Exemplo n.º 1
0
    def evaluate_basis_derivative_all(self, x=None, k=0, argument=0):
        if x is None:
            x = self.mesh(False, False)
        V = self.vandermonde(x)
        M = V.shape[1]
        if k == 1:
            D = np.zeros((M, M))
            D[:-1, :] = lag.lagder(np.eye(M), 1)
            W = np.dot(V, D)
            W -= 0.5*V
            V = W*np.exp(-x/2)[:, np.newaxis]

        elif k == 2:
            D = np.zeros((M, M))
            D[:-2, :] = lag.lagder(np.eye(M), 2)
            D[:-1, :] -= lag.lagder(np.eye(M), 1)
            W = np.dot(V, D)
            W += 0.25*V
            V = W*np.exp(-x/2)[:, np.newaxis]

        elif k == 0:
            V *= np.exp(-x/2)[:, np.newaxis]

        else:
            raise NotImplementedError

        return self._composite_basis(V)
Exemplo n.º 2
0
    def evaluate_basis_derivative(self, x=None, i=0, k=0, output_array=None):
        if x is None:
            x = self.mesh(False, False)
        x = np.atleast_1d(x)
        v = eval_laguerre(i, x, out=output_array)
        X = x[:, np.newaxis]
        if k == 1:
            D = np.zeros((self.N, self.N))
            D[:-1, :] = lag.lagder(np.eye(self.N), 1)
            V = np.dot(v, D)
            V -= 0.5 * v
            V *= np.exp(-X / 2)
            v[:] = V

        elif k == 2:
            D = np.zeros((self.N, self.N))
            D[:-2, :] = lag.lagder(np.eye(self.N), 2)
            D[:-1, :] -= lag.lagder(np.eye(self.N), 1)
            V = np.dot(v, D)
            V += 0.25 * v
            V *= np.exp(-X / 2)
            v[:] = V

        elif k == 0:
            v *= np.exp(-X / 2)

        else:
            raise NotImplementedError

        return v
Exemplo n.º 3
0
    def test_lagder_axis(self):
        # check that axis keyword works
        c2d = np.random.random((3, 4))

        tgt = np.vstack([lag.lagder(c) for c in c2d.T]).T
        res = lag.lagder(c2d, axis=0)
        assert_almost_equal(res, tgt)

        tgt = np.vstack([lag.lagder(c) for c in c2d])
        res = lag.lagder(c2d, axis=1)
        assert_almost_equal(res, tgt)
Exemplo n.º 4
0
    def test_lagder_axis(self):
        # check that axis keyword works
        c2d = np.random.random((3, 4))

        tgt = np.vstack([lag.lagder(c) for c in c2d.T]).T
        res = lag.lagder(c2d, axis=0)
        assert_almost_equal(res, tgt)

        tgt = np.vstack([lag.lagder(c) for c in c2d])
        res = lag.lagder(c2d, axis=1)
        assert_almost_equal(res, tgt)
Exemplo n.º 5
0
    def test_lagder(self) :
        # check exceptions
        assert_raises(ValueError, lag.lagder, [0], .5)
        assert_raises(ValueError, lag.lagder, [0], -1)

        # check that zeroth deriviative does nothing
        for i in range(5) :
            tgt = [0]*i + [1]
            res = lag.lagder(tgt, m=0)
            assert_equal(trim(res), trim(tgt))

        # check that derivation is the inverse of integration
        for i in range(5) :
            for j in range(2, 5) :
                tgt = [0]*i + [1]
                res = lag.lagder(lag.lagint(tgt, m=j), m=j)
                assert_almost_equal(trim(res), trim(tgt))

        # check derivation with scaling
        for i in range(5) :
            for j in range(2, 5) :
                tgt = [0]*i + [1]
                res = lag.lagder(lag.lagint(tgt, m=j, scl=2), m=j, scl=.5)
                assert_almost_equal(trim(res), trim(tgt))
Exemplo n.º 6
0
    def test_lagder(self):
        # check exceptions
        assert_raises(ValueError, lag.lagder, [0], .5)
        assert_raises(ValueError, lag.lagder, [0], -1)

        # check that zeroth deriviative does nothing
        for i in range(5):
            tgt = [0] * i + [1]
            res = lag.lagder(tgt, m=0)
            assert_equal(trim(res), trim(tgt))

        # check that derivation is the inverse of integration
        for i in range(5):
            for j in range(2, 5):
                tgt = [0] * i + [1]
                res = lag.lagder(lag.lagint(tgt, m=j), m=j)
                assert_almost_equal(trim(res), trim(tgt))

        # check derivation with scaling
        for i in range(5):
            for j in range(2, 5):
                tgt = [0] * i + [1]
                res = lag.lagder(lag.lagint(tgt, m=j, scl=2), m=j, scl=.5)
                assert_almost_equal(trim(res), trim(tgt))