Why different Softmax?

[LukeAI]

thanks for this demo!

I was trying to understand the implementation and I see that there is a modified softmax function
The original head uses the standard softmax implementation from pytorch:
https://github.com/Turoad/CLRNet/blob/7269e9d1c1c650343b6c7febb8e764be538b1aed/clrnet/models/heads/clr_head.py#L450

but I see that in your implementation you do something a bit different - you first subtract the max from each element in x. Why is that?

CLRNet-onnxruntime-and-tensorrt-demo/demo_trt.py

Lines 153 to 156 in 07a47e6

 def softmax(self, x, axis=None): 
     x = x - x.max(axis=axis, keepdims=True) 
     y = np.exp(x) 
     return y / y.sum(axis=axis, keepdims=True)