public function init()
    {
        if (! isset($this->lat0)){
            // SR-ORG:6696 does not define lat0 param in wkt
            $this->lat0=0.0;
        }

        $this->e0 = Common::e0fn( $this->es );
        $this->e1 = Common::e1fn( $this->es );
        $this->e2 = Common::e2fn( $this->es );
        $this->e3 = Common::e3fn( $this->es );

        $this->ml0 = $this->a * Common::mlfn( $this->e0, $this->e1, $this->e2, $this->e3, $this->lat0 );
    }