Tie to frequency using F

Hi, I am trying to perform a fft on a series of runs of a vibration analysis with the following code. An empty plot seems to show up, any ideas?

%Frequency Analysis
time = xlsread('Lab-2ciii.xlsx','A1:A300');;        % Time Vector
signal = xlsread('Lab-2ciii.xlsx','B1:B300');;      % Signal data in Time-Domain
N = length(signal);                                 % Number Of Samples
Ts = mean(diff(time));                              % Sampling Interval
Fs = 1/Ts;                                          % Sampling Frequency
Fn = Fs/2;                                          % Nyquist Frequency
FT_Signal = fft(signal)/N;                          % Normalized Fourier Transform Of Data
Fv = linspace(0, 1, fix(N/2)+1)*Fn;                 % Frequency Vector (For ‘plot’ Call)
Iv = 1:length(Fv);                                  % Index Vector (Matches ‘Fv’)
figure(1)
plot(Fv, abs(FT_Signal(Iv))*2)
grid

Answer 1

[Geoff Hayes]

Karl - are you reading the correct columns? For example, on my Mac, the time array

time = xlsread('Lab-2ciii.xlsx','A1:A300');

is empty, and the signal array

signal = xlsread('Lab-2ciii.xlsx','B1:B300');

has just a handful of elements

signal =

    0.0807
   68.4870
    0.0002
   -0.1851
       NaN
   68.2636
    0.0027
   -0.0607

Both correspond to the first and second columns of your spreadsheet. I suspect you want columns E (which seems to correspond to time) and either H, K, or N...all of which have 300 elements.

[Karl Zammit]

My bad for not commenting that the problem was solved. Thanks a lot nonetheless