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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.apache.commons.math4.legacy.linear;
18  
19  import org.apache.commons.math4.legacy.exception.NumberIsTooLargeException;
20  import org.junit.Assert;
21  import org.junit.Test;
22  
23  public final class OpenMapRealMatrixTest {
24  
25      @Test(expected=NumberIsTooLargeException.class)
26      public void testMath679() {
27          new OpenMapRealMatrix(3, Integer.MAX_VALUE);
28      }
29  
30      @Test
31      public void testMath870() {
32          // Caveat: This implementation assumes that, for any {@code x},
33          // the equality {@code x * 0d == 0d} holds. But it is is not true for
34          // {@code NaN}. Moreover, zero entries will lose their sign.
35          // Some operations (that involve {@code NaN} and/or infinities) may
36          // thus give incorrect results.
37          OpenMapRealMatrix a = new OpenMapRealMatrix(3, 3);
38          OpenMapRealMatrix x = new OpenMapRealMatrix(3, 1);
39          x.setEntry(0, 0, Double.NaN);
40          x.setEntry(2, 0, Double.NEGATIVE_INFINITY);
41          OpenMapRealMatrix b = a.multiply(x);
42          for (int i = 0; i < b.getRowDimension(); ++i) {
43              for (int j = 0; j < b.getColumnDimension(); ++j) {
44                  // NaNs and infinities have disappeared, this is a limitation of our implementation
45                  Assert.assertEquals(0.0, b.getEntry(i, j), 1.0e-20);
46              }
47          }
48      }
49  }