how do you plot fft of each sensor for both test

t1=load('201710h1.lvm');  %test 1 
t2=load('201710h2.lvm');  %test 2
 
 
subplot(3,2,1);           
x= t1 (:,1);     % time in test 1
sin = t1 (:,2);  % sensor 1 in test 1 
plot (x,sin)
title('test 1 sensor 1 against time')
xlabel('time') 
ylabel('Sesnor1') 
   
subplot(3,2,3);
x1= t1 (:,1);      
sin1 = t1 (:,3);
plot (x1,sin1)
title('test 1 sensor 2 against time')
xlabel('time') 
ylabel('Sesnor2') 
 
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subplot(3,2,2);
x2= t2 (:,1);
sin2 = t2 (:,2);
plot (x2,sin2)
title('test 2 sensor 1 against time')
xlabel('time') 
ylabel('Sesnor1') 
 
subplot(3,2,4);
x3= t2 (:,1);
sin3 = t2 (:,3);
plot (x3,sin3)
title('test 2 sensor 2 against time')
xlabel('time') 
ylabel('Sesnor2') 

Answer 1

[Hrishikesh Borate]

Hi,

I understand that you want to calculate and plot FFT for each sensor for both the tests. According to the code shared, these values are stored in variables: sin, sin1, sin2, sin3.

You can use the fft function for the same.

[zeshan chishti]

so take fft of sin1 and so on? i.e

y= fft (sin1);

[Hrishikesh Borate]

Yes, correct.

Answer 2

[Peter Perkins]

Zeshan, you have all your data in a numeric array, t1. I strongly recommend that you convert that to a timetable. Then your plot is simple. I don't know what units your times are in, but something like

tt = array2timetable(t1(:,2:end),'RowTimes',seconds(t1(:,1));
stackedplot(tt)

[zeshan chishti]

thanks peter that helpped alot