search for: loess1

I have successfully fitted the model loess.fit1 <- loess(response ~ X*Y) and plotted it in 3D using X.grid <- seq(0,10,length=100) Y.grid <- seq(0,1000,length=100) pred.loess1 <- predict(loess.fit1, expand.grid(x = X.grid, y = Y.grid)) persp(X.grid, Y.grid, pred.loess1, theta = 0, phi = 12) I would like to add a series of points along the fitted surface at X.grid = 2, in red. The example in the online help uses f <- function(x,y) { r <- sqrt(x^2...