module EmpFile where

import Statistics

readPdf :: FilePath -> IO [Distribution]
readPdf f = do 
  cs <- lines `fmap` readFile f
  return (parsePdf ("file '"++f++"'") cs)  
  
parsePdf :: String -> [String] -> [Distribution]
parsePdf f cs = 
  let (_:fs:vss) = transpose (map words cs)
  in if (or $ zipWith (/=) [(0::Int)..] (map read fs))
     then error ("Flow index from "++f++" isn't [0..]!")
     else map (fromPdf 0 0.01 . map (P . read)) vss

transpose :: [[a]] -> [[a]]
transpose xs = let r0 = map head xs  
                   rest = map tail xs
               in if any null rest then [r0] else r0 : transpose rest

-- currently this only works for a single model
combine_models :: [Int -> Distribution] -> [Distribution] -> [Int -> Distribution]
combine_models [f] ds = [\i -> if i < length ds then ds!!i else f i]
combine_models _ _ = error "Can't combine multiple models"