1 files changed, 53 insertions, 0 deletions
diff --git a/vquad/test/test_tables.py b/vquad/test/test_tables.py
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+++ b/vquad/test/test_tables.py
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+# Copyright 2017 Christoph Groth (CEA).
+#
+# This file is part of Vquad.  It is subject to the license terms in the file
+# LICENSE.rst found in the top-level directory of this distribution.
+
+from fractions import Fraction as Frac
+from itertools import combinations
+import numpy as np
+from numpy.testing import assert_allclose
+
+from .. import tables
+
+
+def test_legendre():
+    legs = tables.legendre(11)
+    comparisons = [(legs[0], [1], 1),
+                    (legs[1], [0, 1], 1),
+                    (legs[10], [-63, 0, 3465, 0, -30030, 0,
+                                90090, 0, -109395, 0, 46189], 256)]
+    for a, b, div in comparisons:
+        for c, d in zip(a, b):
+            assert c * div == d
+
+
+def test_scalar_product(n=33):
+    legs = tables.legendre(n)
+    selection = [0, 5, 7, n-1]
+    for i in selection:
+        for j in selection:
+            assert (tables.scalar_product(legs[i], legs[j])
+                    == ((i == j) and Frac(2, 2*i + 1)))
+
+
+def simple_newton(n):
+    """Slower than 'newton()' and prone to numerical error."""
+    nodes = -np.cos(np.arange(n) / (n-1) * np.pi)
+    return [sum(np.prod(-np.asarray(sel))
+                for sel in combinations(nodes, n - d))
+            for d in range(n + 1)]
+
+
+def test_newton():
+    assert_allclose(tables.newton(9), simple_newton(9), atol=1e-15)
+
+
+def test_newton_legendre(level=1):
+    legs = [np.array(leg, float)
+            for leg in tables.legendre(tables.sizes[level] + 1)]
+    result = np.zeros(len(legs[-1]))
+    for factor, leg in zip(tables.newton_coeffs[level], legs):
+        factor *= np.sqrt((2*len(leg) - 1) / 2)
+        result[:len(leg)] += factor * leg
+    assert_allclose(result, tables.newton(tables.sizes[level]), rtol=1e-15)