firgr语法：

b = firgr(n,f,a,w)
b = firgr(n,f,a,'hilbert')
b = firgr(m,f,a,r),
b = firgr({m,ni},f,a,r)
b = firgr(n,f,a,w,e)
b = firgr(n,f,a,s)
b = firgr(n,f,a,s,w,e)
b = firgr(...,'1')
b = firgr(...,'minphase')
b = firgr(..., 'check')
b = firgr(...,{lgrid}),
[b,err] = firgr(...)
[b,err,res] = firgr(...)
b = firgr(n,f,fresp,w)
b = firgr(n,f,{fresp,p1,p2,...},w)
b = firgr(n,f,a,w)

Types 1-4 linear phase:

Type 1 is even order, symmetric

Type 2 is odd order, symmetric

Type 3 is even order, antisymmetric

Type 4 is odd order, antisymmetric

Minimum phase

Maximum phase

Minimum order (even or odd)

Extra ripple

Maximal ripple

Constrained ripple

Single-point band (notching and peaking)

Forced gain

Arbitrary shape frequency response curve filters

设计一个带通滤波器

示例：

Fs  = 96000;
Fn  = Fs/2;
f   = [0 17000 20000 28000 31000 Fn]/Fn;
a   = [0     0     1     1     0  0];
w   = [5 1 5];
b   = firgr(44, f, a, w, 'minphase');
hfvt = fvtool(b,'Fs', Fs,...
              'MagnitudeDisplay', 'Magnitude (dB)',...
              'legend','on');
legend(hfvt,'Min Phase');

matlab mini phase 滤波器的设计_python

matlab mini phase 滤波器的设计_matlab_02

设计一低通滤波器 脉冲响应为最小相位

Fs  = 88200;
Fn  = Fs/2;
f   = [0 20065 22050 Fn]/Fn;
a   = [1   1    0  0];
w   = [800000  80];
b   = firgr(88, f, a, w, 'minphase');
hfvt = fvtool(b,'Fs', Fs,...
              'MagnitudeDisplay', 'Magnitude (dB)',...
              'legend','on');
legend(hfvt,'Min Phase');

matlab mini phase 滤波器的设计_python_03

matlab mini phase 滤波器的设计_matlab_04