[daip] Re: convolv

[Eric Greisen]

Farhad Zadeh writes:

 > I have an integer image (Xray flux image) and tried 

   What do you mean "integer" - there are no  integer format images in
aips - they are all floats.  It is not a power of 2 but that should
only slow things down.

 > convolving it with the paramters stated here. Unfortunately, 
 > covole seems to work but in fact the final image is all 
 > zeros. This is not the first time I have had this trouble. 
 > I know conv works on these integer images. What am doing wrong? 
 > Thanks in advance. 
 > Farhad
 > 
 > purcel> CONVL1: BMAJ=  3.0000 BMIN=  3.0000 BPA=   0.0/Output beam
 > purcel> CONVL1: CVBMAJ=  3.0000 CVBMIN=  3.0000 CVBPA=  90.0/Convl. beam
 > purcel> CONVL1: Appears to have ended successfully
 > purcel> CONVL1: purcell      31DEC01 TST: Cpu=      19.4  Real=     697
 > 
 > >getn 11
 > AIPS 1: Got(1)   disk= 1  user= 150   type=MA   MERGE15_IMG.SUBIM.1
 > >imh
 > AIPS 1: Image=Merged    (MA)         Filename=MERGE15_IMG .SUBIM .   1
 > AIPS 1: Telescope=CHANDRA            Receiver=ACIS
 > AIPS 1: Observer=Merged              User #=  150
 > AIPS 1: Observ. date=21-SEP-1999     Map date=14-SEP-2001
 > AIPS 1: Minimum= 0.00000000E+00      Maximum= 5.80000000E+01
 > AIPS 1: ----------------------------------------------------------------
 > AIPS 1: Type    Pixels   Coord value     at Pixel     Coord incr   Rotat
 > AIPS 1: RA---TAN  1339    17 46 19.736    -334.50      -0.492000    0.00
 > AIPS 1: DEC--TAN  1177   -28 52 20.466    1549.50       0.492000    0.00
 > AIPS 1: ----------------------------------------------------------------
 > AIPS 1: Coordinate equinox 2000.00
 > AIPS 1: Maximum version number of extension files of type HI is   1
 > AIPS 1: Maximum version number of extension files of type UK is   7
 > >getn 12;imh
 > AIPS 1: Got(1)   disk= 1  user= 150   type=MA   MERGE15_IMG.CONVL.1
 > AIPS 1: Image=Merged    (MA)         Filename=MERGE15_IMG .CONVL .   1
 > AIPS 1: Telescope=CHANDRA            Receiver=ACIS
 > AIPS 1: Observer=Merged              User #=  150
 > AIPS 1: Observ. date=21-SEP-1999     Map date=14-SEP-2001
 > AIPS 1: Minimum= 0.00000000E+00      Maximum= 0.00000000E+00
 > AIPS 1: ----------------------------------------------------------------
 > AIPS 1: Type    Pixels   Coord value     at Pixel     Coord incr   Rotat
 > AIPS 1: RA---TAN  1339    17 46 19.736    -334.50      -0.492000    0.00
 > AIPS 1: DEC--TAN  1177   -28 52 20.466    1549.50       0.492000    0.00
 > AIPS 1: ----------------------------------------------------------------
 > AIPS 1: Coordinate equinox 2000.00
 > AIPS 1: Map type=DIRTY               Number of iterations=       0
 > AIPS 1: Conv size=   3.00 X   3.00   Position angle=   0.00
 > AIPS 1: Maximum version number of extension files of type HI is   1

       This does not happen when I CONVL images of the size of yours
on either Solaris or Linux here.

 > >tget conv
 > >inp
 > AIPS 1: CONVL:  Task to convolve two images.
 > AIPS 1: Adverbs     Values                 Comments
 > AIPS 1: ----------------------------------------------------------------
 > AIPS 1:                                    Input image.
 > AIPS 1: INNAME     'MERGE15_IMG '             Image name (name)
 > AIPS 1: INCLASS    'SUBIM '                   Image name (class)
 > AIPS 1: INSEQ         1                       Image name (seq. #)
 > AIPS 1: INDISK        1                       Image disk drive #
 > AIPS 1: OPCODE     '    '                  Operation desired:
 > AIPS 1:                                       GAUS, IMAG, DCON, DGAU
 > AIPS 1: BLC        *all 0                  Bottom left corner
 > AIPS 1: TRC        *all 0                  Top right corner
 > AIPS 1:                                    Convolving image (IMAG, DGAU)
 > AIPS 1: IN2NAME    '            '             Image name (name)
 > AIPS 1: IN2CLASS   '      '                   Image name (class)
 > AIPS 1: IN2SEQ        0                       Image name (seq. #)
 > AIPS 1: IN2DISK       0                       Image disk drive #
 > AIPS 1:                                    Convolved image.
 > AIPS 1: OUTNAME    'MERGE15_IMG '             Image name (name)
 > AIPS 1: OUTCLASS   '      '                   Image name (class)
 > AIPS 1: OUTSEQ        0                       Image name (seq. #)
 > AIPS 1: OUTDISK       1                       Image disk drive #
 > AIPS 1: BMAJ          3                    FWHM(asec) maj. axis output.
 > AIPS 1:                                    beam - required except IMAG
 > AIPS 1: BMIN          3                    FWHM(asec) min. axis output
 > AIPS 1:                                    beam.
 > AIPS 1: BPA           0                    position angle
 > AIPS 1: FACTOR        0                    Unit conversion factor;
 > AIPS 1:                                    clip inv Gaussian level DCON

      I tried with FACTOR =0 and all was well.  But try setting it to
1.


I have no idea why your aips does bad things and ours does not.  I
sent some questions that are better answered with CELGAL to help us
try to figure out what is going on here.

Eric