edits to only calculate subnetworks on first iteration of for loops

[shorvath-noaa]

Changes made to only calculate subnetworks on first iteration of for loops. Subnetwork objects needed in compute.py are stored in a new list, subnetwork_list, which is passed to and returned from functions nwm_route and compute_nhd_routing_v02.

Additions

• New object, subnetwork_list, stores either two (for "by-subnetwork-jit-clustered") or three (for "by-subnetwork-jit") subnetwork objects.
• subnetwork_list is passed to and returned from two functions, nwm_route and compute_nhd_routing_v02, as second item in list. The first item is the original returns from these functions.
• Original returns and subnetwork list are extracted as individual objects upon completion of functions nwm_route and compute_nhd_routing_v02 so as to not interfere with ensuing operations to results.

Removals

Changes

Testing

1. Tested that code completes with loops for all parallel compute methods

Screenshots

Notes

Todos

Checklist

• PR has an informative and human-readable title
• Changes are limited to a single goal (no scope creep)
• Code can be automatically merged (no conflicts)
• Code follows project standards (link if applicable)
• Passes all existing automated tests
• Any change in functionality is tested
• New functions are documented (with a description, list of inputs, and expected output)
• Placeholder code is flagged / future todos are captured in comments
• Visually tested in supported browsers and devices (see checklist below 👇)
• Project documentation has been updated (including the "Unreleased" section of the CHANGELOG)
• Reviewers requested with the Reviewers tool ➡️

Testing checklist

Target Environment support

• Windows
• Linux
• Browser

Accessibility

• Keyboard friendly
• Screen reader friendly

Other

• Is useable without CSS
• Is useable without JS
• Flexible from small to large screens
• No linting errors or warnings
• JavaScript tests are passing

[shorvath-noaa]

@awlostowski-noaa
I got the problem sorted, the model now runs without issues for both methods that require calculation of subnetworks.

[BrianAvant]

I am clocking a 40x speed up in routing computational time and a 20x improvement in total execution time for hybrid diffusive routing w natural cross sections. Outstanding.

Upon further testing I am not seeing a significant difference in execution time for any of the parallel_compute_methods. I had changed the use_natl_xsections flag in the default config but run_hybrid_routing was still set to False.. All changes to parallel_compute_methods are stable though and run for each of the hybrid scenarios including the refactored network.