程序代码：

function sgjg
global L0 L1 L2 L3 th1
str=inputdlg({'请输入机架长L0:','曲柄长L1:','连杆长L2:','摇杆长L3:','w1(rad/sec):','input repeat times m:','input initial theta3(rad):'},'please input!',1,{'20','8','25','20','100','10','1'});
L0=str2num(str{1});
L1=str2num(str{2});
L2=str2num(str{3});
L3=str2num(str{4});
w1=str2num(str{5});
m =str2num(str{6});
theta3=str2num(str{7});
t=linspace(0,2*pi/w1,181);
dt=2*pi/180/w1;
theta1=w1*t;
th1=theta1(1);
theta3(1)=fzero('f',theta3);
x1=0;
y1=0;
x2=x1+L1*cos(theta1(1));
y2=y1+L1*sin(theta1(1));
x4=x1+L0;
y4=y1;
x3=x4+L3*cos(theta3(1));
y3=y4+L3*sin(theta3(1));
figure('Name','四杆机构运动仿真','NumberTitle','off','position',[232 199 617 479]);
line([x1;x4],[y1;y4],'Color','m','LineStyle',':','LineWidth',3,'EraseMode','none');
line(x1,y1,'Color','b','LineStyle','.','EraseMode','none','MarkerSize',40);
line(x4,y4,'Color','b','LineStyle','.','EraseMode','none','MarkerSize',40);
dot2=line(x2,y2,'Color','b','LineStyle','.','EraseMode','xor','MarkerSize',15);
dot3=line(x3,y3,'Color','b','LineStyle','.','EraseMode','xor','MarkerSize',15);
line12=line([x1;x2],[y1,y2],'color','r','linestyle',':','erasemode','xor');
line23=line([x2;x3],[y2;y3],'color','g','linestyle',':','erasemode','xor');
line34=line([x4;x3],[y4;y3],'color','b','linestyle',':','erasemode','xor');
axis([-L1-L0/3 L2+L3 -L0/3-L1 L3]);
axis equal;
for i=1:m
    for j=2:181
        th1=theta1(j);
        theta3(j)=fzero('f',theta3(j-1));
        x2=x1+L1*cos(th1);
        y2=y1+L1*sin(th1);
        x3=x4+L3*cos(theta3(j));
        y3=y4+L3*sin(theta3(j));
        set(dot2,'xData',x2,'yData',y2);
        set(dot3,'xData',x3,'yData',y3);
        set(line12,'xData',[x1;x2],'yData',[y1;y2]);
        set(line23,'xData',[x2;x3],'yData',[y2;y3]);
        set(line34,'xData',[x3;x4],'yData',[y3;y4]);
        drawnow;
    end
end
w3=diff(theta3)/dt;
a3=diff(w3)/dt;
function y=f(th3)
global L0 L1 L2 L3 th1
y=L1*cos(th1)+L2*sqrt(1-(L3*sin(th3)-L1*sin(th1))^2/L2/L2)-L3*cos(th3)-L0;