[PROJ] PROJ 9 & old syntax +init=

[Nicolas Bellaiche]

Hi all, 


I am still puzzled by the difference between the old syntax +init= and the new syntax. I just rebuilt the last release 9.2.1 and tested with it to make sure it's not a bug already fixed. 

1) Example where the grid shift is not taken into account with the new syntax. (it's correct with +init=) 

1.a) NEW SYNTAX: z not correct (grid shift not used) 

echo 600000.00000000 300097.53400000 0.00000000 | ./bin/cs2cs IGNF:LAMB1 +to IGNF:UTM31RGF93 
452845.19 5583309.40 0.00 

1.b) OLD SYNTAX: z correct: 

echo 600000.00000000 300097.53400000 0.00000000 | ./bin/cs2cs +init=IGNF:LAMB1 +to +init=IGNF:UTM31RGF93 
452845.19 5583309.40 43.64 



2) Example where the old syntax gives a wrong result while the new syntax works: 

2.a) OLD SYNTAX from cartographic to geocentric coordinates / result is wrong 

echo 652760.737 7033791.243 43.642 | PROJ_DEBUG=3 ./bin/cs2cs +init=IGNF:LAMB93 +to +init=IGNF:RGF93 
4070355.05 166080.07 4891332.24 


2.b) NEW SYNTAX from cartographic to geocentric coordinates / result is correct 



echo 652760.737 7033791.243 43.642 | PROJ_DEBUG=3 ./bin/cs2cs IGNF:LAMB93 +to IGNF:RGF93 

4070327.25 166078.93 4891298.61 









-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/proj/attachments/20230601/6bee1a0b/attachment-0001.htm>