[Update]
        public bool ByLaplaceDirichletTest
        (
            FeatureUpdateContext updateContext,
            [Replicatable][ParentModel] CoordinateSystem coord,
            int x, // X Dimension of Surface.
            int y, // Y Dimension of Surface.
            int r,  // Sampling rate for surface.
            double p, // Period of X.
            string gx // Function to plot between 0 and 2.
        )
        {
            // Build a cache keyed off the incoming data.
            string key = x.ToString() + y.ToString() + r.ToString() + p.ToString() + gx.GetHashCode().ToString();
            string path = "C:\\temp\\";
            string file = path + key + ".tmp";
                
            DPoint3d[][] points = new DPoint3d[r+1][];
            BinaryFormatter bformatter = new BinaryFormatter();

            if (File.Exists(file)) //There is a cached copy of this configuration, use it.
            {
                // This is a hook into a real time modification of the object.
                // Right here we could hook in and perform tweaks on the object.
                Stream stream = File.Open(file, FileMode.Open);
                points = (DPoint3d[][])bformatter.Deserialize(stream);
                stream.Close();
            }
            else
            {
                try // to delete any old files.
                {
                    string[] files = Directory.GetFiles(path, "*.tmp");
                    if (files.Length > 0)
                    {
                        foreach (string f in files)
                        {
                            System.IO.File.Delete(f);
                        }
                    }
                }
                catch (DirectoryNotFoundException) // First time through path may not exist.
                {
                    Directory.CreateDirectory(path);
                }

                // Write the points to the disk is a serialized stream.
                Stream stream = File.Open(file, FileMode.Create);
                points = GetPoints(x, y, r, p, gx);
                bformatter.Serialize(stream, points);
                stream.Close();
            }

            // Return the points, no matter where we got them from.
            return base.ByPointsAsDPoint3d(coord, points, 0, 0);
        }