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();    }  }}