Eliminating the noise from the raw data using median filter
18 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
Hi everyone,
I have a raw csv file data and when I am to plot it, it seems pretty noisy. What I wanted to do ıs either the entire signal(data); or just along the decay curve to be smoothened; in other words; deleting the noise as much as possible. I'd be appreciated if anyone could help me out.
Here's the code that I am dealing with. Apart from reading the csv file, I also come across a similar code on the community so I was trying to modify it.
% Remove quiet parts of a signal.
clc;
close all;
clear;
workspace;
format long g;
format compact;
fontSize = 25;
data= readmatrix('T0027CH1.CSV');
x=data(:,1);
y=data(:,2);
y=(y+35.6);
x=(x+0.8*10^(-3));
N = 125013; % length(col1) if doing the whole signal
col1 = data(1:N, 1);
subplot(2, 2, 1);
plot(col1,y,'b-')
grid on
title('Original Signal', 'FontSize', fontSize);
subplot(2, 2, 2);
col1a = medfilt1(abs(col1),50000);
plot(col1a,y,'b-')
title('After median filter', 'FontSize', fontSize);
threshold = 50;
yline(threshold, 'Color', 'r', 'LineWidth', 2)
grid on;
badIndexes = col1a < threshold;
subplot(2, 2, 3);
plot(badIndexes,y, 'b-', 'LineWidth', 2);
title('Bad parts', 'FontSize', fontSize);
grid on;
% Remove bad indexes.
col1(badIndexes) = [];
subplot(2, 2, 4);
plot(col1,'b-')
grid on;
title('Bad parts removed', 'FontSize', fontSize);
2 commentaires
Réponses (1)
Mathieu NOE
le 28 Nov 2022
hello again
is it now smooth enough ?
% Remove quiet parts of a signal.
clc;
close all;
clear;
workspace;
format long g;
format compact;
fontSize = 25;
data= readmatrix('T0027CH1.CSV');
x=data(:,1);
y=data(:,2);
y=(y+35.6);
x=(x+0.8*10^(-3));
% removing x NaNs
idx = ~isnan(x);
x = x(idx);
y = y(idx);
ys = smoothdata(y,'gaussian',2500);
plot(x,y,'b',x,ys,'r')
legend('raw','smoothed');
4 commentaires
Mathieu NOE
le 31 Jan 2023
hello again
If my submission fullfills your request, do you mind accepting it ?
tx
Voir également
Catégories
En savoir plus sur Multirate Signal Processing 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!