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
217
218
219
220
221
222
223
224
|
<?php
/**
* PHPExcel
*
* Copyright (c) 2006 - 2012 PHPExcel
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* @category PHPExcel
* @package PHPExcel_Shared_Trend
* @copyright Copyright (c) 2006 - 2012 PHPExcel (http://www.codeplex.com/PHPExcel)
* @license http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt LGPL
* @version 1.7.8, 2012-10-12
*/
require_once PHPEXCEL_ROOT . 'PHPExcel/Shared/trend/bestFitClass.php';
require_once PHPEXCEL_ROOT . 'PHPExcel/Shared/JAMA/Matrix.php';
/**
* PHPExcel_Polynomial_Best_Fit
*
* @category PHPExcel
* @package PHPExcel_Shared_Trend
* @copyright Copyright (c) 2006 - 2012 PHPExcel (http://www.codeplex.com/PHPExcel)
*/
class PHPExcel_Polynomial_Best_Fit extends PHPExcel_Best_Fit
{
/**
* Algorithm type to use for best-fit
* (Name of this trend class)
*
* @var string
**/
protected $_bestFitType = 'polynomial';
/**
* Polynomial order
*
* @protected
* @var int
**/
protected $_order = 0;
/**
* Return the order of this polynomial
*
* @return int
**/
public function getOrder() {
return $this->_order;
} // function getOrder()
/**
* Return the Y-Value for a specified value of X
*
* @param float $xValue X-Value
* @return float Y-Value
**/
public function getValueOfYForX($xValue) {
$retVal = $this->getIntersect();
$slope = $this->getSlope();
foreach($slope as $key => $value) {
if ($value != 0.0) {
$retVal += $value * pow($xValue, $key + 1);
}
}
return $retVal;
} // function getValueOfYForX()
/**
* Return the X-Value for a specified value of Y
*
* @param float $yValue Y-Value
* @return float X-Value
**/
public function getValueOfXForY($yValue) {
return ($yValue - $this->getIntersect()) / $this->getSlope();
} // function getValueOfXForY()
/**
* Return the Equation of the best-fit line
*
* @param int $dp Number of places of decimal precision to display
* @return string
**/
public function getEquation($dp=0) {
$slope = $this->getSlope($dp);
$intersect = $this->getIntersect($dp);
$equation = 'Y = '.$intersect;
foreach($slope as $key => $value) {
if ($value != 0.0) {
$equation .= ' + '.$value.' * X';
if ($key > 0) {
$equation .= '^'.($key + 1);
}
}
}
return $equation;
} // function getEquation()
/**
* Return the Slope of the line
*
* @param int $dp Number of places of decimal precision to display
* @return string
**/
public function getSlope($dp=0) {
if ($dp != 0) {
$coefficients = array();
foreach($this->_slope as $coefficient) {
$coefficients[] = round($coefficient,$dp);
}
return $coefficients;
}
return $this->_slope;
} // function getSlope()
public function getCoefficients($dp=0) {
return array_merge(array($this->getIntersect($dp)),$this->getSlope($dp));
} // function getCoefficients()
/**
* Execute the regression and calculate the goodness of fit for a set of X and Y data values
*
* @param int $order Order of Polynomial for this regression
* @param float[] $yValues The set of Y-values for this regression
* @param float[] $xValues The set of X-values for this regression
* @param boolean $const
*/
private function _polynomial_regression($order, $yValues, $xValues, $const) {
// calculate sums
$x_sum = array_sum($xValues);
$y_sum = array_sum($yValues);
$xx_sum = $xy_sum = 0;
for($i = 0; $i < $this->_valueCount; ++$i) {
$xy_sum += $xValues[$i] * $yValues[$i];
$xx_sum += $xValues[$i] * $xValues[$i];
$yy_sum += $yValues[$i] * $yValues[$i];
}
/*
* This routine uses logic from the PHP port of polyfit version 0.1
* written by Michael Bommarito and Paul Meagher
*
* The function fits a polynomial function of order $order through
* a series of x-y data points using least squares.
*
*/
for ($i = 0; $i < $this->_valueCount; ++$i) {
for ($j = 0; $j <= $order; ++$j) {
$A[$i][$j] = pow($xValues[$i], $j);
}
}
for ($i=0; $i < $this->_valueCount; ++$i) {
$B[$i] = array($yValues[$i]);
}
$matrixA = new Matrix($A);
$matrixB = new Matrix($B);
$C = $matrixA->solve($matrixB);
$coefficients = array();
for($i = 0; $i < $C->m; ++$i) {
$r = $C->get($i, 0);
if (abs($r) <= pow(10, -9)) {
$r = 0;
}
$coefficients[] = $r;
}
$this->_intersect = array_shift($coefficients);
$this->_slope = $coefficients;
$this->_calculateGoodnessOfFit($x_sum,$y_sum,$xx_sum,$yy_sum,$xy_sum);
foreach($this->_xValues as $xKey => $xValue) {
$this->_yBestFitValues[$xKey] = $this->getValueOfYForX($xValue);
}
} // function _polynomial_regression()
/**
* Define the regression and calculate the goodness of fit for a set of X and Y data values
*
* @param int $order Order of Polynomial for this regression
* @param float[] $yValues The set of Y-values for this regression
* @param float[] $xValues The set of X-values for this regression
* @param boolean $const
*/
function __construct($order, $yValues, $xValues=array(), $const=True) {
if (parent::__construct($yValues, $xValues) !== False) {
if ($order < $this->_valueCount) {
$this->_bestFitType .= '_'.$order;
$this->_order = $order;
$this->_polynomial_regression($order, $yValues, $xValues, $const);
if (($this->getGoodnessOfFit() < 0.0) || ($this->getGoodnessOfFit() > 1.0)) {
$this->_error = True;
}
} else {
$this->_error = True;
}
}
} // function __construct()
} // class polynomialBestFit
|
