# # Draw a contour map of the test1 data, to show the non SPD area of # the loglik # x0 <- seq(1, 3, length=20) x1 <- -.745 sig<- seq(-2, 0, length=20) lmat <- matrix(0, length(x0), length(sig)) for (i in 1:length(x0)) { for (j in 1:length(sig)) { fit<- survreg(Surv(time, status)~x, test1, init=c(x0[i], x1, sig[j]), control=list(maxiter=0)) lmat[i,j] <- fit$loglik[1] } } x1 <- -.735 lmat2 <- matrix(0, length(x0), length(sig)) for (i in 1:length(x0)) { for (j in 1:length(sig)) { fit<- survreg(Surv(time, status)~x, test1, init=c(x0[i], x1, sig[j]), control=list(maxiter=0)) lmat2[i,j] <- fit$loglik[1] } } clev <- -1*c(2.5,3:6, 8, 10, 15, 25) contour(x0, sig, lmat, levels=clev) contour(x0, sig, lmat2,levels=clev)