How to Calculate Centroid

Question

I am working with geospatial shapes and looking at the centroid algorithm here,

http://en.wikipedia.org/wiki/Centroid#Centroid_of_polygon

I have implemented the

Answer 1

This answer is inspired by the answer by Jer2654 and this source: http://coding-experiments.blogspot.com/2009/09/xna-quest-for-centroid-of-polygon.html

  /// 

  /// Method to compute the centroid of a polygon. This does NOT work for a complex polygon.
  /// 
  /// points that define the polygon
  /// centroid point, or PointF.Empty if something wrong
  public static PointF GetCentroid(List poly)
  {
     float accumulatedArea = 0.0f;
     float centerX = 0.0f;
     float centerY = 0.0f;

     for (int i = 0, j = poly.Count - 1; i < poly.Count; j = i++)
     {
        float temp = poly[i].X * poly[j].Y - poly[j].X * poly[i].Y;
        accumulatedArea += temp;
        centerX += (poly[i].X + poly[j].X) * temp;
        centerY += (poly[i].Y + poly[j].Y) * temp;
     }

     if (Math.Abs(accumulatedArea) < 1E-7f)
        return PointF.Empty;  // Avoid division by zero

     accumulatedArea *= 3f;
     return new PointF(centerX / accumulatedArea, centerY / accumulatedArea);
  }