error Inner matrix dimensions must agree?

Question

safisay 2017-11-15

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/367106-error-inner-matrix-dimensions-must-agree

评论： safisay 2017-11-15

采纳的回答： David Goodmanson

在 MATLAB Online 中打开

Hi,

Can anyone tell me what's wrong with the code?

if true
k_1=0.423;
F=1.06;
gama=pi/F;
thetac=0:0.1:gama;
theta1=thetac;
theta0=0.4561;
l=0.21818;
j_L_theta1=(theta1*l)/2;
M=(k_1*(sin(theta0 - theta1)*sin(k_1*theta0)*sin(k_1*(gama - theta1)) - k_1*sin(k_1*(gama - theta1)) - sin(theta0 - theta1)*cos(k_1*theta0) + k_1*cos(theta0 - theta1)*sin(k_1*theta0) - sin(theta0 - theta1)*cos(k_1*theta0)*cos(k_1*(gama - theta1)) + k_1*cos(theta0 - theta1)*cos(k_1*theta0)*sin(k_1*(gama - theta1)) + k_1*cos(theta0 - theta1)*sin(k_1*theta0)*cos(k_1*(gama - theta1))))/(2*j_L_theta1*k_1 - k_1*sin(theta0 - theta1) - k_1^2*cos(k_1*theta0)*sin(k_1*(gama - theta1)) - k_1^2*sin(k_1*theta0)*cos(k_1*(gama - theta1)) - k_1*sin(theta0 - theta1)*cos(k_1*theta0)*cos(k_1*(gama - theta1)) + j_L_theta1*sin(theta0 - theta1)*cos(k_1*theta0)*sin(k_1*(gama - theta1)) + j_L_theta1*sin(theta0 - theta1)*sin(k_1*theta0)*cos(k_1*(gama - theta1)) + k_1*sin(theta0 - theta1)*sin(k_1*theta0)*sin(k_1*(gama - theta1)) + k_1^2*cos(theta0 - theta1)*cos(k_1*theta0)*sin(k_1*(gama - theta1)) + k_1^2*cos(theta0 - theta1)*sin(k_1*theta0)*cos(k_1*(gama - theta1)) + j_L_theta1*k_1^2*sin(theta0 - theta1)*cos(k_1*theta0)*sin(k_1*(gama - theta1)) + j_L_theta1*k_1^2*sin(theta0 - theta1)*sin(k_1*theta0)*cos(k_1*(gama - theta1)) + 2*j_L_theta1*k_1*cos(theta0 - theta1)*cos(k_1*theta0)*cos(k_1*(gama - theta1)) - 2*j_L_theta1*k_1*cos(theta0 - theta1)*sin(k_1*theta0)*sin(k_1*(gama - theta1)))
plot(thetac,M)
end

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Answer 1

David Goodmanson 2017-11-15

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/367106-error-inner-matrix-dimensions-must-agree#answer_291167

在 MATLAB Online 中打开

Hi safisay, presumably you want to multiply all the vectors together element-by-element so in the expression for M you have to replace every

* by .*

(I did that in one go with the ctrl-f replace option in the editor). Then also replace the

/ by ./

and you get an answer. If you drop the thetac spacing from .1 to .01 you will see an issue with M.

Your expression for M is so long that I don't know how you would ever check its veracity, or how someone else looking at it would have an idea what it does. You might want to consider breaking it up into pieces. or at least using the ... line break command at strategic spots to get it into a block that's no wider than the page.