Added differentiability for metrics - 4/n

[bhadreshpsavani]

Checklist

• Was this discussed/approved via a Github issue? (no need for typos and docs improvements)
• Did you read the contributor guideline, Pull Request section?
• Did you make sure to update the docs?
• Did you write any new necessary tests?

PR review

@SkafteNicki

[codecov]

Codecov Report

Merging #253 (de97eaa) into master (5d6b0ce) will decrease coverage by 0.04%.
The diff coverage is 83.11%.

@@            Coverage Diff             @@
##           master     #253      +/-   ##
==========================================
- Coverage   87.95%   87.91%   -0.05%     
==========================================
  Files         184      184              
  Lines        6020     6090      +70     
==========================================
+ Hits         5295     5354      +59     
- Misses        725      736      +11     

Flag	Coverage Δ
Linux	78.92% <83.11%> (-0.13%)	⬇️
cpu	78.92% <83.11%> (-0.13%)	⬇️
gpu	96.88% <ø> (+0.03%)	⬆️
pytest	87.91% <83.11%> (-0.05%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
torchmetrics/classification/confusion_matrix.py	95.83% <66.66%> (-4.17%)	⬇️
torchmetrics/classification/f_beta.py	92.00% <66.66%> (-3.46%)	⬇️
torchmetrics/classification/hamming_distance.py	90.90% <66.66%> (-3.83%)	⬇️
torchmetrics/classification/hinge.py	90.90% <66.66%> (-3.83%)	⬇️
torchmetrics/classification/iou.py	93.75% <66.66%> (-6.25%)	⬇️
torchmetrics/classification/matthews_corrcoef.py	94.73% <66.66%> (-5.27%)	⬇️
torchmetrics/classification/precision_recall.py	88.88% <66.66%> (-4.45%)	⬇️
...chmetrics/classification/precision_recall_curve.py	96.42% <66.66%> (-3.58%)	⬇️
torchmetrics/classification/roc.py	96.29% <66.66%> (-3.71%)	⬇️
torchmetrics/classification/stat_scores.py	77.10% <66.66%> (-0.40%)	⬇️
... and 186 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 5d6b0ce...de97eaa. Read the comment docs.

[SkafteNicki]

Hi @bhadreshpsavani,
I pushed some changed to your PR that should resolve the failing tests. Please take a look before I go ahead and approve :]

[bhadreshpsavani]

Hi @SkafteNicki,
Thanks for fixing the issues! I have gone through the changes.

[Borda]

@bhadreshpsavani mind check failing tests?
cc: @PyTorchLightning/core-metrics