C:/Documents and Settings/Stephen/Desktop/Biostatistics Library and Program/Biostatistics/SpearmanRankSumGroupsCollection.cs

Go to the documentation of this file.

using System;
using System.Collections.Generic;

namespace StephenAshley.Biostatistics
{
   using NUMBER = Decimal;

   public class SpearmanRankSumGroupsCollection : GroupsCollection
   {
      #region *** constructors ***
      public SpearmanRankSumGroupsCollection() : base() { }

      public SpearmanRankSumGroupsCollection(List<Group> lstGroups)
         : base(lstGroups)
      {
      }
      #endregion
      #region ***** methods ******
      public override void Add(Group group)
      {
         if (group == null)
            throw new BiostatisticsException(
           "group parameter in the Add method of the SpearmanRankSumGroupsCollection is null.");

         if (groupsArray != null && groupsArray.Length > 0)
         {
            if (groupsArray[0].n() != group.n())
               throw new BiostatisticsException(
"Addition of Group with a different number of elements than other Groups in SpearmanRankSumGroupsCollection.");
         }

         base.Add(group);
      }

      public override void AddRange(List<Group> lstGroups)
      {
         if (lstGroups == null)
         throw new BiostatisticsException(
"lstGroups parameter in AddRange method of SpearmanRankSumGroupsCollection is null.");

         foreach (Group group in lstGroups)
            Add(group);
      }
      #endregion
      #region ***** properties *****
      public Int32 N()
      { return groupsArray[0].n(); } 

      public NUMBER SpearmanCoefficient()
      {
         List<Spearman> lstX = new List<Spearman>(N());
            List<Spearman> lstY = new List<Spearman>(N());
            List<NUMBER> lstRanksAscending = new List<decimal>(N());
            List<NUMBER> lstRanksDescending = new List<decimal>(N());

            foreach (NUMBER decNumber in groupsArray[0])
               lstX.Add(new Spearman(decNumber));
            foreach (NUMBER decNumber in groupsArray[1])
               lstY.Add(new Spearman(decNumber));

            foreach (Spearman sp in lstX)
            {
               lstRanksAscending.Add(sp.Data);
            }
            lstRanksAscending.Sort();
            lstRanksDescending.AddRange(lstRanksAscending);
            lstRanksDescending.Reverse();

            foreach (Spearman sp in lstX)
            {
               NUMBER a = GetRank(sp.Data, lstRanksDescending);
               NUMBER b = GetRank(sp.Data, lstRanksAscending);
               sp.Rank = ((a + N() -
                  b + 1.0m) / 2.0m);
            }
            lstRanksAscending.Clear();
            lstRanksDescending.Clear();

            foreach (Spearman sp in lstY)
            {
               lstRanksAscending.Add(sp.Data);
            }
            lstRanksAscending.Sort();
            lstRanksDescending.AddRange(lstRanksAscending);
            lstRanksDescending.Reverse();

            foreach (Spearman sp in lstY)
            {
               NUMBER a = GetRank(sp.Data, lstRanksDescending);
               NUMBER b = GetRank(sp.Data, lstRanksAscending);
               sp.Rank = ((a + N() -
                  b + 1.0m) / 2.0m);
            }

            NUMBER decSumOfSquaredDifferences = 0.0m;
            for (int i = 0; i < N(); i++)
            {
               NUMBER decDifference = lstX[i].Rank - lstY[i].Rank;
               decSumOfSquaredDifferences += decDifference * decDifference;
            }

            return 1.0m - ((6.0m * decSumOfSquaredDifferences) / (N() * (N() * N() - 1)));
      }

