import js

import matplotlib

from polyscript import xworker

try:

js.document

except AttributeError:

matplotlib.use("agg")

import base64

import io

import matplotlib.pyplot as plt

import matplotlib.tri as tri

import numpy as np

# First create the x and y coordinates of the points.

n_angles = 36

n_radii = 8

min_radius = 0.25

radii = np.linspace(min_radius, 0.95, n_radii)

angles = np.linspace(0, 2 * np.pi, n_angles, endpoint=False)

angles = np.repeat(angles[..., np.newaxis], n_radii, axis=1)

angles[:, 1::2] += np.pi / n_angles

x = (radii * np.cos(angles)).flatten()

y = (radii * np.sin(angles)).flatten()

z = (np.cos(radii) * np.cos(3 * angles)).flatten()

# Create the Triangulation; no triangles so Delaunay triangulation created.

triang = tri.Triangulation(x, y)

# Mask off unwanted triangles.

triang.set_mask(

np.hypot(x[triang.triangles].mean(axis=1), y[triang.triangles].mean(axis=1))

< min_radius

)

fig1, ax1 = plt.subplots()

ax1.set_aspect("equal")

tpc = ax1.tripcolor(triang, z, shading="flat")

fig1.colorbar(tpc)

ax1.set_title("tripcolor of Delaunay triangulation, flat shading")

buf = io.BytesIO()

plt.savefig(buf, format="png")

buf.seek(0)

document = xworker.window.document

img = document.createElement("img")

img.style.transform = "scale(.5)"

img.src = "data:image/png;base64," + base64.b64encode(buf.read()).decode("UTF-8")

document.body.append(img)