DOC: Make usage of `rtol` and `atol` arguments in `pd.testing.assert_frame_equal` clearer

[conorhamill36]

Pandas version checks

• I have checked that the issue still exists on the latest versions of the docs on main here

Location of the documentation

https://pandas.pydata.org/docs/reference/api/pandas.testing.assert_frame_equal.html

Documentation problem

When atol and rtol are used, the check of equality between two dataframes is of the form absolute(a - b) <= (atol + rtol * absolute(b)).

It's not clear that atol and rtol are used together like this, resulting in it being unclear what exact is being checked.

Suggested fix for documentation

Expand the explanation of atol and rtol in the documentation, possibly explicitly including the equation that is testing equality.

[OmarAli-Ibrahim]

assign it to me

[conorhamill36]

@omaraliii I don't seem to have the cog beside the assignees, does someone with more authorisation in this repo need to do that?

[rhshadrach]

@omaraliii - I think it would be good to review the contributor documentation. See here:

https://pandas.pydata.org/docs/dev/development/contributing.html#finding-an-issue-to-contribute-to

[KevsterAmp]

@omaraliii are you still working on this?

[tan-i-ham]

May I take this?

I will add the description near here and maybe add the example if possible

pandas/pandas/_testing/asserters.py

Line 1161 in 70bb855

Whether to compare number exactly.

[tan-i-ham]

take