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diff --git a/src/main/java/org/apache/commons/math/exception/NonMonotonousSequenceException.java b/src/main/java/org/apache/commons/math/exception/NonMonotonousSequenceException.java
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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.commons.math.exception;
+
+import org.apache.commons.math.util.MathUtils;
+import org.apache.commons.math.exception.util.LocalizedFormats;
+
+/**
+ * Exception to be thrown when the a sequence of values is not monotonously
+ * increasing or decreasing.
+ *
+ * @since 2.2
+ * @version $Revision$ $Date$
+ */
+public class NonMonotonousSequenceException extends MathIllegalNumberException {
+
+    /** Serializable version Id. */
+    private static final long serialVersionUID = 3596849179428944575L;
+
+    /**
+     * Direction (positive for increasing, negative for decreasing).
+     */
+    private final MathUtils.OrderDirection direction;
+    /**
+     * Whether the sequence must be strictly increasing or decreasing.
+     */
+    private final boolean strict;
+    /**
+     * Index of the wrong value.
+     */
+    private final int index;
+    /**
+     * Previous value.
+     */
+    private final Number previous;
+
+    /**
+     * Construct the exception.
+     * This constructor uses default values assuming that the sequence should
+     * have been strictly increasing.
+     *
+     * @param wrong Value that did not match the requirements.
+     * @param previous Previous value in the sequence.
+     * @param index Index of the value that did not match the requirements.
+     */
+    public NonMonotonousSequenceException(Number wrong,
+                                          Number previous,
+                                          int index) {
+        this(wrong, previous, index, MathUtils.OrderDirection.INCREASING, true);
+    }
+
+    /**
+     * Construct the exception.
+     *
+     * @param wrong Value that did not match the requirements.
+     * @param previous Previous value in the sequence.
+     * @param index Index of the value that did not match the requirements.
+     * @param direction Strictly positive for a sequence required to be
+     * increasing, negative (or zero) for a decreasing sequence.
+     * @param strict Whether the sequence must be strictly increasing or
+     * decreasing.
+     */
+    public NonMonotonousSequenceException(Number wrong,
+                                          Number previous,
+                                          int index,
+                                          MathUtils.OrderDirection direction,
+                                          boolean strict) {
+        super(direction == MathUtils.OrderDirection.INCREASING ?
+              (strict ?
+               LocalizedFormats.NOT_STRICTLY_INCREASING_SEQUENCE :
+               LocalizedFormats.NOT_INCREASING_SEQUENCE) :
+              (strict ?
+               LocalizedFormats.NOT_STRICTLY_DECREASING_SEQUENCE :
+               LocalizedFormats.NOT_DECREASING_SEQUENCE),
+              wrong, previous, index, index - 1);
+
+        this.direction = direction;
+        this.strict = strict;
+        this.index = index;
+        this.previous = previous;
+    }
+
+    /**
+     * @return the order direction.
+     **/
+    public MathUtils.OrderDirection getDirection() {
+        return direction;
+    }
+    /**
+     * @return {@code true} is the sequence should be strictly monotonous.
+     **/
+    public boolean getStrict() {
+        return strict;
+    }
+    /**
+     * Get the index of the wrong value.
+     *
+     * @return the current index.
+     */
+    public int getIndex() {
+        return index;
+    }
+    /**
+     * @return the previous value.
+     */
+    public Number getPrevious() {
+        return previous;
+    }
+}