Butterworth filter design calls bilinear and fails

Question

Sam Kastner 2021-1-19

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/721429-butterworth-filter-design-calls-bilinear-and-fails

评论： Sam Kastner 2021-1-22

采纳的回答： Adam Danz

I am attempting to set up a simple low-pass Butterworth filter using the following line of code:

[b,a]=butter(2,1/8,'low');

This produces the following error(s):

Error using bilinear

Too many output arguments.

Error in butter>butterImpl (line 130)

[ad,bd,cd,dd] = bilinear(ad,bd,cd,dd,fs);

Error in butter (line 59)

[varargout{1:nargout}] = butterImpl(n,Wn,varargin{:});

As far as I can tell, this is a valid call of bilinear (i.e. five inputs, four outputs). Can anyone replicate this problem? I'm using R2020b Update 3 with the signal processing toolbox. I haven't changed the butter function at all.

2 个评论
显示无隐藏无

Mathieu NOE 2021-1-20

hi

it works on my R2020b Update 1

>> [b,a]=butter(2,1/8,'low');

>> b

b =

0.0300 0.0599 0.0300

>> a

a =

1.0000 -1.4542 0.5741

Sam Kastner 2021-1-20

After a full reinstall, this doesn't seem to be an issue any more.

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Adam Danz 2021-1-20

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/721429-butterworth-filter-design-calls-bilinear-and-fails#answer_602511

编辑：Adam Danz 2021-1-22

在 MATLAB Online 中打开

You likely had another file on your Matlab path with the same name as butter. If the error happens again, the following command will show all functions and files of that name and will indicate which one you're using. Remove the path(s) to the functions that don't point to Matlab's butter() or rename the custom files/functions.

which butter -all

should point to \toolbox\signal\signal\butter.m (in r2020b).