trendClass Class Reference

Collaboration diagram for trendClass:

Static Public Member Functions
static	calculate ($trendType=self::TREND_BEST_FIT, $yValues, $xValues=array(), $const=True)

Data Fields
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'

Static Private Attributes
static	$_trendTypes
static	$_trendTypePolyOrders
static	$_trendCache = array()

Detailed Description

Definition at line 43 of file trendClass.php.

Member Function Documentation

calculate()

static trendClass::calculate (   $trendType = self::TREND_BEST_FIT,   $yValues,   $xValues = array(),   $const = True  )

static

Definition at line 87 of file trendClass.php.

                                                                                                                 {
                //      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()

References $key, getError(), TREND_BEST_FIT, TREND_BEST_FIT_NO_POLY, TREND_EXPONENTIAL, TREND_LINEAR, TREND_LOGARITHMIC, TREND_POLYNOMIAL_2, TREND_POLYNOMIAL_3, TREND_POLYNOMIAL_4, TREND_POLYNOMIAL_5, TREND_POLYNOMIAL_6, and TREND_POWER.

Referenced by PHPExcel_Calculation_Statistical\CORREL(), PHPExcel_Calculation_Statistical\COVAR(), PHPExcel_Calculation_Statistical\FORECAST(), PHPExcel_Calculation_Statistical\GROWTH(), PHPExcel_Calculation_Statistical\INTERCEPT(), PHPExcel_Calculation_Statistical\LINEST(), PHPExcel_Calculation_Statistical\LOGEST(), PHPExcel_Calculation_Statistical\RSQ(), PHPExcel_Calculation_Statistical\SLOPE(), PHPExcel_Calculation_Statistical\STEYX(), and PHPExcel_Calculation_Statistical\TREND().

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Field Documentation

$_trendCache

trendClass::$_trendCache = array()

staticprivate

Definition at line 84 of file trendClass.php.

$_trendTypePolyOrders

trendClass::$_trendTypePolyOrders

staticprivate

Initial value:

= array( self::TREND_POLYNOMIAL_2,
                                                                                                  self::TREND_POLYNOMIAL_3,
                                                                                                  self::TREND_POLYNOMIAL_4,
                                                                                                  self::TREND_POLYNOMIAL_5,
                                                                                                  self::TREND_POLYNOMIAL_6
                                                                                            )

Definition at line 72 of file trendClass.php.

$_trendTypes

trendClass::$_trendTypes

staticprivate

Initial value:

= array( self::TREND_LINEAR,
                                                                                 self::TREND_LOGARITHMIC,
                                                                                 self::TREND_EXPONENTIAL,
                                                                                 self::TREND_POWER
                                                                           )

Definition at line 62 of file trendClass.php.

TREND_BEST_FIT

const trendClass::TREND_BEST_FIT = 'Bestfit'

Definition at line 54 of file trendClass.php.

Referenced by calculate().

TREND_BEST_FIT_NO_POLY

const trendClass::TREND_BEST_FIT_NO_POLY = 'Bestfit_no_Polynomials'

Definition at line 55 of file trendClass.php.

Referenced by calculate().

TREND_EXPONENTIAL

const trendClass::TREND_EXPONENTIAL = 'Exponential'

Definition at line 47 of file trendClass.php.

Referenced by calculate(), PHPExcel_Calculation_Statistical\GROWTH(), and PHPExcel_Calculation_Statistical\LOGEST().

TREND_LINEAR

const trendClass::TREND_LINEAR = 'Linear'

Definition at line 45 of file trendClass.php.

Referenced by calculate(), PHPExcel_Calculation_Statistical\CORREL(), PHPExcel_Calculation_Statistical\COVAR(), PHPExcel_Calculation_Statistical\FORECAST(), PHPExcel_Calculation_Statistical\INTERCEPT(), PHPExcel_Calculation_Statistical\LINEST(), PHPExcel_Calculation_Statistical\RSQ(), PHPExcel_Calculation_Statistical\SLOPE(), PHPExcel_Calculation_Statistical\STEYX(), and PHPExcel_Calculation_Statistical\TREND().

TREND_LOGARITHMIC

const trendClass::TREND_LOGARITHMIC = 'Logarithmic'

Definition at line 46 of file trendClass.php.

Referenced by calculate().

TREND_POLYNOMIAL_2

const trendClass::TREND_POLYNOMIAL_2 = 'Polynomial_2'

Definition at line 49 of file trendClass.php.

Referenced by calculate().

TREND_POLYNOMIAL_3

const trendClass::TREND_POLYNOMIAL_3 = 'Polynomial_3'

Definition at line 50 of file trendClass.php.

Referenced by calculate().

TREND_POLYNOMIAL_4

const trendClass::TREND_POLYNOMIAL_4 = 'Polynomial_4'

Definition at line 51 of file trendClass.php.

Referenced by calculate().

TREND_POLYNOMIAL_5

const trendClass::TREND_POLYNOMIAL_5 = 'Polynomial_5'

Definition at line 52 of file trendClass.php.

Referenced by calculate().

TREND_POLYNOMIAL_6

const trendClass::TREND_POLYNOMIAL_6 = 'Polynomial_6'

Definition at line 53 of file trendClass.php.

Referenced by calculate().

TREND_POWER

const trendClass::TREND_POWER = 'Power'

Definition at line 48 of file trendClass.php.

Referenced by calculate().

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The documentation for this class was generated from the following file:

• libs/composer/vendor/phpoffice/phpexcel/Classes/PHPExcel/Shared/trend/trendClass.php