Reference: createNet

createNet(x0, x1, δx, Δx, y0, y1, δy, Δy) returns a planar set with a 2D grid, in the region x ∈ [x0, x1], y ∈ [y0, y1]. The horizontal lines have the resolution δx, and the vertical lines have the resolution δy. The spacing between vertical lines is Δx, and the spacing between horizontal lines is Δy.

Example: A square grid.
         net ≔ createNet(-10, 10, 0.01, 1, -10, 10, 0.01, 1)
         drawSet("net")

         An illustrative way to draw a grid cylinder with radius 4.
         net ≔ createNet(0, 2⋅π, 0.01, π/12, -10, 10, 0.1, 1)
         paramNet ≔ createImage("❨4, r_1, r_2❩", "r", net)
         cylinder ≔ cylindricalCoords(paramNet)
         drawSet3("cylinder")