zpk

Zero-pole-gain conversion of discrete-time filter System object

Description

example

[z,p,k] = zpk(sysobj) returns the zeros, poles, and gain corresponding to the filter System object™ in vector z, vector p, and scalar k, respectively.

[z,p,k] = zpk(sysobj,'Arithmetic',arithType) analyzes the filter System object based on the arithmetic specified in arithType.

For more input options, see zpk.

Examples

collapse all

Compute the zero-pole-gain form of the highpass filter using the zpk function.

Design a minimum order highpass FIR filter with a passband frequency of 75 kHz and passband ripple of 0.2 dB. Specify a sample rate of 200 kHz.

hFilt = dsp.HighpassFilter('PassbandFrequency',75e3,'PassbandRipple',0.2,'SampleRate',200e3)
hFilt = 
  dsp.HighpassFilter with properties:

               FilterType: 'FIR'
    DesignForMinimumOrder: true
        StopbandFrequency: 8000
        PassbandFrequency: 75000
      StopbandAttenuation: 80
           PassbandRipple: 0.2000
               SampleRate: 200000

  Show all properties

Find the zeros, poles, and the gain of the designed filter using the zpk function.

[z,p,k] = zpk(hFilt)
z = 8×1 complex

  17.2236 + 0.0000i
  -3.0709 + 0.0000i
   0.9732 + 0.2300i
   0.9732 - 0.2300i
   0.9954 + 0.0957i
   0.9954 - 0.0957i
  -0.3256 + 0.0000i
   0.0581 + 0.0000i

p = 8×1

     0
     0
     0
     0
     0
     0
     0
     0

k = -0.0023

Input Arguments

collapse all

Specify the arithmetic used during analysis. When the arithmetic input is not specified and the filter System object is unlocked, the analysis tool assumes a double-precision filter. The 'Arithmetic' property set to 'Fixed' applies only to filter System objects with fixed-point properties.

Output Arguments

collapse all

Zeros of the filter, returned as a column vector.

Data Types: double
Complex Number Support: Yes

Poles of the filter, returned as a column vector.

Data Types: double
Complex Number Support: Yes

Gain of the filter, returned as a real scalar.

Data Types: double

Introduced in R2011a