Hello,
There seems to be some instability which leads to strange behaviour when the values in a NHeatMapSeries has both positive and negative values.
example from the Nevron example code in NHeatMapContourUC.xaml.cs lines 113 - 121


Original code (Works)

                for (int row = 0; row < GridStepY; row++, x += dIncrementX)
                {
                    y = 10 - Math.Sqrt((x * x) + (z * z) + 2);
                    y += 3.0 * Math.Sin(x) * Math.Cos(z);

                    double value = y;

                    data.SetValue(row, col, value);
                }

Slightly altered code (Fails). Note change in line 3 below

               for (int row = 0; row < GridStepY; row++, x += dIncrementX)
                {
                    y = 1 - Math.Sqrt((x * x) + (z * z) + 2);
                    y += 3.0 * Math.Sin(x) * Math.Cos(z);

                    double value = y;

                    data.SetValue(row, col, value);
                }

Best regards,
Lennart