private void CreateRenderingOptions()
        {
            renderingOptions = null;
            if (dataSet != null)
            {
                renderingOptions = new RenderingOptions();
                renderingOptions.MinValue = double.MaxValue;
                renderingOptions.MaxValue = double.MinValue;

                int startIndex = (dataSet.Length < DataPointCount) ? 0 : dataSet.Length - DataPointCount;

                for (int i = startIndex; i < dataSet.Length; i++)
                {
                    renderingOptions.MinValue = Math.Min(dataSet[i].HeartRateValue, renderingOptions.MinValue);
                    renderingOptions.MaxValue = Math.Max(dataSet[i].HeartRateValue, renderingOptions.MaxValue);
                }
            }
        }