Error using plot Vectors must be the same length. Error in rain_analysis (line 15) plot(t/T,yt,'-b');

clear all;
close all;

T = 30*24*60*60;             % Sampling interval
LT = 360;              % Number of sampling 
t = (0:LT-1)*T;        % Sampling time

%Read data
fid=fopen('caps.dat','rb');
yt=fread(fid,'float32');
fclose(fid);
yt(361) = [];
figure;

plot(t/T,yt,'-b');
grid on;
set(gca,'xlim',[0 max(t/T)]);
xlabel('Time (month)','fontweight','bold');
ylabel('Rainfall (mm)','fontweight','bold');
title('GPCC Rainfall Data in West Java','fontsize',14);

%Fourier transform
F = 1/T;                    % Maximum sampling frequency
f = F*linspace(0,1,LT);     % All sampling frequency 
Y = fft(yt)/LT;
Yf = abs(Y);

% All frequency plot
figure;
plot(f,Yf,'-r');
xlabel('Frequency (Hz)','fontweight','bold');
ylabel('Amplitude','fontweight','bold');
title('GPCC Rainfall All Amplitude Spectrum Plot','fontsize',14);
set(gca,'xlim',[0 max(f)]);
grid on;

% True half-frequency plot
NF = F/2;            % Nyquist frequency
figure;
plot(f(1:LT/2+1),Yf(1:LT/2+1),'-r');
xlabel('Frequency (Hz)','fontweight','bold');
ylabel('Amplitude','fontweight','bold');
title('GPCC Rainfall One Side Amplitude Spectrum Plot','fontsize',14);
set(gca,'xlim',[0 f(LT/2+1)]);
grid on;

Answer 1

[Walter Roberson]

yt=fread(fid,'float32');
fclose(fid);
yt(361) = [];

As outside observers, we have no way to know that the file contained exactly 361 single precision values, such that removing the 361 would leave you with exactly 360 values. Perhaps the file had more values.

yt=fread(fid, [1 360], 'float32');
fclose(fid);

would read exactly 360 values (provided they exist in the file.)

[Walter Roberson]

F = 1/T;                    % Maximum sampling frequency

That is incorrect. T is your total time interval (30 days), and the sampling frequency is the number of samples, LT, divided by T (seconds), giving samples per second. The result would be about 0.000139, in particular the value 1/7200 Hz (that is, samples every 2 hours)

[iyya pangesti]

it's work. thank you so much