Signal Processing Toolbox | ![]() ![]() |
This region allows you to specify the filter design method options. FIR Equiripple
, FIR Window
, and some Filter Design Toolbox design methods have settable options.
The FIR Equiripple
design method, which uses the remez
function, has a Density Factor option. This option controls the density of the frequency grid. Increasing the value creates a filter which more closely approximates an ideal equiripple filter, but the time required for computation increases.
The FIR Window design method has four options:
The following windows and settable parameters are available.
Window |
Corresponding Function |
Parameter |
Bartlett |
bartlett |
none |
Bartlett-Hanning |
barthannwin |
none |
Blackman |
blackman |
none |
Blackman-Harris |
blackmanharris |
none |
Bohman |
bohmanwin |
none |
Chebyshev |
chebwin |
Sidelobe atten. --amount of dB sidelobe is below mainlobe |
Flat Top |
flattopwin |
none |
Gaussian |
gausswin |
Alpha --affects the width of the window. Larger alpha produces a more narrow window. |
Hamming |
hamming |
none |
Hann |
hann |
none |
Kaiser |
kaiser |
Beta --affects sidelobe attenuation. Higher beta widens the mainlobe and decreases the sidelobe amplitude. |
Nuttall |
nuttallwin |
none |
Rectangular |
rectwin |
none |
Tukey (cosine-tapered) |
tukeywin |
Alpha --specifies the ratio of taper to constant sections, affecting the window shape. Alpha is between 0 and 1. |
Triangular |
triang |
none |
User defined |
user defined function name |
user-defined parameter |
View Button
The View button launches the Window Visualization Tool (wvtool
) where you can view and compare windows.
Filter Design Toolbox Methods Options
The following filter types or design methods, available only with the Filter Design Toolbox, have the following settable parameters. See the corresponding function reference page for more information.
Filter Type or Design Method |
Corresponding Function |
Parameters |
Arbitrary Group Delay |
iirgrpdelay |
Pth norm Density factor More options (initial values and estimates) |
IIR Least Pth- norm |
iirlpnorm |
Pth norm Density factor More options (initial values and estimates) |
IIR Constrained Least Pth-norm |
iirlpnormc |
Pth norm Density factor Max pole radius More options (initial values and estimates) |
FIR Least Pth-norm |
firlpnorm |
Pth norm Density factor Minimum phase More options (initial values and estimates) |
FIR Constrained Equiripple |
firceqrip |
Minimum phase Stopband slope (dB) Inverse sinc passband More options (values of c and p) |
![]() | Filter Order Region | Frequency Specifications Region | ![]() |