1 files changed, 95 insertions, 0 deletions
diff --git a/src/main/java/org/apache/commons/math3/optimization/AbstractConvergenceChecker.java b/src/main/java/org/apache/commons/math3/optimization/AbstractConvergenceChecker.java
new file mode 100644
index 0000000..98248ce
--- /dev/null
+++ b/src/main/java/org/apache/commons/math3/optimization/AbstractConvergenceChecker.java
@@ -0,0 +1,95 @@
+/*
+ * 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.math3.optimization;
+
+import org.apache.commons.math3.util.Precision;
+
+/**
+ * Base class for all convergence checker implementations.
+ *
+ * @param <PAIR> Type of (point, value) pair.
+ * @deprecated As of 3.1 (to be removed in 4.0).
+ * @since 3.0
+ */
+@Deprecated
+public abstract class AbstractConvergenceChecker<PAIR> implements ConvergenceChecker<PAIR> {
+    /**
+     * Default relative threshold.
+     *
+     * @deprecated in 3.1 (to be removed in 4.0) because this value is too small to be useful as a
+     *     default (cf. MATH-798).
+     */
+    @Deprecated private static final double DEFAULT_RELATIVE_THRESHOLD = 100 * Precision.EPSILON;
+
+    /**
+     * Default absolute threshold.
+     *
+     * @deprecated in 3.1 (to be removed in 4.0) because this value is too small to be useful as a
+     *     default (cf. MATH-798).
+     */
+    @Deprecated private static final double DEFAULT_ABSOLUTE_THRESHOLD = 100 * Precision.SAFE_MIN;
+
+    /** Relative tolerance threshold. */
+    private final double relativeThreshold;
+
+    /** Absolute tolerance threshold. */
+    private final double absoluteThreshold;
+
+    /**
+     * Build an instance with default thresholds.
+     *
+     * @deprecated in 3.1 (to be removed in 4.0). Convergence thresholds are problem-dependent. As
+     *     this class is intended for users who want to set their own convergence criterion instead
+     *     of relying on an algorithm's default procedure, they should also set the thresholds
+     *     appropriately (cf. MATH-798).
+     */
+    @Deprecated
+    public AbstractConvergenceChecker() {
+        this.relativeThreshold = DEFAULT_RELATIVE_THRESHOLD;
+        this.absoluteThreshold = DEFAULT_ABSOLUTE_THRESHOLD;
+    }
+
+    /**
+     * Build an instance with a specified thresholds.
+     *
+     * @param relativeThreshold relative tolerance threshold
+     * @param absoluteThreshold absolute tolerance threshold
+     */
+    public AbstractConvergenceChecker(
+            final double relativeThreshold, final double absoluteThreshold) {
+        this.relativeThreshold = relativeThreshold;
+        this.absoluteThreshold = absoluteThreshold;
+    }
+
+    /**
+     * @return the relative threshold.
+     */
+    public double getRelativeThreshold() {
+        return relativeThreshold;
+    }
+
+    /**
+     * @return the absolute threshold.
+     */
+    public double getAbsoluteThreshold() {
+        return absoluteThreshold;
+    }
+
+    /** {@inheritDoc} */
+    public abstract boolean converged(int iteration, PAIR previous, PAIR current);
+}