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# -*- coding: utf-8; -*-
# Copyright (C) 2006-2016 Alan W. Irwin
# Multi-lingual version of the first page of example 4.
# Thanks to the following for providing translated strings for this example:
# Valery Pipin (Russian)
#
#
# This file is part of PLplot.
#
# PLplot is free software; you can redistribute it and/or modify
# it under the terms of the GNU Library General Public License as published
# by the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# PLplot is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Library General Public License for more details.
#
# You should have received a copy of the GNU Library General Public License
# along with PLplot; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
#
# This example designed just for devices (e.g., psttfc and the
# cairo-related devices) that use the pango and fontconfig libraries. The
# best choice of glyph is selected by fontconfig and automatically rendered
# by pango in way that is sensitive to complex text layout (CTL) language
# issues for each unicode character in this example. Of course, you must
# have the appropriate TrueType fonts installed to have access to all the
# required glyphs.
#
# Translation instructions: The strings to be translated are given by
# x_label, y_label, alty_label, title_label, and line_label below. The encoding
# used must be UTF-8.
# The following strings to be translated involve some scientific/mathematical jargon
# which is now discussed further to help translators.
# (1) dB is a decibel unit, see http://en.wikipedia.org/wiki/Decibel .
# (2) degrees is an angular measure, see http://en.wikipedia.org/wiki/Degree_(angle) .
# (3) low-pass filter is one that transmits (passes) low frequencies.
# (4) pole is in the mathematical sense, see
# http://en.wikipedia.org/wiki/Pole_(complex_analysis) . "Single Pole"
# means a particular mathematical transformation of the filter function has
# a single pole, see
# http://ccrma.stanford.edu/~jos/filters/Pole_Zero_Analysis_I.html . Furthermore,
# a single-pole filter must have an inverse square decline (or -20 db/decade).
# Since the filter plotted here does have that characteristic, it must by
# definition be a single-pole filter, see also
# http://www-k.ext.ti.com/SRVS/Data/ti/KnowledgeBases/analog/document/faqs/1p.htm
# (5) decade represents a factor of 10, see
# http://en.wikipedia.org/wiki/Decade_(log_scale) .
import sys
from numpy import *
# main
#
# Illustration of first page of example 4 in different languages.
def main(w):
x_label = [\
"Frequency",\
"Частота",\
]
y_label = [\
"Amplitude (dB)",\
"Амплитуда (dB)",\
]
alty_label = [\
"Phase shift (degrees)",\
"Фазовый сдвиг (градусы)",\
]
# Short rearranged versions of y_label and alty_label.
legend_text = [\
[ "Amplitude", "Phase shift"],\
[ "Амплитуда", "Фазовый сдвиг" ],\
]
title_label = [\
"Single Pole Low-Pass Filter",\
"Однополюсный Низко-Частотный Фильтр",\
]
line_label = [\
"-20 dB/decade",\
"-20 dB/десяток",\
]
nlang = len(x_label)
if len(y_label) != nlang or \
len(alty_label) != nlang or \
len(title_label) != nlang or \
len(line_label) != nlang:
raise RuntimeError("Internal inconsistency in label dimension")
w.plfont(2)
for i in range(nlang):
plot1(w, 0, x_label[i], y_label[i], alty_label[i], \
title_label[i], line_label[i], legend_text[i])
# Restore defaults
w.plfont(1)
# cmap0 default color palette.
w.plspal0("cmap0_default.pal")
# Must be done independently because otherwise this changes output files
# and destroys agreement with C examples.
#w.plcol0(1)
def plot1(w, type, x_label, y_label, alty_label, title_label, line_label, legend_text):
w.pladv(0)
f0 = 1.0
freql = -2.0 + arange(101)/20.0
freq = pow(10.0, freql)
ampl = 20.0 * log10(1.0 / sqrt(1.0 + pow((freq / f0), 2.)))
phase = -(180.0 / pi) * arctan(freq / f0)
w.plvpor(0.15, 0.85, 0.1, 0.9)
w.plwind(-2., 3.0, -80.0, 0.0)
w.plcol0(1)
if type == 0:
w.plbox("bclnst", 0.0, 0, "bnstv", 0.0, 0)
elif type == 1:
w.plbox("bcfghlnst", 0.0, 0, "bcghnstv", 0.0, 0)
else:
print("error: type must be either 0 or 1")
w.plcol0(2)
w.plline(freql, ampl)
w.plcol0(2)
w.plptex(1.6, -30.0, 1.0, -20.0, 0.5, line_label)
# Put labels on
w.plcol0(1)
w.plmtex("b", 3.2, 0.5, 0.5, x_label)
w.plmtex("t", 2.0, 0.5, 0.5, title_label)
w.plcol0(2)
w.plmtex("l", 5.0, 0.5, 0.5, y_label)
# For the gridless case, put phase vs freq on same plot
if type == 0:
w.plcol0(1)
w.plwind(-2.0, 3.0, -100.0, 0.0)
w.plbox("", 0.0, 0, "cmstv", 30.0, 3)
w.plcol0(3)
w.plline(freql, phase)
w.plstring(freql, phase, "#(728)")
w.plcol0(3)
w.plmtex("r", 5.0, 0.5, 0.5, alty_label)
nlegend = 2
else:
nlegend = 1
# Draw a legend.
# Set up legend arrays with the correct size, type.
# legend_text is already supplied by argument.
opt_array = zeros(nlegend, "int")
# Be generous with size of string since raw UTF-8 is involved.
text = zeros(nlegend, "S100")
text_colors = zeros(nlegend, "int")
box_colors = zeros(nlegend, "int")
box_patterns = zeros(nlegend, "int")
box_scales = zeros(nlegend)
box_line_widths = zeros(nlegend)
line_colors = zeros(nlegend, "int")
line_styles = zeros(nlegend, "int")
line_widths = zeros(nlegend)
symbol_colors = zeros(nlegend, "int")
symbol_scales = zeros(nlegend)
symbol_numbers = zeros(nlegend, "int")
symbols = zeros(nlegend, "S10")
# Only specify legend data that are required according to the
# value of opt_array for that entry.
# Data for first legend entry.
opt_array[0] = w.PL_LEGEND_LINE
text_colors[0] = 2
text[0] = legend_text[0].encode() if (sys.version_info > (3, 0)) else legend_text[0]
line_colors[0] = 2
line_styles[0] = 1
line_widths[0] = 1.
# Data for second legend entry.
if nlegend > 1:
opt_array[1] = w.PL_LEGEND_LINE | w.PL_LEGEND_SYMBOL
text_colors[1] = 3
text[1] = legend_text[1].encode() if (sys.version_info > (3, 0)) else legend_text[1]
line_colors[1] = 3
line_styles[1] = 1
line_widths[1] = 1.
symbol_colors[1] = 3
symbol_scales[1] = 1.
symbol_numbers[1] = 4
symbols[1] = "#(728)"
w.plscol0a( 15, 32, 32, 32, 0.70 )
(legend_width, legend_height) = \
w.pllegend( w.PL_LEGEND_BACKGROUND | w.PL_LEGEND_BOUNDING_BOX, 0, 0.0, 0.0,
0.1, 15, 1, 1, 0, 0, opt_array, 1.0, 1.0, 2.0,
1., text_colors, text,
box_colors, box_patterns, box_scales, box_line_widths,
line_colors, line_styles, line_widths,
symbol_colors, symbol_scales, symbol_numbers, symbols )
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