A computational statistics class

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Introduction

This is a computational statistics class written in C#. The public methods are described below.

Public methods

• Constructor: public statistics(params double[] list)
• Update the design: public void update(params double[] list)
• Compute the mode: public double mode() - If there is more then one mode the NaN value will be returned.
• Compute the size of the design: public int length()
• Compute the minimum value of the design: public double min()
• Compute the maximum value of the design: public double max()
• Compute the first quarter : public double Q1()
• Compute the median : public double Q2()
• Compute the third quarter : public double Q3()
• Compute the average: public double mean()
• Compute the range: public double range()
• Compute the inter quantile range: public double IQ()
• Compute middle of range: public double middle_of_range()
• Compute sample variance: public double var()
• Compute standard deviation: public double s()
• Compute the YULE index: public double YULE()
• Compute the index standard of a given member of the design: public double Z(double member)
• Compute the covariance: public double cov(statistics s), public static double cov(statistics s1,statistics s2)
• Compute the correlation coefficient: public double r(statistics design), public static double r(statistics design1,statistics design2)
• Compute the "a" factor of the linear function of design: public double a(statistics design)
• Compute the "a" factor of the linear function of design2: public static double a(statistics design1,statistics design2)
• Compute the "b" factor of the linear function of design: public double b(statistics design)
• Compute the "b" factor of the linear function of design 2: public static double b(statistics design1,statistics design2)

Source code

using System;
 
namespace statistic
{
    
    public class statistics
    {
 
      private double[] list;
 
      public statistics(params double[] list)
      {
        this.list=list;
      }
      
      public void update(params double[] list)
      {
         this.list=list;
      }
 
      public double mode()
      {
         try
         {
              double[] i=new double[list.Length];
              list.CopyTo(i,0);
              sort(i);
              double val_mode=i[0],help_val_mode=i[0];
              int old_counter=0,new_counter=0;
              int j=0;
              for (;j<=i.Length-1;j++)
               if (i[j]==help_val_mode) new_counter++;
               else if (new_counter>old_counter) 
               {
                   old_counter=new_counter;
                   new_counter=1;
                   help_val_mode=i[j];
                   val_mode=i[j-1];
               }
               else if (new_counter==old_counter) 
               {
                   val_mode=double.NaN;
                   help_val_mode=i[j];
                   new_counter=1;
               }
               else 
               {
                   help_val_mode=i[j];
                   new_counter=1;
               }
              if (new_counter>old_counter) val_mode=i[j-1]; 
              else if (new_counter==old_counter) val_mode=double.NaN;
              return val_mode;
         }
         catch (Exception)
         {
            return double.NaN;
         }
      }
 
      public int length()
      {
         return list.Length;
      }
 
      public double min()
      {
         double minimum=double.PositiveInfinity;
         for (int i=0;i<=list.Length-1;i++)
                  if (list[i]<minimum) minimum=list[i];
         return minimum;
      }
 
      public double max()
      {
         double maximum=double.NegativeInfinity;
         for (int i=0;i<=list.Length-1;i++)
                  if (list[i]>maximum) maximum=list[i];
         return maximum;
      }   
    
      public double Q1()
      {
         return Qi(0.25);
      }
 
      public double Q2()
      {
         return Qi(0.5);
      }
 
      public double Q3()
      {
         return Qi(0.75);
      }
 
      public double mean()
      {
         try
         {
          double sum=0;
          for (int i=0;i<=list.Length-1;i++)
                   sum+=list[i];
          return sum/list.Length;
         }
         catch (Exception)
         {
                  return double.NaN;
         }
      }
 
      public double range()
      {
         double minimum=min();
         double maximum=max();
         return (maximum-minimum);
      }
 
      public double IQ()
      { 
         return Q3()-Q1();
      }
 
      public double middle_of_range()
      {
         double minimum=min();
         double maximum=max();
         return (minimum+maximum)/2; 
      }
 
      public double var()
      {
         try
         {
              double s=0;
              for (int i=0;i<=list.Length-1;i++)
                       s+=Math.Pow(list[i],2);
              return (s-list.Length*Math.Pow(mean(),2))/(list.Length-1);
         }
         catch (Exception)
         {
            return double.NaN;
         }
      }
 
      public double s()
      {
         return Math.Sqrt(var());
      }
 
      public double YULE()
      {
         try
         {
            return ((Q3()-Q2())-(Q2()-Q1()))/(Q3()-Q1());
         }
         catch (Exception)
         {
      return double.NaN;
         }
      }
 
