removed unused Gershgorin circles class

Gershgorin circles are now handles (simply) inside the EigenDecomposition class

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/math/trunk@723363 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/commons/math/linear/GershgorinCirclesUnion.java

@@ -1,94 +0,0 @@
-/*
- * 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.linear;
-
-/** Class representing a union of Gershgorin circles.
- * <p>Gershgorin circles are bounding areas where eigenvalues must lie.
- * They are used as starting values for eigen decomposition algorithms.
- * In the real case, Gershgorin circles are simple intervals.</p>
- * @see EigenDecompositionImpl
- * @version $Revision$ $Date$
- * @since 2.0
- */
-class GershgorinCirclesUnion implements Comparable<GershgorinCirclesUnion> {
-
-    /** Lower bound of the interval. */
-    private double low;
-
-    /** Higher bound of the interval. */
-    private double high;
-
-    /** Create a simple Gershgorin circle.
-     * @param d diagonal element of the current row
-     * @param sum sum of the absolute values of the off-diagonal elements
-     * of the current row
-     */
-    public GershgorinCirclesUnion(final double d, final double sum) {
-        low  = d - sum;
-        high = d + sum;
-    }
-
-    /**
-     * Get the lower bound of the interval.
-     * @return lower bound of the interval
-     */
-    public double getLow() {
-        return low;
-    }
-
-    /**
-     * Get the higher bound of the interval.
-     * @return higher bound of the interval
-     */
-    public double getHigh() {
-        return high;
-    }
-
-    /**
-     * Check if a Gershgorin circles union intersects instance.
-     * @param other Gershgorin circles union to test against instance
-     * @return true if the other Gershgorin circles union intersects instance
-     */
-    public boolean intersects(final GershgorinCirclesUnion other) {
-        return (other.low <= this.high) && (other.high >= this.low);
-    }
-
-    /**
-     * Swallow another Gershgorin circles union.
-     * <p>Swallowing another Gershgorin circles union changes the
-     * instance such that it contains everything that was formerly in
-     * either circles union. It is mainly intended for circles unions
-     * that {@link #intersects(GershgorinCirclesUnion) intersect}
-     * each other beforehand.</p>
-     * @param other Gershgorin circles union to swallow
-     */
-    public void swallow(final GershgorinCirclesUnion other) {
-        low  = Math.min(low,  other.low);
-        high = Math.max(high, other.high);
-    }
-
-    /** Compare another Gershgorin circles union in interval start order.
-     * @param other Gershgorin circles union to compare to instance
-     * @return a negative, zero or positive value depending on the other
-     * union starting before, at same location or after instance
-     */
-    public int compareTo(GershgorinCirclesUnion other) {
-        return Double.compare(low, other.low);
-    }
-
-}