/*
* 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.complex;
import org.apache.commons.math3.exception.MathIllegalArgumentException;
import org.apache.commons.math3.exception.util.LocalizedFormats;
/**
* Static implementations of common
* {@link org.apache.commons.math3.complex.Complex} utilities functions.
*
*/
public class ComplexUtils {
/**
* Default constructor.
*/
private ComplexUtils() {}
/**
* Creates a complex number from the given polar representation.
* <p>
* The value returned is <code>r·e<sup>i·theta</sup></code>,
* computed as <code>r·cos(theta) + r·sin(theta)i</code></p>
* <p>
* If either <code>r</code> or <code>theta</code> is NaN, or
* <code>theta</code> is infinite, {@link Complex#NaN} is returned.</p>
* <p>
* If <code>r</code> is infinite and <code>theta</code> 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, π/4) = INFINITY + INFINITY i
* polar2Complex(INFINITY, 0) = INFINITY + NaN i
* polar2Complex(INFINITY, -π/4) = INFINITY - INFINITY i
* polar2Complex(INFINITY, 5π/4) = -INFINITY - INFINITY i </code></pre></p>
*
* @param r the modulus of the complex number to create
* @param theta the argument of the complex number to create
* @return <code>r·e<sup>i·theta</sup></code>
* @throws MathIllegalArgumentException if {@code r} is negative.
* @since 1.1
*/
public static Complex polar2Complex(double r, double theta) throws MathIllegalArgumentException {
if (r < 0) {
throw new MathIllegalArgumentException(
LocalizedFormats.NEGATIVE_COMPLEX_MODULE, r);
}
return new Complex(r * Math.cos(theta), r * Math.sin(theta));
}
/**
* Convert an array of primitive doubles to an array of {@code Complex} objects.
*
* @param real Array of numbers to be converted to their {@code Complex}
* equivalent.
* @return an array of {@code Complex} objects.
*
* @since 3.1
*/
public static Complex[] convertToComplex(double[] real) {
final Complex c[] = new Complex[real.length];
for (int i = 0; i < real.length; i++) {
c[i] = new Complex(real[i], 0);
}
return c;
}
}