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
|
<?php
/**
* PHPExcel
*
* Copyright (c) 2006 - 2014 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 - 2014 PHPExcel (http://www.codeplex.com/PHPExcel)
* @license http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt LGPL
* @version 1.8.0, 2014-03-02
*/
require_once PHPEXCEL_ROOT . 'PHPExcel/Shared/trend/linearBestFitClass.php';
require_once PHPEXCEL_ROOT . 'PHPExcel/Shared/trend/logarithmicBestFitClass.php';
require_once PHPEXCEL_ROOT . 'PHPExcel/Shared/trend/exponentialBestFitClass.php';
require_once PHPEXCEL_ROOT . 'PHPExcel/Shared/trend/powerBestFitClass.php';
require_once PHPEXCEL_ROOT . 'PHPExcel/Shared/trend/polynomialBestFitClass.php';
/**
* PHPExcel_trendClass
*
* @category PHPExcel
* @package PHPExcel_Shared_Trend
* @copyright Copyright (c) 2006 - 2014 PHPExcel (http://www.codeplex.com/PHPExcel)
*/
class trendClass
{
const TREND_LINEAR = 'Linear';
const TREND_LOGARITHMIC = 'Logarithmic';
const TREND_EXPONENTIAL = 'Exponential';
const TREND_POWER = 'Power';
const TREND_POLYNOMIAL_2 = 'Polynomial_2';
const TREND_POLYNOMIAL_3 = 'Polynomial_3';
const TREND_POLYNOMIAL_4 = 'Polynomial_4';
const TREND_POLYNOMIAL_5 = 'Polynomial_5';
const TREND_POLYNOMIAL_6 = 'Polynomial_6';
const TREND_BEST_FIT = 'Bestfit';
const TREND_BEST_FIT_NO_POLY = 'Bestfit_no_Polynomials';
/**
* Names of the best-fit trend analysis methods
*
* @var string[]
**/
private static $_trendTypes = array( self::TREND_LINEAR,
self::TREND_LOGARITHMIC,
self::TREND_EXPONENTIAL,
self::TREND_POWER
);
/**
* Names of the best-fit trend polynomial orders
*
* @var string[]
**/
private static $_trendTypePolyOrders = array( self::TREND_POLYNOMIAL_2,
self::TREND_POLYNOMIAL_3,
self::TREND_POLYNOMIAL_4,
self::TREND_POLYNOMIAL_5,
self::TREND_POLYNOMIAL_6
);
/**
* Cached results for each method when trying to identify which provides the best fit
*
* @var PHPExcel_Best_Fit[]
**/
private static $_trendCache = array();
public static function calculate($trendType=self::TREND_BEST_FIT, $yValues, $xValues=array(), $const=True) {
// Calculate number of points in each dataset
$nY = count($yValues);
$nX = count($xValues);
// Define X Values if necessary
if ($nX == 0) {
$xValues = range(1,$nY);
$nX = $nY;
} elseif ($nY != $nX) {
// Ensure both arrays of points are the same size
trigger_error("trend(): Number of elements in coordinate arrays do not match.", E_USER_ERROR);
}
$key = md5($trendType.$const.serialize($yValues).serialize($xValues));
// Determine which trend method has been requested
switch ($trendType) {
// Instantiate and return the class for the requested trend method
case self::TREND_LINEAR :
case self::TREND_LOGARITHMIC :
case self::TREND_EXPONENTIAL :
case self::TREND_POWER :
if (!isset(self::$_trendCache[$key])) {
$className = 'PHPExcel_'.$trendType.'_Best_Fit';
self::$_trendCache[$key] = new $className($yValues,$xValues,$const);
}
return self::$_trendCache[$key];
break;
case self::TREND_POLYNOMIAL_2 :
case self::TREND_POLYNOMIAL_3 :
case self::TREND_POLYNOMIAL_4 :
case self::TREND_POLYNOMIAL_5 :
case self::TREND_POLYNOMIAL_6 :
if (!isset(self::$_trendCache[$key])) {
$order = substr($trendType,-1);
self::$_trendCache[$key] = new PHPExcel_Polynomial_Best_Fit($order,$yValues,$xValues,$const);
}
return self::$_trendCache[$key];
break;
case self::TREND_BEST_FIT :
case self::TREND_BEST_FIT_NO_POLY :
// If the request is to determine the best fit regression, then we test each trend line in turn
// Start by generating an instance of each available trend method
foreach(self::$_trendTypes as $trendMethod) {
$className = 'PHPExcel_'.$trendMethod.'BestFit';
$bestFit[$trendMethod] = new $className($yValues,$xValues,$const);
$bestFitValue[$trendMethod] = $bestFit[$trendMethod]->getGoodnessOfFit();
}
if ($trendType != self::TREND_BEST_FIT_NO_POLY) {
foreach(self::$_trendTypePolyOrders as $trendMethod) {
$order = substr($trendMethod,-1);
$bestFit[$trendMethod] = new PHPExcel_Polynomial_Best_Fit($order,$yValues,$xValues,$const);
if ($bestFit[$trendMethod]->getError()) {
unset($bestFit[$trendMethod]);
} else {
$bestFitValue[$trendMethod] = $bestFit[$trendMethod]->getGoodnessOfFit();
}
}
}
// Determine which of our trend lines is the best fit, and then we return the instance of that trend class
arsort($bestFitValue);
$bestFitType = key($bestFitValue);
return $bestFit[$bestFitType];
break;
default :
return false;
}
} // function calculate()
} // class trendClass
|