#40 ElementMapper bug

[Jan Gregersen]

I have discovered an error in the OATC.OpenMI.Sdk.SpatialPackage (the elementMapper) (version 1.4.0). When mapping regular grids (collection of rectangular polygons) with the data operation PolygonToPolygon mean values (ElementMapper 800 method), the mapping produces values which are all zero when the two elementSets are identical or when the accepting elementSet is a subset of the providing elementSet . (or in other words, in cases where you can only see one elementSet in the Configuration Editor because the elements are on top of each others). This error only occurs when the coordinates are large values (e.g. x and y values are larger than 1000000). With small coordinates things work ok and things also works ok with large coordinates when the two grids are not exactly overlapping. I god a bit suspicious about the statement: “private const double EPSILON = 1e-5;” in the OATC.OpenMI.Sdk.Spatial. XYGeometryTools. If I change the values to e.g. 1e-15 that mapping works fine, but this will make some of the unit tests in the SpatialPackage fail. So, simply changing the Epsilon values does not seem to be a safe solution. I think we need to investigte the meaning of epsilon to find a lasting solution.
Kind regards Jan