Hello Martin, Thank you very much for your support!
Best regards, Andreea From: Martin Desruisseaux <[email protected]> Sent: Wednesday, 17 October 2018 19:12 To: PLOCON Andreea <[email protected]> Cc: [email protected] Subject: Re: Hotine Oblique Mercator (variant B) Hello Andreea The 4 cm error was a bug in SIS. But the issue was not in the Oblique Mercator projection; it was rather a rounding error in the unit conversion of the following map projection parameter: Latitude of projection centre: 46°57'8.66"N The EPSG database stores this parameter value in sexagesimal unit: 46.570866. The conversion to decimal degrees is performed by org.apache.sis.measure.SexagesimalConverter, which splits the sexagesimal value in degrees, minutes and seconds components using multiplications and divisions by 100 and 10000. The problem was in this operation: 46.570866 * 10000 = 465708.66000000003 This 3E-11 error introduced by IEEE 754 arithmetic, after cascading in the initialization of map projection internal coefficients, resulted in this 4 cm error. A correction had been pushed on the source repository (all branches). Regards, Martin
