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