standaard-deviatie-stdev
Gesponsorde koppelingen
PHP script bestanden
Code (php)
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<?PHP
function standard_deviation ($a)
{
//variable and initializations
$the_standard_deviation = 0.0;
$the_variance = 0.0;
$the_mean = 0.0;
$the_array_sum = array_sum($a); //sum the elements
$number_elements = count($a); //count the number of elements
//calculate the mean
$the_mean = $the_array_sum / $number_elements;
//calculate the variance
for ($i = 0; $i < $number_elements; $i++)
{
//sum the array
$the_variance = $the_variance + ($a[$i] - $the_mean) * ($a[$i] - $the_mean);
}
$the_variance = $the_variance / ($number_elements - 1.0);
//calculate the standard deviation
$the_standard_deviation = pow( $the_variance, 0.5);
//return the variance
return $the_standard_deviation;
}
$a = array(2, 3, 5, 2, 10, 0, 10, 10, 0, 10, 0, 0);
$STDEV = standard_deviation ($a);
echo $STDEV; // uitkomst 4,438126823
?>
function standard_deviation ($a)
{
//variable and initializations
$the_standard_deviation = 0.0;
$the_variance = 0.0;
$the_mean = 0.0;
$the_array_sum = array_sum($a); //sum the elements
$number_elements = count($a); //count the number of elements
//calculate the mean
$the_mean = $the_array_sum / $number_elements;
//calculate the variance
for ($i = 0; $i < $number_elements; $i++)
{
//sum the array
$the_variance = $the_variance + ($a[$i] - $the_mean) * ($a[$i] - $the_mean);
}
$the_variance = $the_variance / ($number_elements - 1.0);
//calculate the standard deviation
$the_standard_deviation = pow( $the_variance, 0.5);
//return the variance
return $the_standard_deviation;
}
$a = array(2, 3, 5, 2, 10, 0, 10, 10, 0, 10, 0, 0);
$STDEV = standard_deviation ($a);
echo $STDEV; // uitkomst 4,438126823
?>