;The function momentbadval uses the idl function moment to calculate the
;mean, variance, skewness and kurtosis of a vector excluding a selected badval.
;Use is as follows:
;                m=momentbadval(x,badval)
;Where
; input |             x = data vector
;       |        badval = value of points in data vector to exclude when
;                        calculating statistics
;
;output |             m = array of statistics
;       |                 m(0)=mean
;       |                 m(1)=variance
;       |                 m(2)=skewness
;       |                 m(3)=kurtosis
;
;Note: There must be at least 2 good values in the vector x or statistics
;      are not calculated and m is returned as an array of badvals.
;
;Written by BWBerger 8/99

function momentbadval,x,badval

r=where(x ne badval,c)

if c ge 2 then begin
   mom=moment(x(r))
endif else begin
   mom=[badval,badval,badval,badval]
endelse

return,mom
end