Inverse of Coordinate Transformation.
| call | DclGrid2DInverseCoordinateTransform | (tx,ty,ux,uy) | 
| tx | <R> | Source Coordinates.(No 1).(Input)D  | 
  
| ty | <R> | Source Coordinates.(No 2).(Input) | 
| ux | <R> | Destination Coordinates.(No 1).(Output) | 
| uy | <R> | Destination Coordinates.(No 2).(Output) | 
(a) If it has not been initialized with G2SCTR, an error occurs.
(b) If inputs out of range of TXA,TYA which is set with G2SCTR, an error occurs.