Python tensor.verify_grad函数代码示例

    def test_maxpool():
        # generate flatted images
        maxpoolshps = ((2,2),(3,3),(4,4),(5,5),(6,6))
        imval = N.random.rand(4,5,10,10)

        images = T.dmatrix()
        for maxpoolshp in maxpoolshps:

            # symbolic stuff
            output, outshp = sp.max_pool(images, imval.shape[1:], maxpoolshp)
            f = function([images,],[output,])
            output_val = f(imval.reshape(imval.shape[0],-1))

            # numeric verification
            my_output_val = N.zeros((imval.shape[0], imval.shape[1],
                                     imval.shape[2]/maxpoolshp[0],
                                     imval.shape[3]/maxpoolshp[1]))
            assert N.prod(my_output_val.shape[1:]) == N.prod(N.r_[imval.shape[1],outshp])

            for n in range(imval.shape[0]):
                for k in range(imval.shape[1]):
                    for i in range(imval.shape[2]/maxpoolshp[0]):
                        for j in range(imval.shape[3]/maxpoolshp[1]):
                            ii,jj = i*maxpoolshp[0], j*maxpoolshp[1]
                            patch = imval[n,k,ii:ii+maxpoolshp[0],jj:jj+maxpoolshp[1]]
                            my_output_val[n,k,i,j] = N.max(patch)
            my_output_val = my_output_val.reshape(imval.shape[0],-1)
            assert N.all(output_val == my_output_val)

            def mp(input):
                output, outshp = sp.max_pool(input, imval.shape[1:], maxpoolshp)
                return output
            T.verify_grad(None, mp, [imval.reshape(imval.shape[0],-1)])

def test_col_scale():
    x = theano.sparse.csc_dmatrix()
    s = theano.tensor.dvector()

    def d(x, s):
        return sp.sp_sum(sp.col_scale(x, s), sparse_grad=True)

    rng = numpy.random.RandomState(8723)
    R = 5
    C = 8

    x_val_dense = numpy.zeros((R, C), dtype="d")
    for idx in [(0, 0), (4, 1), (2, 1), (3, 3), (4, 4), (3, 7), (2, 7)]:
        x_val_dense.__setitem__(idx, rng.randn())
    x_val = scipy.sparse.csc_matrix(x_val_dense)

    s_val = rng.randn(C)

    f = theano.function([x, s], sp.col_scale(x, s))

    print "A", f(x_val, s_val).toarray()
    print "B", (x_val_dense * s_val)

    assert numpy.all(f(x_val, s_val).toarray() == (x_val_dense * s_val))

    if 0:
        tensor.verify_grad(None, d, [x_val, s_val], mode=theano.Mode(linker="py", optimizer="fast_compile"))
    else:
        print >> sys.stderr, "WARNING: skipping gradient test because verify_grad doesn't support sparse arguments"

def test_eigvalsh_grad():
    rng = numpy.random.RandomState(utt.fetch_seed())
    a = rng.randn(5, 5)
    a = a + a.T
    b = 10 * numpy.eye(5, 5) + rng.randn(5, 5)
    tensor.verify_grad(lambda a, b: eigvalsh(a, b).dot([1, 2, 3, 4, 5]),
                       [a, b], rng=numpy.random)

def test_det_grad():
    # If scipy is not available, this test will fail, thus we skip it.
    if not use_scipy:
        raise SkipTest('Scipy is not available')
    rng = numpy.random.RandomState(utt.fetch_seed())

    r = rng.randn(5,5)
    tensor.verify_grad(det, [r], rng=numpy.random)

def test_expm_grad_3():
    # with non-symmetric matrix (complex eigenvectors)
    if not imported_scipy:
        raise SkipTest("Scipy needed for the expm op.")
    rng = numpy.random.RandomState(utt.fetch_seed())
    A = rng.randn(5, 5).astype(config.floatX)

    tensor.verify_grad(expm, [A,], rng=rng)

def test_expm_grad_3():
    # with non-symmetric matrix (complex eigenvectors)
    if not imported_scipy:
        raise SkipTest("Scipy needed for the expm op.")
    rng = numpy.random.RandomState(utt.fetch_seed())
    # Always test in float64 for better numerical stability.
    A = rng.randn(5, 5)

    tensor.verify_grad(expm, [A], rng=rng)

def test_inverse_grad():
    rng = np.random.RandomState(utt.fetch_seed())
    r = rng.randn(4, 4)
    tensor.verify_grad(matrix_inverse, [r], rng=np.random)

    rng = np.random.RandomState(utt.fetch_seed())

    r = rng.randn(4, 4)
    tensor.verify_grad(matrix_inverse, [r], rng=np.random)

def verify_grad(op, pt, n_tests=2, rng=None, *args, **kwargs):
    """
    Wrapper for tensor/basic.py:verify_grad
    Takes care of seeding the random number generator if None is given
    """
    if rng is None:
        seed_rng()
        rng = numpy.random
    T.verify_grad(op, pt, n_tests, rng, *args, **kwargs)

    def test_fractional_max_pooling_numeric_gradient():
        def fun(x):
            return fmp.DisjointPseudorandomFractionalMaxPooling2DOp(
                alpha=1.414,
                u=0.5
            )(x)

