Dimensions of matrices being concatenated are not consistent
2 views (last 30 days)
Show older comments
t = 0:5640; % time taken for the system to run is from 0 to 5640s
i = 83*pi/180; % inclination angle in rad
w0 = 0.0011; % angular velocity in rad/s
a1 = sin(i)*cos(w0*t);
a2 = -cos(i);
a3 = 2*sin(i)*sin(w0*t);
A = [0 -a3 a2; a3 0 -a1; -a2 a1 0];
This is my coding and I would like to create a matrix A. It shows the error Error using vertcat: Dimensions of matrices being concatenated are not consistent when I computed it. I know the reason why, but how can I compute a matrix A with varying number of a1 and a3 while a2 is a constant?
2 Comments
Peng Li
on 10 Apr 2020
I don’t really know the reason why you did this. But would an extension of a2 to size(t) fit your need? a2 = -cos(i) * ones(size(t));
Accepted Answer
Ameer Hamza
on 10 Apr 2020
In MATLAB, rows of a matrix cannot have different number of elements. For that, you will need to use a cell array
t = 0:5640; % time taken for the system to run is from 0 to 5640s
i = 83*pi/180; % inclination angle in rad
w0 = 0.0011; % angular velocity in rad/s
a1 = sin(i)*cos(w0*t);
a2 = -cos(i);
a3 = 2*sin(i)*sin(w0*t);
A = {[0 -a3 a2]; [a3 0 -a1]; [-a2 a1 0]};
3 Comments
Ameer Hamza
on 10 Apr 2020
Edited: Ameer Hamza
on 10 Apr 2020
Ok It is clear now. Try this
t = 0:5640; % time taken for the system to run is from 0 to 5640s
i = 83*pi/180; % inclination angle in rad
w0 = 0.0011; % angular velocity in rad/s
a1 = sin(i)*cos(w0*t);
a2 = -cos(i)*ones(size(t));
a3 = 2*sin(i)*sin(w0*t);
ONE = ones(1,1,numel(a1));
ZERO = zeros(1,1,numel(a1));
a1 = reshape(a1, 1,1,[]);
a2 = reshape(a2, 1,1,[]);
a3 = reshape(a3, 1,1,[]);
A = [ONE ZERO ZERO ZERO a3 a2;
ZERO ONE ZERO -a3 ZERO a1;
ZERO ZERO ONE a2 -a1 ZERO;
-ONE ZERO ZERO ZERO ZERO ZERO;
ZERO -ONE ZERO ZERO ZERO ZERO;
ZERO ZERO -ONE ZERO ZERO ZERO;
zeros(3,3,numel(a1)) zeros(3,3,numel(a1))];
The matrix A is 9x6x5641. You can access value like this
A(:,:,1) % <-- t = 0
A(:,:,2) % <-- t = 1
A(:,:,3) % <-- t = 2
..
..
A(:,:,5641) % <-- t = 5640
More Answers (0)
See Also
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!