levels.py

def density_plot(subplot_number, value, label, name, labels):
    extent = (gx[0, 0], gx[-1, -1], gy[0, 0], gy[-1, -1])

    ax = fig.add_subplot(120 + subplot_number, aspect='equal')
    ax.set_xlabel(labels[0])
    ax.set_ylabel(labels[1])
    ax.set_title(name)
    ax.imshow(value[0], extent=extent)
    ax.contour(gx, gy, value[1].real, [0.0], colors='red', extent=extent)
    ax.contour(gx, gy, value[1].imag, [0.0], colors='blue', extent=extent)