/*
    * 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.giraph.aggregators.matrix.sparse;
  
  import static org.junit.Assert.assertEquals;
  
  import org.apache.giraph.utils.WritableUtils;
  import org.junit.Test;
  
  public class TestDoubleSparseMatrix {
    private static double E = 0.0001f;
  
    @Test
    public void testVectorAdd() {
      // The default value should be 0
      DoubleSparseVector vec1 = new DoubleSparseVector();
      assertEquals(0.0, vec1.get(0), E);
  
      // Basic get/set
      vec1.set(0, 0.1);
      vec1.set(10, 1.4);
      assertEquals(0.1, vec1.get(0), E);
      assertEquals(0.0, vec1.get(5), E);
      assertEquals(1.4, vec1.get(10), E);
  
      // Add another vector
      DoubleSparseVector vec2 = new DoubleSparseVector();
      vec2.set(0, 0.5);
      vec2.set(5, 1.7);
  
      vec1.add(vec2);
      assertEquals(0.6, vec1.get(0), E);
      assertEquals(1.7, vec1.get(5), E);
      assertEquals(1.4, vec1.get(10), E);
      assertEquals(0.0, vec1.get(15), E);
    }
  
    @Test
    public void testVectorSerialize() throws Exception {
      int size = 100;
  
      // Serialize from
      DoubleSparseVector from = new DoubleSparseVector(size);
      from.set(0, 10.0);
      from.set(10, 5.0);
      from.set(12, 1.0);
      byte[] data = WritableUtils.writeToByteArray(from);
  
      // De-serialize to
      DoubleSparseVector to = new DoubleSparseVector();
      WritableUtils.readFieldsFromByteArray(data, to);
  
      // The vectors should be equal
      for (int i = 0; i < size; ++i) {
        assertEquals(from.get(i), to.get(i), E);
      }
    }
  }