Hexagonal lattice followup

[jpacold]

Follow-up to #1213.

• Addressed comments on the previous PR

  • Split tests with a lot of sub-cases into subtests
  • Removed unnecessary module

• We now pre-compute the number of edges in each graph, so that we can call G::with_capacity(self.num_nodes, self.num_edges) to create the graph where before we had G::with_capacity(self.num_nodes, self.num_nodes)

• Fixed two bugs in the position calculation

  • In my initial implementation I missed a factor of two, so the hexagons were not actually regular
  • For lattices with an odd number of columns, the node index arithmetic had an error that led to configurations like this:
    
    Probably the reason I missed this is that I mostly wrote tests for cases with an even number of columns (required when periodic = True). We now get the expected result:
    

[mtreinish]

Could you add a release note to document the bugfixes? I'm planning to push a 0.15.1 release shortly and we can include this in it if you think it's warranted.

[coveralls]

Pull Request Test Coverage Report for Build 9712370219

Details

• 130 of 131 (99.24%) changed or added relevant lines in 2 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage increased (+0.4%) to 95.781%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
rustworkx-core/src/generators/hexagonal_lattice_graph.rs	128	129	99.22%

Files with Coverage Reduction	New Missed Lines	%
rustworkx-core/src/generators/hexagonal_lattice_graph.rs	1	98.4%

Totals
Change from base Build 9711339379:	0.4%
Covered Lines:	18048
Relevant Lines:	18843

---

💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 9712885224

Details

• 130 of 131 (99.24%) changed or added relevant lines in 2 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage increased (+0.4%) to 95.781%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
rustworkx-core/src/generators/hexagonal_lattice_graph.rs	128	129	99.22%

Files with Coverage Reduction	New Missed Lines	%
rustworkx-core/src/generators/hexagonal_lattice_graph.rs	1	98.4%

Totals
Change from base Build 9711339379:	0.4%
Covered Lines:	18048
Relevant Lines:	18843

---

💛 - Coveralls

[mtreinish]

This LGTM, thanks for catching and fixing this.

[coveralls]

Pull Request Test Coverage Report for Build 9713815577

Details

• 130 of 131 (99.24%) changed or added relevant lines in 2 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage increased (+0.4%) to 95.781%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
rustworkx-core/src/generators/hexagonal_lattice_graph.rs	128	129	99.22%

Files with Coverage Reduction	New Missed Lines	%
rustworkx-core/src/generators/hexagonal_lattice_graph.rs	1	98.4%

Totals
Change from base Build 9711339379:	0.4%
Covered Lines:	18048
Relevant Lines:	18843

---

💛 - Coveralls