| public static cumulativeFrequency ( array $values ) : array | ||
| $values | array | Ex: ( A, A, A, A, A, A, B, B, B, C ) |
| return | array | cumulative frequency distribution Ex: ( A => 6, B => 9, C => 10 ) |
public static function cumulativeFrequency(array $values) : array
{
$running_total = 0;
$cumulative_frequencies = array();
foreach (self::frequency($values) as $value => $frequency) {
$running_total += $frequency;
$cumulative_frequencies[$value] = $running_total;
}
return $cumulative_frequencies;
}