Collaboration diagram for ilStatistics:

Public Member Functions
	ilStatistics ($nan_handling=NAN_HANDLING_REMOVE)
	Constructor of ilStatistics class. More...

	setNANHandling ($nan_handling=NAN_HANDLING_REMOVE)
	Set the handling of elements which are not a number. More...

	getNANHandling ()
	Get the handling of elements which are not a number. More...

	setData ($stat_data)
	Sets the data and checks for invalid values. More...

	getData ()
	Returns the numeric value array containing the data. More...

	min ()
	Calculates the minimum value. More...

	max ()
	Calculates the maximum value. More...

	count ()
	Calculates number of data values. More...

	sum_n ($n)
	Calculates the sum of x_1^n + x_2^n + ... + x_i^n. More...

	sum ()
	Calculates the sum of x_1 + x_2 + ... + x_i. More...

	sum2 ()
	Calculates the sum of x_1^2 + x_2^2 + ... + x_i^2. More...

	product_n ($n)
	Calculates the product of x_1^n * x_2^n * ... * x_i^n. More...

	product ($n)
	Calculates the product of x_1 * x_2 * ... * x_i. More...

	arithmetic_mean ()
	Arithmetic mean of the data values xbar = (1/n)*∑x_i. More...

	geometric_mean ()
	Geometric mean of the data values geometric_mean = (x_1 * x_2 * ... * x_n)^(1/n) More...

	harmonic_mean ()
	Harmonic mean of the data values harmonic_mean = n/(1/x_1 + 1/x_2 + ... + 1/x_n) More...

	median ()
	Median of the data values. More...

	rank ($value)
	Returns the rank of a given value. More...

	rank_median ()
	Returns the rank of the median. More...

	quantile ($n)
	n-Quantile of the data values More...

	validate ()
	Validates the numeric data and handles values which are not a number according to the $nan_handling variable. More...

Data Fields
	$nan_handling

	$stat_data

Detailed Description

Definition at line 18 of file class.ilStatistics.php.

Member Function Documentation

◆ arithmetic_mean()

ilStatistics::arithmetic_mean ( )

Arithmetic mean of the data values xbar = (1/n)*∑x_i.

Returns: mixed The arithmetic mean or false, if there is an error or no values @access public

Definition at line 231 of file class.ilStatistics.php.

                                   {
                $sum = $this->sum();
                if ($sum === false)
                {
                        return false;
                }
                $count = $this->count();
                if ($count == 0)
                {
                        return false;
                }
                return (double)($sum/$count);
        }

References count(), and sum().

Here is the call graph for this function:

◆ count()

ilStatistics::count ( )

Calculates number of data values.

Returns: mixed The number of data values @access public

Definition at line 144 of file class.ilStatistics.php.

                         {
                return count($this->stat_data);
        }

References count().

Referenced by arithmetic_mean(), count(), geometric_mean(), harmonic_mean(), max(), median(), min(), product_n(), quantile(), rank(), rank_median(), and sum_n().

Here is the call graph for this function:

Here is the caller graph for this function:

◆ geometric_mean()

ilStatistics::geometric_mean ( )

Geometric mean of the data values geometric_mean = (x_1 * x_2 * ... * x_n)^(1/n)

The geometric mean of a set of positive data is defined as the product of all the members of the set, raised to a power equal to the reciprocal of the number of members.

Returns: mixed The geometric mean or false, if there is an error or no values @access public

Definition at line 256 of file class.ilStatistics.php.

                                  {
                $prod = $this->product();
                if (($prod === false) or ($prod === 0))
                {
                        return false;
                }
                $count = $this->count();
                if ($count == 0)
                {
                        return false;
                }
                return pow((double)$prod, (double)(1/$count));
        }

References count(), and product().

Here is the call graph for this function:

◆ getData()

ilStatistics::getData ( )

Returns the numeric value array containing the data.

Returns: array An array containing the sorted numeric data @access public

Definition at line 95 of file class.ilStatistics.php.

        {
                return $this->stat_data;
        }

References $stat_data.

◆ getNANHandling()

ilStatistics::getNANHandling ( )

Get the handling of elements which are not a number.

Returns NAN_HANDLING_REMOVE if all elements which are not a number will be removed. Returns NAN_HANDLING_ZERO if all elements which are not a number will be set to zero.

Returns: integer A constant defining the handling of elements which are not a number @access public

Definition at line 72 of file class.ilStatistics.php.

        {
                return $this->nan_handling;
        }

References $nan_handling.

◆ harmonic_mean()

ilStatistics::harmonic_mean ( )

Harmonic mean of the data values harmonic_mean = n/(1/x_1 + 1/x_2 + ... + 1/x_n)

Returns: mixed The harmonic mean or false, if there is an error or no values @access public

Definition at line 277 of file class.ilStatistics.php.

