search

pyproj4 / pyproj

Python interface to PROJ (cartographic projections and coordinate transformations library)
https://pyproj4.github.io/pyproj
MIT License
1.05k stars 212 forks source link

Functions of `loxodrome` or `rhumb line` is needed #1332

Open AkexStar opened 1 year ago

AkexStar commented 1 year ago

I have did a lot of surveys, but found that there is few libs about rhumb_inverse and rhumb_direct. I noticed that Geographiclib has a solution for rhumb, but does not support python. pyproj has geodesic.inv_intermediate and geodesic.fwd_intermediate for great-circle(geodesic), but lacks of functions to calculate rhumb line.

Rhumb Line is very important for air/sea track calculation. I hope that there will be funtions just similar to geodesic.fwd_intermediate to compute rhumb line.

I will be very grateful if any developer could reply me.

snowman2 commented 1 year ago

The geodesic functions use c functions from PROJ which are imported from the GeographicLib library you reference (https://proj.org/en/9.2/geodesic.html). To get the logic in pyproj, the logic will need to be added to PROJ first.

See: https://github.com/OSGeo/PROJ/

AkexStar commented 1 year ago

@snowman2 Thank you! I'll go to PROJ and raise an Issue

snowman2 commented 1 year ago

Related:

jjimenezshaw commented 1 year ago

Some people showed in the ticket in PROJ (https://github.com/OSGeo/PROJ/issues/3855) how to easily compute a loxodrome using the Mercator projection. Should this issue be closed?

snowman2 commented 1 year ago

Do you think that their suggestion is worth documenting?

jjimenezshaw commented 1 year ago

https://github.com/OSGeo/PROJ/issues/3855#issuecomment-1698098657 I don't know if it is worth it, maybe.