[v1.0.1] Drop quadpy dependency

[adtzlr]

As mentioned in #92 quadpy increases the import time drastically. We can drop that dependency and use built-in functions of numpy.

[adtzlr]

this would be a simple replacement

def gauss_legendre(order, dim):
    "Gauss-Legendre Points and Weights."
    
    x, w = np.polynomial.legendre.leggauss(order)
    
    points = np.stack(
        np.meshgrid(*([x] * dim), indexing="ij")
    )[::-1].reshape(dim, -1).T
    
    idx = ["i", "j", "k"][:dim]
    weights = np.einsum(", ".join(idx), *([w] * dim)).ravel()
    
    return points, weights

[adtzlr]

even nicer because it works on arbitrary dimensions...

import numpy as np
from string import ascii_lowercase


def gauss_legendre(order, dim):
    "Gauss-Legendre Points and Weights."
    
    x, w = np.polynomial.legendre.leggauss(order)
    
    points = np.stack(
        np.meshgrid(*([x] * dim), indexing="ij")
    )[::-1].reshape(dim, -1).T
    
    idx = list(ascii_lowercase)[: dim]
    weights = np.einsum(", ".join(idx), *([w] * dim)).ravel()
    
    return points, weights

[adtzlr]

see

felupe/felupe/quadrature/_gausslegendre.py

Lines 34 to 60 in 20771c9

	class GaussLegendre(Scheme):
	"A n-dimensional Gauss-Legendre quadrature rule."
	def __init__(self, order: int, dim: int):
	"""Arbitrary `order` Gauss-Legendre quadrature rule of `dim` 1, 2 or 3
	on the interval [-1, 1] as approximation of
	∫ f(x) dx ≈ ∑ f(x_a) w_a (1)
	with `a` quadrature points `x_a` and corresponding weights `w_a`.
	"""
	# integration point weights and coordinates
	if dim not in [1, 2, 3]:
	raise ValueError("Wrong dimension.")
	x, w = np.polynomial.legendre.leggauss(1 + order)
	points = (
	np.stack(np.meshgrid(*([x] * dim), indexing="ij"))[::-1].reshape(dim, -1).T
	)
	idx = list(ascii_lowercase)[:dim]
	weights = np.einsum(", ".join(idx), *([w] * dim)).ravel()
	super().__init__(points, weights)

[adtzlr]

fixed by #96