Filtering data points and smoothing

10 次查看（过去 30 天）
friet
friet 2017-6-16
评论： friet 2017-6-16
Hello I have a filter designed to filter out some noisy datapoints. My filter works well from 100-10000 in x -axis. However, at the beginning of the plot i.e., 1-100, it didn't filter, the filtered data point deviates from the original data points.
Any suggestion is appreciated Best regards, Friet
clear all
clc
close all
M=dlmread('rrawData.txt');
x=M(1:14250,1);
y=(M(1:14250,2));
%Filter design
wn=0.01;
[B,A]=butter(2,wn,'low');
yf=filter(B,A,y);
figure(1)
loglog(x,y,x,yf)
grid on

请先登录，再回答此问题。

回答（1 个）

Image Analyst
Image Analyst 2017-6-16
Then don't use that data. Just replace it with the original data. Or have a smaller filter window for x < 10.
  3 个评论
显示 1更早的评论
Image Analyst
Image Analyst 2017-6-16
You only have 20 data points with x < 10. In fact the first 2 or 3 points are wildly different.
If you don't want the points at 10^-12 and 10^-13 smoothed, then where should they be? Tell me where the first point should be if it is not to be in the original location of 10^-12. Tell me where is the preferred location for the point at 5e-14 if it's not right there at 5e-14.
friet
friet 2017-6-16
Thanks I think i figure it out

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Filter Design 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by