Documentation on moment

Task: moment
Purpose: Calculate moments of a Miriad image.
Categories: image analysis

        MOMENT calculates the nth moment of a Miriad image. Currently only
        the moment of axis 1 or axis 3 is calculated for 3 dimensional images.
        To obtain the moments for other axes use the task REORDER to reorder
        the axes.

Key: in
        The input image. No default.

Key: region
        The region of the input image to be used. See documentation for region
        on how to specify this. Only the bounding box is supported.

Key: out
        The output image. No default.

Key: mom
       -1      Average intensity. (units are same as individual channels)
        0      Integrated intensity. (e.g. units Jy x km/s)
        1      1st moment = sum(I*v)/sum(I)
        2      dispersion = sqrt(sum(I*(v-M1)**2)/sum(I))
               The v(i) are the axis values (e.g. velocities).  M1 is the first
               moment. The moment is calculated independently for each pixel
               within the specified clip range. Default = 0.

Key: axis
        The axis for which the moment is calculated. Default = 3.

Key: clip
        Two values. Exclude pixels with values in the range clip(1) to clip(2).
        If only one value is given, then exclude -abs(clip) to abs(clip).