Python tensor.vectors函数代码示例

    def test_connection_pattern_override(self, cls_ofg):
        x, y = T.vectors('xy')

        def f1(x, y):
            del x
            # but we know how to backpropagate for x for some reasons
            # and we don't care about the gradient wrt y.
            return y + T.round(y)

        def f1_back(inputs, output_gradients):
            return [
                output_gradients[0],
                theano.gradient.disconnected_type()]

        op = cls_ofg(
            inputs=[x, y],
            outputs=[f1(x, y)],
            grad_overrides=f1_back,
            connection_pattern=[[True], [False]],  # This is new
            on_unused_input='ignore')  # This is new

        c = op(x, y)

        g1 = theano.grad(c.sum(), x)

        out = g1.eval({
            x: np.ones((5,), dtype=np.float32),
            y: np.ones((5,), dtype=np.float32)})
        assert np.allclose(out, [1.] * 5)

 def test_input_dimensions_overflow(self):
     # Elemwise.perform used to compute the product
     # of input shapes to check if there was a zero in them,
     # it overflowed in this case.
     a, b, c, d, e, f = tensor.vectors("abcdef")
     s = a + b + c + d + e + f
     g = theano.function([a, b, c, d, e, f], s, mode=theano.compile.Mode(linker="py"))
     g(*[numpy.zeros(2 ** 11, config.floatX) for i in xrange(6)])

    def test_single_var(self):
        # Test `is_same_graph` with some trivial graphs (one Variable).

        x, y, z = tensor.vectors('x', 'y', 'z')
        self.check([
                   (x, x, (({}, True), )),
                   (x, y, (({}, False), ({y: x}, True), )),
                   (x, tensor.neg(x), (({}, False), )),
                   (x, tensor.neg(y), (({}, False), )),
                   ])

 def test_single_var(self):
     """
     Test `is_same_graph` with some trivial graphs (one Variable).
     """
     x, y, z = tensor.vectors("x", "y", "z")
     self.check(
         [
             (x, x, (({}, True),)),
             (x, y, (({}, False), ({y: x}, True))),
             (x, tensor.neg(x), (({}, False),)),
             (x, tensor.neg(y), (({}, False),)),
         ]
     )

    def test_full_graph(self):
        # Test `is_same_graph` with more complex graphs.

        x, y, z = tensor.vectors('x', 'y', 'z')
        t = x * y
        self.check([
                   (x * 2, x * 2, (({}, True), )),
                   (x * 2, y * 2, (({}, False), ({y: x}, True), )),
                   (x * 2, y * 2, (({}, False), ({x: y}, True), )),
                   (x * 2, y * 3, (({}, False), ({y: x}, False), )),
                   (t * 2, z * 2, (({}, False), ({t: z}, True), )),
                   (t * 2, z * 2, (({}, False), ({z: t}, True), )),
                   (x * (y * z), (x * y) * z, (({}, False), )),
                   ])

    def test_nested(self, cls_ofg):
        x, y = T.vectors('xy')
        u, v = x + y, x - y
        op_ft = cls_ofg([x, y], [u, v])
        op_ift = cls_ofg([x, y], [u / 2, v / 2])

        xx, yy = T.vector('xx'), T.vector('yy')
        xx2, yy2 = op_ift(*op_ft(xx, yy))
        fn = function([xx, yy], [xx2, yy2])

        xv = np.random.rand(16).astype(config.floatX)
        yv = np.random.rand(16).astype(config.floatX)
        xv2, yv2 = fn(xv, yv)
        assert np.allclose(xv, xv2)
        assert np.allclose(yv, yv2)

    def test_rop_override(self, cls_ofg):
        x, y = T.vectors('xy')

        def ro(inps, epts):
            x, y = inps
            u, v = epts
            return [u * y * 2. + x * v * 1.5]

        u, v = T.vectors('uv')
        op_mul_rop = cls_ofg([x, y, u, v], ro([x, y], [u, v]))
        op_mul = cls_ofg([x, y], [x * y], rop_overrides=ro)
        op_mul2 = cls_ofg([x, y], [x * y], rop_overrides=op_mul_rop)

        # single override case
        xx, yy = T.vector('xx'), T.vector('yy')
        du, dv = T.vector('du'), T.vector('dv')
        for op in [op_mul, op_mul2]:
            zz = op_mul(xx, yy)
            dw = T.Rop(zz, [xx, yy], [du, dv])
            fn = function([xx, yy, du, dv], dw)
            vals = np.random.rand(4, 32).astype(config.floatX)
            dwval = fn(*vals)
            assert np.allclose(
                dwval, vals[0] * vals[3] * 1.5 + vals[1] * vals[2] * 2.)

