well_fft.m

来自「实现了测井数据的fft变化分析」· M 代码 · 共 20 行

%功率谱
%load 'w1627_gam.dat';
%X=w1627_gam(:,2)';
load 'EF_w1627_gam.txt';
X=EF_w1627_gam;
Xfft = abs(fft(X));
% Avoid taking the log of 0.
index = find(Xfft == 0);
Xfft(index) = 1e-17;
blocksize=length(X);
Fs=1/8;
mag = 20*log10(Xfft);
mag = mag(1:floor(blocksize/2))
f = (0:length(mag)-1)*Fs/blocksize;
f = f(:)
plot(f,mag)
grid on 
ylabel('Magnitude (dB)');
xlabel('Frequency (Hz)');
title('Frequency Components of Tuning Fork');