Error using * Inner matrix dimensions must agree - using meshplot

11 次查看（过去 30 天）
Will
Will 2014-3-4
评论： Will 2014-3-4
I have been trying to draw the direction fields of some first order differential equations and sometimes I can get it to work, others not.
This is an example of a problem I have just had:
To sketch the direction field of dy/dt - 2*y = t^2 . e^(2t)
I have tried the following:
>> [t y]=meshgrid(0:0.5:2,-4:0.5:4); >> dy=t.^2*exp(2.*t)+2.*y;
But an it immediately states there is an error: Error using * Inner matrix dimensions must agree.
I can't see what the problem is because in other instances this error does not occur. For example, this worked perfectly:
>> [t y]=meshgrid(-4:0.5:4,-4:0.5:4); >> dy=t - 3*y +exp(-2*t); >> dt=ones(size(dy)); >> L=sqrt(1+dy.^2); >> quiver (t, y, dt./L, dy./L, 0.5), axis tight;

请先登录，再回答此问题。

采纳的回答

Mischa Kim
Mischa Kim 2014-3-4
编辑：Mischa Kim 2014-3-4
Will, use
[t y] = meshgrid(0:0.5:2,-4:0.5:4);
dy = t.^2.*exp(2*t) + 2.*y; % need to use dot operators all the way
dt = ones(size(dy));
L = sqrt(1 + dy.^2);
quiver (t, y, dt./L, dy./L, 0.5)
axis tight;

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Statistics and Machine Learning Toolbox 的更多信息

标签

产品

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by