HROTATE

     Apply the IDL ROTATE function and update astrometry in a FITS header

     Apply the intrinsic IDL ROTATE function to an image and update
     astrometry in the associated FITS header.

     HROTATE, oldim, oldhd, newim, newhd, direction
               or
     HROTATE, oldim, oldhd, direction

     OLDIM - the original image array
     OLDHD - the original FITS image header, string array
     DIRECTION - Scalar integer (0-7) specifying rotation direction,
               exactly as specified by the IDL ROTATE function.
        Direction  Transpose?  Rot. CCW  X1  Y1
       ----------------------------------------
       0          No          None     X0  Y0    (no change)
       1          No          90      -Y0  X0
       2          No          180     -X0 -Y0
       3          No          270      Y0 -X0
       4          Yes         None     Y0  X0
       5          Yes         90      -X0  Y0
       6          Yes         180     -Y0 -X0
       7          Yes         270      X0 -Y0

     NEWIM - the rotated image, with the same dimensions as Oldim
     NEWHD - header for newim containing updated astrometry info
               If output parameters are not supplied, the program
               will modify the input parameters OLDIM and OLDHD
               to contain the rotated image and updated header.

     ERRMSG - If this keyword is supplied, then any error mesasges will be
               returned to the user in this parameter rather than depending on
               on the MESSAGE routine in IDL.   If no errors are encountered
               then a null string is returned.

     Rotate an image exactly 90 degrees counterclockwise and update the
     FITS image array and header.
       IDL>  HROT, im, h, im_new, h_new, 1

      The image array is rotated using the ROTATE function.
      The CD (or CROTA) and CRPIX parameters, if present in the FITS header,
      are updated for the new rotation.
      History records are also added to the header

     Does not work Guide Star Survey (GSS) astrometry.    Use GSSS_STDAST to
     first convert

     CHECK_FITS(), SXADDPAR, EXTAST

     Written,  Mar 1997    W. Landsman,  Hughes STX
     Work for non-square images   W. Landsman   June 1998 Raytheon STX
     Converted to IDL V5.0  W. Landsman     June 1998
     Fix for different plate scales, and CROTA2 defined, November 1998
     Added ERRMSG, Use double precision formatting, W. Landsman April 2000
     Consistent conversion between CROTA and CD matrix W. Landsman Oct 2000
     Correct update when CROTA keyword present W. Landsman  June 2003
     Update CDELT for AIPS-style astrometry headers M. Perrin/WL Jul 2003
     Convert GSS astrometry to WCS W. Landsman  November 2004

[Home Page] [Software, Documentation] [IDL Documentation] [Quick Reference] [Feedback]