From b34a3340995e83a193a2b8aea5168acd9a1a29a4 Mon Sep 17 00:00:00 2001
From: Alex Zubiaga <a.zubiaga@controlexpert.com>
Date: Wed, 29 Mar 2017 15:00:44 +0200
Subject: [PATCH] capturing the training set in a closure to avoid retraining
 for each item

---
 .../MachineLearningInAction/NaiveBayes.fs     | 26 ++++++++++---------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/MachineLearningInAction/MachineLearningInAction/NaiveBayes.fs b/MachineLearningInAction/MachineLearningInAction/NaiveBayes.fs
index e9b1a94..8145a04 100644
--- a/MachineLearningInAction/MachineLearningInAction/NaiveBayes.fs
+++ b/MachineLearningInAction/MachineLearningInAction/NaiveBayes.fs
@@ -101,6 +101,7 @@ module NaiveBayes =
             label, 
             prop(total, size), 
             Map.map (fun token count -> prop(count, totTokens)) tokenCount)
+        |> Seq.toList
 
     // Classifier function:
     // the classifier is trained on the dataset,
@@ -112,16 +113,17 @@ module NaiveBayes =
     // and returning the highest scoring label.
     // Probabilities are log-transformed to avoid underflow.
     // See "Chapter4.fsx" for an illustration.
-    let classifier frequency dataset words text =
+    let classifier frequency dataset words =
         let estimator = train frequency dataset words
-        let tokenized = vocabulary text
-        estimator
-        |> Seq.map (fun (label, proba, tokens) ->
-            label,
-            tokens
-            |> Map.fold (fun p token value -> 
-                if Set.exists (fun w -> w = token) tokenized 
-                then p + log(value) 
-                else p) (log proba))
-        |> Seq.maxBy snd
-        |> fst
\ No newline at end of file
+        fun text ->
+            let tokenized = vocabulary text
+            estimator
+            |> Seq.map (fun (label, proba, tokens) ->
+                label,
+                tokens
+                |> Map.fold (fun p token value -> 
+                    if Set.exists (fun w -> w = token) tokenized 
+                    then p + log(value) 
+                    else p) (log proba))
+            |> Seq.maxBy snd
+            |> fst
\ No newline at end of file