Source code for fe_utils.scripts.plot_lagrange_points

#! /usr/bin/env python
from matplotlib import pyplot as plt
from fe_utils.finite_elements import lagrange_points
from fe_utils import ReferenceTriangle
from argparse import ArgumentParser


def plot_lagrange_points():
    parser = ArgumentParser(
        description="""Plot the nodes on the reference triangle"""
    )
    parser.add_argument(
        "degree", type=int, nargs=1,
        help="The degree of Lagrange polynomials for which to plot the nodes")

    args = parser.parse_args()

    fig = plt.figure()
    ax = fig.add_subplot(111)

    p = lagrange_points(ReferenceTriangle, args.degree[0])

    plt.plot(p[:, 0], p[:, 1], 'bo')

    for i, x in enumerate(p):
        ax.annotate(str(i), xy=x, xytext=(10, 0), textcoords='offset points')

    ax.axis([-.1, 1.1, -.1, 1.1])
    plt.show()