Dear Anders and Paulo,
Thanks very much for your recommendations!
I did it this way:
test2 <- unlist(lapply(test, function(x)
cbind(x$par[1], x$par[2], x$value, x$conv)))
m<- as.data.frame(matrix(test2, nrow = dim(grid)[1], ncol = 4, byrow = T))
names(m) <- c("s2", "rho", "value", "conv")
but I sure there are better ways....
Sincerely,
Tord