Home > classes > @miir > private > mklowpass.m

mklowpass

PURPOSE ^

MKLOWPASS return a low pass filter miir(). A Butterworth filter is used.

SYNOPSIS ^

function f = mklowpass(f, pl)

DESCRIPTION ^

 MKLOWPASS return a low pass filter miir(). A Butterworth filter is used.

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 DESCRIPTION: MKLOWPASS return a low pass filter miir().
              A Butterworth filter is used.

 CALL:        f = mklowpass(f, pl)

 VERSION: $Id: mklowpass.m,v 1.4 2007/08/16 13:27:32 ingo Exp $

 HISTORY: 27-08-2002 M Hewitson
             Creation

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CROSS-REFERENCE INFORMATION ^

This function calls: This function is called by:

SOURCE CODE ^

0001 function f = mklowpass(f, pl)
0002 % MKLOWPASS return a low pass filter miir(). A Butterworth filter is used.
0003 %
0004 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
0005 %
0006 % DESCRIPTION: MKLOWPASS return a low pass filter miir().
0007 %              A Butterworth filter is used.
0008 %
0009 % CALL:        f = mklowpass(f, pl)
0010 %
0011 % VERSION: $Id: mklowpass.m,v 1.4 2007/08/16 13:27:32 ingo Exp $
0012 %
0013 % HISTORY: 27-08-2002 M Hewitson
0014 %             Creation
0015 %
0016 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
0017 
0018 g     = find(pl, 'gain');
0019 fc    = find(pl, 'fc');
0020 fs    = find(pl, 'fs');
0021 order = find(pl, 'order');
0022 
0023 if(fc > fs/2)
0024   error('fc must be < fs/2');
0025 end
0026 
0027 f.name  = 'std lowpass';
0028 f.fs    = fs;
0029 f.ntaps = order+1;
0030 [f.a, f.b] = butter(order, 2*fc/fs);
0031 f.g = g;
0032 f.histin   = zeros(1,f.ntaps-1);   % initialise input history
0033 f.histout  = zeros(1,f.ntaps-1);   % initialise output history
0034 
0035 % END
0036

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