Github user myui commented on a diff in the pull request:
https://github.com/apache/incubator-hivemall/pull/167#discussion_r226578495
--- Diff: core/src/main/java/hivemall/mf/CofactorModel.java ---
@@ -0,0 +1,715 @@
+/*
+ * 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 hivemall.mf;
+
+import hivemall.annotations.VisibleForTesting;
+import hivemall.fm.Feature;
+import hivemall.utils.lang.Preconditions;
+import hivemall.utils.math.MathUtils;
+import it.unimi.dsi.fastutil.objects.Object2DoubleArrayMap;
+import it.unimi.dsi.fastutil.objects.Object2DoubleMap;
+import org.apache.commons.math3.linear.ArrayRealVector;
+import org.apache.commons.math3.linear.Array2DRowRealMatrix;
+import org.apache.commons.math3.linear.RealMatrix;
+import org.apache.commons.math3.linear.RealVector;
+import org.apache.commons.math3.linear.SingularValueDecomposition;
+import org.apache.hadoop.hive.ql.metadata.HiveException;
+
+import javax.annotation.Nonnegative;
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Random;
+
+
+public class CofactorModel {
+
+ public enum RankInitScheme {
+ random /* default */, gaussian;
+
--- End diff --
please remove unnessesary line breaks.
---
