[ https://issues.apache.org/jira/browse/SIS-486?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Martin Desruisseaux closed SIS-486. ----------------------------------- > Some map projections produce wrong results when |Δλ| > 180° > ----------------------------------------------------------- > > Key: SIS-486 > URL: https://issues.apache.org/jira/browse/SIS-486 > Project: Spatial Information Systems > Issue Type: Task > Components: Referencing > Affects Versions: 0.8, 1.0 > Reporter: Martin Desruisseaux > Assignee: Martin Desruisseaux > Priority: Major > Fix For: 1.1 > > > Some map projections produce a wrong result when the difference Δλ between > the longitude value and the central meridian is greater than 180°. For most > map projections there is no problem because the Δλ value is used directly in > trigonometric functions which perform automatically the range reduction for > us. For example sin(200°) = sin(-160°). However there is a few map > projections where the longitude value is transformed (e.g. multiplied by some > factor) _before_ to be given to a trigonometric function. For such map > projections, we must apply the range reduction ourselves. > Impacted map projection methods in Apache SIS 1.0 are: > * Albers Equal Area (EPSG::9822) > * Lambert Conic Conformal (EPSG::9801, 9802, 9826) > * Oblique Stereographic (EPSG::9809) > * Satellite-Tracking projection > This problem impacts in particular the cases when one of above projections is > used in an area crossing the anti-meridian (±180°). -- This message was sent by Atlassian Jira (v8.3.4#803005)