Corona Product

[alifa98]

Hi all,

I have added the "corona product" of two graphs in the product algorithms.
I also had written a blog post here about this product months ago.

Thank you

[dschult]

Thank you for this PR. The Corona product is a helpful feature to add. And this implementation looks good to me.

Can you add corona_product to the list of functions to link to in the documentation? doc/reference/algorithms/operators.rst That will link this doc_string to the reference section of the docs.

Are there performance issues we should think about? I think CPU usage is not an issue. What about memory? If you have a really big H (or G) will there be a bottleneck in new_edges getting huge? If so, you could loop over list(GH) and add the nodes/edges to GH as you go. Anything else like that?

Thanks!

[alifa98]

Hi,
As you said, I have added corona_product to doc/reference/algorithms/operators.rst.

Your concern about memory usage in large graphs was correct, so I changed my implementation a little bit to avoid temp lists.

Thank you.

[dschult]

oops... my suggestion had quotes around the output string when it shouldn't have. I think taking out those quotes gets rid of the test failures.

[alifa98]

oops... my suggestion had quotes around the output string when it shouldn't have. I think taking out those quotes gets rid of the test failures.

I do not know what to do!!!?!

[dschult]

Take the single quotes out of line 508 where the output of the example appears as 'Graph with 12 nodes and 16 edges' when it should be Graph with 12 nodes and 16 edges

[dschult]

I have some minor typos in the docs, an extra line to name G and H, and a shorter assert line in the test (which matches the previous test's use of G.size() over G.number_of_edges().

With these changes I'm ready to approve it. Thanks very much!!

[dschult]

Thanks!

[MridulS]

Thanks @alifa98!