Note: These formulas have been transcribed from EPSG Guidance Note #7-2. Users are encouraged to use that document rather than the text which follows as reference because limitations in the transcription will be avoided.¶¶XT   =  A0  +  A1 * XS  +  A2 * YS¶YT   =  B0  +  B1 * XS  +  B2 * YS¶where¶XT , YT  are the coordinates of a point P in the target coordinate reference system;¶XS , YS   are the coordinates of P in the source coordinate reference system.¶¶Reversibility¶The reverse transformation is another affine transformation using the same formulas but with different parameter values.  The reverse parameter values, indicated by a prime (’), can be calculated from those of the forward transformation as follows:¶¶D    = A1 * B2   –   A2 * B1¶A0’ = (A2 * B0   –   B2 * A0) / D¶B0’ = (B1 * A0   –   A1 * B0) / D¶A1’ = +B2 / D¶A2’ = – A2 / D¶B1’ = – B1 / D¶B2’ = +A1 / D¶¶Then¶	XS   =  A0'  +  A1' * XT  +  A2' * YT¶		YS   =  B0'  +  B1' * XT  +  B2' *