GLMakie: plot surface and nonlinear constraints

Hi,
I’m plotting the surface of a function (the objective function of an optimization problem) with this code:

using GLMakie
let
    # range
    x = LinRange(-2, 0.5, 51)
    y = LinRange(-2, 2, 51)
    # objective function
    z = 100 .* (y' .- x .^ 2) .^ 2 .+ (1 .- x) .^ 2

    zmin, zmax = minimum(z), maximum(z)
    cmap = :greens
    fig = Figure(resolution = (900,900))
    ax = Axis3(fig, perspectiveness = 0.5, elevation = π/9,
       zgridcolor = :grey, ygridcolor = :grey, xgridcolor = :grey)
    surface!(ax, x, y, z, colormap = cmap, colorrange = (zmin, zmax)) 
    fig[1,1] = ax
    fig
end

found here.

I’d like to portray the nonlinear constraints of the problem as well, for example:
x*y >= 1
x + y^2 >= 0
by e.g. displaying the infeasible points with a different color (throwing them out altogether wouldn’t help a lot for the visualization).
I don’t know if Makie supports that natively, or if I need to filter the LinRanges and display 2 surfaces. Can you help me out?
Best,

Charlie

Color accepts Matrix{Float} and Matrix{<:Colorant}, which should make that possible!

I think its not as easy as to pass a colour matrix. At least I didn’t see how to do it. It’s not possible to use colorrange, and clips, because the regions of interest are not constant. Well, this is my attempt at the problem.

https://lazarusa.github.io/BeautifulMakie/surfWireLines/surfaceConstraints/

3 Likes

What’s happening on the right edge?

image

Thanks a lot (even with the funny axis label :grin:)!