Add functionality for infinity norm of matrices #13986
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The docstring of norm method should be edited to reflect the existence of inf-norm.
A test needs to be added too.
The proposed addition of "-inf norm" needs some justification: what other CAS implement this norm, and how? Unlike positive-order norms, the negative orders lack universally accepted mathematical interpretation.
Also, please edit the PR text according to Wiki page Writing pull request title and description
sympy/matrices/matrices.py
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| m = self.applyfunc(abs) | ||
| return Max(*[sum(m.row(i)) for i in range(m.rows)]) | ||
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| elif ord == S.NegativeInfinity: # Negative Infinity Norm - Maximum column sum |
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The "negative infinity norm" or matrices would not be maximum column sum. The maximum column sum is 1-norm, already implemented above.
If we want to introduce -oo norm for matrices, that merits a separate discussion. For example, Matlab docs do not define it.
Generally, one may think that the order -p norm for matrices should be min||Ax||_p over ||x||_p = 1 (this is how it works for p=2 currently) but this is just one interpretation.
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Sure, I'll make the changes |
RavicharanN
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@normalhuman Can you please review it now? |
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The table of norms in the docstring of the method should have an entry for oo norm: see the line 3381. |
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PR updated |
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Looks good.
In the future, please follow the Developer Workflow, in particular: (1) create a branch for each feature (instead of committing to master), (2) follow GitHub rules for automatic closing of issues by writing "Fixes #NNNNN" or "Closed #NNNNN" in the text of a pull request.
References to other Issues or PRs
Fixes #13985.
Brief description of what is fixed or changed
Functionality for the infinity norm (maximum of absolute row sums) has been added.
DocString has been modified and also the corresponding test has been added.