From 26f2cbabc4c40b950cc17989ecaa2fbe097eed2e Mon Sep 17 00:00:00 2001
From: Arkadiusz Kondas <arkadiusz.kondas@gmail.com>
Date: Thu, 16 Jun 2016 10:26:29 +0200
Subject: [PATCH] fix Pipeline transformation

---
 src/Phpml/Pipeline.php       |  2 +-
 tests/Phpml/PipelineTest.php | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/src/Phpml/Pipeline.php b/src/Phpml/Pipeline.php
index 3f98f29..2c2d984 100644
--- a/src/Phpml/Pipeline.php
+++ b/src/Phpml/Pipeline.php
@@ -68,7 +68,7 @@ class Pipeline implements Estimator
     public function train(array $samples, array $targets)
     {
         foreach ($this->transformers as $transformer) {
-            $samples = $transformer->transform($samples);
+            $transformer->transform($samples);
         }
 
         $this->estimator->train($samples, $targets);
diff --git a/tests/Phpml/PipelineTest.php b/tests/Phpml/PipelineTest.php
index b00a60a..b1d5bf7 100644
--- a/tests/Phpml/PipelineTest.php
+++ b/tests/Phpml/PipelineTest.php
@@ -7,6 +7,9 @@ namespace tests;
 use Phpml\Classification\SVC;
 use Phpml\FeatureExtraction\TfIdfTransformer;
 use Phpml\Pipeline;
+use Phpml\Preprocessing\Imputer;
+use Phpml\Preprocessing\Normalizer;
+use Phpml\Preprocessing\Imputer\Strategy\MostFrequentStrategy;
 
 class PipelineTest extends \PHPUnit_Framework_TestCase
 {
@@ -22,4 +25,33 @@ class PipelineTest extends \PHPUnit_Framework_TestCase
         $this->assertEquals($transformers, $pipeline->getTransformers());
         $this->assertEquals($estimator, $pipeline->getEstimator());
     }
+
+    public function testPipelineWorkflow()
+    {
+        $transformers = [
+            new Imputer(null, new MostFrequentStrategy()),
+            new Normalizer(),
+        ];
+        $estimator = new SVC();
+
+        $samples = [
+            [1, -1, 2],
+            [2, 0, null],
+            [null, 1, -1],
+        ];
+
+        $targets = [
+            4,
+            1,
+            4
+        ];
+
+        $pipeline = new Pipeline($transformers, $estimator);
+        $pipeline->train($samples, $targets);
+
+        $predicted = $pipeline->predict([[0, 0, 0]]);
+
+        $this->assertEquals(4, $predicted[0]);
+    }
+
 }