
   fit (-q) x y (order) (-dy wt) (-clip sig N)

   perform a lease-square polynomial fit to the data defined 
   by vectors x and y.  the coefficients are placed in the variables
   $C0, $C1, ..., and the order is placed in $Cn.

   order: order of fit
   -q: quiets the fit (no output to window)
   -dy: take into account the error vector wt
   -clip: remove outliers beyond sig*sigma from the fit;
           perform N iterations of this

   See also: applyfit

