Total Variation Loss

[ragavvenkatesan]

What does this PR do?

This PR adds Total Variation Loss.
Fixes #972

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• Did you make sure to update the docs?
• Did you write any new necessary tests?

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[codecov]

Codecov Report

Merging #978 (49c32b3) into master (4aeb6cb) will decrease coverage by 48%.
The diff coverage is 98%.

Additional details and impacted files

@@           Coverage Diff            @@
##           master    #978     +/-   ##
========================================
- Coverage      86%     38%    -48%     
========================================
  Files         193     195      +2     
  Lines       11404   11461     +57     
========================================
- Hits         9778    4303   -5475     
- Misses       1626    7158   +5532     

[Borda]

@ragavvenkatesan how is it going here? 🐰
we are considering a new feature release next week, do you think we can finish this addition by then so it will be included? 🙏

[ragavvenkatesan]

So, I was waiting on you folks for some feedback on the initial code. I am working on tests this weekend, I can prioritize for next release since you brought it up.

[ragavvenkatesan]

So, @Borda I think the metric is implemented. I working on unit test (taking suggestions for tests now). I have tested this on actual model training and seems like it is working as expected. Let me know how this looks.

[SkafteNicki]

some initial comments

[ragavvenkatesan]

Addressed all comments @SkafteNicki Anything on tests?

[Borda]

@ragavvenkatesan, could you pls check and resolve conflicts? 🦦

[Borda]

It seems to be failing for all the latest tests; in fact, it hangs and dies...