C#利用Random得随机数求均值、方差、正态分布的方法

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.Collections;
using System.Text.RegularExpressions;
namespace random
{
  classProgram
  { 
    //求随机数平均值方法
    staticdouble Ave(double[] a)
    { 
      double sum=0;
      foreach(double din a)
      {  
        sum=sum+d;
      }
      doubleave=sum/a.Length;
      return ave;
    }
    //求随机数方差方法
    staticdouble Var(double[] v)
    {
      //double tt = 2;
      //double mm = tt ^ 2;
      double sum1= 0;
      for (int i =0; i< v.Length; i++)
      {
        double temp= v[i] * v[i];
        sum1 = sum1 + temp;
      }
      double sum =0;
      foreach (double din v)
      {
        sum = sum + d;
      }
      double var =sum1 / v.Length - (sum / v.Length) * (sum / v.Length);
      return var;
    }
    //求正态分布的随机数
    staticvoidFenbu(double[] f)
    {  
      //doublefenbu=new double[f.Length ];
      for (int i =0; i< f.Length; i++)
      {
        double a = 0, b = 0;
        a =Math.Sqrt((-2)*Math.Log(f[i], Math.E));
        b = Math.Cos(2 *Math.PI * f[i]);
        f[i] = a * b * 0.3 + 1;
      }
    }
    static void Main(string[]args)
    {  
      //生成100个（0，1）之间的随机数
      Random ran = newRandom();
      double[] dou= new double[100];
      for(int i=0;i<dou.Length;i++)
      {
        dou[i]= ran.NextDouble();
      }
      //调用Ave方法、Var方法求得随机数均值和方差
      doubleavenum = Ave(dou);
      doublevarnum = Var(dou);
      //写入文件
      //将100个随机数，均值，方差保存到文件“d:\SourceData.txt”中
      stringDatapath = (@"d:\SourceData.txt");
       FileStream fs = new FileStream(Datapath,FileMode.Create);
       StreamWriter sw = newStreamWriter(fs);
       for (int j =0; j< dou.Length;j++ )
       {
         sw.WriteLine(dou[j]);
       }
       sw.Write("100个随机数均值和方差分别是{0}和{1}",avenum,varnum);
       sw.Close();
       //读取数据文件“d:\SourceData.txt”
       FileStream fs1= new FileStream(Datapath, FileMode.Open);
       StreamReader sr = newStreamReader(fs1);
       string temp=null;
       string str =null;
       while((temp=sr.ReadLine())!=null)
       {
        str = str+temp+"";
       }
       //对数组进行分割Regax
       Regex re = newRegex(" ");
       string[]str1=re.Split(str);
       double[]nums=newdouble[str1.Length-2];
       for(int i=0;i<str1.Length-2;i++)
       {
       nums[i]=Convert.ToDouble(str1[i]);
       }
      //调用正态分布随机函数,求均值和方差
      Fenbu(nums);
      doubleaveresult= Ave(nums);
      doublevarresult = Var(nums);
      //写入文件
      //将100个随机数，均值，方差保存到文件“d:\ResultData.txt”中
      stringResultpath = (@"d:\ResultData.txt");
      FileStream fs2 = newFileStream(Resultpath, FileMode.Create);
      StreamWriter sw1 = newStreamWriter(fs2);
      for (int j =0; j< nums.Length; j++)
      {
        sw1.WriteLine(nums[j]);
      }
      sw1.Write("100个随机数均值和方差分别是{0}和{1}",averesult, varresult);
      sw1.Close();
      Console.ReadKey();
    }
  }
}