using TyPlot
x = -2:0.2:2;
y = -2:0.2:3;
X = [x for x in x for y in y]
Y = [y for x in x for y in y]
Z = X .* exp.(-X .^ 2 .- Y .^ 2);
XM = reshape(X, (length(y), length(x)))
YM = reshape(Y, (length(y), length(x)))
ZM = reshape(Z, (length(y), length(x)))
con = contour(
    XM, YM, ZM; levels=[-0.4, -0.3, -0.2, -0.1, 0, 0.1, 0.2, 0.3, 0.4], showtext="on"
)
con.get_levels()