I wish to create contour of P = f(X,Y), where
X <- seq(-10, 10, 0.1)
Y <- seq(-10, 10, 0.1)
How do I create a grid of points and store them in data.frame/tibble of X and Y? such that for each value of X, Y ranges from -10 to 10. So that I can calculate P for all combinations of X and Y to draw contour.
Thanks