[daip] IMEAN can't count above 16777216. pixels

[Andrea Petric]

Hi DAIP,
  IMEAN, run on a 1024x1024x63 cube, reports 16777216 pixels (1024x1024x16),
even with blc=trc=0.  I spoke with Eric about this, and he suspects it's
because AIPS is counting pixels into a floating point number, so BIG+1 is
the same as BIG.  

  Version TST, run on spectra, an Ultra 10.

> input imean
AIPS 1: IMEAN:  Task to print the mean, rms and extrema in an image
AIPS 1: Adverbs         Values            Comments
AIPS 1: ----------------------------------------------------------------
AIPS 1: DOHIST       -1                    True (1.0) do histogram plot.
AIPS 1:                                    = 2 => flux on x axis
AIPS 1: USERID        0                    User ID.  0=>current user
AIPS 1:                                      32000=>all users
AIPS 1: INNAME     'N1058 C+CS+D'          Image name (name)
AIPS 1: INCLASS    'ICLN 3'                Image name (class)
AIPS 1: INSEQ         1                    Image name (seq. #)
AIPS 1: INDISK        2                    Disk drive #
AIPS 1: BLC           0           0        Bottom left corner of image
AIPS 1:               1        *rest 0       0=>entire image
AIPS 1: TRC           0           0        Top right corner of image
AIPS 1:              16        *rest 0       0=>entire image
AIPS 1: NBOXES        0                    No. of ranges for histogram.
AIPS 1: PIXRANGE      0           0        Min and max range for hist.
AIPS 1: FUNCTYPE   '  '                    'LG' => do log10 plot of #
AIPS 1:                                    samples, else linear
AIPS 1: PIXAVG        0                    Estimate of mean noise value
AIPS 1: PIXSTD        0                    Estimate of true noise rms
AIPS 1:                                       < 0 => don't do one
AIPS 1:                                       = 0 => 2-passes to get
AIPS 1: DOCAT        -1                    Put true RMS in header
AIPS 1: LTYPE         3                    Type of labeling: 1 border,
AIPS 1:                                    2 no ticks, 3 - 6 standard,
AIPS 1:                                    7 - 10 only tick labels
AIPS 1:                                    <0 -> no date/time
AIPS 1: OUTFILE    *all ' '                Name of output log file,
AIPS 1:                                    No output to file if blank
AIPS 1: DOTV         -1                    > 0 Do plot on the TV, else
AIPS 1:                                    make a plot file
AIPS 1: GRCHAN        0                    Graphics channel 0 => 1.
>
> go imean
IMEAN1: Task IMEAN  (release of 31DEC99) begins
IMEAN1: Image= N1058 C+CS+D.ICLN 3.   1 2   xywind=    1    1 1024 1024
IMEAN1: Mean and rms found by fitting peak in histogram:
IMEAN1: Mean= 9.9846E-09 Rms= 5.0259E-04  **** from histogram
IMEAN1: Mean and rms found by including all data:
IMEAN1: Mean=-1.7756E-09 Rms= 5.0548E-04 JY/BEAM   over16777216. pixels
IMEAN1: Flux density = -2.0162E-03 Jy.   beam area =  14.78 pixels
IMEAN1: Minimum=-3.2558E-03 at 1023 1024   16    1
IMEAN1: Skypos: RA 02 37 30.983  DEC 37 41 44.31
IMEAN1: Skypos: 562.0 KM/S  IPOL
IMEAN1: Maximum= 3.6451E-03 at    3    3   16    1
IMEAN1: Skypos: RA 02 43 12.191  DEC 36 33 40.41
IMEAN1: Skypos: 562.0 KM/S  IPOL
IMEAN1: Appears to have ended successfully
IMEAN1: spectra      31DEC99 TST: Cpu=       7.0  Real=      23
 Note: IEEE floating-point exception traps enabled: 
    overflow;  division by zero;  invalid operation; 
 Nonstandard floating-point mode enabled 
 See the Numerical Computation Guide, ieee_handler(3M), ieee_sun(3M) 
>
> trc 0 0 17
> go imean
IMEAN1: Task IMEAN  (release of 31DEC99) begins
IMEAN1: Image= N1058 C+CS+D.ICLN 3.   1 2   xywind=    1    1 1024 1024
IMEAN1: Mean and rms found by fitting peak in histogram:
IMEAN1: Mean=-5.9727E-08 Rms= 5.0256E-04  **** from histogram
IMEAN1: Mean and rms found by including all data:
IMEAN1: Mean=-1.8725E-08 Rms= 5.2084E-04 JY/BEAM   over16777216. pixels
IMEAN1: Flux density = -2.1262E-02 Jy.   beam area =  14.78 pixels
IMEAN1: Minimum=-3.2558E-03 at 1023 1024   16    1
IMEAN1: Skypos: RA 02 37 30.983  DEC 37 41 44.31
IMEAN1: Skypos: 562.0 KM/S  IPOL
IMEAN1: Maximum= 3.6451E-03 at    3    3   16    1
IMEAN1: Skypos: RA 02 43 12.191  DEC 36 33 40.41
IMEAN1: Skypos: 562.0 KM/S  IPOL
IMEAN1: Appears to have ended successfully
IMEAN1: spectra      31DEC99 TST: Cpu=       6.7  Real=      15
 Note: IEEE floating-point exception traps enabled: 
    overflow;  division by zero;  invalid operation; 
 Nonstandard floating-point mode enabled 
 See the Numerical Computation Guide, ieee_handler(3M), ieee_sun(3M) 
>

Note that the number of pixels reported is the same whether I ask for
IMEAN to run on 16 or 17 channels.

Cheers,

      Andreea & Michael R.