)) k<-rep(1,9) x<-data.frame(k,x1,x2) xx<-data.frame(y,x1,x2) freg<-function(y,x1,x2){ reg<- lm(y ~ x1 + x2 , data=x) return(reg) } fit<-freg(y,x1,x2) b<-as.matrix((coef(fit))) f<-function(b,x1,x2){ fit<-nlrob(y ~ x1 / (1+ b[1]*x2^b[2]),data = xx, start list(b[2],b[3])) return(fit) } fit1<-f(b,x1,x2) Error in nlrob(y ~ x1/(1 + b[1] * x2^b[2]), data = xx, start = list(b[2], : 'start' must be fully named (list or numeric vector) [[alternative HTML version deleted]]