How do I plot a matrix in Plots instead of gadfly

New to Julia
2

Another way to do this in Gadfly:

p = plot(z=(x,y)->Mandelbrot(x+y*im), 
    xmin=[-2.5], xmax=[1.0], ymin=[-1.75], ymax=[1.75],
    Stat.contour(levels=[10:30;], samples=200), Geom.path,
    Theme(panel_fill="midnightblue")
)

Mandelbrot

  1. Gadfly.spy is aimed at the quick plotting of numerical matrices e.g. where would expect to see the diagonal here?:
using LinearAlgebra
eye = Matrix(I,10,10)
Gadfly.spy(eye)