Inverse MFI

using System;
using cAlgo.API;
using cAlgo.API.Indicators;

namespace cAlgo.Indicators
{
    [Indicator(IsOverlay = false, AccessRights = AccessRights.None)]
    public class InverseMFI : Indicator
    {
        [Parameter(DefaultValue = 21, MinValue = 8)]
        public int Length { get; set; }

        [Output("InverseMFI", Color = Colors.CadetBlue, Thickness = 2)]
        public IndicatorDataSeries invmfi { get; set; }

        private MoneyFlowIndex mfi;
        private IndicatorDataSeries value1;
        private IndicatorDataSeries smooth;

        protected override void Initialize()
        {
            mfi = Indicators.MoneyFlowIndex(Length);
            value1 = CreateDataSeries();
            smooth = CreateDataSeries();
        }

        public override void Calculate(int index)
        {
            double mfiL = mfi.Result[index];
            double mfiH = mfi.Result[index];
            for (int i = index - Length + 1; i <= index; i++)
            {
                if (mfiH < mfi.Result[i])
                {
                    mfiH = mfi.Result[i];
                }
                if (mfiL > mfi.Result[i])
                {
                    mfiL = mfi.Result[i];
                }
            }
            if (mfiH != mfiL)
            {
                value1[index] = 0.1 * (mfi.Result[index] - 50);
                smooth[index] = (value1[index] + 2 * value1[index - 1] + 2 * value1[index - 2] + value1[index - 3]) / 6;
            }
            invmfi[index] = (Math.Exp(2 * smooth[index]) - 1) / (Math.Exp(2 * smooth[index]) + 1);
        }
    }
}