Paddle：reshape算子与pytorch中的view算子_paddle view

pytorch中的view算子 = paddle中的reshape算子

# pytorch
# AvgPool2d比AdaptiveAvgPool2d更快,但是使用View 和 Mean会比AvgPool2d快5倍.
class FastGlobalAvgPool2d(nn.Module):
    def __init__(self, flatten=False):
        super(FastGlobalAvgPool2d, self).__init__()
        self.flatten = flatten
 
    def forward(self, x):
        if self.flatten:
            in_size = x.size()
            return x.view((in_size[0], in_size[1], -1)).mean(dim=2)
        else:
            return x.view(x.size(0), x.size(1), -1).mean(-1).view(x.size(0), x.size(1), 1, 1)

# paddle
# AvgPool2d比AdaptiveAvgPool2d更快,但是使用View 和 Mean会比AvgPool2d快5倍.
class FastGlobalAvgPool2d(nn.Layer):
    def __init__(self, flatten=False):
        super(FastGlobalAvgPool2d, self).__init__()
        self.flatten = flatten
 
    def forward(self, x):
        in_size = x.shape
        if self.flatten:
            return x.reshape((in_size[0], in_size[1], -1)).mean(axis=-1)
        else:
            return x.reshape(in_size[0], in_size[1], -1).mean(axis=-1).reshape(in_size[0], in_size[1], 1, 1)

此外：

1：需要注意mean的参数，pytorch中是dim指定维度，paddle中是axis指定维度。