using AbstractPlotting NL = 30 NR = 31 function xy_data(x, y) r = sqrt(x^2 + y^2) r == 0.0 ? 1f0 : (sin(r)/r) end lspace = range(-10, stop = 10, length = NL) rspace = range(-10, stop = 10, length = NR) z = Float32[xy_data(x, y) for x in lspace, y in rspace] l = range(0, stop = 3, length = NL) r = range(0, stop = 3, length = NR) surface( l, r, z, colormap = :Spectral )