From a1439c219167eb697ed6b938873c208d75df5677 Mon Sep 17 00:00:00 2001
From: Xiangrui Meng <meng@databricks.com>
Date: Mon, 17 Mar 2014 10:23:06 -0700
Subject: [PATCH 1/2] faster construction of features with intercept

---
 .../spark/mllib/regression/GeneralizedLinearAlgorithm.scala   | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mllib/src/main/scala/org/apache/spark/mllib/regression/GeneralizedLinearAlgorithm.scala b/mllib/src/main/scala/org/apache/spark/mllib/regression/GeneralizedLinearAlgorithm.scala
index f98b0b536deaa..b9e4ab8dfca96 100644
--- a/mllib/src/main/scala/org/apache/spark/mllib/regression/GeneralizedLinearAlgorithm.scala
+++ b/mllib/src/main/scala/org/apache/spark/mllib/regression/GeneralizedLinearAlgorithm.scala
@@ -136,13 +136,13 @@ abstract class GeneralizedLinearAlgorithm[M <: GeneralizedLinearModel]
 
     // Add a extra variable consisting of all 1.0's for the intercept.
     val data = if (addIntercept) {
-      input.map(labeledPoint => (labeledPoint.label, Array(1.0, labeledPoint.features:_*)))
+      input.map(labeledPoint => (labeledPoint.label, labeledPoint.features.+:(1.0)))
     } else {
       input.map(labeledPoint => (labeledPoint.label, labeledPoint.features))
     }
 
     val initialWeightsWithIntercept = if (addIntercept) {
-      Array(1.0, initialWeights:_*)
+      initialWeights.+:(1.0)
     } else {
       initialWeights
     }

From b5cfc530143c71ed4ef6c1b761379e73a5416563 Mon Sep 17 00:00:00 2001
From: Xiangrui Meng <meng@databricks.com>
Date: Mon, 17 Mar 2014 11:13:01 -0700
Subject: [PATCH 2/2] set default weights to zeros

---
 .../spark/mllib/regression/GeneralizedLinearAlgorithm.scala   | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mllib/src/main/scala/org/apache/spark/mllib/regression/GeneralizedLinearAlgorithm.scala b/mllib/src/main/scala/org/apache/spark/mllib/regression/GeneralizedLinearAlgorithm.scala
index b9e4ab8dfca96..b9621530efa22 100644
--- a/mllib/src/main/scala/org/apache/spark/mllib/regression/GeneralizedLinearAlgorithm.scala
+++ b/mllib/src/main/scala/org/apache/spark/mllib/regression/GeneralizedLinearAlgorithm.scala
@@ -119,7 +119,7 @@ abstract class GeneralizedLinearAlgorithm[M <: GeneralizedLinearModel]
    */
   def run(input: RDD[LabeledPoint]) : M = {
     val nfeatures: Int = input.first().features.length
-    val initialWeights = Array.fill(nfeatures)(1.0)
+    val initialWeights = new Array[Double](nfeatures)
     run(input, initialWeights)
   }
 
@@ -134,7 +134,7 @@ abstract class GeneralizedLinearAlgorithm[M <: GeneralizedLinearModel]
       throw new SparkException("Input validation failed.")
     }
 
-    // Add a extra variable consisting of all 1.0's for the intercept.
+    // Prepend an extra variable consisting of all 1.0's for the intercept.
     val data = if (addIntercept) {
       input.map(labeledPoint => (labeledPoint.label, labeledPoint.features.+:(1.0)))
     } else {