public function setTimeStep($timeStep)
    {
        $timeStep = abs(intval($timeStep));
        $this->timeStep = $timeStep;

        return $this;
    }
public function setTimeStep($timeStep)
    {
        $timeStep = abs(intval($timeStep));
        $this->timeStep = $timeStep;

        return $this;
    }
public function setTimeStep ( $ timeStep ) { $ timeStep = abs ( intval ( $ timeStep ) ) ; $ this -> timeStep = $ timeStep ; return $ this ; }
Set the timestep value

@param  integer $timeStep The timestep value.
@return self    Returns an instance of self for method chaining.
Set the timestep value