问题如题,想请教下为什么最后一层使用conv而不是linear,改成conv会导致最终输出维度不定 ``` self.linear=nn.Conv2d(self.base_channel*4*block.expansion,self.base_channel*4*block.expansion,1,1,0) # self.linear = nn.Linear(self.base_channel*4*block.expansion, num_classes) ```