matlab入门练习之杂例二

• 留数计算函数residue的使用

clcclearb=[3 5 2 9]a=[4 6 0 -5][r,p,k]=residue(b,a)

• 逻辑运算符的使用

a=[1,2,-3,0,0]b=[0,1,0,2,0]xor(a,b)any(a)%一真即真，相当于或运算all(a)isequal(a,b)ismember(a,b)

• matlab中的循环及其控制

clear; clc ;close all;s=0;t=0;for i=1:10;    i    s=s+1    t=t+iendistop=0while ~istop    t=t-1    i=i+1    if i>10        istop=1;    end;endt=t-1i=i+1if i>10    istop=1else    istop=0end

• plot、meshgrid与mesh的使用

clcclear[X,Y] = meshgrid(-8:.5:8);R = sqrt(X.^2 + Y.^2) + eps;Z = sin(R)./R;C = del2(Z);figuremesh(X,Y,Z,C,'FaceLighting','gouraud','LineWidth',0.3)

a_log=logspace(1,2)plot(a_log,'.')x=-1:0.01:1x=x*piy=sin(x)plot(x,y,'.')hold ony2=cos(x)plot(x,y2,'*')[x1,x2]=ndgrid(-2:.2:2,-2:.2:2)z=x1.*exp(-x1.^2-x2.^2)mesh(x1,x2,z)figureplot(x1,x2,'*')surfc(x1,x2,z)meshc(x1,x2,z)pause(10);close all

• 矩阵的一些操作

A=[1 2 3 4;5 6 7 8;9 10 11 12;13 14 15 16]zeros(3,7)ones(3,4)eye(3,5)a=magic(10)b=sum(a)rand(5)speye(4)isvector(a)isequal(a,b)

• 解决线性最优问题（线性规划）

clcclear;f=[-5 -4 -6]A=[1 -1 1;3 2 4;3 2 0]B=[20;42;30]lb=zeros(3,1)linprog(f,A,B,[],[],lb,[])

• 鼠标取点函数与入门练习

clccleara2=[15,21,27,93,101]a1=[15;21;27;93;101]vec1=80:-9:10vec2=linspace(10,58,8)vec1=linspace(30,98,8)sum(vec1./vec2)a=[1,2,3,4]ab=[1 3 0 0]a>bA=rand(1,1000)B=sort(A)A(4)A(2:3)A([1:3,5])A=magic(6);AA(4,3)x=[1 3 4]y=[3 8 9]x.^y4+3<=6ginput(1)%取点函数

• area的使用

x=[1,2,3,4,5,6]y=[4,8,5,3,5,8]area(x,y)hold on;figurex=[1,2,3]'y=[1,3,4;6,5,8]'area(x,y)x=[1,2,3;4,5,6;7,8,9]'y=[1,3,4;6,5,8;1,1,1]'area(x,y)%第一个画第一个，第n个话第n-1个累积到和第n个累积x=[23,45,48,56,48,64,41;45,85,82,52,90,52,37]y=[1,5,1,4,6,8,8;4,8,2,4,6,5,6];area(x,y)%区域图x=[23;45]y=[1;4]area(x,y)%区域图figure;pause(2)x=[23,45;45,85]y=[1,5;4,8]area(x,y)%区域图pause(2)figure;x=[23,45,48;45,85,82]y=[1,5,1;4,8,2]area(x,y)%区域图pause(2)figure;x=[23,45,48,56;45,85,82,52]y=[1,5,1,4;4,8,2,4]area(x,y)%区域图pause(2)figure;x=[23,45,48,56,48;45,85,82,52,90]y=[1,5,1,4,6;4,8,2,4,6]area(x,y)%区域图pause(2)figure;x=[23,45,48,56,48,64;45,85,82,52,90,52]y=[1,5,1,4,6,8;4,8,2,4,6,5]area(x,y)%区域图pause(2)figure;x=[23,45,48,56,48,64,41;45,85,82,52,90,52,37]y=[1,5,1,4,6,8,8;4,8,2,4,6,5,6]area(x,y)%区域图pause(2)figure;x=[1,3;2,4]y=[1,2;3,4]area(x,y)%区域图,斜率一样，分段衔接，第一种情况。x=[1,3;2,5]y=[1,2;3,4]area(x,y)%区域图