Transform 2-dimensional coordinates   astTran2 
  
" npoint" X-coordinate values
for the input (untransformed) points.  " npoint" Y-coordinate
values for the input (untransformed) points.  ’ s forward coordinate transformation is to be applied, while a zero
value indicates that the inverse transformation should be used.  " npoint" elements) into which the X-coordinates of the output (transformed)
points will be written.  " npoint" elements) into which the
Y-coordinates of the output (transformed) points will be written.  "
8-byte" interface for this function should be used. This alternative interface uses 8
byte integer arguments (instead of 4-byte). Specifically, the argument " npoint" , is
changed from type " int" to type " int64_t" (defined in header file stdint.h). The
function name is changed by appending the digit " 8" to the name. Thus, astTran2
becomes astTran28