Thank you Martin. I will take a closer look at this in the coming days. Marco
On Sun, Dec 12, 2021 at 7:08 PM Martin Desruisseaux < [email protected]> wrote: > Le 12/12/2021 à 19:32, Marco Neumann a écrit : > > Just when I say this I get automated test failures for the British > National Grid EPSG:27700 transformations with 1.1 that run fine in 1.0 > > Are you aware of any deliberate changes to the grid databases here? > > I'm not aware of significant changes for this code in the EPSG database. > On the implementation side, this is a "Transverse Mercator" projection, > whose formulas have been modified in SIS 1.1 for better stability. I would > not expect a difference so large however, unless the coordinates are far > from the CRS domain of validity. Can you confirm that the geographic > coordinates in the test are between 9°W and 2°E? (a few degrees outside > should not be a problem). > > The new Transverse Mercator projection has been tested using Karney (2009) > Test data for the transverse Mercator projection ( > https://zenodo.org/record/32470). Results compared to SIS 1.0 may differ > significantly for points that far outside the domain of validity (e.g. at a > distance of more than 40° of longitude), but should not differ > significantly for points inside the domain of validity. > > If points are inside the domain of validity, can you execute a code like > below with SIS 1.0 and SIS 1.1 and check if the strings differ? Source CRS > and target CRS would be the CRS used by the SRSInfo.buildDomainEnvelope(…) > method implementation. > > System.out.println(CRS.findOperation(sourceCRS, targetCRS, null)); > > Martin > > > -- --- Marco Neumann KONA
