三维空间中直角坐标与球坐标的相互转换

package hans_gis.coord

{

    public class CoordsTransform

    {

        public function CoordsTransform()

        {

        }

         

        public function CartesianToSpherical(coord:CartesianCoord):SphericalCoord{

            var radius = this.GetModuloFromCartesianCoord(coord);

            var theta = this.GetThetaFromCartesianCoord(coord);

            var phi = this.GetPhiFromCartesianCoord(coord);

            return new SphericalCoord(radius, theta, phi);

        }

         

        protected function GetModuloFromCartesianCoord(coord:CartesianCoord):Number

        {

            return Math.sqrt( coord.x*coord.x + coord.y*coord.y + coord.z*coord.z );

        }

         

        protected function GetThetaFromCartesianCoord(coord:CartesianCoord):Number{

//          return Math.atan(Math.sqrt(coord.x*coord.x + coord.y*coord.y)/coord.z);

            return Math.acos(coord.z/this.GetModuloFromCartesianCoord(coord));

        }

         

        protected function GetPhiFromCartesianCoord(coord:CartesianCoord):Number{

            return Math.atan(coord.y/coord.x);

        }

         

        public function SphericalToCartesian(coord:SphericalCoord):CartesianCoord{

            var x = this.GetXFromSphericalCoord(coord);

            var y = this.GetYFromSphericalCoord(coord);

            var z = this.GetZFromSphericalCoord(coord);

            return new CartesianCoord(x, y, z);

        }

         

        protected function GetXFromSphericalCoord(coord:SphericalCoord):Number{

            return coord.radius*Math.sin(coord.theta)*Math.cos(coord.phi);

        }

         

        protected function GetYFromSphericalCoord(coord:SphericalCoord):Number{

            return coord.radius*Math.sin(coord.theta)*Math.sin(coord.phi);

        }

         

        protected function GetZFromSphericalCoord(coord:SphericalCoord):Number{

            return coord.radius*Math.cos(coord.theta);

        }

    }

}