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 /**
20 * Marker class for RealVectors that require sparse backing storage
21 * <p>
22 * Caveat: Implementation are allowed to assume that, for any {@code x},
23 * the equality {@code x * 0d == 0d} holds. But it is is not true for
24 * {@code NaN}. Moreover, zero entries will lose their sign.
25 * Some operations (that involve {@code NaN} and/or infinities) may
26 * thus give incorrect results, like multiplications, divisions or
27 * functions mapping.
28 * </p>
29 * @since 2.0
30 */
31 public abstract class SparseRealVector extends RealVector {}