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The Apache Commons Math project is a library of lightweight, self-contained mathematics and statistics components addressing the most common practical problems not immediately available in the Java programming language or commons-lang.
/*
* 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;
import org.apache.commons.math3.util.FastMath;
/**
* 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.
*
* The value returned is r·ei·theta,
* computed as r·cos(theta) + r·sin(theta)i
*
* If either r or theta is NaN, or
* theta is infinite, {@link Complex#NaN} is returned.
*
* If 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.
* Examples:
*
* 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
*
* @param r the modulus of the complex number to create
* @param theta the argument of the complex number to create
* @return r·ei·theta
* @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 * FastMath.cos(theta), r * FastMath.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;
}
}