Clear Filters
Clear Filters

In an assignment A(I) = B, the number of elements in B and I must be the same.

1 view (last 30 days)
Hi all,
I am using Matlab for a university tutorial, and have been assigned the task of:
"Plot the response of G1(s) to the first cycle of a sine wave
G1(s) = (3s+2) / (2s^3+4s^2+5s+1)
u(t) = | 0 for t<0 | 2*sin(10*pi*t) for 0<t>8 | 0 for t>=8"
In order to solve the problem, I have written the following code:
num=[3 2];
den=[2 4 5 1];
time=[0:0.02:10]';
u=zeros(length(time),1);
x=2*sin(10*pi*time);
for i=min(find(time>=0 & time<8):length(time))
u(i)=x;
end
sys=tf(num,den);
y=lsim(sys,u,time);
plot(time,y,'r',time,u,'m')
However, I am receiving the error "In an assignment A(I) = B, the number of elements in B and I must be the same."
I understand that this issue is arising because I am trying to input a vector (x) into a scalar (i), however, I am unsure how I can overcome this issue, as my value for x is constantly changing. Could anyone advise me on a function which can be used, or any modification I could use to resolve the issue.
Thank you in advance, Ben

Accepted Answer

Erik S.
Erik S. on 18 Feb 2015
I attach a file, is it the result you need?
  1 Comment
Ben Booth
Ben Booth on 18 Feb 2015
Hi Erik,
This looks very similar to the result which I require.
Thank you very much for all your help.

Sign in to comment.

More Answers (2)

Erik S.
Erik S. on 18 Feb 2015
Hi Your x in the loop is a vector write
y(i)=x(i)
  1 Comment
Ben Booth
Ben Booth on 18 Feb 2015
Hi Erik,
Thank you for your quick reply.
After making the modification you suggested the error is removed, however, I am not getting the desired plot. As shown below, the output remains at a constant 0, and does not alter with time. Is there anything else which you can suggest?
Thanks in advance, Ben

Sign in to comment.


Erik S.
Erik S. on 18 Feb 2015
Hi
Your loop condition is not correct I think. It will only run 1 time. At which iteration should it start and finish?

Categories

Find more on Graphics Objects in Help Center and File Exchange

Community Treasure Hunt

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

Start Hunting!