      list_astro

      read a series of lines consisting of 4 columns.  the columns
      represent the X,Y coordinate of a series of objects in first one
      coordinate frame, then in a second coordinate frame.  list_astro
      will return the linear transformation (and errors) from the first
      frame to the second frame in the form:

      X0 X1 X2 dX
      Y0 Y1 Y2 dY

      where

      X = X0 + X1*x + X2*y
      Y = Y0 + Y1*x + Y2*y

      and dX and dY are the errors in the output coordinate frame.