        T.verify_grad(fun,
                      [np.arange(25).reshape(1, 1, 5, 5).astype(fX)],
                      rng=np.random)

def test_eigvalsh_grad():
    if not imported_scipy:
        raise SkipTest("Scipy needed for the geigvalsh op.")
    import scipy.linalg

    rng = numpy.random.RandomState(utt.fetch_seed())
    a = rng.randn(5, 5)
    a = a + a.T
    b = 10 * numpy.eye(5, 5) + rng.randn(5, 5)
    tensor.verify_grad(lambda a, b: eigvalsh(a, b).dot([1, 2, 3, 4, 5]), [a, b], rng=numpy.random)

def test_expm_grad_2():
    # with non-symmetric matrix with real eigenspecta
    if not imported_scipy:
        raise SkipTest("Scipy needed for the expm op.")
    rng = numpy.random.RandomState(utt.fetch_seed())
    A = rng.randn(5, 5).astype(config.floatX)
    w = (rng.randn(5).astype(config.floatX))**2
    A = (numpy.diag(w**0.5)).dot(A + A.T).dot(numpy.diag(w**(-0.5)))
    assert not numpy.allclose(A, A.T)

    tensor.verify_grad(expm, [A,], rng=rng)

def test_expm_grad_2():
    # with non-symmetric matrix with real eigenspecta
    if not imported_scipy:
        raise SkipTest("Scipy needed for the expm op.")
    rng = numpy.random.RandomState(utt.fetch_seed())
    # Always test in float64 for better numerical stability.
    A = rng.randn(5, 5)
    w = rng.randn(5)**2
    A = (numpy.diag(w**0.5)).dot(A + A.T).dot(numpy.diag(w**(-0.5)))
    assert not numpy.allclose(A, A.T)

    tensor.verify_grad(expm, [A], rng=rng)

    def test_softmax_grad(self):
        def cmp(n, m, f, f_gpu):
            data = numpy.arange(n * m, dtype="float32").reshape(n, m)
            gdata = numpy.asarray(data)[:, :, None, None]

            out = f(data)
            gout = numpy.asarray(f_gpu(gdata))[:, :, 0, 0]
            utt.assert_allclose(out, gout)

        x = T.matrix("x", "float32")
        x_gpu = T.tensor4("x_gpu", "float32")
        f_z = T.nnet.softmax_op
        f_gpu = dnn.GpuDnnSoftmax("accurate", "channel")

        # Verify the grad operation
        dims = (2, 3, 4, 5)
        gdata = numpy.arange(numpy.product(dims), dtype="float32").reshape(dims)
        T.verify_grad(f_gpu, [gdata], rng=numpy.random, mode=mode_with_gpu)

        # Verify that the CPU and GPU implementations return the same results
        # up to a tolerance.

        self._test_softmax(x, x_gpu, f_z, f_gpu, cmp)

        self._test_softmax(x, x, f_z, f_z, self._cmp)

        # Verify that the SoftmaxGrad -> Gpu[Dnn]SoftmaxGrad
        # optimization is applied when cudnn is required
        y = T.fvector("y")
        f = theano.function([y], T.grad(T.nnet.softmax(y).mean(), y), mode=mode_with_gpu)
        sorted_f = f.maker.fgraph.toposort()
        assert len([i for i in sorted_f if isinstance(i.op, self.gpu_grad_op)]) == 1
        assert len([i for i in sorted_f if isinstance(i.op, theano.tensor.nnet.SoftmaxGrad)]) == 0

        # Verify that the SoftmaxGrad -> Gpu[Dnn]SoftmaxGrad
        # optimization is not applied when cudnn is excluded or not
        # available
        mode_wo_cudnn = mode_with_gpu.excluding("cudnn")
        y = T.fvector("y")
        f = theano.function([y], T.grad(T.nnet.softmax(y).mean(), y), mode=mode_wo_cudnn)
        sorted_f = f.maker.fgraph.toposort()
        assert len([i for i in sorted_f if isinstance(i.op, self.gpu_grad_op)]) == 0
        assert len([i for i in sorted_f if isinstance(i.op, theano.tensor.nnet.SoftmaxGrad)]) == 1

        # Verify that the SoftmaxGrad -> GpuDnnSoftmaxGrad do not
        # crash with manual graph
        y = T.fvector("y")
        o = theano.tensor.nnet.SoftmaxGrad()(y, y * 2)
        f = theano.function([y], o, mode=mode_with_gpu)
        sorted_f = f.maker.fgraph.toposort()
        assert len([i for i in sorted_f if isinstance(i.op, self.gpu_grad_op)]) == 1
        assert len([i for i in sorted_f if isinstance(i.op, theano.tensor.nnet.SoftmaxGrad)]) == 0

def test_verify_exprgrad():
    from theano import tensor
    import numpy
    x = tt.scalar()
    f = theano.function([x], x)
    #def f(x):
    #    return x

    x_val = numpy.asarray([0.1, 0.2])

    rng = numpy.random.RandomState(42)

    print 'going'
    print tensor.verify_grad(f, [x_val], rng=rng)

    def test_grad(self):
        x = tensor.matrix('x')
        one_of_n = tensor.lvector('one_of_n')
        op = crossentropy_categorical_1hot
        xe = op(x, one_of_n)
        f = theano.function([x, one_of_n], xe)
        x_val = numpy.asarray([[.4, .6, .0], [.1, .8, .1]],
                dtype=config.floatX)
        xe_val = f(x_val, [0, 1])
        assert numpy.allclose(xe_val, -numpy.log([.4, .8]))

        def oplike(x):
            return op(x, [0, 1])

        tensor.verify_grad(oplike, [x_val], rng=numpy.random)