index :: flt

flt.freqz

compute the frequency response of a digital filter

available since version: 0.9.2

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information

Given the M-order numerator b and N-order denominator a of a digital filter, compute its frequency response: H(eʲʷ) = B(eʲʷ)/A(eʲʷ) = (b⁰+b¹e⁻ʲʷ+…+bᴹe⁻ʲʷᴹ)/(1+a¹e⁻ʲʷ+…+aᴺe⁻ʲʷᴺ)

arguments:

• N number of points
  type: int
  

methods:

• biquad set 'b' and 'a' coefficients, no output
  parameters:

  • b0 b0
    type: float
    required: True
    

  • b1 b1
    type: float
    required: True
    

  • b2 b2
    type: float
    required: True
    

  • a1 a1
    type: float
    required: True
    

  • a2 a2
    type: float
    required: True
    

properties:

• @a Get/set denominator (poles) coefficients. 'a0' always implicitly set to 1, property value set a1…an coefficients
  type: list
  

• @b Get/set numerator (zeros) coefficients
  type: list
  default: 1
  

• @n Get/set number of points
  type: int
  range: 4..1024
  default: 256
  

• @db Get/set output amp response in db scale
  type: bool
  default: 0
  

inlets:

• calculate and output frequency responses
  type: control

outlets:

• list: amplitude response data
  type: control
• list: phase response data
  type: control
• int: number of points
  type: control

keywords:

filter calc bode frequence response phase plot

See also: [flt.freqz~]

Authors: Serge Poltavsky

License: GPL3 or later