PHPExcel_Power_Best_Fit Class Reference

Inheritance diagram for PHPExcel_Power_Best_Fit:

Collaboration diagram for PHPExcel_Power_Best_Fit:

Public Member Functions
	getValueOfYForX ($xValue)
	Return the Y-Value for a specified value of X. More...
	getValueOfXForY ($yValue)
	Return the X-Value for a specified value of Y. More...
	getEquation ($dp=0)
	Return the Equation of the best-fit line. More...
	getIntersect ($dp=0)
	Return the Value of X where it intersects Y = 0. More...
	__construct ($yValues, $xValues=array(), $const=True)
	Define the regression and calculate the goodness of fit for a set of X and Y data values. More...
Public Member Functions inherited from PHPExcel_Best_Fit
	getError ()
	getBestFitType ()
	getValueOfYForX ($xValue)
	Return the Y-Value for a specified value of X. More...
	getValueOfXForY ($yValue)
	Return the X-Value for a specified value of Y. More...
	getXValues ()
	Return the original set of X-Values. More...
	getEquation ($dp=0)
	Return the Equation of the best-fit line. More...
	getSlope ($dp=0)
	Return the Slope of the line. More...
	getSlopeSE ($dp=0)
	Return the standard error of the Slope. More...
	getIntersect ($dp=0)
	Return the Value of X where it intersects Y = 0. More...
	getIntersectSE ($dp=0)
	Return the standard error of the Intersect. More...
	getGoodnessOfFit ($dp=0)
	Return the goodness of fit for this regression. More...
	getGoodnessOfFitPercent ($dp=0)
	getStdevOfResiduals ($dp=0)
	Return the standard deviation of the residuals for this regression. More...
	getSSRegression ($dp=0)
	getSSResiduals ($dp=0)
	getDFResiduals ($dp=0)
	getF ($dp=0)
	getCovariance ($dp=0)
	getCorrelation ($dp=0)
	getYBestFitValues ()
	__construct ($yValues, $xValues=array(), $const=True)
	Define the regression. More...

Protected Attributes
	$_bestFitType = 'power'
Protected Attributes inherited from PHPExcel_Best_Fit
	$_error = False
	$_bestFitType = 'undetermined'
	$_valueCount = 0
	$_xValues = array()
	$_yValues = array()
	$_adjustToZero = False
	$_yBestFitValues = array()
	$_goodnessOfFit = 1
	$_stdevOfResiduals = 0
	$_covariance = 0
	$_correlation = 0
	$_SSRegression = 0
	$_SSResiduals = 0
	$_DFResiduals = 0
	$_F = 0
	$_slope = 0
	$_slopeSE = 0
	$_intersect = 0
	$_intersectSE = 0
	$_Xoffset = 0
	$_Yoffset = 0

Private Member Functions
	_power_regression ($yValues, $xValues, $const)
	Execute the regression and calculate the goodness of fit for a set of X and Y data values. More...

Additional Inherited Members
Protected Member Functions inherited from PHPExcel_Best_Fit
	_calculateGoodnessOfFit ($sumX, $sumY, $sumX2, $sumY2, $sumXY, $meanX, $meanY, $const)
	_leastSquareFit ($yValues, $xValues, $const)

Detailed Description

Definition at line 39 of file powerBestFitClass.php.

Constructor & Destructor Documentation

__construct()

PHPExcel_Power_Best_Fit::__construct	(		$yValues,
			$xValues = array(),
			$const = True
	)

Define the regression and calculate the goodness of fit for a set of X and Y data values.

Parameters

	float[]	$yValues The set of Y-values for this regression
	float[]	$xValues The set of X-values for this regression
boolean	$const

Definition at line 136 of file powerBestFitClass.php.

References _power_regression().

                                                                      {
                if (parent::__construct($yValues, $xValues) !== False) {
                        $this->_power_regression($yValues, $xValues, $const);
                }
        }       //      function __construct()

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Member Function Documentation

_power_regression()

PHPExcel_Power_Best_Fit::_power_regression (   $yValues,   $xValues,   $const  )

private

Execute the regression and calculate the goodness of fit for a set of X and Y data values.

Parameters

	float[]	$yValues The set of Y-values for this regression
	float[]	$xValues The set of X-values for this regression
boolean	$const

Definition at line 107 of file powerBestFitClass.php.

References PHPExcel_Best_Fit\_leastSquareFit().

Referenced by __construct().

                                                                       {
                foreach($xValues as &$value) {
                        if ($value < 0.0) {
                                $value = 0 - log(abs($value));
                        } elseif ($value > 0.0) {
                                $value = log($value);
                        }
                }
                unset($value);
                foreach($yValues as &$value) {
                        if ($value < 0.0) {
                                $value = 0 - log(abs($value));
                        } elseif ($value > 0.0) {
                                $value = log($value);
                        }
                }
                unset($value);

                $this->_leastSquareFit($yValues, $xValues, $const);
        }       //      function _power_regression()

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getEquation()

PHPExcel_Power_Best_Fit::getEquation

(

$dp = 0

)

Return the Equation of the best-fit line.

Parameters

int

$dp

Number of places of decimal precision to display

Returns

string

Definition at line 78 of file powerBestFitClass.php.

References getIntersect(), and PHPExcel_Best_Fit\getSlope().

                                           {
                $slope = $this->getSlope($dp);
                $intersect = $this->getIntersect($dp);

                return 'Y = '.$intersect.' * X^'.$slope;
        }       //      function getEquation()

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getIntersect()

PHPExcel_Power_Best_Fit::getIntersect

(

$dp = 0

)

Return the Value of X where it intersects Y = 0.

Parameters

int

$dp

Number of places of decimal precision to display

Returns

string

Definition at line 92 of file powerBestFitClass.php.

Referenced by getEquation(), getValueOfXForY(), and getValueOfYForX().

                                            {
                if ($dp != 0) {
                        return round(exp($this->_intersect),$dp);
                }
                return exp($this->_intersect);
        }       //      function getIntersect()

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getValueOfXForY()

PHPExcel_Power_Best_Fit::getValueOfXForY

(

$yValue

)

Return the X-Value for a specified value of Y.

Parameters

float

$yValue

Y-Value

Returns

float X-Value

Definition at line 67 of file powerBestFitClass.php.

References getIntersect(), and PHPExcel_Best_Fit\getSlope().

                                                 {
                return pow((($yValue + $this->_Yoffset) / $this->getIntersect()),(1 / $this->getSlope()));
        }       //      function getValueOfXForY()

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getValueOfYForX()

PHPExcel_Power_Best_Fit::getValueOfYForX

(

$xValue

)

Return the Y-Value for a specified value of X.

Parameters

float

$xValue

X-Value

Returns

float Y-Value

Definition at line 56 of file powerBestFitClass.php.

References getIntersect(), and PHPExcel_Best_Fit\getSlope().

                                                 {
                return $this->getIntersect() * pow(($xValue - $this->_Xoffset),$this->getSlope());
        }       //      function getValueOfYForX()

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Field Documentation

$_bestFitType

PHPExcel_Power_Best_Fit::$_bestFitType = 'power'

protected

Definition at line 47 of file powerBestFitClass.php.

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

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