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cremez
has a group delay of n/2+d in units of the sample interval. Negative values
create less delay; positive values create more delay. By default, d = 0.
• lowpass, highpass, bandpass, bandstop
These functions share a common syntax, exemplified here by 'lowpass':
b = cremez(n,f,'lowpass',...) and
b = cremez(n,f,{'lowpass',d},...) design a linear-phase (n/2+d delay)
filter.
• multiband designs a linear-phase frequency response filter with arbitrary
band amplitudes.
b = cremez(n,f,{'multiband',a},...) and
b = cremez(n,f,{'multiband',a,d},...) specify vector a containing the
desired amplitudes at the band edges in f. The desired amplitude at
frequencies between pairs of points f(k) and f(k+1) for k odd is the line
segment connecting the points (f(k),a(k)) and (f(k+1),a(k+1)).
• differentiator designs a linear-phase differentiator. For these designs,
zero-frequency must be in a transition band, and band weighting is set to be
inversely proportional to frequency.
b = cremez(n,f,{'differentiator',Fs},...) and
b = cremez(n,f,{'differentiator',Fs,d},...) specify the sample rate Fs
used to determine the slope of the differentiator response. If omitted, Fs
defaults to 1.
• hilbfilt designs a linear-phase Hilbert transform filter response. For
Hilbert designs, zero-frequency must be in a transition band.
b = cremez(n,f,'hilbfilt',...) and
b = cremez(N,F,{'hilbfilt',d},...) design a linear-phase (n/2+d delay)
Hilbert transform filter.
b = cremez(n,f,a,w) is a synonym for
b = cremez(n,f,{'multiband',a},w).
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