Method test_polyint

numpy/polynomial/tests/test_polynomial.py:303–381

(self)

class TestIntegral:

    def test_polyint(self):
        # check exceptions
        assert_raises(TypeError, poly.polyint, [0], .5)
        assert_raises(ValueError, poly.polyint, [0], -1)
        assert_raises(ValueError, poly.polyint, [0], 1, [0, 0])
        assert_raises(ValueError, poly.polyint, [0], lbnd=[0])
        assert_raises(ValueError, poly.polyint, [0], scl=[0])
        assert_raises(TypeError, poly.polyint, [0], axis=.5)
        with assert_warns(DeprecationWarning):
            poly.polyint([1, 1], 1.)

        # test integration of zero polynomial
        for i in range(2, 5):
            k = [0]*(i - 2) + [1]
            res = poly.polyint([0], m=i, k=k)
            assert_almost_equal(res, [0, 1])

        # check single integration with integration constant
        for i in range(5):
            scl = i + 1
            pol = [0]*i + [1]
            tgt = [i] + [0]*i + [1/scl]
            res = poly.polyint(pol, m=1, k=[i])
            assert_almost_equal(trim(res), trim(tgt))

        # check single integration with integration constant and lbnd
        for i in range(5):
            scl = i + 1
            pol = [0]*i + [1]
            res = poly.polyint(pol, m=1, k=[i], lbnd=-1)
            assert_almost_equal(poly.polyval(-1, res), i)

        # check single integration with integration constant and scaling
        for i in range(5):
            scl = i + 1
            pol = [0]*i + [1]
            tgt = [i] + [0]*i + [2/scl]
            res = poly.polyint(pol, m=1, k=[i], scl=2)
            assert_almost_equal(trim(res), trim(tgt))

        # check multiple integrations with default k
        for i in range(5):
            for j in range(2, 5):
                pol = [0]*i + [1]
                tgt = pol[:]
                for k in range(j):
                    tgt = poly.polyint(tgt, m=1)
                res = poly.polyint(pol, m=j)
                assert_almost_equal(trim(res), trim(tgt))

        # check multiple integrations with defined k
        for i in range(5):
            for j in range(2, 5):
                pol = [0]*i + [1]
                tgt = pol[:]
                for k in range(j):
                    tgt = poly.polyint(tgt, m=1, k=[k])
                res = poly.polyint(pol, m=j, k=list(range(j)))