      public double Z(double member)
      {
         try
         {
            if (exist(member)) return (member-mean())/s();
                else return double.NaN;
         }
         catch(Exception)
         {
            return double.NaN;
         }
      }
 
      public double cov(statistics s)
      {
         try
         {
              if (this.length()!=s.length()) return double.NaN;
              int len=this.length();
              double sum_mul=0;
              for (int i=0;i<=len-1;i++)
                sum_mul+=(this.list[i]*s.list[i]);
              return (sum_mul-len*this.mean()*s.mean())/(len-1);
         }
         catch(Exception)
         {
            return double.NaN;
         }
      }
 
      public static double cov(statistics s1,statistics s2)
      {
         try
         {
              if (s1.length()!=s2.length()) return double.NaN;
              int len=s1.length();
              double sum_mul=0;
              for (int i=0;i<=len-1;i++)
                sum_mul+=(s1.list[i]*s2.list[i]);
              return (sum_mul-len*s1.mean()*s2.mean())/(len-1);
         }
         catch(Exception)
         {
            return double.NaN;
         }
      }
 
      public double r(statistics design)
      {
         try
         {
            return this.cov(design)/(this.s()*design.s());
         }
         catch(Exception)
         {
            return double.NaN;
         }
      }
 
      public static double r(statistics design1,statistics design2)
      {
         try
         {
            return cov(design1,design2)/(design1.s()*design2.s());
         }
         catch(Exception)
         {
            return double.NaN;
         }
      }
 
      public double a(statistics design)
      {
         try
         {
            return this.cov(design)/(Math.Pow(design.s(),2));
         }
         catch(Exception)
         {
             return double.NaN;
         }
      }
 
      public static double a(statistics design1,statistics design2)
      {
         try
         {
            return cov(design1,design2)/(Math.Pow(design2.s(),2));
         }
         catch (Exception)
         {
            return double.NaN;
         }
      }
 
      public double b(statistics design)
      {
         return this.mean()-this.a(design)*design.mean();
      }
 
      public static double b(statistics design1,statistics design2)
      {
         return design1.mean()-a(design1,design2)*design2.mean();
      }
 
      private double Qi(double i)
      {
         try
         {
              double[] j=new double[list.Length];
              list.CopyTo(j,0);
              sort(j);
              if (Math.Ceiling(list.Length*i)==list.Length*i) 
                  return (j[(int)(list.Length*i-1)]+j[(int)(list.Length*i)])/2;
              else return j[((int)(Math.Ceiling(list.Length*i)))-1];
          }
         catch(Exception)
         {
            return double.NaN;
         }
      }
      
      private void sort(double[] i)
      {
         double[] temp=new double[i.Length];
          merge_sort(i,temp,0,i.Length-1);
      }
 
      private void  merge_sort(double[] source,
           double[] temp,int left,int right)
      {
         int mid;
         if (left<right) 
         {
              mid=(left+right) / 2;
              merge_sort(source,temp,left,mid);
              merge_sort(source,temp,mid+1,right);
              merge(source,temp,left,mid+1,right);
         }
      }
 
      private void  merge(double[] source,double[] temp,
           int left,int mid,int right)
      {
         int i,left_end,num_elements,tmp_pos;
         left_end=mid - 1;
         tmp_pos=left;
         num_elements=right - left + 1;
         while ((left <= left_end) && (mid <= right)) 
         {
              if (source[left] <= source[mid]) 
              {            
                   temp[tmp_pos]= source[left];
                   tmp_pos++;
                   left++;
              }
              else
              {   
                   temp[tmp_pos] = source[mid];
                   tmp_pos++;
                   mid++;
              }
         }
         while (left <= left_end) 
         {
              temp[tmp_pos]= source[left];
              left++;
              tmp_pos++;
         }
         while (mid <= right) 
         {
              temp[tmp_pos]= source[mid];
              mid++;
              tmp_pos++;
         }
         for (i=1;i<=num_elements;i++)
         {
              source[right]= temp[right];
              right--;
         }
      }
 
      private bool exist(double member)
      {
         bool is_exist=false;
         int i=0;
         while (i<=list.Length-1 && !is_exist)
         {
           is_exist=(list[i]==member);
           i++;
         }
         return is_exist;
      }
    }
}