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. You can also request the output to be a FITS file, i.e. a FITS image with a single line. See the -f or --fits option. OPTIONS -d or --dir x | y Collapse along the X or Y direction. Default is to col- lapse 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. -f or --fits Save the result to a FITS file containing a single line, instead of an ASCII file. This is useful as input if you want to 'uncollapse' the image. -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 values before applying a median collapse. Default for these rejection parameters is zero. -u or --uncollapse width This option actually performs a "reverse" collapse and will create a 2d image from a single line or column. This is useful to subtract out from the initial image some row or column-specific defects. With this option, the input file must be a FITS file, which means that you should have used the -f or --fits option previously to save the collapsed image to a one-row or one-column FITS image. The specified width indicates the size you want to give to this new image, in the newly created direction. This option is incompatible with all others. 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