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
|
/***************************************************************************
File : Interpolation.cpp
Project : SciDAVis
--------------------------------------------------------------------
Copyright : (C) 2007 by Ion Vasilief
Email (use @ for *) : ion_vasilief*yahoo.fr
Description : Numerical interpolation of data sets
***************************************************************************/
/***************************************************************************
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
* This program 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 General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program; if not, write to the Free Software *
* Foundation, Inc., 51 Franklin Street, Fifth Floor, *
* Boston, MA 02110-1301 USA *
* *
***************************************************************************/
#include "Interpolation.h"
#include <QMessageBox>
#include <gsl/gsl_sort.h>
#include <gsl/gsl_spline.h>
#include <gsl/gsl_interp.h>
Interpolation::Interpolation(ApplicationWindow *parent, Graph *g, const QString& curveTitle, int m)
: Filter(parent, g)
{
init(m);
setDataFromCurve(curveTitle);
}
Interpolation::Interpolation(ApplicationWindow *parent, Graph *g, const QString& curveTitle,
double start, double end, int m)
: Filter(parent, g)
{
init(m);
setDataFromCurve(curveTitle, start, end);
}
void Interpolation::init(int m)
{
if (m < 0 || m > 2)
{
QMessageBox::critical((ApplicationWindow *)parent(), tr("SciDAVis") + " - " + tr("Error"),
tr("Unknown interpolation method. Valid values are: 0 - Linear, 1 - Cubic, 2 - Akima."));
d_init_err = true;
return;
}
d_method = m;
switch(d_method)
{
case 0:
setName(tr("Linear") + tr("Int"));
d_explanation = tr("Linear") + " " + tr("Interpolation");
break;
case 1:
setName(tr("Cubic") + tr("Int"));
d_explanation = tr("Cubic") + " " + tr("Interpolation");
break;
case 2:
setName(tr("Akima") + tr("Int"));
d_explanation = tr("Akima") + " " + tr("Interpolation");
break;
}
d_sort_data = true;
d_min_points = d_method + 3;
}
void Interpolation::setMethod(int m)
{
if (m < 0 || m > 2)
{
QMessageBox::critical((ApplicationWindow *)parent(), tr("Error"),
tr("Unknown interpolation method, valid values are: 0 - Linear, 1 - Cubic, 2 - Akima."));
d_init_err = true;
return;
}
int min_points = m + 3;
if (d_n < min_points)
{
QMessageBox::critical((ApplicationWindow *)parent(), tr("SciDAVis") + " - " + tr("Error"),
tr("You need at least %1 points in order to perform this operation!").arg(min_points));
d_init_err = true;
return;
}
d_method = m;
d_min_points = min_points;
}
void Interpolation::calculateOutputData(double *x, double *y)
{
gsl_interp_accel *acc = gsl_interp_accel_alloc ();
const gsl_interp_type *method;
switch(d_method)
{
case 0:
method = gsl_interp_linear;
break;
case 1:
method = gsl_interp_cspline;
break;
case 2:
method = gsl_interp_akima;
break;
}
gsl_spline *interp = gsl_spline_alloc (method, d_n);
gsl_spline_init (interp, d_x, d_y, d_n);
double step = (d_to - d_from)/(double)(d_points - 1);
for (int j = 0; j < d_points; j++)
{
x[j] = d_from + j*step;
y[j] = gsl_spline_eval (interp, x[j], acc);
}
gsl_spline_free (interp);
gsl_interp_accel_free (acc);
}
int Interpolation::sortedCurveData(QwtPlotCurve *c, double start, double end, double **x, double **y)
{
if (!c || c->rtti() != QwtPlotItem::Rtti_PlotCurve)
return 0;
int i_start = 0, i_end = c->dataSize();
for (int i = 0; i < i_end; i++)
if (c->x(i) > start && i)
{
i_start = i - 1;
break;
}
for (int i = i_end-1; i >= 0; i--)
if (c->x(i) < end && i < c->dataSize())
{
i_end = i + 1;
break;
}
int n = i_end - i_start + 1;
(*x) = new double[n];
(*y) = new double[n];
double *xtemp = new double[n];
double *ytemp = new double[n];
double pr_x;
int j=0;
for (int i = i_start; i <= i_end; i++)
{
xtemp[j] = c->x(i);
if (xtemp[j] == pr_x)
{
delete (*x);
delete (*y);
return -1;//this kind of data causes division by zero in GSL interpolation routines
}
pr_x = xtemp[j];
ytemp[j++] = c->y(i);
}
size_t *p = new size_t[n];
gsl_sort_index(p, xtemp, 1, n);
for (int i=0; i<n; i++)
{
(*x)[i] = xtemp[p[i]];
(*y)[i] = ytemp[p[i]];
}
delete[] xtemp;
delete[] ytemp;
delete[] p;
return n;
}
|