simple test passed

geval.cabal

@@ -39,6 +39,7 @@ test-suite geval-test
   build-depends:       base
                      , geval
                      , hspec
+                     , HUnit
   ghc-options:         -threaded -rtsopts -with-rtsopts=-N
   default-language:    Haskell2010
 

src/Lib.hs

@@ -10,16 +10,35 @@ import Control.Monad.Trans.Resource
 import qualified Data.Conduit.List as CL
 import Data.Text
 import Data.Text.Read as TR
+import Control.Applicative
 
 geval :: String -> String -> IO (Double)
 geval expectedFilePath outFilePath = do
-  runResourceT $
-    CB.sourceFile expectedFilePath
-    $$ CT.decode CT.utf8
+  mse <- runResourceT $
+    (getZipSource $ (,)
+       <$> ZipSource (items expectedFilePath)
+       <*> ZipSource (items outFilePath))
+     $$ (CL.map itemError
+         =$ averageC)
+  return $ mse ** 0.5
+
+averageC :: MonadResource m => Sink Double m Double
+averageC = getZipSink
+    $ (\total count -> total / fromIntegral count)
+  <$> ZipSink CC.sum
+  <*> ZipSink CC.length
+
+items :: MonadResource m => String -> Source m Double
+items filePath =
+  CB.sourceFile filePath
+  $= (CT.decode CT.utf8
       =$= CT.lines
       =$= CL.map TR.double
-    =$= CC.map getValue
-    =$ CC.sum
+      =$= CC.map getValue)
+
+
+itemError :: (Double, Double) -> Double
+itemError (exp, out) = (exp-out)**2
 
 getValue :: Either String (Double, Text) -> Double
 getValue (Right (x, _)) = x

test/Spec.hs

@@ -1,9 +1,25 @@
 import Test.Hspec
 
 import Lib
+import qualified Test.HUnit as HU
 
 main :: IO ()
 main = hspec $ do
   describe "mean square error" $ do
     it "simple test" $ do
-      geval "test/mse-simple/mse-simple/test-A/expected.tsv" "test/mse-simple/mse-simple-solution/test-A/out.tsv" `shouldReturn` 1.118033988749
+      geval "test/mse-simple/mse-simple/test-A/expected.tsv" "test/mse-simple/mse-simple-solution/test-A/out.tsv" `shouldReturnAlmost` 0.64549722436790
+
+class AEq a where
+    (=~) :: a -> a -> Bool
+
+instance AEq Double where
+    x =~ y = abs ( x - y ) < (1.0e-8 :: Double)
+
+(@=~?) :: (Show a, AEq a) => a -> a -> HU.Assertion
+(@=~?) expected actual  = expected =~ actual HU.@? assertionMsg
+    where
+      assertionMsg = "Expected : " ++ show expected ++
+                     "\nActual   : " ++ show actual
+
+shouldReturnAlmost :: (AEq a, Show a, Eq a) => IO a -> a -> Expectation
+shouldReturnAlmost action expected = action >>= (@=~? expected)

test/mse-simple/mse-simple-solution/test-A/out.tsv

@@ -0,0 +1,3 @@
+3.0
+3.0
+2.0

test/mse-simple/mse-simple/test-A/expected.tsv

@@ -0,0 +1,3 @@
+2.0
+3.0
+1.5