Remove high frequency noise

2014 2 7
1 个回答
回答已采纳
更新时间：2014 2 10
12 次查看（30 天）

0 个投票

I have a highly corrupted data set (blue in attached image). How do I remove the high frequency noise and recover the original signal (red)? I want to use a low pass Butterworth filter of first order.

请先登录，再回答此问题。

 采纳的回答

Patrik Ek
Patrik Ek 2014-2-10

0 个投票

There is a function in matlab called "butter" that creates the coefficients to a butterworth filter of order N with cut-off frequency Wn. See MATLAB help. Then the function "filter" can be used to filter the signal. Notice however that the functions uses normalized frequencies here.

2 个评论
显示 无 隐藏 无

Deepayan Bhadra
Deepayan Bhadra 2014-2-10
Thank you! I eventually found out from a youtube video. But I could not understand exactly what 'normalized' here means. For e.g, say my cut-off is 5 Hz and the total f range is 500 Hz, is it 5/500?
Patrik Ek
Patrik Ek 2014-2-10
It is kind of right, but not accurate enough. I am not a hundred sure of how matlab normalizes these function, but I think that matlab uses the convention,
fnorm = 2*freal/fsample
There are a difference between range, since that is specified by you. Eg you may have a valid range for some model as 0 to 20hz even though the sample rate is 100 hz

请先登录，再进行评论。

更多回答（0 个）

类别

在 帮助中心 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