To plot the model error against time

Anyone please help me plot the model error against time in the subplot(212)

     V=20; 

   t_sim=30; 

   sample_distance=0.2;

   ts=sample_distance/V; 

   collect_ts=ts*1; 

   t_plot=(0:collect_ts:t_sim);

[Image Analyst]

Please format your code properly: http://www.mathworks.com/matlabcentral/answers/13205-tutorial-how-to-format-your-question-with-markup

Answer 1

[Mischa Kim]

Priya, the "correct" syntax for subplots is:

 subplot(2,1,1)  % notice the commas

Other than that, what is

 size(deltaSignal)
 size(percentageDifference)

And finally, I believe what you are trying to do is:

 plot(deltaSignal,percentageDifference)

[Mischa Kim]

With

 t_sim = 30;

you could simply do

 t_psim = linspace(0,t_sim,length(percentageDifference))
 plot(t_psim,percentageDifference)

You are using as x-axis deltaSignal(:) which does not seem to be related to time. Am I missing something?

[Priya]

I got it now.That was of great help Kim. Thanks very much.

[Mischa Kim]

I do not know what exactly your variables mean, I am trying to interpret based on your code and information. It seems that in

 deltaSignal = abs(simout_ss(:,19)-simout_b(:,19));

you compute the difference between two signals (models?) and in

 percentageDifference=deltaSignal./simout_b(:,19);

you calculate the relative difference ( not percentage; for that you need to multiply the result by 100). So using

 plot(t_psim,percentageDifference)

should plot what you are looking for.