26 Mar
2009
26 Mar
'09
2:09 p.m.
On Thu, Mar 26, 2009 at 09:19:18AM -0700, Michael Mossey wrote:
myAvg' :: Int -> [Int] -> [ Double ] -> Double myAvg' sum count [] = sum / fromIntegral count myAvg' sum count (x:xs) = myAvg' (x + sum) (n + 1) xs
The definition of myAvg' looks fine, but I think you have the wrong type signature there.
myAvg :: [Double] -> Double myAvg xs = myAvg' 0 0 xs
You could also do it without accumulating parameters, like this: myAvg xs = sum / count where (sum, count) = sumCount xs sumCount :: [Double] -> (Double, Int) sumCount [] = (0,0) sumCount (x:xs) = (s+x, c+1) where (s,c) = sumCount xs -Brent