                                 {
                $min = $this->min();
                if (($min === false) or ($min === 0))
                {
                        return false;
                }
                $count = $this->count();
                if ($count == 0)
                {
                        return false;
                }
                $sum = 0;
                foreach ($this->stat_data as $value)
                {
                        $sum += 1/$value;
                }
                return $count/$sum;
        }

References count(), and min().

Here is the call graph for this function:

◆ ilStatistics()

ilStatistics::ilStatistics ( $nan_handling = NAN_HANDLING_REMOVE )

Constructor of ilStatistics class.

@access public

Definition at line 43 of file class.ilStatistics.php.

        {
                $this->nan_handling = $nan_handling;
                $this->stat_data = array();
        }

References $nan_handling.

◆ max()

ilStatistics::max ( )

Calculates the maximum value.

Returns: mixed The maximum value or false, if no maximum exists

See also: min() @access User interface

Definition at line 126 of file class.ilStatistics.php.

                       {
                if (count($this->stat_data))
                {
                        $max = max($this->stat_data);
                }
                else
                {
                        $max = false;
                }
                return $max;
        }

References count(), and max().

Referenced by max().

Here is the call graph for this function:

Here is the caller graph for this function:

◆ median()

ilStatistics::median ( )

Median of the data values.

Returns: mixed The median or false, if there are no data values @access public

Definition at line 302 of file class.ilStatistics.php.

                          {
                $median = false;
                if (count($this->stat_data))
                {
                        $median = 0;
                        $count = $this->count();
                        if ((count($this->stat_data) % 2) == 0)
                        {
                                $median = ($this->stat_data[($count / 2) - 1] + $this->stat_data[($count / 2)]) / 2;
                        }
                        else
                        {
                                $median = $this->stat_data[(($count + 1) / 2) - 1];
                        }
                }
                return $median;
        }

References count().

Here is the call graph for this function:

◆ min()

ilStatistics::min ( )

Calculates the minimum value.

Returns: mixed The minimum value or false, if no minimum exists

See also: max() @access User interface

Definition at line 107 of file class.ilStatistics.php.

                       {
                if (count($this->stat_data))
                {
                        $min = min($this->stat_data);
                }
                else
                {
                        $min = false;
                }
                return $min;
        }

References count(), and min().

Referenced by harmonic_mean(), min(), and product_n().

Here is the call graph for this function:

Here is the caller graph for this function:

◆ product()

ilStatistics::product ( $n )

Calculates the product of x_1 * x_2 * ... * x_i.

Parameters

numeric $n The exponent

Returns: mixed The product of x_1 * x_2 * ... * x_i or false, if no values exist @access public

Definition at line 220 of file class.ilStatistics.php.

                             {
                return $this->product_n(1);
        }

References product_n().

Referenced by geometric_mean().

Here is the call graph for this function:

Here is the caller graph for this function:

◆ product_n()

ilStatistics::product_n ( $n )

Calculates the product of x_1^n * x_2^n * ... * x_i^n.

Parameters

numeric $n The exponent

Returns: mixed The product of x_1^n * x_2^n * ... * x_i^n or false, if no values exist @access public

Definition at line 196 of file class.ilStatistics.php.

                               {
                $prod_n = false;
                if (count($this->stat_data))
                {
                        if ($this->min() === 0)
                        {
                                return 0.0;
                        }
                        $prod_n = 1.0;
                        foreach ($this->stat_data as $value)
                        {
                                $prod_n *= pow((double)$value, (double)$n);
                        }
                }
                return $prod_n;
        }

References $n, count(), and min().

Referenced by product().

Here is the call graph for this function:

Here is the caller graph for this function:

◆ quantile()

ilStatistics::quantile ( $n )

n-Quantile of the data values

Parameters

double $n A value between 0 an 100 calculating the n-Quantile

Returns: mixed The n-quantile or false, if there are no data values @access public

Definition at line 376 of file class.ilStatistics.php.

                              {
                $count = $this->count();
                if ($count == 0)
                {
                        return false;
                }
                $nprod = ($n/100)*$count;
                if (intval($nprod) == $nprod)
                {
                        $k = $nprod;
                        if ($k == 0)
                        {
                                return $this->stat_data[$k];
                        }
                        else if ($k == $count)
                        {
                                return $this->stat_data[$k-1];
                        }
                        else
                        {
                                return ($this->stat_data[$k-1] + $this->stat_data[$k])/2;
                        }
                }
                else
                {
                        $k = ceil($nprod);
                        return $this->stat_data[$k-1];
                }
        }

References $n, and count().

Here is the call graph for this function:

◆ rank()

ilStatistics::rank ( $value )

Returns the rank of a given value.

Returns: mixed The rank, if the value exists in the data, otherwise false @access public

Definition at line 326 of file class.ilStatistics.php.

        {
                if (!is_numeric($value))
                {
                        return false;
                }
                $rank = array_search($value, $this->stat_data);
                if ($rank !== FALSE)
                {
                        $rank = $this->count() - $rank;
                }
                return $rank;
        }

References count().

Here is the call graph for this function:

◆ rank_median()

ilStatistics::rank_median ( )

Returns the rank of the median.

