Error:Dimensions of matrices being concatenated are not consistent

This is my code to optimize a function. I get the error when i run the code. The error is in the line

[to,yo]=sim('hw',5,[],[t',u]);

and

[u_final,cost]=fmincon('find_cost',u,[],[],[],[],l_b,u_b,'find_constraint',options);

This is the code

%Control input to define 0.1 for one half and -0.1 for the other half of
%the time interval
t=0:.1:5;

u(1:25)=.1;

u(26:51)=-.1;

plot(t,u);

[to,yo]=sim('hw',5,[],[t',u']);

%Finding u_final and cost

l_b=ones(51,1)*(-50);

u_b=ones(51,1)*50;

options=optimset('Display','iter','PlotFcns','optimplotx');

[u_final,cost]=fmincon('find_cost',u,[],[],[],[],l_b,u_b,'find_constraint',options);

[t_f,x_f,y_f]=sim('hw',5,[],[t' u_final']);

figure(3);
subplot(t_f,y_f(:,1));
grid;
xlabel('Time');
ylabel('Position');

figure(4);
subplot(t_f,y_f(:,2));
grid;
xlabel('Time');
ylabel('Velocity');

figure(5);
subplot(t_f,y_f(:,3));
grid;
xlabel('Time');
ylabel('Acceleration');

figure(6);
subplot(t_f,y_f(:,4));
grid;
xlabel('Time');
ylabel('Jerk');

figure(7);
subplot(t_f,y_f(:,5));
grid;
xlabel('Time');
ylabel('Jounce');

Kindly help me. I need to do this very soon

[Stephen23]

@Aishwarya Bangalore Kumar: please show us the complete error message. This means all of the red text.

[Aishwarya Bangalore Kumar]

Error using horzcat Dimensions of matrices being concatenated are not consistent.

Error in hw3q2b (line 11) [to,yo]=sim('hw',5,[],[t',u]);

[Aishwarya Bangalore Kumar]

This is the error message

Answer 1

[Walter Roberson]

 t=0:.1:5;
 u(1:25)=.1;
 u(26:51)=-.1;

Those both create row vectors. You do not change them in the code you show.

Then at some point you have

[to,yo]=sim('hw',5,[],[t',u]);

With t being a row vector, t' is a column vector. u is still a row vector. So you are trying to use [,] between a column vector and a row vector, which fails because the two do not have the same number of rows.

The line you indicate you are having a problem with does not appear in the code you posted. In the code you posted, the similar line uses u' which makes a column vector, which should be fine with t' provided that t and u are the same length.

[Aishwarya Bangalore Kumar]

there are 2 functions in the code, find_constraint and find cost, i removed one error but this remains

[Aishwarya Bangalore Kumar]

the problem is really in y0 because its a 51x4 matrix while t0 is 51x1 matrix

[Walter Roberson]

No, t0 and y0 are outputs from the sim() call.

I repeat again: the code you posted is

[to,yo]=sim('hw',5,[],[t',u']);

but your error message is for

[to,yo]=sim('hw',5,[],[t',u]);

which you did not post. Notice that the code you posted has [t', u'] but the error message you are getting is for [t', u] . You need to resolve that.

[Aishwarya Bangalore Kumar]

I changed it but the error is still the same

[Walter Roberson]

Please confirm that you are now using

[to,yo]=sim('hw',5,[],[t',u']);

and show us size(t) and size(u) when the error occurs.

[Aishwarya Bangalore Kumar]

This is the code I am using now

t=0:.1:5;

u(1:25)=.1;

u(26:51)=-.1;

plot(t,u);

[to,yo]=sim('hw',5,[],[t',u]);

%Finding u_final and cost

l_b=ones(51,1)*(-50);

u_b=ones(51,1)*50;

options=optimset('Display','iter','PlotFcns','optimplotx');

[u_final,cost]=fmincon('find_cost',u,[],[],[],[],l_b,u_b,'find_constraint',options);

[t_f,x_f,y_f]=sim('hw',5,[],[t u_final]);

figure(3);
subplot(t_f,y_f(:,1));
grid;
xlabel('Time');
ylabel('Position');

figure(4);
subplot(t_f,y_f(:,2));
grid;
xlabel('Time');
ylabel('Velocity');

figure(5);
subplot(t_f,y_f(:,3));
grid;
xlabel('Time');
ylabel('Acceleration');

figure(6);
subplot(t_f,y_f(:,4));
grid;
xlabel('Time');
ylabel('Jerk');

figure(7);
subplot(t_f,y_f(:,5));
grid;
xlabel('Time');
ylabel('Jounce');

[Aishwarya Bangalore Kumar]

This is the error message Error using horzcat Dimensions of matrices being concatenated are not consistent.

Error in hw3q2b (line 11)

[to,yo]=sim('hw',5,[],[t',u]);

This is the size of the two

t 1x51 double

u 1x51 double

[Walter Roberson]

You need to use

[to,yo]=sim('hw',5,[],[t',u']);

[Aishwarya Bangalore Kumar]

I got it now. Thank you for your help sir.