src/Common.php
public static function invlatiso($eccent, $ts)
    {
        $phi = static::fL(1.0, $ts);
        $Iphi = 0.0;
        $con = 0.0;

        do {
            $Iphi = $phi;
            $con = $eccent * sin($Iphi);
            $phi = static::fL(exp($eccent * log((1.0 + $con) / (1.0 - $con)) / 2.0 ), $ts);
        } while(abs($phi - $Iphi) > 1.0e-12);

        return $phi;
    }
public static function invlatiso($eccent, $ts)
    {
        $phi = static::fL(1.0, $ts);
        $Iphi = 0.0;
        $con = 0.0;

        do {
            $Iphi = $phi;
            $con = $eccent * sin($Iphi);
            $phi = static::fL(exp($eccent * log((1.0 + $con) / (1.0 - $con)) / 2.0 ), $ts);
        } while(abs($phi - $Iphi) > 1.0e-12);

        return $phi;
    }
public static function invlatiso ( $ eccent , $ ts ) { $ phi = static :: fL ( 1.0 , $ ts ) ; $ Iphi = 0.0 ; $ con = 0.0 ; do { $ Iphi = $ phi ; $ con = $ eccent * sin ( $ Iphi ) ; $ phi = static :: fL ( exp ( $ eccent * log ( ( 1.0 + $ con ) / ( 1.0 - $ con ) ) / 2.0 ) , $ ts ) ; } while ( abs ( $ phi - $ Iphi ) > 1.0e-12 ) ; return $ phi ; }
Inverse Latitude Isometrique - close to ph2z

@param float $eccent
@param float $ts
@return float
Inverse Latitude Isometrique - close to ph2z