using System;
using System.Linq;

namespace BaseLibDataProcess
{
    public class CPK
    {
        /// <summary>
        /// 计算CPK
        /// </summary>
        /// <param name="UCL">上限</param>
        /// <param name="LCL">下限</param>
        /// <param name="data">数据</param>
        /// <returns></returns>
        public double CalcCPK(double UCL, double LCL, double[] data)
        {
            double cpk = 0;
            if (data.Length > 1)
            {
                cpk = (1 - CalcCa(UCL, LCL, data)) * CalcCp(UCL, LCL, data);
                //cpk = Math.Min((UCL - data.Average()) / (3 * CalcStdDev(data)), (data.Average() - LCL) / (3 * CalcStdDev(data)));
            }
            return cpk;
        }
        /// <summary>
        /// 计算CpU
        /// </summary>
        /// <param name="UCL">上限</param>
        /// <param name="data">数据</param>
        /// <returns></returns>
        public double CalcCpU(double UCL, double[] data)
        {
            double CpU = 0;
            if (data.Length > 1)
            {
                CpU = (UCL - data.Average()) / (3 * CalcStdDev(data));
            }
            return CpU;
        }
        /// <summary>
        /// 计算Ca
        /// </summary>
        /// <param name="UCL">上限</param>
        /// <param name="LCL">下限</param>
        /// <param name="data">数据</param>
        /// <returns></returns>
        public double CalcCa(double UCL, double LCL, double[] data)
        {
            double Ca = 0;
            if (data.Length > 1)
            {
                Ca = Math.Abs((data.Average() - (UCL + LCL) / 2) / ((UCL - LCL) / 2));     //准确度
            }
            return Ca;
        }
        /// <summary>
        /// 计算Cp
        /// </summary>
        /// <param name="UCL">上限</param>
        /// <param name="LCL">下限</param>
        /// <param name="data">数据</param>
        /// <returns></returns>
        public double CalcCp(double UCL, double LCL, double[] data)
        {
            double cp = 0;
            if (data.Length > 1)
            {
                cp = (UCL - LCL) / (6 * CalcStdDev(data));  //精确度
            }
            return cp;
        }
        /// <summary>
        /// 计算CpL
        /// </summary>
        /// <param name="LCL">下限</param>
        /// <param name="data">数据</param>
        /// <returns></returns>
        public double CalcCpL(double LCL, double[] data)
        {
            double cpl = 0;
            if (data.Length > 1)
            {
                cpl = (data.Average() - LCL) / (3 * CalcStdDev(data));
            }
            return cpl;
        }
        /// <summary>
        /// 计算标准偏差
        /// </summary>
        /// <param name="data">数据</param>
        /// <returns></returns>
        public double CalcStdDev(double[] data)
        {
            double dTemp = 0;
            for (int i = 0; i < data.Length; i++)
            {
                dTemp += Math.Pow(data[i] - data.Average(), 2);
            }
            double ret = Math.Sqrt(dTemp / (data.Length - 1));
            return ret;
            //double xSum = 0F;
            //double xAvg = 0F;
            //double sSum = 0F;
            //double tmpStDev = 0F;
            //int arrNum = data.Count;
            //for (int i = 0; i < arrNum; i++)
            //{
            //    xSum += data[i];
            //}
            //xAvg = xSum / arrNum;
            //for (int j = 0; j < arrNum; j++)
            //{
            //    sSum += ((data[j] - xAvg) * (data[j] - xAvg));
            //}
            //tmpStDev = Convert.ToSingle(Math.Sqrt((sSum / (arrNum - 1))).ToString());
            //return tmpStDev;
        }
    }
}