均匀分布实验

1、a.图1.11-1的源代码-th_3.m：th_3.m%-th_3.m-绘制均匀分布的密度函数及累积分布函数图的程序%-图2.11-1=%-copyrighttanhao &&huangwei-%clear,clfx=0:10; %x的范围 y=unifpdf(x,2,8); %求分布密度z=unifcdf(x,2,8); %累积分布x1=x(1:2) 2 x(3:9) 8 x(10:11); %取点y=y(1:2) 0 y(3:9) 0 y(10:11); %对应点概率 subplot(1,2,1);plot(x1,y,'r'); %分割窗口，画分布密度函数

2、axis(0,10,-0.01,0.3); %标明x轴范围subplot(1,2,2);plot(x,z,'k'); %分割窗口，画累积分布函数axis(0,10,-0.1,1.1);b.图1.11-2及1.11-3的源代码(tongfenbu.m):tongfenbu.m%-2.11-3-同分布模拟-%-coprighttanhao&&huangwei-%function tongfenbu()clear,clc, clf %清屏x1=0,1;f1=1,1;hold on %同一图形显示plot(x1,f1); x11=-0.5 0; f11=0 0;x2=1

3、 2; plot(x11,f11); plot(x2,f11);plot(0 0,0 1,'-'); % 虚线plot(1 1,0 1,'-');f2=x1;f22=2-x2; %»f2图形-plot(x1,f2,'r:*');plot(x2,f22,'r:*');%-画图-x31=linspace(0,1,100);%y31=f31(x31);plot(x31,y31,'k');%f3 y41=f41(x31);plot(x31,y41,'c');%f4 y51=f51(x31);plo

4、t(x31,y51,'g');%f5x32=linspace(1,2,100);y32=f32(x32);plot(x32,y32,'k'); y42=f42(x32);plot(x32,y42,'c'); y52=f52(x32);plot(x32,y52,'g');x33=linspace(2,3,100);y33=f33(x33);plot(x33,y33,'k'); y43=f43(x33);plot(x33,y43,'c'); y53=f53(x33);plot(x33,y53,'

5、g');x44=linspace(3,4,100);y44=f44(x44);plot(x44,y44,'c'); y54=f54(x44);plot(x44,y54,'g');x55=linspace(4,5,100);y55=f55(x55);plot(x55,y55,'g');%-¼正态分布的情形-% x10=linspace(0,10,1000);y10=fe(x10);plot(x10,y10);x11=linspace(0,11,1000);y10=fe(x11);plot(x10,y10);x12=linspace

6、(0,12,1000);y10=fe(x12);plot(x10,y10);x13=linspace(0,13,1000);y10=fe(x13);plot(x10,y10);x14=linspace(0,14,1000);y10=fe(x14);plot(x10,y10);x15=linspace(0,15,1000);y10=fe(x15);plot(x10,y10);x16=linspace(0,16,1000);y10=fe(x16);plot(x10,y10);axis(-0.5 12 -0.05 1.55) %设定坐标轴范围text(0.3,1,'f1=1');te

7、xt(0.8,0.8,'f2');text(2,0.5,'f3'); %图形加注text(3,f43(3),'f4');text(4,f54(4),'f5');text(6,fe(6),'fe');%-部分函数改写文件-%function yy=f31(x)clear yy,clc,yy=(x.2)/2; %function yy=f32(x)clear yy,clc,yy=(x.2-3*(x-1).2)/2; %function yy=f33(x)clear yy,clc,yy=(x.2-3*(x-1).2+3*

8、(x-2).2)/2;%-%function yy=f41(x)clear yy,clc,yy=x.3/6; %function yy=f42(x)clear yy,clc,yy=(x.3-4*(x-1).3)/6; %function yy=f43(x)clear yy,clc,yy=(x.3-4*(x-1).3+6*(x-2).3)/6; %function yy=f44(x)clear yy,clc,yy=(x.3-4*(x-1).3+6*(x-2).3-4*(x-3).3)/6;%-%function yy=f51(x)clear yy,clc,yy=x.4/24; %function

