loglik=function (para){
N=length(totalexp)
e=foodexp-para[1]-para[2]*totalexp
ll=-0.5*N*log(2*pi)-0.5*N*log(para[3]^2)-0.5*sum(e^2/para[3]^2)
return(ll)
}
library(maxLik)
res=maxLik(loglik,start=c(0.1,1,1))
summary(res)
Error in qr.solve(H[!fixed, !fixed, drop = FALSE], G0[!fixed], tol = slot(control, :
singular matrix 'a' in solve
请问到底哪错了?