import numpy as np
import holoviews as hv
from holoviews import opts

hv.extension('matplotlib')

img = hv.Image(np.random.rand(10, 10))

fig = hv.render(img)

print('Figure: ', fig)
print('Axes:   ', fig.axes)

hv.output(fig='svg')

from holoviews.operation import contours

x = y = np.arange(-3.0, 3.0, 0.1)
X, Y = np.meshgrid(x, y) 

def g(x,y,c):
    return 2*((x-y)**2/(x**2+y**2)) + np.exp(-(np.sqrt(x**2+y**2)-c)**2)

img = hv.Image(g(X,Y,2))
filled_contours = contours(img, filled=True)

filled_contours

hv.save(filled_contours, 'contours.png', dpi=144)

from IPython.display import Image
Image('contours.png', width=400)

holomap = hv.HoloMap([(t, hv.Image(g(X,Y, 4 * np.sin(np.pi*t)))) for t in np.linspace(0,1,21)]).opts(
    cmap='fire', colorbar=True, show_title=False, xaxis='bare', yaxis='bare')

contour_hmap = contours(holomap, filled=True)

hv.output(contour_hmap, holomap='gif', fps=5)

hv.output(contour_hmap, holomap='mp4', fps=5)

hv.output(fig='png', dpi=72)
filled_contours.opts(aspect=2, fig_inches=5, fig_bounds=(0, 0, 1, 1))

line_contours = contours(img).opts(aspect=3)
fill_contours = filled_contours.opts(aspect=2)

opts.defaults(opts.Layout(sublabel_format='', fig_size=150))

(line_contours + fill_contours).opts(tight=True)

(line_contours + fill_contours).opts(aspect_weight=True, tight=True)