Hello; Can someone please help me matlab doesn't plot my excel data it show the axis only I am trying to make spectral analysis.i have attested the excel file and code as well.
1 vue (au cours des 30 derniers jours)
Afficher commentaires plus anciens
filename = 'datacollect2.xlsx';
N = length(filename);
fs = 400;
fnyquest = fs/2;
num = xlsread(filename);
y = num(: ,2);
mags = abs(fft(y));
bin_vals = [0 : N-1];
fax_Hz = bin_vals*fs/N;
N_2 = ceil(N/2);
plot(mags(1:N_2),fax_hz(1:N_2))
xlabel('Frequency (Hz)')
ylabel('Power (dB)');
title('Single-sided Power spectrum (Hertz)');
axis tight
5 commentaires
Réponse acceptée
dpb
le 15 Mai 2017
Modifié(e) : dpb
le 15 Mai 2017
filename = 'datacollect2.xlsx';
N = length(filename);
fs = 400;
fnyquest = fs/2;
num = xlsread(filename);
y = num(: ,2);
mags = abs(fft(y));
bin_vals = [0 : N-1];
Probably biggest problem is you've used the length of the filename as the length of the data. The file name is just that; the string containing the name of the file on the disk, it has nothing whatsoever to do with the data contained in the file.
Here,
>> filename = 'datacollect2.xlsx';
N = length(filename)
N =
17
>>
so all you've plotted are the first 9 points out of the arrays; not much at all... :)
N = length(y);
after you've defined y will undoubtedly help a lot, particularly when you get the roles of X,Y corrected in the plot statement.
You may want to also plot 2*abs(fft(y))/N to normalize the spectrum amplitude to input. See
doc fft % example there shows some other details as well
Plus de réponses (0)
Voir également
Catégories
En savoir plus sur Line Plots dans Help Center et File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!