9、 yy=f52(x)clear yy,clc,yy=(x.4-5*(x-1).4)/24; %function yy=f53(x)clear yy,clc,yy=(x.4-5*(x-1).4+10*(x-2).4)/24; %function yy=f54(x)clear yy,clc,yy=(x.4-5*(x-1).4+10*(x-2).4-10*(x-3).4)/24; %function yy=f55(x)clear yy,clc,yy=(x.4-5*(x-1).4+10*(x-2).4-10*(x-3).4+5*(x-4).4)/24;%-%function yy=fe(x)clc,c

10、lear yy;yy=exp(-(x-5).2/(2*(5/6).2)/(sqrt(2*pi)*5/6);%-%function yy=f(x)clc,clear;yy=exp(-(x-5).2/(2*(5/6).2);源程序： th_4.m th_4.m% th_4.m 求线段两点间距离的期望模拟clc,clear,clf, %清屏%-对话窗口创建-%prompt='请选择区间L长度：'dlg_title='th_2.12-2'num_lines=1;def='1'result=inputdlg(prompt,dlg_title,num_lin

11、es,def);Nb=str2num(char(result);%-if(Nb<=0) errordlg('阶数为非正数，请重新选择'); return;endL=Nb;m=100;% m 观察次数初始化axis(0,L,0,L);plot(0,L,L/3,L/3,'y:','linewidth',2);%画线标识均值(期望距离）hold onplot(L/3,L/3,0,L,'y:','linewidth',2); plot(0,L,0,L,'k','linewidth',2

12、); theAxs =axis; %取出当前坐标轴，使得后继图形保持与当前坐标相同尺度set(gca,'xtick',0 L/3 L,'xticklabel','0|L/3|L');set(gca,'ytick',0 L/3 L,'yticklabel','0|L/3|L');% gca为当前轴对象，使用get(gca)可观察其值，这里设定y轴的刻度'ytick'和各个刻度的显示字符'yticklabel' xx=; %xx赋初值（空矩阵），注意动态记录向量或矩阵 y

13、y=; zz=;figure（1） %第一张图 mm=moviein(m); % 动画开始for i=1:m %for循环开始，逐步模拟距离 x1(i)=unifrnd(0,L);xx=xx;x1(i); %按行记录x1位置 x2(i)=unifrnd(0,L);yy=yy;x2(i); y(i)=abs(x1(i)-x2(i);zz=zz;y(i); if y(i)<=L/3 % 判断是否在期望距离以内 plot(x1(i),x2(i),'m*');hold on %是用紫色*点标记 else plot(x1(i),x2(i),'ko') %不是用黑色o

14、点标记 end plot(x1(i),x1(i),0,x2(i),'color','b','linewidth',1);% 将点投影到x轴，画相应的投影示意线 plot(x1(i),0,'ro'); % 画投点坐标的示意点 plot(0,x1(i),x2(i),x2(i),'color','c','linewidth',1); plot(0,x2(i),'ro'); if i<=4 %if块语句，前几次模拟慢显示 pause(0.1) % 暂停0.1秒 end

15、%if块中止 mm(i)=getframe; %hold offend movie(mm,1) ; figure(2) %第二张图 ，分别画个人在坐标轴投点 bar(xx,zz) figure(3) %第三张图 bar(yy,zz)d.实验1.13源代码：%-2.13B-模拟正态分布随机数-%clc ,clear,x=;for i=1:10 n=12; r=rand(1,n); x(i)=sum(r)-6;endx%-%e.蒙特卡罗积分模拟源程序:(th_5.m)th_5.m%-th_5.m-%-2.31-蒙特卡罗模拟求积分-%-coprighttanhao-%clc,clear,clf, %

16、清屏%prompt='请选择试验次数N：'dlg_title='th_2.2'num_lines=1;def='300'result=inputdlg(prompt,dlg_title,num_lines,def); %对话框创建Nb=str2num(char(result);%判定选择是否合理if(Nb<=0) errordlg('次数为非正数，请重新选择'); return;endx=linspace(0,1,100);y= x.3; %要求的积分函数并且可以事先画出其图，由定积分知%不难得出其积分值为1/4plot(x,y,'rx');hold onN=