Python theano.tensor 模块，nonzero() 实例源码

def _get_hidden_layer_connectivity(self, layerIdx):
        layer_size = self._hidden_sizes[layerIdx]
        if layerIdx == 0:
            p_vals = self._get_p(T.min(self.layers_connectivity[layerIdx]))
        else:
            p_vals = self._get_p(T.min(self.layers_connectivity_updates[layerIdx-1]))

        # #Implementations of np.choose in theano GPU
        # return T.nonzero(self._mrng.multinomial(pvals=[self._p_vals] * layer_size, dtype=theano.config.floatX))[1].astype(dtype=theano.config.floatX)
        # return T.argmax(self._mrng.multinomial(pvals=[self._p_vals] * layer_size, dtype=theano.config.floatX), axis=1)
        return T.sum(T.cumsum(self._mrng.multinomial(pvals=T.tile(p_vals[::-1][None, :], (layer_size, 1)), dtype=theano.config.floatX), axis=1), axis=1)

def from_onehot(x_var):
    ret = np.zeros((len(x_var),), 'int32')
    nonzero_n, nonzero_a = np.nonzero(x_var)
    ret[nonzero_n] = nonzero_a
    return ret

def from_onehot(x_var):
    ret = np.zeros((len(x_var),), 'int32')
    nonzero_n, nonzero_a = np.nonzero(x_var)
    ret[nonzero_n] = nonzero_a
    return ret

def nonzero(self, t, keepdims):
            return T.nonzero(t, return_matrix=keepdims)

def from_onehot(x_var):
    ret = np.zeros((len(x_var),), 'int32')
    nonzero_n, nonzero_a = np.nonzero(x_var)
    ret[nonzero_n] = nonzero_a
    return ret

def fun(x):
    return TT.nonzero(x, True)

def step(x):
    return TT.max(TT.nonzero(x,True))

def from_onehot(x_var):
    ret = np.zeros((len(x_var),), 'int32')
    nonzero_n, nonzero_a = np.nonzero(x_var)
    ret[nonzero_n] = nonzero_a
    return ret

def from_onehot(x_var):
    ret = np.zeros((len(x_var),), 'int32')
    nonzero_n, nonzero_a = np.nonzero(x_var)
    ret[nonzero_n] = nonzero_a
    return ret

def past_weight_grad_step(xs, es, kp_x, kd_x, kp_e, kd_e, shape, dws=None):
    """
    Do an efficient update of the weights given the two spike-update.

    (This still runs FING SLOWLY!)

    :param xs: An (n_in) vector
    :param es: An (n_out) vector
    :param kp_x:
    :param kd_x:
    :param kp_e:
    :param kd_e:
    :param shapes: (n_in, n_out)
    :return:
    """
    kp_x, kd_x, kp_e, kd_e = [as_floatx(k) for k in (kp_x, kd_x, kp_e, kd_e)]
    n_in, n_out = shape
    rx = kd_x/(kp_x+kd_x)
    re = kd_e/(kp_e+kd_e)

    tx_last = create_shared_variable(np.zeros(n_in)+1)
    te_last = create_shared_variable(np.zeros(n_out)+1)
    x_last = create_shared_variable(np.zeros(n_in))
    e_last = create_shared_variable(np.zeros(n_out))
    x_spikes = tt.neq(xs, 0)
    e_spikes = tt.neq(es, 0)
    x_spike_ixs, = tt.nonzero(x_spikes)
    e_spike_ixs, = tt.nonzero(e_spikes)

    if dws is None:
        dws = tt.zeros(shape)

    t_last = tt.minimum(tx_last[x_spike_ixs, None], te_last)  # (n_x_spikes, n_out)
    dws = tt.inc_subtensor(dws[x_spike_ixs, :], x_last[x_spike_ixs, None]*e_last
        * rx**(tx_last[x_spike_ixs, None]-t_last)
        * re**(te_last[None, :]-t_last)
        * geoseries_sum(re*rx, t_end=t_last, t_start=1)
        )

    new_x_last = tt.set_subtensor(x_last[x_spike_ixs], x_last[x_spike_ixs]*rx**tx_last[x_spike_ixs]+ xs[x_spike_ixs]/as_floatx(kd_x))
    new_tx_last = tt.switch(x_spikes, 0, tx_last)

    t_last = tt.minimum(new_tx_last[:, None], te_last[e_spike_ixs])  # (n_in, n_e_spikes)
    dws = tt.inc_subtensor(dws[:, e_spike_ixs], new_x_last[:, None]*e_last[e_spike_ixs]
        * rx**(new_tx_last[:, None]-t_last)
        * re**(te_last[None, e_spike_ixs]-t_last)
        * geoseries_sum(re*rx, t_end=t_last, t_start=1)
        )

    add_update(x_last, new_x_last)
    add_update(e_last, tt.set_subtensor(e_last[e_spike_ixs], e_last[e_spike_ixs]*re**te_last[e_spike_ixs]+ es[e_spike_ixs]/as_floatx(kd_e)))
    add_update(tx_last, new_tx_last+1)
    add_update(te_last, tt.switch(e_spikes, 1, te_last+1))
    return dws