钱晓明 wrote:
I find that OGR does not support M value in Geometry? So there is no way to read M values in ESRI Shapefile? If I want, how can I handle this?
Kyle, I believe that OGR does not support reading M values from shapefiles at this time. There has been discussion of providing a mechanism to read it in place of Z or perhaps as a "list" attribute on the feature but to the best of my knowledge neither of those approaches has been implemented. It is anticipated that at some point in the future OGR will advance to the new OGC/ISO geometry model which includes "M" values for geometries. I don't know when that might be though. Shapelib does support reading M values if you are willing to program against it's C API. http://shapelib.maptools.org/ Best regards, -- ---------------------------------------+-------------------------------------- I set the clouds in motion - turn up | Frank Warmerdam, [email protected] light and sound - activate the windows | http://pobox.com/~warmerdam and watch the world go round - Rush | Geospatial Programmer for Rent _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
