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bundles / scipy latest / scipy / signal / _filter_design / lp2hp_zpk

function

scipy.signal._filter_design:lp2hp_zpk

source: /scipy/signal/_filter_design.py :3095

Signature

def   lp2hp_zpk ( z ,  p ,  k ,  wo = 1.0 )

Summary

Transform a lowpass filter prototype to a highpass filter.

Extended Summary

Return an analog high-pass filter with cutoff frequency wo from an analog low-pass filter prototype with unity cutoff frequency, using zeros, poles, and gain ('zpk') representation.

Parameters

z : array_like

Zeros of the analog filter transfer function.

p : array_like

Poles of the analog filter transfer function.

k : float

System gain of the analog filter transfer function.

wo : float

Desired cutoff, as angular frequency (e.g., rad/s). Defaults to no change.

Returns

z : ndarray

Zeros of the transformed high-pass filter transfer function.

p : ndarray

Poles of the transformed high-pass filter transfer function.

k : float

System gain of the transformed high-pass filter.

Notes

This is derived from the s-plane substitution

This maintains symmetry of the lowpass and highpass responses on a logarithmic scale.

Array API Standard Support

lp2hp_zpk has experimental support for Python Array API Standard compatible backends in addition to NumPy. Please consider testing these features by setting an environment variable SCIPY_ARRAY_API=1 and providing CuPy, PyTorch, JAX, or Dask arrays as array arguments. The following combinations of backend and device (or other capability) are supported.

====================  ====================  ====================
Library               CPU                   GPU
====================  ====================  ====================
NumPy                 ✅                     n/a                 
CuPy                  n/a                   ✅                   
PyTorch               ✅                     ✅                   
JAX                   ⚠️ no JIT             ⛔                   
Dask                  ⚠️ computes graph     n/a                 
====================  ====================  ====================

See dev-arrayapi for more information.

Examples

Use the 'zpk' (Zero-Pole-Gain) representation of a lowpass filter to transform it to a highpass filter with a cutoff frequency wo. 
from scipy.signal import lp2hp_zpk
z   = [ -2 + 3j ,  -0.5 - 0.8j ]
p   = [ -1      ,  -4          ]
k   = 10
wo  = 0.6
✓
lp2hp_zpk(z, p, k, wo)
✗

See also

bilinear
lp2bp_zpk
lp2bs_zpk
lp2hp
lp2lp_zpk

Aliases

  • scipy.signal.lp2hp_zpk

Referenced by

This package