weighted_cross_entropy.py 文件源码

def forward_gpu(self, inputs):
        cupy = cuda.cupy
        x, t = inputs
        log_y = cupy.log(x + 1e-5)
        self.y = x

    if(self.debug):
        ipdb.set_trace()

        if getattr(self, 'normalize', True):
            coeff = cupy.maximum(1, (t != self.ignore_label).sum())
        else:
            coeff = max(1, len(t))
        self._coeff = cupy.divide(1.0, coeff, dtype=x.dtype)

        log_y = cupy.rollaxis(log_y, 1, log_y.ndim)
        ret = cuda.reduce(
            'S t, raw T log_y, int32 n_channel, raw T coeff, raw T weights', 'T out',
            't == -1 ? 0 : log_y[_j * n_channel + t] * weights[t]',
            'a + b', 'out = a * -coeff[0]', '0', 'crossent_fwd'
        )(t, log_y.reduced_view(), log_y.shape[-1], self._coeff, self.weights.reduced_view())
        return ret,