/** * Returns the log-log interpolated or extrapolated y-value using the * supplied x- and y-value arrays. * * @param xs x-values of some function * @param ys y-values of some function * @param x value at which to find y * @return the log-log interpolated y-value */ public static function findLogLogY($xs, $ys, $x) { $i = RTGM_Util::dataIndex($xs, $x); return exp(RTGM_Util::findY(log($xs[$i]), log($ys[$i]), log($xs[$i + 1]), log($ys[$i + 1]), log($x))); }