Question

关于MATLAB

在matlab输入：
function dy=myfile(t,y);
dy=zeros(2,1);
dy(1)=-300*y(1)+10*y(2)+2000;
dy(2)=-1000*y(1)-100*y(2);
[t,y]=ode45('my file',[0,0.2],[5,100]);
plot(t,y( : ,1),'LineWidth',1.5);
set(gcf,'color','w');
plot(t,y( : ,2),'LineWidth',1.5);
set(gcf,'color','w');
grid;
显示：??? function dy=myfile(t,y);
|
Error: Function definitions are not permitted at the prompt or in scripts.
出错在哪里呢？

Answer 1

在Matlab下输入：edit，然后将下面两行百分号之间的内容，复制进去，保存
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function dy=myfile(t,y);
dy=zeros(2,1);
dy(1)=-300*y(1)+10*y(2)+2000;
dy(2)=-1000*y(1)-100*y(2);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

在Matlab下面输入：
[t,y]=ode45('my file',[0,0.2],[5,100]);
plot(t,y( : ,1),'LineWidth',1.5);
set(gcf,'color','w');
plot(t,y( : ,2),'LineWidth',1.5);
set(gcf,'color','w');
grid;

Answer 2

[t,y]=ode45('my file',[0,0.2],[5,100]);
里面'my file'不能用空格
如果你的'my file'文件名就有空格那么把空格去掉，再把这里的也去掉

Answer 3