dfilt.parallel (Signal Processing Toolbox)

Discrete-time, parallel structure filter

Syntax

```
Hd = dfilt.parallel(Hd1,Hd2,...)
```

Description

Hd = dfilt.parallel(Hd1,Hd2,...) returns a discrete-time filter, Hd, which is a structure of two or more dfilt filters, Hd1, Hd2, etc. arranged in parallel. Each filter in a parallel structure is a separate stage. You can display states for individual stages only. To view the states of a stage use

```
Hd.stage(1).states
```

You can also use the nondot notation format for calling a parallel structure.

```
parallel(Hd1,Hd2,...)
```

Examples

Using a parallel structure, create a coupled-allpass decomposition of a 7th order lowpass digital, elliptic filter with a normalized cutoff frequency of 0.5, 1 decibel of peak-to-peak ripple and a minimum stopband attenuation of 40 decibels.

k1 = [-0.0154    0.9846   -0.3048    0.5601]; 
Hd1 = dfilt.latticeallpass(k1);
k2 = [-0.1294    0.8341   -0.4165];
Hd2 = dfilt.latticeallpass(k2);
Hpar = parallel(Hd1 ,Hd2);
gain = dfilt.scalar(0.5);         % Normalize the passband gain
Hcas = cascade(gain,Hpar);
fvtool(Hcas)

See Also

dfilt, dfilt.cascade

dfilt.latticemamin dfilt.scalar