2nd Order Digital Butterworth filter

32 次查看（过去 30 天）
Aman
Aman 2012-3-26
Hi Guys,
I need help designing a 2nd order low pass Butterworth filter with a frequency cut off of 12 Hz that is to be bi-directionally filtering the data.
How do I go about designing a filter like this in Matlab?
I realize there is a function 'butter' to design a lowpass filter, but was kind of confused on applying it to my matrix that has about 9 columns and 30,000 rows, and I need to apply the filter for every row.
Thanks for your help in advance!
  4 个评论
显示 2更早的评论
Jan
Jan 2012-3-26
I'm sure "9 columns and 30'000 rows" mean "columns of length 9 and rows of length 30'000".

请先登录，再进行评论。

请先登录，再回答此问题。

回答（1 个）

Jan
Jan 2012-3-26
[B, A] = butter(2, 12 / (Freq * 0.5), 'high');
filtered = transpose(filtfilt(B, A, transpose(Signal)));
Freq is the frequency of your signal. If you need a low-pass filter change the 'high'. See help butter on demand.
  3 个评论
显示 1更早的评论
Honglei Chen
Honglei Chen 2012-3-26
Designing the filter is independent to your signal. Once the filter is designed, you can filter your signal using filter function, such as filter(B,A,Signal)
Aman
Aman 2012-3-26
ah ok that makes much more sense, thank you

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Butterworth 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