    def test_merge_only(self):
        # Test `is_same_graph` when `equal_computations` cannot be used.

        x, y, z = tensor.vectors('x', 'y', 'z')
        t = x * y
        self.check([
                   (x, t, (({}, False), ({t: x}, True))),
                   (t * 2, x * 2, (({}, False), ({t: x}, True), )),
                   (x * x, x * y, (({}, False), ({y: x}, True), )),
                   (x * x, x * y, (({}, False), ({y: x}, True), )),
                   (x * x + z, x * y + t, (({}, False),
                                           ({y: x}, False),
                                           ({y: x, t: z}, True))),
                   ],
                   debug=False)

def test_c_thunks():
    a = tensor.scalars('a')
    b, c = tensor.vectors('bc')
    cases = [False]
    if theano.config.cxx:
        cases.append(True)
    for c_thunks in cases:
        f = function([a, b, c], ifelse(a, a * b, b * c),
                     mode=Mode(
                         optimizer=None,
                         linker=vm.VM_Linker(c_thunks=c_thunks,
                                             use_cloop=False)))
        f(1, [2], [3, 2])
        from nose.tools import assert_raises
        assert_raises(ValueError, f, 0, [2], [3, 4])
        assert any([hasattr(t, 'cthunk') for t in f.fn.thunks]) == c_thunks

    def compile(self,X,n_negative_samples=None):
        if n_negative_samples is None:
            n_negative_samples = 1000
        
        pos_samples = X.loc[:, self.column_ranges.keys()].values.astype(floatX)

        pos_data, neg_data = T.matrices('SigData', 'BckData')
        pos_w, neg_w, parameters = T.vectors('SigW', 'BckW', 'parameters')

        neg_samples, neg_weight = self.generate_negative_samples(n_negative_samples=n_negative_samples,
                                                                 strategy=self.sampling_strategy)

        givens = {pos_data: pos_samples, neg_data: neg_samples,  neg_w: neg_weight}

        pdf = self.prepare_pdf()
        pdfs, summands = pdf(pos_data, neg_data, neg_weights=neg_w, weights=parameters)
        result = - T.mean(pos_w * T.log(pdfs))

        self.Tfunction = theano.function([parameters,pos_w], result, givens=givens)
        self.Tderivative = theano.function([parameters,pos_w], T.grad(result, parameters), givens=givens)
        self.X=X

    def test_grad_override(self, cls_ofg):
        x, y = T.vectors('xy')

        def go(inps, gs):
            x, y = inps
            g, = gs
            return [g * y * 2, g * x * 1.5]

        dedz = T.vector('dedz')
        op_mul_grad = cls_ofg([x, y, dedz], go([x, y], [dedz]))

        op_mul = cls_ofg([x, y], [x * y], grad_overrides=go)
        op_mul2 = cls_ofg([x, y], [x * y], grad_overrides=op_mul_grad)

        # single override case (function or OfG instance)
        xx, yy = T.vector('xx'), T.vector('yy')
        for op in [op_mul, op_mul2]:
            zz = T.sum(op(xx, yy))
            dx, dy = T.grad(zz, [xx, yy])
            fn = function([xx, yy], [dx, dy])
            xv = np.random.rand(16).astype(config.floatX)
            yv = np.random.rand(16).astype(config.floatX)
            dxv, dyv = fn(xv, yv)
            assert np.allclose(yv * 2, dxv)
            assert np.allclose(xv * 1.5, dyv)

        # list override case
        def go1(inps, gs):
            x, w, b = inps
            g = gs[0]
            return g * w * 2

        def go2(inps, gs):
            x, w, b = inps
            g = gs[0]
            return g * x * 1.5

        w, b = T.vectors('wb')
        # we make the 3rd gradient default (no override)
        op_linear = cls_ofg([x, w, b], [x * w + b], grad_overrides=[go1, go2, 'default'])
        xx, ww, bb = T.vector('xx'), T.vector('yy'), T.vector('bb')
        zz = T.sum(op_linear(xx, ww, bb))
        dx, dw, db = T.grad(zz, [xx, ww, bb])
        fn = function([xx, ww, bb], [dx, dw, db])
        xv = np.random.rand(16).astype(config.floatX)
        wv = np.random.rand(16).astype(config.floatX)
        bv = np.random.rand(16).astype(config.floatX)
        dxv, dwv, dbv = fn(xv, wv, bv)
        assert np.allclose(wv * 2, dxv)
        assert np.allclose(xv * 1.5, dwv)
        assert np.allclose(np.ones(16, dtype=config.floatX), dbv)

