Distributed ndcg

[ili0820]

Fixes #2632

This PR is based on #2632 (thanks a lot to kamalojasv181!)

Description:

I ve tried to fix distributed NDCG tests like the examples. I am not really sure whether this is the way you guys wanted, but still, I tried my best and let me know which parts should be fixed (It's my first time contributing, so be kind plz 😯 )

Check list:

• New tests are added (if a new feature is added)
• New doc strings: description and/or example code are in RST format
• Documentation is updated (if required)

[vfdev-5]

Thanks a lot for finalizing this PR @ili0820 !
I left few comments on how to make CI happy and improve a bit the tests

[vfdev-5]

Let's check here: https://github.com/catalyst-team/catalyst/blob/master/catalyst/metrics/_ndcg.py if there is another way to implement this in a vectorized way, https://github.com/pytorch/ignite/pull/2632/files#r930048810

[ili0820]

@vfdev-5 while studying about this, I found out that sklearn is using for loop too. is there any particular reason why this for loop need to be changed?

[vfdev-5]

It is purely perf reasons. For example, computing s1 below will be faster than s2:

tensor = torch.rand(100)
s1 = tensor.sum()

s2 = 0
for v in tensor:
    s2 += v

[vfdev-5]

Also, we need to write a docstring like here:

ignite/ignite/metrics/accuracy.py

Line 94 in 34a707e

class Accuracy(_BaseClassification):

Please read this section of contributing guide: https://github.com/pytorch/ignite/blob/master/CONTRIBUTING.md#writing-documentation, especially about .. versionadded::

[ili0820]

I ve deleted "test_output_cuda", added "n_epoch" and alligned code format for now. I will work on vectorizing and wrting docstring @vfdev-5

[vfdev-5]

@ili0820 any blockers that we can help to move forward with this PR ?

[ili0820]

@vfdev-5 sorry for no updates for a long time, I was still struggling with vectorizing for loop. 😢

[vfdev-5]

@ili0820 no worries, let's update the docstring and merge this PR. Vectorization part could be done later in a follow-up PR.

[ili0820]

@vfdev-5 wow sounds great. does it matter if i copy and paste docstring from sklearn or other opensource?

[vfdev-5]

@ili0820 yes, you can inspire from scikit-learn to write ignite's docstring. Please check this contrib part: https://github.com/pytorch/ignite/blob/master/CONTRIBUTING.md#writing-documentation
You can take this metric https://github.com/pytorch/ignite/blob/master/ignite/metrics/psnr.py as an example

[ili0820]

@vfdev-5 thanks I ll look into that. 😄

[vfdev-5]

@ili0820 can you please also add the metric to this list: https://github.com/pytorch/ignite/blob/master/docs/source/metrics.rst

Also please fix formatting issues: https://github.com/pytorch/ignite/actions/runs/6251715047/job/16981806158?pr=3054#step:11:104

[ili0820]

@vfdev-5 I accidently deleted the branch................................ 🤢
will try to restore....

[ili0820]

restored. sorry for inconvenience

[vfdev-5]

@ili0820 can you update the PR according to the review, please?

[exitflynn]

hey @ili0820! this PR appears to have a lot of progress already. I wonder if you'd be available for seeing it through? I'd be available to take over otherwise, let me know! 🤠

[vfdev-5]

@exitflynn go ahead and take over