Bugs: dmcopy

Bugs

1. Rebinning an image with different values for the two axes causes the coordinate information to be lost

2. The BLANK header keyword that an older version of some FTOOLs (e.g. chimgtyp) write to the FITS file header causes problems for dmcopy.

3. The tool always copies the data in the primary image, even when "[opt all]" is not used.

4. Specifying a fixed number of output image bins (06 Mar 2007)

5. # DMCOPY (CIAO 4.1): Can't convert region filter using unequal scaling factors.
   Pixels outside region will not be set to null. (10 Oct 2007)

6. dmcopy cannot delete file when file and process group IDs differ (17 Jul 2009)

Bugs

1. Rebinning an image with different values for the two axes causes the coordinate information to be lost

   For example:

   unix% dmcopy acis.img"[bin x=::5,y=::6]" acis5x6.img
   

   Using the same value for both axes works correctly:

   unix% dmcopy acis.img"[bin (x,y)=::5]" acis5.img
   

2. The BLANK header keyword that an older version of some FTOOLs (e.g. chimgtyp) write to the FITS file header causes problems for dmcopy.

   Workarounds:

   1. Use a CIAO tool in place of the FTOOL that created the BLANK keyword, e.g. instead of chimgtyp, try

      unix% dmcopy input.fits"[opt type=i4,null=-9999]" output.fits 
      

      changing the opt type as appropriate.

   2. Delete the BLANK keyword before passing the file to dmcopy or any other CIAO tool.

3. The tool always copies the data in the primary image, even when "[opt all]" is not used.

   For example:

   unix% dmcopy acis.fits"[spectrum]" spectrum.fits
   unix% dmlist spectrum.fits blocks 
    
   --------------------------------------------------------------------------------
   Dataset: spectrum.fits
   --------------------------------------------------------------------------------
    
        Block Name                          Type         Dimensions
   --------------------------------------------------------------------------------
   Block    1: WMAP                           Image      Int2(1024x1024)
   Block    2: SPECTRUM                       Table         5 cols x 1024     rows
   ...
   

   Here we expected to only get the SPECTRUM block, not the as WMAP well.

   Workaround:

   There is an odd sort of workaround:

   unix% dmtcalc acis.fits spectrum2.fits expr="(1==1)"
   unix% dmlist spectrum2.fits blocks 
    
   --------------------------------------------------------------------------------
   Dataset: spectrum2.fits
   --------------------------------------------------------------------------------
    
        Block Name                          Type         Dimensions
   --------------------------------------------------------------------------------
   Block    1: PRIMARY                        Null        
   Block    2: SPECTRUM                       Table         5 cols x 1024     rows
   ...
   

4. Specifying a fixed number of output image bins (06 Mar 2007)

   The number of bins that dmcopy creates is different than the input specification:

   unix% dmcopy acis_evt2.fits"[bin x=3482:4708:#122,y=3406:4630:#122]" test.fits
   
   unix% dmlist test.fits blocks
   ....
   Block    1: EVENTS_IMAGE                   Image      Int2(123x122)
   ...
   

5. # DMCOPY (CIAO 4.1): Can't convert region filter using unequal scaling factors.
   Pixels outside region will not be set to null. (10 Oct 2007)

   This error is printed when the pixels in the input image are not square, e.g. if an exposure map is created with the binning xygrid="3175.0:4555.0:#690,3609.0:4983.0:#690" (1380x1374).

   Workaround:

   Rebin to make an image with square pixels.

6. dmcopy cannot delete file when file and process group IDs differ (17 Jul 2009)

   The DM first checks the file's world read/write permissions. If permissions are not read and write, then it checks the group permissions. However, the process group ID and the file group ID must be the same in order for it to check for read and write permission. When they are different, it moves on to check owner permissions.

   Workaround:

   Be sure that you are running dmcopy as the same group as the file to be overwritten.