      public string p()
      {
         NUMBER decTemp = DecMath.Abs(SpearmanCoefficient());
            // TODO: Make sure using the absolute value is right.
            switch (N())
            {
               case 0:
               case 1:
               case 2:
               case 3:
               case 4:
                  throw new BiostatisticsException(
"Sample size too small to reach statistical significance.");
               case 5:
                  if (decTemp == 1.0m)
                     return "< 0.02";
                  else return "> 0.05";
               case 6:
                  if (decTemp == 1.0m)
                     return "< 0.01";
                  else if (decTemp > 0.943m)
                     return "< 0.02";
                  else if (decTemp > 0.886m)
                     return "< 0.05";
                  else return "> 0.05";
               //case 7:                        // http://www.sussex.ac.uk/Users/grahamh/RM1web/Rhotable.htm
               //   if (decTemp > 0.929m)
               //      return "< 0.01";
               //   else if (decTemp > 0.893m)
               //      return "< 0.02";
               //   else if (decTemp > 0.786m)
               //      return "< 0.05";
               //   else return "> 0.05";
               //case 8:
               //   if (decTemp > 0.881m)
               //      return "< 0.01";
               //   else if (decTemp > 0.833m)
               //      return "< 0.02";
               //   else if (decTemp > 0.738m)
               //      return "< 0.05";
               //   else return "> 0.05";
               //case 9:
               //   if (decTemp > 0.833m)
               //      return "< 0.01";
               //   else if (decTemp > 0.783m)
               //      return "< 0.02";
               //   else if (decTemp > 0.683m)
               //      return "< 0.05";
               //   else return "> 0.05";
               //case 10:
               //case 11:
               //   if (decTemp > 0.794m)
               //      return "< 0.01";
               //   else if (decTemp > 0.746m)
               //      return "< 0.02";
               //   else if (decTemp > 0.648m)
               //      return "< 0.05";
               //   else return "> 0.05";
               //case 12:
               //case 13:
               //   if (decTemp > 0.777m)
               //      return "< 0.01";
               //   else if (decTemp > 0.712m)
               //      return "< 0.02";
               //   else if (decTemp > 0.591m)
               //      return "< 0.05";
               //   else return "> 0.05";
               //case 14:
               //case 15:
               //   if (decTemp > 0.715m)
               //      return "< 0.01";
               //   else if (decTemp > 0.645m)
               //      return "< 0.02";
               //   else if (decTemp > 0.544m)
               //      return "< 0.05";
               //   else return "> 0.05";
               //case 16:
               //case 17:
               //   if (decTemp > 0.665m)
               //      return "< 0.01";
               //   else if (decTemp > 0.601m)
               //      return "< 0.02";
               //   else if (decTemp > 0.506m)
               //      return "< 0.05";
               //   else return "> 0.05";
               //case 18:
               //case 19:
               //   if (decTemp > 0.625m)
               //      return "< 0.01";
               //   else if (decTemp > 0.564m)
               //      return "< 0.02";
               //   else if (decTemp > 0.475m)
               //      return "< 0.05";
               //   else return "> 0.05";
               //case 20:
               //case 21:
               //   if (decTemp > 0.591m)
               //      return "< 0.01";
               //   else if (decTemp > 0.534m)
               //      return "< 0.02";
               //   else if (decTemp > 0.45m)
               //      return "< 0.05";
               //   else return "> 0.05";
               //case 22:
               //case 23:
               //   if (decTemp > 0.562m)
               //      return "< 0.01";
               //   else if (decTemp > 0.508m)
               //      return "< 0.02";
               //   else if (decTemp > 0.428m)
               //      return "< 0.05";
               //   else return "> 0.05";
               //case 24:
               //case 25:
               //   if (decTemp > 0.537m)
               //      return "< 0.01";
               //   else if (decTemp > 0.485m)
               //      return "< 0.02";
               //   else if (decTemp > 0.409m)
               //      return "< 0.05";
               //   else return "> 0.05";
               //case 26:
               //case 27:
               //   if (decTemp > 0.515m)
               //      return "< 0.01";
               //   else if (decTemp > 0.465m)
               //      return "< 0.02";
               //   else if (decTemp > 0.392m)
               //      return "< 0.05";
               //   else return "> 0.05";
               //case 28:
               //case 29:
               //   if (decTemp > 0.496m)
               //      return "< 0.01";
               //   else if (decTemp > 0.448m)
               //      return "< 0.02";
               //   else if (decTemp > 0.377m)
               //      return "< 0.05";
               //   else return "> 0.05";
               //case 30:
               //   if (decTemp > 0.478m)
               //      return "< 0.01";
               //   else if (decTemp > 0.432m)
               //      return "< 0.02";
               //   else if (decTemp > 0.364m)
               //      return "< 0.05";
               //   else return "> 0.05";
               default:
                  return string.Format("{0:N27}", Distributions.ProbabilityRho(
                     SpearmanCoefficient(), (Int16)N())).TrimEnd(new char[] { '0' });
            }
      }

      public NUMBER Rs() 
      {return SpearmanCoefficient(); } 

      #endregion

      private UInt16 GetRank(NUMBER decTarget, List<NUMBER> lstRanks)
      {
         UInt16 i = 0;
         for (; i < N(); i++)
            if (decTarget == lstRanks[i])
               return i;
         return 0;
      }
   }

   class Spearman
   {
      public Spearman(NUMBER decNumber)
      {
         decData = decNumber;
      }
      NUMBER decData;
      NUMBER decRank;


      public NUMBER Data { get { return decData; } set { decData = value; } }
      public NUMBER Rank { get { return decRank; } set { decRank = value; } }
   }
}

---