Strange 'Inverse' gradient flow

Hi there,

I am a newbie in Pytorch and I have got some problem in my current project.

I am working on depth map generation from 2D images and the source code is as follows:
https://github.com/shuuchen/depth_eigen/blob/master/test.ipynb

In the first plot:


I plot the gradient flow of each layer with reference to Check gradient flow in network - #7 by RoshanRane

However, the gradient seems to flow ‘inversely’: the gradients of late layers are much smaller than early layers, which is opposite to Check gradient flow in network - #7 by RoshanRane

The second plot seems to be normal.

Anyone can help explain ? Thanks !