From b058cd0095d442849f459515c0bfb7741bf1df6a Mon Sep 17 00:00:00 2001
From: Filip Gralinski <filipg@amu.edu.pl>
Date: Mon, 3 Apr 2017 10:07:58 +0200
Subject: [PATCH] implement softmax in LogLossHashed

---
 src/GEval/LogLossHashed.hs                    | 20 ++++++++++++++-----
 test/Spec.hs                                  |  2 ++
 .../test-A/out.tsv                            |  2 ++
 .../log-loss-hashed-not-normalized/config.txt |  1 +
 .../test-A/expected.tsv                       |  2 ++
 5 files changed, 22 insertions(+), 5 deletions(-)
 create mode 100644 test/log-loss-hashed-not-normalized/log-loss-hashed-not-normalized-solution/test-A/out.tsv
 create mode 100644 test/log-loss-hashed-not-normalized/log-loss-hashed-not-normalized/config.txt
 create mode 100644 test/log-loss-hashed-not-normalized/log-loss-hashed-not-normalized/test-A/expected.tsv

diff --git a/src/GEval/LogLossHashed.hs b/src/GEval/LogLossHashed.hs
index dd96573..3e092ab 100644
--- a/src/GEval/LogLossHashed.hs
+++ b/src/GEval/LogLossHashed.hs
@@ -30,11 +30,21 @@ murmurSeedValue = 0
 parseDistribution :: Word32 -> Word32 -> T.Text -> Either String HashedDistribution
 parseDistribution nbOfBits seed distroSpec =
   -- distribution spec is either...
-  if T.any (== ':') distroSpec
-   -- a space-separated list of words with their log probs
-   then parseDistributionFromWordList nbOfBits seed distroSpec
-   -- a direct list of 2^nbOfBits log probs
-   else parseDistributionFromLogProbList nbOfBits distroSpec
+  normalizeDistribution <$> if T.any (== ':') distroSpec
+                            -- a space-separated list of words with their log probs
+                            then parseDistributionFromWordList nbOfBits seed distroSpec
+                            -- a direct list of 2^nbOfBits log probs
+                            else parseDistributionFromLogProbList nbOfBits distroSpec
+
+normalizeDistribution :: HashedDistribution -> HashedDistribution
+normalizeDistribution distro =
+  -- we do softmax (if needed)
+  if probSum > 1.0 || probSum < (1.0 - epsilon)
+  then normalized
+  else distro
+  where probSum = V.foldl' (\s l -> (s + exp l)) 0.0 distro
+        normalized = V.map (\v -> log ((exp v) / probSum)) distro
+        epsilon = 0.00000001
 
 type DistroMonad s = ReaderT (VM.MVector s Double) (ST s)
 
diff --git a/test/Spec.hs b/test/Spec.hs
index 0b91148..b41722a 100644
--- a/test/Spec.hs
+++ b/test/Spec.hs
@@ -87,6 +87,8 @@ main = hspec $ do
   describe "LogLossHashed challenge" $ do
     it "simple example" $ do
       runGEvalTest "log-loss-hashed-simple" `shouldReturnAlmost` 2.398479083333333
+    it "example with unnormalized values" $ do
+      runGEvalTest "log-loss-hashed-not-normalized" `shouldReturnAlmost` 1.0468455186722887
   describe "reading options" $ do
     it "can get the metric" $ do
       extractMetric "bleu-complex" `shouldReturn` (Just BLEU)
diff --git a/test/log-loss-hashed-not-normalized/log-loss-hashed-not-normalized-solution/test-A/out.tsv b/test/log-loss-hashed-not-normalized/log-loss-hashed-not-normalized-solution/test-A/out.tsv
new file mode 100644
index 0000000..02c35e7
--- /dev/null
+++ b/test/log-loss-hashed-not-normalized/log-loss-hashed-not-normalized-solution/test-A/out.tsv
@@ -0,0 +1,2 @@
+tak:10 nie:8.9
+niebieski:0 żółty:1.5 czerwony:-0.5
diff --git a/test/log-loss-hashed-not-normalized/log-loss-hashed-not-normalized/config.txt b/test/log-loss-hashed-not-normalized/log-loss-hashed-not-normalized/config.txt
new file mode 100644
index 0000000..b5ace1e
--- /dev/null
+++ b/test/log-loss-hashed-not-normalized/log-loss-hashed-not-normalized/config.txt
@@ -0,0 +1 @@
+--metric LogLossHashed8
diff --git a/test/log-loss-hashed-not-normalized/log-loss-hashed-not-normalized/test-A/expected.tsv b/test/log-loss-hashed-not-normalized/log-loss-hashed-not-normalized/test-A/expected.tsv
new file mode 100644
index 0000000..70d9d14
--- /dev/null
+++ b/test/log-loss-hashed-not-normalized/log-loss-hashed-not-normalized/test-A/expected.tsv
@@ -0,0 +1,2 @@
+tak
+niebieski