Documentation on zeeeta

Task: zeeeta
Purpose: Compute Zeeman parameter eta
Categories: profile analysis

        ZEEETA is a MIRIAD task to compute the Zeeman S/N parameter 
        eta = (dI/dnu)_rms / sigma

Key: in
        The input Stokes I image in vxy order. No default.

Key: out
        The output eta image, if blc,trc is not specified

Key: sigma
        r.m.s. noise of signal free I spectrum

Key: chan
        The channel range. Default is all channels.

Key: blc
        Specify the blc of the spatial window in pixels.  If unset,
        the whole image is done, with no spatial summing, and
        an output eta image made.  If blc and trc are set, then
        eta is computed for this window, and the results output to
        the terminal.

Key: trc
        Specify the trc of the spatial window in pixels

Key: der
        1 or 2 for one or two sided derivative.  If you would
        like to see a plot of the last derivative spectrum, include
        a `p' as well.  E.g., 2p or 1p

Key: aveop
        'a' to average spectra before computing eta. Only if blc,trc set