1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134
|
# Log plot demo.
#
# Copyright (C) 2001-2016 Alan W. Irwin
#
# 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
#
from numpy import *
# main
#
# Illustration of logarithmic axes, and redefinition of window.
def main(w):
w.plfont(2)
plot1(w,0)
plot1(w,1)
# 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):
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, "-20 dB/decade")
# Put labels on
w.plcol0(1)
w.plmtex("b", 3.2, 0.5, 0.5, "Frequency")
w.plmtex("t", 2.0, 0.5, 0.5, "Single Pole Low-Pass Filter")
w.plcol0(2)
w.plmtex("l", 5.0, 0.5, 0.5, "Amplitude (dB)")
# 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, "Phase shift (degrees)")
nlegend = 2
else:
nlegend = 1
# Draw a legend.
# Set up legend arrays with the correct size, type.
opt_array = zeros(nlegend, "int")
text_colors = zeros(nlegend, "int")
text = zeros(nlegend, "S20")
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] = "Amplitude"
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] = "Phase shift"
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 )
|