        # NullType and DisconnectedType
        op_linear2 = cls_ofg(
            [x, w, b], [x * w + b],
            grad_overrides=[go1, NullType()(), DisconnectedType()()])
        zz2 = T.sum(op_linear2(xx, ww, bb))
        dx2, dw2, db2 = T.grad(
            zz2, [xx, ww, bb],
            return_disconnected='Disconnected',
            disconnected_inputs='ignore',
            null_gradients='return')
        assert isinstance(dx2.type, T.TensorType)
        assert dx2.ndim == 1
        assert isinstance(dw2.type, NullType)
        assert isinstance(db2.type, DisconnectedType)

from theano import tensor as T
from theano.ifelse import ifelse
import theano, time
import numpy as np


if __name__ == "__main__":
    a,b = T.scalars('a', 'b')
    x,y = T.vectors('x', 'y')

    z_lazy = ifelse(T.eq(a, b), # condition
                    T.mean(x),  # then branch
                    T.mean(y))  # else branch

    var_1 = np.array([1, 2])
    var_2 = np.array([3, 4])
    condition_1 = 1
    condition_2 = 1
    iffunction = theano.function([a,b,x,y],[z_lazy])
    result = iffunction(condition_1, condition_2, var_1, var_2)
    print result

#
# if any([x.op.__class__.__name__ in ['Gemv', 'CGmv', 'Gemm', 'CGemm'] for x in
#         train.maker.fgraph.toposort()]):
#     print 'Used the cpu'
# elif any([x.op.__class__.__name__ in ['GpuGemm', 'GpuGemv'] for x in
#           train.maker.fgraph.toposort()]):
#     print 'Used the gpu'
# else:
#     print('ERROR, not able to tell if theano used the cpu or the gpu')
#     print(train.maker.fgraph.toposort())
#
# for i in range(training_step):
#     pred, err = train(D[0], D[1])
#
# print("target values for D")
# print(D[1])
#
# print("prediction on D")
# print(predict(D[0]))

# x = T.dvector('x')
# f = theano.function(inputs=[x], outputs=10*x, mode='DebugMode')
# f([5])
# f([0])
# f([7])

from theano import ProfileMode
profmode = theano.ProfileMode(optimizer='fast_run', linker=theano.gof.OpWiseCLinker())
v1, v2 = T.vectors(2)
o = v1 + v2
f = theano.function([v1,v2],[o], mode=profmode)

    def test_functions(self):
        Case = namedtuple("Case", "func input_data answer")

        testcases = [
            Case(
                func=cg.fletcher_reeves,
                input_data=(
                    np.array([1.35,  0.3]),
                    np.array([0.11, -0.5]),
                    np.array([0, 0]),
                ),
                answer=0.137
            ),
            Case(
                func=cg.polak_ribiere,
                input_data=(
                    np.array([1.,  -0.5]),
                    np.array([1.2, -0.45]),
                    np.array([0, 0]),
                ),
                answer=0.174
            ),
            Case(
                func=cg.hentenes_stiefel,
                input_data=(
                    np.array([1.,  -0.5]),
                    np.array([1.2, -0.45]),
                    np.array([0.2, 0.05]),
                ),
                answer=5.118
            ),
            Case(
                func=cg.conjugate_descent,
                input_data=(
                    np.array([1.,  -0.5]),
                    np.array([1.2, -0.45]),
                    np.array([0.2, 0.05]),
                ),
                answer=-7.323
            ),
            Case(
                func=cg.liu_storey,
                input_data=(
                    np.array([1.,  -0.5]),
                    np.array([1.2, -0.45]),
                    np.array([0.2, 0.05]),
                ),
                answer=1.243
            ),
            Case(
                func=cg.dai_yuan,
                input_data=(
                    np.array([1.,  -0.5]),
                    np.array([1.2, -0.45]),
                    np.array([0.2, 0.05]),
                ),
                answer=38.647
            ),
        ]

        for testcase in testcases:
            input_data = asfloat(np.array(testcase.input_data))
            variables = T.vectors(3)
            # For functions some input variables can be optional and we
            # ignore them during the computation. This solution cause errors
            # related to the Theano computational graph, because we
            # do not use all defined variables. That's why we need
            # simple hack that fix this issue and do not add changes to
            # the output result.
            hack = asfloat(0) * variables[-1][0]
            output_func = theano.function(
                variables,
                testcase.func(*variables) + hack
            )
            result = output_func(*input_data)
            self.assertAlmostEqual(result, testcase.answer, places=3)