pro medfil,arr,width,narr,mean,badval

;Modified 1/4/98 by BWBerger to change the initialization of narr from 
;all zeros to all -999. This repairs a likely situation where the zeros
;can't be weeded out later if they exist where a badval is (if narr is 
;all zeros, zeros remain where the indexes are not equal to g).


; applies a median filter of width WIDTH to an array ARR, then
; computes the mean MEAN, while avoid bad data denoted by BADVAL
; also returns median filtered array, NARR.

g=where(arr ne badval,n)
narr=fltarr(n_elements(arr))-999.
; the number of good data values must be greater than the width of
;   the filter in order to proceed.
if (n gt width) then begin
  narr(g)=median(arr(g),width)
  mean=total(narr(g))/n
endif else begin
  mean=badval
endelse

return
end