Custom Loss Function Caffe (Spearman Coefficient) while FInetuning (Regression)

Question

I am finetuning imagenet for a regression problem in caffe. At present I am using Eucliden Loss, but I don't think it is any good in my case.
I want the loss values to be the spearman coefficient between predicted labels and actual labels. How can I do so?

Please help!

Answer 1

As cleared in the comment section, since the loss function needs to be differentiable, and spearman coefficient isn't, we can't use it as a loss function.