Name
       collapse - collapse an image along X or Y

Synopsis
       collapse [options] <in> [out]

Description
       collapse  is  used  to  create  a  1D signal from an input
       image, collapsing pixels along the X or Y  direction.  The
       default  collapsing  method  is a simple sum of all pixels
       along lines or columns. A median collapse (-m  option)  is
       done  by  keeping only the median value for each processed
       line or column. A number of lowest/highest pixels  can  be
       rejected before the median is computed, see the -r option.

       The output is an ASCII file containing  two  columns.  The
       first  column  contains the X or Y pixel position, and the
       second column contains the  collapsed  value.  The  output
       file  name  is  either provided on the command-line as the
       last argument, or will be built as:
       If the input name is inputname.fits, the  output  name  is
       inputname_line.

Options
       -d or --dir x | y
              Collapse  along the X or Y direction. Default is to
              collapse along the Y direction, i.e. the output  is
              a  line  of  pixels, each pixel being computed as a
              collapse of the column it belongs to.

       -g or --gnuplot
              Activate a gnuplot output. This  option  will  only
              work  if gnuplot is installed for your user account
              and accessible from the command-line.

       -m or --median
              Collapse the image with  a  median  method,  rather
              than a simple sum.

       -r or --reject 'lo hi'
              Rejects the 'lo' lowest and 'hi' highest pixel val-
              ues before applying a median collapse. Default  for
              these rejection parameters is zero.

Examples
       Collapse  the  image  'im.fits'  along Y, with simple sum.
       Keep default output name 'im_line'.
       collapse im.fits

       Collapse the image 'im.fits' along X, with median collapse
       without rejection, keep default output name 'im_line':
       collapse -d x -m im.fits

       Collapse the image 'im.fits' along X, with median collapse
       rejecting the 80 low and 90 high pixels, naming the output
       'coll_line':
       collapse -d x -m -r '80 90' im.fits coll_line