Hi, I'm a french student and I need some help for my project. I have to calcul the gradient of the function : f <- function(x,y) { (1 - x^2) + (y - x^2)^2 } Thanks ! :) -- View this message in context: http://r.789695.n4.nabble.com/gradient-tp4650734.html Sent from the R help mailing list archive at Nabble.com.