实验计算机模拟

1、实验：计算机模拟、实验目的和要求1 .掌握计算机模拟的基本原理及方法；2 .掌握利用随机数解决问题；二、实验内容1.已知零件C由零件A和零件B连接而成，已知零件 A B的长度为随机变量,数值如下表，试抽取10个样本计算C的平均长度零件A的长 度56789概率0.070.190.380.250.11零件B的长 度14151617概率0.230.410.270.09解答：输入xxx.m文件aaa=;fo门=1:10a=rand;if a<=007a1=5;elseif a>0.07&&a<=0.26 a1=6;elseif a>0.26&&a

2、<=0.64 a1=7;elseif a>0.64&&a<=0.89 a1=8;elseif a>0.89&&a<=1 a1=9;endb=rand;if b<=0.23b1=14;elseif a>0.23&&a<=0.64 b1=15;elseif a>0.64&&a<=0.91 b1=16;elseif a>0.91&&a<=1 b1=17;endc=a1+b1aaa=aaa a1+b1;end10个样本计算C的平均长度为19。2.某服装

3、公司欲预定一批冬装出售，每件冬装的加工费不确切，估计如下:单件成本789101112概率0.050.150.20.30.250.05已知该服装销售量与订价有关预测各销售量概率如下:定价概率预计销售500600700800900191 0.050.150.40.250.15200.30.20.20.20.12110.20.30.350.10.05运行xxx得到以下结果:xxxc =21c = 19c =20c =21c =20 c =20 c =21 c =19c =19c =19>> mean(aaa) ans =19.9000试用模拟方法决定该公司冬装的订购数与订价，使利润最大（

4、如订购量大于销量 时，每件以5元处理）根据题设编写代码：a.mb=500 600 700 800 900;a=19,20,21;x1=rand;if x1<0.05c=7;elseif x1>0.05&x2<0.20c=8;elseif x1>0.20&x1<0.4 c=9;elseif x1>0.4&x1<0.7c=10;elseif x1>0.7&x1<0.95c=11;elsec=12;endx2=rand;if x2<0.05d=500;elseif x2>0.05&x2<0

5、.2d=600;elseif x2>0.2&x2<0.6d=700;elseif x2>0.6&x2<0.85d=800;elsed=900;enddfor i=1:5for j=1:3b(i) a(j) if b(i)<=dz=b(i)*a(j)-b(i)*c elsez=d*a(j)-b(i)*c+(b(i)-d)*5 endendend运行a.mc =11ans =19ans =20ans =21d =600z =4800z =4800z=4800ans =500ans =600ans =700ans =900ans =19ans =20an

6、s =21ans =19z=4000z =5400z =5400z=3000ans =500ans =600ans =800ans =900ans =20ans =21ans =19ans =20z=4500z =6000z =3600z=3600ans =500ans =700ans =800ans =900ans =21ans =19ans =20ans =21z=5000z =4200z =4200z=4200ans =600ans =700ans =800可知：当生产600件定价为21元时，利润最大为6000元。3 一个慢跑者在平面上沿椭圆以恒定的速率 v=1跑步，设椭圆方程为： x=10+20cos t, y=20+5sin t.突然有一只狗攻击他.这只狗从原点出发以恒定速率w跑向慢跑者，狗的运动方向始终指向慢跑者.分别求出 w=20, w=5 时狗的运动轨迹.（用计算机模拟的方法）建立m3.m文件：w=20;v=1;dt=0.1d=100x=0;y=0;for t=0:0.1:100d=sqrt(x1(t)-xF2+(y1(t)-y)A2);x=w*(x1(t)-x)/d)*dt+x;y=w*(y1(t)-y)/d)*dt+y;plot(x1(t),y1(t),'r+',x,y,'*' )h