How to plot from certain range of data?

Hi everyone,

Actually I want find the stepinfo value but I have huge amount of data (many square waves of data). As far as I know stepinfo can determine if the signal in one square wave. Therefore I want to plot the data in certain range. The data (x and y) are in same folder of the workspace. What I did is below but did not work.

1.

>> x=Scope1(:,1);  
>> x=[10:0.02:20];  
>> y=Scope1(:,3);  
>> plot(x,y)  
Error using plot.
Vectors must be the same lengths.

2.

>> x=Scope1(:,1);  
>> xlim=([10 20]);  
>> y=Scope1(:,3);  
>> plot(x,y)

Number 2 produce no error but it plots whole data (xlim is not functioning).

I also tried with fplot (function, xlim ) but it didn't work (it plot y=x).

>> x=Scope1(:,1);  
>> y=Scope1(:,3);  
>> fplot('y' , [10 20])

Can anybody help me how to plot?

Thank you in advance!

arys

[Star Strider]

Is ‘Scope’ the output of one or more stepinfo calls? We have no idea.

[arymas]

Scope1(:,1) --> is x4 double data which from simulink to workspace. number 1 and 3 are refer to coloum 1 and 3.

Answer 1

[Image Analyst]

First of all, what is Scope? Is it a 2D array of square wave data where each column is one square wave?

Next, what is stepinfo? And how is it able to determine anything ? Did you write a function called stepinfo?

Then, why do you set x = a column of Scope then overwrite it with a linear vector? So of course x is a different length than y since they are not both columns of Scope anymore.

Why do you want to plot y vs. x anyway? If they're both square waves, what sense would that make?

Then, to set the axes limits you cannot do this

xlim=([10 20]);

You must do it this way:

xlim([10 20]);  % No equal sign.

[arymas]

First of all, thank you very much for xlim correction. I will try. Second very sorry for lack of info provided.

Scope1(:,1) --> is x4 double data which from simulink to workspace. number 1 and 3 are refer to coloum 1 (for x) and 3 ( for y). The stepinfo is one of the matlab tools to get control system performance (settling time, overshoot, etc..).

thank you again !

[Image Analyst]

Sorry I can't help - I don't have Simulink or stepinfo.

Answer 2

[Sudharsana Iyengar]

Did you try the following

 x=Scope1(:,1);  
y=Scope1(:,3);  
plot(x,y)
xlim([10 20])

More easier option would be to use

    plot(Scope(:,1),Scope(:,2))
xlim([10 20])