public static function constructFromString($str) {
		$str = strtoupper($str);
		$i = substr($str, -1) == 'I';

		preg_match('/^T[0-9]{1,}/', $str, $matches);
//		print_r($matches);
		$r = $matches[0];

		return new PitchClassSetTransformation($r, $i);
	}
public static function constructFromString($str) {
		$str = strtoupper($str);
		$i = substr($str, -1) == 'I';

		preg_match('/^T[0-9]{1,}/', $str, $matches);
//		print_r($matches);
		$r = $matches[0];

		return new PitchClassSetTransformation($r, $i);
	}
public static function constructFromString ( $ str ) { $ str = strtoupper ( $ str ) ; $ i = substr ( $ str , - 1 ) == 'I' ; preg_match ( '/^T[0-9]{1,}/' , $ str , $ matches ) ; //		print_r($matches); $ r = $ matches [ 0 ] ; return new PitchClassSetTransformation ( $ r , $ i ) ; }
constructs the object from a string descriptor, eg "T3" or "T10I"

@return PitchClassSetTransformation
constructs the object from a string descriptor eg T3 or T10I