Commons Math example source code file (ComplexUtils.java)

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Java - Commons Math tags/keywords

complex, complex, complexutils, complexutils

The Commons Math ComplexUtils.java source code

/*
 * 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.complex;

import org.apache.commons.math.MathRuntimeException;

/**
 * Static implementations of common
 * {@link org.apache.commons.math.complex.Complex} utilities functions.
 *
 * @version $Revision: 811685 $ $Date: 2009-09-05 13:36:48 -0400 (Sat, 05 Sep 2009) $
 */
public class ComplexUtils {

    /**
     * Default constructor.
     */
    private ComplexUtils() {
        super();
    }

    /**
     * Creates a complex number from the given polar representation.
     * <p>
     * The value returned is <code>r·ei·theta,
     * computed as <code>r·cos(theta) + r·sin(theta)i

     * <p>
     * If either <code>r or theta is NaN, or
     * <code>theta is infinite, {@link Complex#NaN} is returned.

     * <p>
     * If <code>r is infinite and theta is finite,
     * infinite or NaN values may be returned in parts of the result, following
     * the rules for double arithmetic.<pre>
     * Examples:
     * <code>
     * polar2Complex(INFINITY, ?/4) = INFINITY + INFINITY i
     * polar2Complex(INFINITY, 0) = INFINITY + NaN i
     * polar2Complex(INFINITY, -?/4) = INFINITY - INFINITY i
     * polar2Complex(INFINITY, 5?/4) = -INFINITY - INFINITY i </code>

* * @param r the modulus of the complex number to create * @param theta the argument of the complex number to create * @return <code>r·e^i·theta * @throws IllegalArgumentException if r is negative * @since 1.1 */ public static Complex polar2Complex(double r, double theta) { if (r < 0) { throw MathRuntimeException.createIllegalArgumentException( "negative complex module {0}", r); } return new Complex(r * Math.cos(theta), r * Math.sin(theta)); } }