Use the GeographicLib routines exposed through PROJ for all ellipsoidal calculations #41726
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This was referenced Feb 22, 2021
calculations Since GRASS upstream is moving away from the previous calculations which all of QGIS' ellipsoidal distance/areas formulas are based on, let's follow suit and delegate all these calculations to the GeographicLib routines exposed through the PROJ api. Refs OSGeo/grass#1283
nyalldawson
force-pushed
the
geographic_lib
branch
from
c28da71
to
43ae3fe
Compare
While these results are very different to the previous reference values, the geometries measured are extremely narrow polygons which range from ~-45 to ~45 degrees latitude, and accordingly large variations are expected depending on the area/length measurement formula used. Results have been checked against the R geosphere library and PostGIS geography type measurements, and match the measurements calculated using those packages (which are also based on GeographicLib calculations).
|
Anyone cares to review this one? |
nirvn
approved these changes
Feb 24, 2021
m-kuhn
reviewed
Feb 24, 2021
m-kuhn
approved these changes
Feb 25, 2021
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Since GRASS upstream is moving away from the previous calculations which
all of QGIS' ellipsoidal distance/areas formulas are based on, let's
follow suit and delegate all these calculations to the GeographicLib
routines exposed through the PROJ api.
Refs OSGeo/grass#1283