Python tensor.minimum方法代碼示例

# 需要導入模塊: from theano import tensor [as 別名]
# 或者: from theano.tensor import minimum [as 別名]
def ctc_update_log_p(skip_idxs, zeros, active, log_p_curr, log_p_prev):
    active_skip_idxs = skip_idxs[(skip_idxs < active).nonzero()]
    active_next = T.cast(T.minimum(
        T.maximum(
            active + 1,
            T.max(T.concatenate([active_skip_idxs, [-1]])) + 2 + 1
        ), log_p_curr.shape[0]), 'int32')

    common_factor = T.max(log_p_prev[:active])
    p_prev = T.exp(log_p_prev[:active] - common_factor)
    _p_prev = zeros[:active_next]
    # copy over
    _p_prev = T.set_subtensor(_p_prev[:active], p_prev)
    # previous transitions
    _p_prev = T.inc_subtensor(_p_prev[1:], _p_prev[:-1])
    # skip transitions
    _p_prev = T.inc_subtensor(_p_prev[active_skip_idxs + 2], p_prev[active_skip_idxs])
    updated_log_p_prev = T.log(_p_prev) + common_factor

    log_p_next = T.set_subtensor(
        zeros[:active_next],
        log_p_curr[:active_next] + updated_log_p_prev
    )
    return active_next, log_p_next 

# 需要導入模塊: from theano import tensor [as 別名]
# 或者: from theano.tensor import minimum [as 別名]
def rprop_core(params, gradients, rprop_increase=1.01, rprop_decrease=0.99, rprop_min_step=0, rprop_max_step=100,
               learning_rate=0.01):
    """
    Rprop optimizer.
    See http://sci2s.ugr.es/keel/pdf/algorithm/articulo/2003-Neuro-Igel-IRprop+.pdf.
    """
    for param, grad in zip(params, gradients):
        grad_tm1 = theano.shared(np.zeros_like(param.get_value()), name=param.name + '_grad')
        step_tm1 = theano.shared(np.zeros_like(param.get_value()) + learning_rate, name=param.name+ '_step')

        test = grad * grad_tm1
        same = T.gt(test, 0)
        diff = T.lt(test, 0)
        step = T.minimum(rprop_max_step, T.maximum(rprop_min_step, step_tm1 * (
            T.eq(test, 0) +
            same * rprop_increase +
            diff * rprop_decrease)))
        grad = grad - diff * grad
        yield param, param - T.sgn(grad) * step
        yield grad_tm1, grad
        yield step_tm1, step 

# 需要導入模塊: from theano import tensor [as 別名]
# 或者: from theano.tensor import minimum [as 別名]
def minimum(x, y):
    return T.minimum(x, y) 

# 需要導入模塊: from theano import tensor [as 別名]
# 或者: from theano.tensor import minimum [as 別名]
def relu(x, alpha=0., max_value=None):
    _assert_has_capability(T.nnet, 'relu')
    x = T.nnet.relu(x, alpha)
    if max_value is not None:
        x = T.minimum(x, max_value)
    return x 

# 需要導入模塊: from theano import tensor [as 別名]
# 或者: from theano.tensor import minimum [as 別名]
def minimum(x, y):
    if checkgrad:
        return x + y
    return T.minimum(x, y) 

# 需要導入模塊: from theano import tensor [as 別名]
# 或者: from theano.tensor import minimum [as 別名]
def minimum(x, y):
    return T.minimum(x, y)


# SHAPE OPERATIONS 

# 需要導入模塊: from theano import tensor [as 別名]
# 或者: from theano.tensor import minimum [as 別名]
def relu(x, alpha=0., max_value=None):
    assert hasattr(T.nnet, 'relu'), ('It looks like like your version of '
                                     'Theano is out of date. '
                                     'Install the latest version with:\n'
                                     'pip install git+git://github.com/Theano/Theano.git --upgrade --no-deps')
    x = T.nnet.relu(x, alpha)
    if max_value is not None:
        x = T.minimum(x, max_value)
    return x 

# 需要導入模塊: from theano import tensor [as 別名]
# 或者: from theano.tensor import minimum [as 別名]
def infer_shape(self, nodes, shapes):
        return [(tensor.minimum(*shapes[0]), )] 

# 需要導入模塊: from theano import tensor [as 別名]
# 或者: from theano.tensor import minimum [as 別名]
def structured_minimum(x, y):
    """
    Structured elemwise minimum of sparse matrix x by scalar y.

