Fair enough. I presume you aren't drawing the linestring by hand yes? and that there are no obvious rounding errors?
Toby On 15 January 2012 21:23, Jim White <[email protected]> wrote: > I tried that first. It was way off. I think by a factor of cos(lat)**2. > > > > > On 01/15/2012 03:24 PM, Toby Reinicke wrote: >> >> Do you have the same issue if you just use ring.getArea() function? >> >> On 15 Jan 2012, at 18:31, Jim White<[email protected]> wrote: >> >>> Hi, >>> >>> I use this to calculate the number of acres enclosed by a linestring: >>> >>> ring = new OpenLayers.Geometry.LinearRing(geometry.getVertices()); >>> area = ring.getGeodesicArea(new OpenLayers.Projection("EPSG:900913")); >>> area = Math.floor(Math.abs(area*0.000247105381)); >>> >>> The calculated area consistently produces results that are 2-3% too >>> small. Is this an error in my code or is my data the problem? >>> >>> Thanks, >>> Jim White >>> _______________________________________________ >>> Users mailing list >>> [email protected] >>> http://lists.osgeo.org/mailman/listinfo/openlayers-users > > _______________________________________________ Users mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/openlayers-users
