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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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 | (* -*- coding: utf-8; -*-
$Id: x26.ml 12313 2013-05-01 01:12:18Z hezekiahcarty $
Multi-lingual version of the first page of example 4.
Copyright (C) 2006 Alan Irwin
Copyright (C) 2006 Andrew Ross
Copyright (C) 2008 Hezekiah M. Carty
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) .
*)
open Plplot
let x_label = [|
"Frequency";
"Частота";
|]
let y_label = [|
"Amplitude (dB)";
"Амплитуда (dB)";
|]
let alty_label = [|
"Phase shift (degrees)";
"Фазовый сдвиг (градусы)";
|]
let title_label = [|
"Single Pole Low-Pass Filter";
"Однополюсный Низко-Частотный Фильтр";
|]
let line_label = [|
"-20 dB/decade";
"-20 dB/десяток";
|]
(* Short rearranged versions of y_label and alty_label. *)
let legend_text = [|
[|"Amplitude"; "Phase shift"|];
[|"Амплитуда"; "Фазовый сдвиг"|];
|]
let pi = atan 1.0 *. 4.0
(*--------------------------------------------------------------------------*\
* plot1
*
* Log-linear plot.
\*--------------------------------------------------------------------------*)
let plot1 label_type x_label y_label alty_label legend_text title_label line_label =
pladv 0;
(* Set up data for log plot *)
let freql = Array.init 101 (fun i -> ~-.2.0 +. float_of_int i /. 20.0) in
let freq = Array.map (fun f -> 10.0**f) freql in
let f0 = 1.0 in
let ampl =
Array.map (
fun f ->
20.0 *. log10 (1.0 /. sqrt (1.0 +. (f /. f0)**2.0))
) freq
in
let phase =
Array.map (
fun f ->
~-.(180.0 /. pi) *. atan (f /. f0)
) freq
in
plvpor 0.15 0.85 0.1 0.9;
plwind (-2.0) 3.0 (-80.0) 0.0;
(* Try different axis and labelling styles. *)
plcol0 1;
let () =
match label_type with
0 ->
plbox "bclnst" 0.0 0 "bnstv" 0.0 0;
| 1 ->
plbox "bcfghlnst" 0.0 0 "bcghnstv" 0.0 0;
| _ -> raise (Failure "invalid label_type")
in
(* Plot ampl vs freq *)
plcol0 2;
plline freql ampl;
plcol0 2;
plptex 1.6 (-30.0) 1.0 (-20.0) 0.5 line_label;
(* Put labels on *)
plcol0 1;
plmtex "b" 3.2 0.5 0.5 x_label;
plmtex "t" 2.0 0.5 0.5 title_label;
plcol0 2;
plmtex "l" 5.0 0.5 0.5 y_label;
(* For the gridless case, put phase vs freq on same plot *)
if label_type = 0 then (
plcol0 1;
plwind (-2.0) 3.0 (-100.0) 0.0;
plbox "" 0.0 0 "cmstv" 30.0 3;
plcol0 3;
plline freql phase;
plstring freql phase "*";
plcol0 3;
plmtex "r" 5.0 0.5 0.5 alty_label;
);
(* Draw a legend *)
(* First legend entry. *)
let opt_array = [| [PL_LEGEND_LINE]; [PL_LEGEND_LINE; PL_LEGEND_SYMBOL] |] in
let text_colors = [| 2; 3 |] in
let line_colors = [| 2; 3 |] in
let line_styles = [| 1; 1 |] in
let line_widths = [| 1.0; 1.0 |] in
(* note from the above opt_array the first symbol (and box) indices
do not matter *)
(* Second legend entry. *)
let symbol_colors = [| 0; 3 |] in
let symbol_scales = [| 0.0; 1.0 |] in
let symbol_numbers = [| 0; 4 |] in
let symbols = [| ""; "*" |] in
(* from the above opt_arrays we can completely ignore everything
to do with boxes *)
plscol0a 15 32 32 32 0.70;
let _, _ =
pllegend [PL_LEGEND_BACKGROUND; PL_LEGEND_BOUNDING_BOX] []
0.0 0.0 0.10 15
1 1 0 0
opt_array
1.0 1.0 2.0
1.0 text_colors legend_text
[||] [||] [||] [||]
line_colors line_styles line_widths
symbol_colors symbol_scales symbol_numbers symbols
in
()
(*--------------------------------------------------------------------------*\
* Illustration of logarithmic axes, and redefinition of window.
\*--------------------------------------------------------------------------*)
let () =
(* Parse and process command line arguments *)
plparseopts Sys.argv [PL_PARSE_FULL];
(* Initialize plplot *)
plinit ();
plfont 2;
(* Make log plots using two different styles. *)
Array.iteri (
fun i xl ->
plot1 0 xl y_label.(i) alty_label.(i) legend_text.(i) title_label.(i) line_label.(i)
) x_label;
plend ();
()
|