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path: root/mllib/src/test/scala/org/apache/spark/ml/feature/StandardScalerSuite.scala
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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.spark.ml.feature


import org.apache.spark.SparkFunSuite
import org.apache.spark.mllib.linalg.{DenseVector, SparseVector, Vector, Vectors}
import org.apache.spark.mllib.util.MLlibTestSparkContext
import org.apache.spark.mllib.util.TestingUtils._
import org.apache.spark.sql.{DataFrame, Row, SQLContext}

class StandardScalerSuite extends SparkFunSuite with MLlibTestSparkContext{

  @transient var data: Array[Vector] = _
  @transient var resWithStd: Array[Vector] = _
  @transient var resWithMean: Array[Vector] = _
  @transient var resWithBoth: Array[Vector] = _

  override def beforeAll(): Unit = {
    super.beforeAll()

    data = Array(
      Vectors.dense(-2.0, 2.3, 0.0),
      Vectors.dense(0.0, -5.1, 1.0),
      Vectors.dense(1.7, -0.6, 3.3)
    )
    resWithMean = Array(
      Vectors.dense(-1.9, 3.433333333333, -1.433333333333),
      Vectors.dense(0.1, -3.966666666667, -0.433333333333),
      Vectors.dense(1.8, 0.533333333333, 1.866666666667)
    )
    resWithStd = Array(
      Vectors.dense(-1.079898494312, 0.616834091415, 0.0),
      Vectors.dense(0.0, -1.367762550529, 0.590968109266),
      Vectors.dense(0.917913720165, -0.160913241239, 1.950194760579)
    )
    resWithBoth = Array(
      Vectors.dense(-1.0259035695965, 0.920781324866, -0.8470542899497),
      Vectors.dense(0.0539949247156, -1.063815317078, -0.256086180682),
      Vectors.dense(0.9719086448809, 0.143033992212, 1.103140470631)
    )
  }

  def assertResult(dataframe: DataFrame): Unit = {
    dataframe.select("standarded_features", "expected").collect().foreach {
      case Row(vector1: Vector, vector2: Vector) =>
        assert(vector1 ~== vector2 absTol 1E-5,
          "The vector value is not correct after standardization.")
    }
  }

  test("Standardization with default parameter") {
    val df0 = sqlContext.createDataFrame(data.zip(resWithStd)).toDF("features", "expected")

    val standardscaler0 = new StandardScaler()
      .setInputCol("features")
      .setOutputCol("standarded_features")
      .fit(df0)

    assertResult(standardscaler0.transform(df0))
  }

  test("Standardization with setter") {
    val df1 = sqlContext.createDataFrame(data.zip(resWithBoth)).toDF("features", "expected")
    val df2 = sqlContext.createDataFrame(data.zip(resWithMean)).toDF("features", "expected")
    val df3 = sqlContext.createDataFrame(data.zip(data)).toDF("features", "expected")

    val standardscaler1 = new StandardScaler()
      .setInputCol("features")
      .setOutputCol("standarded_features")
      .setWithMean(true)
      .setWithStd(true)
      .fit(df1)

    val standardscaler2 = new StandardScaler()
      .setInputCol("features")
      .setOutputCol("standarded_features")
      .setWithMean(true)
      .setWithStd(false)
      .fit(df2)

    val standardscaler3 = new StandardScaler()
      .setInputCol("features")
      .setOutputCol("standarded_features")
      .setWithMean(false)
      .setWithStd(false)
      .fit(df3)

    assertResult(standardscaler1.transform(df1))
    assertResult(standardscaler2.transform(df2))
    assertResult(standardscaler3.transform(df3))
  }
}