PlotHelper/bode.dart at master · eviallet/PlotHelper · GitHub

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
import 'dart:io';
import 'params.dart';

/* https://matheplanet.com/default3.html?call=article.php?sid=1358 */

void bode(
		var exp, {
		var laplace='s',
		var format='png',
		var labels=Labels.defaultLabels(),
		var frm=0.01,
		var to=100000.0,
		var showGrid=false,
		var out="bode",
		var width=640,
		var height=480,
		var scale=1
	})
{
	exp = exp.replaceAll(laplace, '{0,1}*$laplace');

	var str = "" +
	"set terminal $format size ${width*scale},${height*scale};" +
	"set output '$out.$format';"+

	"A($laplace) = $exp;"+
	"set dummy $laplace;"+

	"set multiplot layout 2,1;"+
	"unset xlabel;"+
	"set grid x;"+
	"set logscale x;"+
	"set xrange [$frm : $to];"+
	"set ytics nomirror;"+
	"set autoscale y;"+
	"set xzeroaxis;"+
	"set format x '';"+

	"set tmargin at screen 0.95;"+
	"set bmargin at screen 0.51;"+

	"set ylabel \"${labels.ylabel}\";"+
	"set title \" ${labels.title }\";"+

	"plot 20*log10(abs(A($laplace)));"+

	"set format x '10^{%L}';"+
	"set tmargin at screen 0.49;"+
	"set bmargin at screen 0.05;"+
	"set xlabel \"${labels.xlabel}\";"+
	"set ylabel \"${labels.xlabel}\";"+
	"plot 180/pi*arg(A($laplace));"+

	"unset multiplot;"+
	"set output;";


	Process.start('gnuplot', ["-e", str]);
}

String fromCoefs(
	var num,
	var den)
{
	var str = "(";
	for ( var i = 0; i<num.length-1; i++)
		str+="${num[i]}*s**${num.length-1-i}+";
	str+=(num[num.length-1]==0?'0':'1');
	str += ")/(";
	for ( var i = 0; i<den.length-1; i++)
		str+="${den[i]}*s**${den.length-1-i}+";
	str+=(den[den.length-1]==0?'0':'1');
	str += ")";

	return str;
}