datasette-haversine-point-to-path

I got to play around with spherical trig last week under the guise of improving the accuracy of the model that KO6BTY's and my F2 skip maps utilize.

Today, I took the first steps towards formalizing the algorithm I modeled into a datasette plugin so we can use our kml plugin to create skip maps (I'll probably also add a configuration flag to turn skip mapping on and off.) Using datasette-haversine as a model, I created datasette-haversine-point-path. The new plugin allows users to specify three lat/lng pairs that define the enpoints of a QSO and the location of an ionosonde. Given this information, the newly defined sqlite method will return the shortest distance between the ionosonde and the QSO's propagation path along the Earth. (I still need to add the special case where the shortest distance to the path is in fact between the ionosonde and one of the endpoints. I'll talk about this in my next post.)

I re-puprosed the test case from datasette-haversine as well. This new test case made for really easy, really systematic debugging as unit test cases almost always do. Just a little more work to do on this one!

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