[daip] Re: Aips gripe: hgeom

[Eric Greisen]

To tell you the truth I am a bit mystefied by the output too.
However, you did ignore the help file.

  APARM........Transformation parameters:
               1 = Order of Everett interpolation formula
                  [range 1-7: 1=bilinear, 3=bicubic,
                   5=biquintic, 7=biseptic] 0 => 3.
               2 = zero-flag. If > 0.0, zeroes are used wherever
                   blanks would normally be created in the output
                   image.  Else "magic value" blanks are used.
               3 = X reference pixel in output pixels;
               4 = Y reference pixel in output pixels;  If BOTH
               APARM(3) and APARM(4) are zero, but IMSIZE is not, then
               the numeric center of the input (sub)image is placed at
               the numeric center of the output image.  If IMSIZE is
               all 0 and both APARM(3) and APARM(4) are zero, then the
               reference pixels are taken as the refernce pixels of
               the 2nd image.

You have to set APARM(3) and APARM(4) to get what you were expecting.

Please try that and see if it gives you correct results.

Eric