matlab实验4,5,8.docVIP

实验四：线性方程组的求解（2课时） 参考程序： 方法一：A=[7 14 -9 -2 5;3 -15 -13 -6 -4;-11 -9 -2 5 7;5 7 14 16 -2;-2 5 12 -11 -4] B=[100;200;300;400;500] X=A\B X = 370.9455 -224.7276 238.3333 -138.1891 503.6378 方法二： [x1,x2,x3,x4,x5]=solve(7*x1+14*x2-9*x3-2*x4+5*x5=100,3*x1-15*x2-13*x3-6*x4-4*x5+200,-11*x1-9*x2-2*x3+5*x4+7*x5=300,5*x1+7*x2+14*x3+16*x4-2*x5=400,-2*x1+5*x2+12*x3-11*x4-4*x5=500,x1,x2,x3,x4,x5) x1 = 115735/312 x2 = -70115/312 x3 = 715/3 x4 = -43115/312 x5 = 157135/312 2.参考程序： A=[6 9 14 -11 5;1 14 -7 -15 -6;-2 1 -7 12 -1;6 11 11 -9 -13] B=[68;294;-441;103] X=A\B X =[X1; X2; X3; X4; X5] 0 -26.3759 -5.4126 -38.3960 -8.2392 3.参考程序： A=[0 0 -1 0;0 20 40 0;60 0 40 0;0 0 40 40]; B=[0;10;50;-40]; I=A\B I =[Ia Ib Ic Id] 0.8333 0.5000 0 -1.0000 实验五：函数编写与程序设计（2课时） 参考程序： function [y,y1,y2]=mwave(f1,m1,f2,m2) t=0:2*pi/(500-1):2*pi; y1=m1*sin(2*pi*f1*t); y2=m2*sin(2*pi*f2*t); y=y1+y2; figure subplot(311); plot(t,y1); title(y12¨D?); subplot(312); plot(t,y2); title(y22¨D?); subplot(313); plot(t,y); title(y=y1+y22¨D?); [y,y1,y2]=mwave(2,20,05,2) 2. a=1; s=0 for i=1:64 s=s+a; a=2*a; end n=s/1.4/10^8 s = 0 n = 1.3176e+011 3. for x=0:19 for y=0:33 for z=0:100 if (x+y+z==100)(5*x+3*y+z/3==100) d=[x,y,z] end end end end d = 0 25 75 d = 4 18 78 d = 8 11 81 d = 12 4 84 实验八：线性时不变系统的时域响应 1.参考程序： x=[zeros(1,4),1,zeros(1,15)]; subplot(1,2,1) stem(k,x) y=[zeros(1,4),ones(1,16)] subplot(1,2,2) stem(k,y) 参考程序： f=2; t=0:0.001:2; w=2*pi*f*t; y=square(w,30) axis([0 2 0 2]); hold on plot(t,y) 参考程序： k=0.5; z=[1,-3]; p=[-1,-2,-4]; sys_zpk=zpk(z,p,k) Zero/pole/gain: 0.5 (s-1) (s+3) ----------------- (s+1) (s+2) (s+4) [b,a]=zp2tf(z,p,k); sys_tf=tf(b,a) Transfer function: 0.5 s^2 + s - 1.5 ---------------------- s^3 + 7 s^2 + 14 s + 8