Contour plot for quadratic equation in R

Question

I\'m trying to recreate contour plot shown in the picture below using R. It is a contour plot of constant syrup loss as a function of speed and pressure.

Answer 1

In the outer function, the Y argument is missing. The code

z <- outer(x, y, function(x, y) 1217.30556 - 31.25625*x + 86.01667*y + 0.1291*x^2  - 2.87333*y^2 + 0.02875*x*y) 

fixed the problem.