Polygon area calculation with Pro SDK
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2
a week ago
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I am migrating an ArcObject module into Pro SDK that calculates the area of polygons that would be copied from one feature class to another.
In the legacy code polygons reprojected into Albers US 1983 coordinate (102003) system from NAD 1983 GCS.
There are discrepancies when calculating area of a polygon between Calculate Geometry on the attribute table and the code I tried in Pro SDK. I need to produce the same result what Calculate Geometry on the attribute table or Measurement tool.
Here is my code:
public static double CalculateArea(List<Geometry> geos)
{
List<Polygon> polygons = [];
var spRefAlbers = SpatialReferenceBuilder.CreateSpatialReference(AlbersUS1983WkId);
foreach (var geo in geos)
{
if (GeometryEngine.Instance.Project(geo, spRefAlbers) is Polygon plg)
{
polygons.Add(plg);
}
}
PolygonBuilderEx pLbuilderEx = new(polygons, AttributeFlags.None)
{
HasZ = false,
SpatialReference = spRefAlbers
};
//Unit for AlbersUS1983 is meter
return Math.Round((pLbuilderEx.ToGeometry().Area * 0.000247105381), 3);
}
I also tried pLbuilderEx.ToGeometry().Extent.Area, getting polygon exterior ring, geodesic area calculation etc. but no luck
There is about 500 acres difference any idea why?
I'd appreciate any help. Thanks!
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