[gnuastro-devel] [bug #50073] ImageWarp 'rotate' does not correctly propagate WCS pixel scale information into header

[Mohammad Akhlaghi]

Follow-up Comment #5, bug #50073 (project gnuastro):

Sorry, I just remembered you had uploaded your version of
`input_rotated.fits'. So I downloaded it and tried it out. Indeed the `WCSLIB'
keyword wasn't present. But more importantly/strangely after "blink"ing
(sorry, in the previous comment, I mistakenly said "flip"!) I also noticed a
shift!

So after renaming your output to `input_rotated_lee.fits', I exported both
headers to text files to see the difference:


$ astheader input_rotated.fits > mohammad.txt
address@hidden desktop]$ astheader input_rotated_lee.fits > lee.txt
address@hidden desktop]$ diff mohammad.txt lee.txt 
15,17c15,17
< PC1_1   =             -1.0E+00 / Coordinate transformation matrix element   
   
< CDELT1  =   9.416666295793E-05 / [deg] Coordinate increment at reference
point  
< CDELT2  =   9.416666295793E-05 / [deg] Coordinate increment at reference
point  
---
> PC1_1   =                 -1.0 / Coordinate transformation matrix element   
   
> CDELT1  =    9.41666629579E-05 / [deg] Coordinate increment at reference
point  
> CDELT2  =    9.41666629579E-05 / [deg] Coordinate increment at reference
point  
28,29d27
< MJD-OBS =        55238.2821457 / [d] MJD of observation                     
   
<                                                                             
   
44,46c42,43
< DATE    = '2017-01-20T16:37:28' / file creation date (YYYY-MM-DDThh:mm:ss
UT)   
< CFITSIO = '3.41    '           / CFITSIO version.                           
   
< WCSLIB  = '5.15    '           / WCSLIB version.                            
   
---
> DATE    = '2017-01-20T14:42:33' / file creation date (YYYY-MM-DDThh:mm:ss
UT)   
> CFITSIO = '3.37    '           / CFITSIO version.


Besides the missing `3' digit in the `CDELT' keywords, your header file
doesn't have `MJD-OBS' while `input.fits' does have it. This must be another
feature that has been added to WCSLIB since version 2.24.

    _______________________________________________________

Reply to this item at:

  <http://savannah.gnu.org/bugs/?50073>

_______________________________________________
  Message sent via/by Savannah
  http://savannah.gnu.org/