NAME
     average - cube averaging

SYNOPSIS
     average [options] [parameters]

DESCRIPTION
     average reduces a FITS cube over  its  third  dimension,  by
     applying one of several possible algorithms described below.
     Users should specify a cut and a method. The  cut  describes
     how  planes in the input cube are grouped for averaging, the
     method specifies what kind of average is applied.

PARAMETERS
     -i <incube> or --in <incube>
          Specifies the name of the input cube (mandatory).

     -o <outcube> or --out <outcube>
          Specifies the  name  of  the  output  cube  (optional).
          Default output name for an input cube named incube.fits
          is incube.avg.fits.

OPTIONS
     Cuts

     Cuts specify how to group the  input  planes  to  apply  the
     average. Default cut is --cut whole.

     --cut whole
          applies the average on the whole cube, i.e. all  planes
          are averaged to a single one according to the requested
          method.

     --cut cycle --step <n>
          applies the average for every <n> planes in  the  input
          cube. For example, if the input cube contains 50 planes
          and this cut is specified with n=10, the planes will be
          averaged  10  by  10 to produce one cube in output con-
          taining 5 planes.

     --cut running --halfwidth <h>
          Performs a running average: the output is a  cube  con-
          taining as many planes as the input cube. Each plane is
          the result of an average over an interval  centered  on
          the  same plane in the input, plus or minus <h> planes.
          This means that central planes will be the  average  of
          2h+1  input  planes, and edge planes will be an average
          of between h+1 and 2h+1 input planes.

     Example: the input cube has 6  planes,  h=2.  Brackets  show
     where the central plane is at each iteration.
     plane 1 is built from [1] 2  3
     plane 2 is built from  1 [2] 3  4
     plane 3 is built from  1  2 [3] 4  5
     plane 4 is built from     2  3 [4] 5  6
     plane 5 is built from        3  4 [5] 6
     plane 6 is built from           4  5 [6]

     Methods

     Methods specify how  to  perform  the  average.  Default  is
     linear.

     --method linear
          Performs a normal, linear average of the input planes.

     --method sum
          Same as linear, but does not divide by  the  number  of
          averaged  planes  at the end. Useful for cubes which do
          not have much signal.

     --method median
          Median filtering along the z-axis.

     --method filtered
          with additional parameters --filt-low npix and  --filt-
          high npix.  This is actually an extension of the median
          average. A time line is extracted for each pixel  posi-
          tion  on  the  detector  (along  the  z-axis), and then
          sorted out. The median average would only keep the cen-
          tral  value,  whereas  this method requests two numbers
          specifying how  many  low  and  high  pixels  shall  be
          rejected before making an average.

FILES
     Input files shall all comply with FITS format.

BUGS
     It is not yet possible to combine a running filter cut  with
     a filtered average method.