; COVAR--Calculates the covariance between two arrays
; Linsey Marr, 1994

pro covar, array1, array2, result , badval

; Use good points only
g = where((array1 ne badval) and (array2 ne badval), count)
if (count gt 0) then begin
  result = total(array1(g) * array2(g)) / count
endif else begin
  result=badval
endelse

return
end