[PROJ] Change in behaviour (ONLY_BEST option)

[Even Rouault]

Hi Javier,

Fixed per https://github.com/OSGeo/PROJ/pull/3707

doh, I hadn't anticipated that the only_best functionality would 
introduce such complexity. The fundamental issue is that the pipeline 
computation engine has subtle behavioral differences depending if you 
ask it to assume that all registered grids are available (which is used 
to get the "universe of possible", from which we can see if we are 
missing the "best" transformation), which corresponds projinfo 
--grid-check known_available mode, or if you ask it to discard early 
transformations using grid not available. In the former case, PROJ may 
sometimes not need to synthetize the ballkpark transformation when it 
sees that the extent of the grids cover the extent of the CRS. So in the 
warn-only mode of only_best we must actually hybrid the 2 strategies to 
discover both missing best transformation, and get a ballpark 
transformation. Not sure if the above makes sense...

Even

Le 12/04/2023 à 16:46, Javier Jimenez Shaw a écrit :
> Hi
>
> I am trying to migrate an application from PROJ 9.1.0 to PROJ 9.2.0, 
> and I found a change in behaviour, that I was not expecting in this 
> release:
> Transform a coordinate not having the proper geoid file (the Spanish 
> one in this test). I was expecting that the z component is not 
> changed. But I am getting an error instead, and "* * inf" value.
> I know that ONLY_BEST is there, but I understood that the default was 
> to keep the same behaviour as before, and show a warning asking for a 
> "definition".
> But that is not what I experience. See this command lines:
>
> echo 39 -3 0 | PROJ_DEBUG=2 PROJ_NETWORK=OFF cs2cs EPSG:4326+5773 
> EPSG:4326+5782
> pj_open_lib(proj.ini): call 
> fopen(/home/jshaw/work/PROJ/install-sh/share/proj/proj.ini) - succeeded
> pj_open_lib(proj.db): call 
> fopen(/home/jshaw/work/PROJ/install-sh/share/proj/proj.db) - succeeded
> pj_open_lib(us_nga_egm96_15.tif): call fopen(us_nga_egm96_15.tif) - failed
> pj_open_lib(egm96_15.gtx): call fopen(egm96_15.gtx) - failed
> pj_open_lib(es_ign_egm08-rednap.tif): call 
> fopen(es_ign_egm08-rednap.tif) - failed
> pj_open_lib(es_2019m.asc): call fopen(es_2019m.asc) - failed
> pj_open_lib(es_2019z.asc): call fopen(es_2019z.asc) - failed
> pj_open_lib(us_nga_egm96_15.tif): call fopen(us_nga_egm96_15.tif) - failed
> pj_open_lib(egm96_15.gtx): call fopen(egm96_15.gtx) - failed
> pj_open_lib(es_ign_egm08-rednap.tif): call 
> fopen(es_ign_egm08-rednap.tif) - failed
> Attempt to use coordinate operation Inverse of WGS 84 to EGM96 height 
> (1) + ETRS89 to Alicante height (1) using ETRS89 to WGS 84 (1) failed. 
> Grid es_ign_egm08-rednap.tif is not available. Consult 
> https://proj.org/resource_files.html for guidance. Grid 
> us_nga_egm96_15.tif is not available. Consult 
> https://proj.org/resource_files.html for guidance. This might become 
> an error in a future PROJ major release. Set the ONLY_BEST option to 
> YES or NO. This warning will no longer be emitted (for the current 
> transformation instance).
> * * inf
>
>
> echo 39 -3 0 | PROJ_DEBUG=2 PROJ_ONLY_BEST_DEFAULT=NO PROJ_NETWORK=OFF 
> cs2cs EPSG:4326+5773 EPSG:4326+5782
> pj_open_lib(proj.ini): call 
> fopen(/home/jshaw/work/PROJ/install-sh/share/proj/proj.ini) - succeeded
> pj_open_lib(proj.db): call 
> fopen(/home/jshaw/work/PROJ/install-sh/share/proj/proj.db) - succeeded
> pj_open_lib(us_nga_egm96_15.tif): call fopen(us_nga_egm96_15.tif) - failed
> pj_open_lib(egm96_15.gtx): call fopen(egm96_15.gtx) - failed
> pj_open_lib(es_ign_egm08-rednap.tif): call 
> fopen(es_ign_egm08-rednap.tif) - failed
> pj_open_lib(es_2019m.asc): call fopen(es_2019m.asc) - failed
> pj_open_lib(es_2019z.asc): call fopen(es_2019z.asc) - failed
> 39.00 -3.00 0.00
>
>
> echo 39 -3 0 | PROJ_DEBUG=2 PROJ_NETWORK=ON cs2cs EPSG:4326+5773 
> EPSG:4326+5782
> pj_open_lib(proj.ini): call 
> fopen(/home/jshaw/work/PROJ/install-sh/share/proj/proj.ini) - succeeded
> pj_open_lib(proj.db): call 
> fopen(/home/jshaw/work/PROJ/install-sh/share/proj/proj.db) - succeeded
> pj_open_lib(us_nga_egm96_15.tif): call fopen(us_nga_egm96_15.tif) - failed
> pj_open_lib(egm96_15.gtx): call fopen(egm96_15.gtx) - failed
> pj_open_lib(us_nga_egm96_15.tif): call fopen(us_nga_egm96_15.tif) - failed
> pj_open_lib(egm96_15.gtx): call fopen(egm96_15.gtx) - failed
> Using https://cdn.proj.org/us_nga_egm96_15.tif
> pj_open_lib(es_ign_egm08-rednap.tif): call 
> fopen(es_ign_egm08-rednap.tif) - failed
> pj_open_lib(es_2019m.asc): call fopen(es_2019m.asc) - failed
> pj_open_lib(es_2019z.asc): call fopen(es_2019z.asc) - failed
> pj_open_lib(es_ign_egm08-rednap.tif): call 
> fopen(es_ign_egm08-rednap.tif) - failed
> Using https://cdn.proj.org/es_ign_egm08-rednap.tif
> pj_open_lib(us_nga_egm96_15.tif): call fopen(us_nga_egm96_15.tif) - failed
> pj_open_lib(egm96_15.gtx): call fopen(egm96_15.gtx) - failed
> Using https://cdn.proj.org/us_nga_egm96_15.tif
> pj_open_lib(es_ign_egm08-rednap.tif): call 
> fopen(es_ign_egm08-rednap.tif) - failed
> Using https://cdn.proj.org/es_ign_egm08-rednap.tif
> 39.00 -3.00 0.30
>
>
> The behaviour in 9.1.0 was the same as with 
> "PROJ_ONLY_BEST_DEFAULT=NO", that is what I was expecting now (plus 
> warning message).
>
> Am I missing something? Is this a bug?
>
> Thanks.
>
> .___ ._ ..._ .. . ._.  .___ .. __ . _. . __..  ... .... ._ .__
>
> _______________________________________________
> PROJ mailing list
> PROJ at lists.osgeo.org
> https://lists.osgeo.org/mailman/listinfo/proj

-- 
http://www.spatialys.com
My software is free, but my time generally not.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/proj/attachments/20230412/c0dd148e/attachment.htm>