This method is different from the rank method because the median could be the arithmetic mean of the two middle values when the data size is even. In this case the median could a value which is not part of the data set.

Returns: mixed The rank of the median, otherwise false @access public

Definition at line 350 of file class.ilStatistics.php.

        {
                $count = $this->count();
                if ($count == 0)
                {
                        return false;
                }
                
                if (($count % 2) == 0)
                {
                        $rank_median = ($count + 1) / 2;
                }
                else
                {
                        $rank_median = ($count + 1) / 2;
                }
                return $rank_median;
        }

References count().

Here is the call graph for this function:

◆ setData()

ilStatistics::setData ( $stat_data )

Sets the data and checks for invalid values.

Parameters

array $stat_data An array containing the numeric data @access public

Definition at line 83 of file class.ilStatistics.php.

        {
                $this->stat_data = array_values($stat_data);
                $this->validate();
        }

References $stat_data, and validate().

Here is the call graph for this function:

◆ setNANHandling()

ilStatistics::setNANHandling ( $nan_handling = NAN_HANDLING_REMOVE )

Set the handling of elements which are not a number.

If set to NAN_HANDLING_REMOVE, all elements which are not a number will be removed, if set to NAN_HANDLING_ZERO, all elements which are not a number will be set to zero.

Parameters

integer $nan_handling A constant defining the handling of elements which are not a number @access public

Definition at line 58 of file class.ilStatistics.php.

        {
                $this->nan_handling = $nan_handling;
        }

References $nan_handling.

◆ sum()

ilStatistics::sum ( )

Calculates the sum of x_1 + x_2 + ... + x_i.

Returns: mixed The sum of x_1 + x_2 + ... + x_i or false, if no values exist @access public

Definition at line 174 of file class.ilStatistics.php.

                       {
                return $this->sum_n(1);
        }

References sum_n().

Referenced by arithmetic_mean().

Here is the call graph for this function:

Here is the caller graph for this function:

◆ sum2()

ilStatistics::sum2 ( )

Calculates the sum of x_1^2 + x_2^2 + ... + x_i^2.

Returns: mixed The sum of x_1^2 + x_2^2 + ... + x_i^2 or false, if no values exist @access public

Definition at line 185 of file class.ilStatistics.php.

                        {
                return $this->sum_n(2);
        }

References sum_n().

Here is the call graph for this function:

◆ sum_n()

ilStatistics::sum_n ( $n )

Calculates the sum of x_1^n + x_2^n + ... + x_i^n.

Parameters

numeric $n The exponent

Returns: mixed The sum of x_1^n + x_2^n + ... + x_i^n or false, if no values exist @access public

Definition at line 155 of file class.ilStatistics.php.

                           {
                $sum_n = false;
                if (count($this->stat_data))
                {
                        $sum_n = 0;
                        foreach ($this->stat_data as $value)
                        {
                                $sum_n += pow((double)$value, (double)$n);
                        }
                }
                return $sum_n;
        }

References $n, and count().

Referenced by sum(), and sum2().

Here is the call graph for this function:

Here is the caller graph for this function:

◆ validate()

ilStatistics::validate ( )

Validates the numeric data and handles values which are not a number according to the $nan_handling variable.

After validation the data is sorted.

Returns: boolean Returns true on success, otherwise false @access private

Definition at line 414 of file class.ilStatistics.php.

        {
                $result = true;
                foreach ($this->stat_data as $key => $value)
                {
                        if (!is_numeric($value)) {
                                switch ($this->nan_handling) {
                                        case NAN_HANDLING_REMOVE:
                                                unset($this->stat_data[$key]);
                                                break;
                                        case NAN_HANDLING_ZERO:
                                                $this->stat_data[$key] = 0;
                                                break;
                                        default:
                                                $result = false;
                                }
                        }
                }
                sort($this->stat_data);
                return $result;
        }

References $result, NAN_HANDLING_REMOVE, and NAN_HANDLING_ZERO.

Referenced by setData().

Here is the caller graph for this function:

Field Documentation

◆ $nan_handling

ilStatistics::$nan_handling

Definition at line 28 of file class.ilStatistics.php.

Referenced by getNANHandling(), ilStatistics(), and setNANHandling().

◆ $stat_data

ilStatistics::$stat_data

Definition at line 36 of file class.ilStatistics.php.

Referenced by getData(), and setData().

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

Modules/Test/classes/class.ilStatistics.php

Public Member Functions

Data Fields

Detailed Description

Member Function Documentation

◆ arithmetic_mean()

◆ count()

◆ geometric_mean()

◆ getData()

◆ getNANHandling()

◆ harmonic_mean()

◆ ilStatistics()

◆ max()

◆ median()

◆ min()

◆ product()

◆ product_n()

◆ quantile()

◆ rank()

◆ rank_median()

◆ setData()

◆ setNANHandling()

◆ sum()

◆ sum2()

◆ sum_n()

◆ validate()

Field Documentation

◆ $nan_handling

◆ $stat_data