    """
    # see decorator for function body 

# 需要導入模塊: from theano import tensor [as 別名]
# 或者: from theano.tensor import minimum [as 別名]
def parse_transfer_function(string_identifier, slope_parameter = None):
    """ This function returns the appropriate activation function, as selected by the string argument.
    
    string_identifier: 
        possible values are tanh, ReLU/relu, sigmoid/sig, abs, maxout <number>, linear/lin
    
    RETURNS: 
        transfer_function(python/theano function), string_identifier (normalized), dict (for special cases)
            
    """
    cross_channel_pooling_groups=None
    
    
    if string_identifier=='tanh':
        Activation_f = T.tanh
    elif string_identifier in ['ReLU', 'relu']: #rectified linear unit
        string_identifier = "relu"
        Activation_f = lambda x: x*(x>0)
    elif string_identifier in ['sigmoid', 'sig']:
        string_identifier = "sigmoid"
        Activation_f = T.nnet.sigmoid
    elif string_identifier in ['abs', 'Abs', 'absolute']:
        string_identifier='abs'
        Activation_f = T.abs_
    elif string_identifier in ['plu','PLu','PLU','piecewise']: #piece-wise linear function
        string_identifier = "PLU"
        print "parse_transfer_function::Remember to optimize the 'slope_parameter'"
        assert slope_parameter is not None,"...and better pass it to this function, as well! (type: Theano.Tensor, shape: same as activation, unif. random values [-1,1] should be fine)"
        Activation_f = lambda x: T.maximum(0,x) + T.minimum(0,x) * slope_parameter
    elif "maxout" in string_identifier:
        r=int(string_identifier.split(" ")[1])
        assert r>=2
        cross_channel_pooling_groups = r
    elif string_identifier in ['linear',"lin"]:
        string_identifier = "linear"
        Activation_f = lambda x:x
    else:
        raise NotImplementedError()
    return Activation_f, string_identifier, {"cross_channel_pooling_groups":cross_channel_pooling_groups} 

# 需要導入模塊: from theano import tensor [as 別名]
# 或者: from theano.tensor import minimum [as 別名]
def q_loss(self, y_true, y_pred):
        # assume clip_delta is 1.0
        # along with sum accumulator.
        diff = y_true - y_pred
        _quad = T.minimum(abs(diff), 1.0)
        _lin = abs(diff) - _quad
        loss = 0.5 * _quad ** 2 + _lin
        loss = T.sum(loss)

        return loss 

# 需要導入模塊: from theano import tensor [as 別名]
# 或者: from theano.tensor import minimum [as 別名]
def cliplin(X):
    return T.minimum(T.maximum(X, -2.), 2.) 

# 需要導入模塊: from theano import tensor [as 別名]
# 或者: from theano.tensor import minimum [as 別名]
def rescaled_weights(self, c): # c is the maximal norm of the weight vector going into a single filter.
        norms = T.sqrt(T.sqr(self.W).mean(0, keepdims=True))
        scale_factors = T.minimum(c / norms, 1)
        return self.W * scale_factors 

# 需要導入模塊: from theano import tensor [as 別名]
# 或者: from theano.tensor import minimum [as 別名]
def PReLU(a, x):
    return T.maximum(0.0, x) + a * T.minimum(0.0, x) 

# 需要導入模塊: from theano import tensor [as 別名]
# 或者: from theano.tensor import minimum [as 別名]
def _get_updates_for(self, param, grad):
        grad_tm1 = util.shared_like(param, 'grad')
        step_tm1 = util.shared_like(param, 'step', self.learning_rate.eval())
        test = grad * grad_tm1
        diff = TT.lt(test, 0)
        steps = step_tm1 * (TT.eq(test, 0) +
                            TT.gt(test, 0) * self.step_increase +
                            diff * self.step_decrease)
        step = TT.minimum(self.max_step, TT.maximum(self.min_step, steps))
        grad = grad - diff * grad
        yield param, TT.sgn(grad) * step
        yield grad_tm1, grad
        yield step_tm1, step