/**
* Checks that the data are valid
*/
protected function CheckValues()
{
parent::CheckValues();
$this->largest_value = $this->GetMaxValue();
$this->smallest_value = $this->largest_value;
// want smallest non-0 value
foreach ($this->values[0] as $item) {
if ($item->value < $this->smallest_value) {
$this->smallest_value = $item->value;
}
}
}
