deconvolution_2d.py 文件源码

def backward_cpu(self, inputs, grad_outputs):
        x, W = inputs[:2]
        b = inputs[2] if len(inputs) == 3 else None
        gy = grad_outputs[0]
        kh, kw = W.shape[2:]
        col = conv.im2col_cpu(
            gy, kh, kw, self.sy, self.sx, self.ph, self.pw)
        gW = numpy.tensordot(x, col, ([0, 2, 3], [0, 4, 5]))
        gx = numpy.tensordot(col, W, ([1, 2, 3], [1, 2, 3]))
        gx = numpy.rollaxis(gx, 3, 1)

        if b is None:
            return gx, gW
        else:
            gb = gy.sum(axis=(0, 2, 3))
            return gx, gW, gb