def __init__(self, N):
from hedge.quadrature import legendre_gauss_lobatto_points
from hedge.interpolation import newton_interpolation_function
# Find lgl and equidistant interpolation points
r_lgl = legendre_gauss_lobatto_points(N)
r_eq = numpy.linspace(-1, 1, N + 1)
self.int_f = newton_interpolation_function(r_eq, r_lgl - r_eq)
def __init__(self, N):
from hedge.quadrature import legendre_gauss_lobatto_points
from hedge.interpolation import newton_interpolation_function
# Find lgl and equidistant interpolation points
r_lgl = legendre_gauss_lobatto_points(N)
r_eq = numpy.linspace(-1, 1, N + 1)
self.int_f = newton_interpolation_function(r_eq, r_lgl - r_eq)
def test_newton_interpolation():
"""Verify Newton interpolation"""
from hedge.interpolation import newton_interpolation_function
x = [-1.5, -0.75, 0, 0.75, 1.5]
y = [-14.1014, -0.931596, 0, 0.931596, 14.1014]
nf = newton_interpolation_function(x, y)
errors = [abs(yi-nf(xi)) for xi, yi in zip(x, y)]
#print errors
assert sum(errors) < 1e-14
def test_newton_interpolation():
"""Verify Newton interpolation"""
from hedge.interpolation import newton_interpolation_function
x = [-1.5, -0.75, 0, 0.75, 1.5]
y = [-14.1014, -0.931596, 0, 0.931596, 14.1014]
nf = newton_interpolation_function(x, y)
errors = [abs(yi-nf(xi)) for xi, yi in zip(x, y)]
#print errors
assert sum(errors) < 1e-14