# contours 

using Plots
x = 1:0.5:20
y = 1:0.5:10
f(x, y) = begin
        (3x + y ^ 2) * abs(sin(x) + cos(y))
    end
X = repeat(reshape(x, 1, :), length(y), 1)
Y = repeat(y, 1, length(x))
Z = map(f, X, Y)
p1 = contour(x, y, f, fill = true)
p2 = contour(x, y, Z)
plot(p1, p2)



#Makie

using CairoMakie

f = Figure(backgroundcolor = :honeydew)
Axis(f[1, 1])

xs = LinRange(0, 10, 100)
ys = LinRange(0, 15, 100)
zs = [cos(x) * sin(y) for x in xs, y in ys]

CairoMakie.contour!(zs,levels=-1:0.1:1)

f
