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Description

English: Frequency response curves of four linear analog filters: Butterworth filter, Chebyshev filter of type 1 and 2 and Elliptic filter, each one as 5th order filter.

Português: Curvas de resposta em frequência de quatro filtros lineares analógicos: Butterworth, Chebyshev tipos 1 e 2 e elíptico, todos de quinta ordem.

Русский: Сравнение амплитудно-частотных характеристик фильтров 5-го порядка: Баттерворта, Чебышёва 1-го и 2-го типов и эллиптического.

Date

10 December 2016

Source

Own work

Author

Geek3

Other versions

Russian .svg
Portuguese .svg

SVG development

The SVG code is valid.

This plot was created with Matplotlib.

Category:Valid SVG created with Matplotlib code#Filters%20order5.svg

Category:Translation possible - SVGThis file uses embedded text that can be easily translated using a text editor.

Source code

Python Matplotlib source code

#!/usr/bin/python
# -*- coding: utf8 -*-

import numpy as np
import scipy.signal as sig
import matplotlib as mpl
import matplotlib.pyplot as plt
from math import *

N = 5 # order of the filters
band = 1.0 # cut-off normalized frequency
Rpass = 1.0 # ripple in the pass-band (dB)
Rstop = 20 # ripple in the stop-band (dB)
frange = np.linspace(0, 2, 2001)
color = 'r'
fname = 'filters_order5.svg'

mpl.rcParams['axes.grid'] = True
plt.figure(figsize=(6, 5.4))

(num, den) = sig.butter(N, band, analog=True)
filterfy = sig.freqs(num, den, frange)
plt.subplot(221)
plt.title('Butterworth')
plt.plot(filterfy[0], np.abs(filterfy[1]), lw=3, color=color)

(num, den) = sig.cheby1(N, 1, band, analog=True)
filterfy = sig.freqs(num, den, frange)
plt.subplot(222)
plt.title('Chebyshev type 1')
plt.plot(filterfy[0], np.abs(filterfy[1]), lw=3, color=color)

(num, den) = sig.cheby2(N, Rstop, band, analog=True)
filterfy = sig.freqs(num, den, frange)
plt.subplot(223)
plt.title('Chebyshev type 2')
plt.plot(filterfy[0], np.abs(filterfy[1]), lw=3, color=color)

(num, den) = sig.ellip(N, Rpass, Rstop, band, analog=True)
filterfy = sig.freqs(num, den, frange)
plt.subplot(224)
plt.title('Elliptic')
plt.plot(filterfy[0], np.abs(filterfy[1]), lw=3, color=color)

for ax in plt.gcf().get_axes():
    ax.set_xlim(*frange[[0,-1]])
    ax.set_ylim(0, 1.1)
    ax.set_xlabel('f/f$_0$')
    ax.xaxis.set_label_coords(0.65, -0.1)
    ax.set_ylabel('G', rotation=0)
    ax.yaxis.set_label_coords(-0.05, 1.0)

plt.tight_layout(pad=1, w_pad=2, h_pad=2)
plt.savefig(fname)

def postprocess(fname):
    from lxml import etree
    with open(fname, 'r') as svgfile:
        tree = etree.parse(svgfile, etree.XMLParser(remove_blank_text=True))
    svg = tree.getroot()
    nsmap = '{' + svg.nsmap[None] + '}'

    # move all definitions to the front
    svg[:] = sorted(svg, key=lambda el: {False:0, True:1}[el.tag!=nsmap+'defs'])
    with open(fname, 'w') as svgfile:
        tree.write(svgfile,
            xml_declaration=True, pretty_print=True, encoding='utf-8')

postprocess(fname)

Licensing

I, the copyright holder of this work, hereby publish it under the following license:

This file is licensed under the Creative Commons Attribution 4.0 International license.

You are free:

to share – to copy, distribute and transmit the work
to remix – to adapt the work

Under the following conditions:

attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.

Category:CC-BY-4.0#Filters%20order5.svg

Category:Self-published work Category:Photos by User:Geek3 Category:Linear filters Category:Butterworth filters Category:Chebyshev filters Category:Elliptic filters

Wikimore

File:Filters order5.svg

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