Index exceeds matrix dimensions

Question

Chet Price 2012-5-11

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/38048-index-exceeds-matrix-dimensions

回答： Steve Miller 2022-12-21

在 MATLAB Online 中打开

I get an error for this code, i dont know where or why. Any help would be appreciated.

function project Penduli

function Penduli

close all clear all %user input gravity = 5; mass = 1; Beta = 0.2; y0 = [45 0]; time = [0:.1:30];

for L = linspace(.5,1.5,5) [T,Y] = ode45(@pendulum,time,y0,[],gravity,L,mass,Beta); hold on animatePendulum(T,Y,L); end hold off

function dydt = pendulum(t,y,gravity,L,mass,Beta)

dydt = zeros(2,1);

dydt(1) = y(2); dydt(2) = -Beta*y(2)-mass*gravity/L*sin(y(1));

function animatePendulum(T,Y,L) nT = length(T); hold on for pt = 1:nT origin=zeros(size(L)); x_pos = L*sin(Y(pt,1)); y_pos = -L*cos(Y(pt,1));

   for x=1:5
 axis equal
 axis([-1 1 -1.8 .2])
 pendulA =  line([origin;origin],[origin;origin],'Marker','o')
 set(pendulA(x),'visible','on');
 set(pendulA(x),'XData',[0 x_pos(x)]);
 set(pendulA(x),'YData',[0 y_pos(x)]);
 drawnow
 end

% plot(0,0,'g.','markersize',25) % hold on % plot([0 xpos],[0 ypos],'r') % plot(xpos,ypos,'g.','markersize',25) % hold off

   drawnow
end

2 个评论
显示无隐藏无

Geoff 2012-5-11

The usual procedure is to read the error message, go to the source file and line number that the error message tells you, and look at the code. If you want to ask us what's wrong, then you should tell us which line the error occurs on. Unless you want to rely on somebody here taking the time to fix your unformatted code, run it and debug it for you.

This is also helpful... Run the following command and then run your script.

dbstop if error

That will break execution where your error occurs. Then you can play with the data values that are in scope, examining them in the command window and whatnot.

Jan 2012-5-11

@geoff: I'd vote this, if it was posted as answer.

@Chet: Please format the code. Using "clear all" on top of a function is strange and not useful. Using an anonymous function to carry additional parameters is recommended. Please format the code such that it is readable. All these three topics have been discussed repeatedly in this forum and a search is recommended.

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Steve Miller 2022-12-21

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/38048-index-exceeds-matrix-dimensions#answer_1133007

As posted by Geoff in the comments above:

The usual procedure is to read the error message, go to the source file and line number that the error message tells you, and look at the code. If you want to ask us what's wrong, then you should tell us which line the error occurs on. Unless you want to rely on somebody here taking the time to fix your unformatted code, run it and debug it for you.

This is also helpful... Run the following command and then run your script.

dbstop if error

That will break execution where your error occurs. Then you can play with the data values that are in scope, examining them in the command window and whatnot.

--Steve