function eit_gt_corner, header ;+ ; Name: ; eit_gt_corner ; ; Purpose: ; Return the defining corners of an EIT image. ; ; Input Parameters: ; header = FITS header or EIT index structure for image ; ; Output: ; corners = [P1_X, P2_X, P1_Y, P2_Y] ; ; Calling Sequence: ; corners = eit_gt_corner(index) ; corners = eit_gt_corner(fits_header) ; ; Restrictions: ; The one defining reason for this routine is to work around the ; COMMENT header definitions. If P[12]_[XY] ever were to become ; real FITS header keywords instead of comments, it is my hope that ; we would only have to fix this one spot to deal with it. ; ; History: ; 31-October-96 - (BNH) - Written ;- if (n_elements(header) eq 0) then begin message, /info, 'No index/fits header supplied!' return, -1 endif if ((data_chk(header,/type) ne 7) and (data_chk(header,/type) ne 8)) then begin message, /info, 'Argument is not a valid fits header/index structure.' return, -1 endif a = intarr(4) a(0) = eit_fxpar(header, 'P1_X') a(1) = eit_fxpar(header, 'P2_X') a(2) = eit_fxpar(header, 'P1_Y') a(3) = eit_fxpar(header, 'P2_Y') return, a end
Last revised: - Wed May 9 21:45:18 2007- F. Auchère