Java Number Power pow2(double x, int n)

Description

Alternate implementation of the power method.

License

Apache License

Declaration

public static double pow2(double x, int n) 

Method Source Code

//package com.java2s;
/*//www.  j  a  va2 s.c o m
 * Copyright  2005 PB Consult Inc.
 *
 *  Licensed 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.
 *
 */

public class Main {
    /**
     * Alternate implementation of the power method.
     **/
    public static double pow2(double x, int n) {
        if (x == 0 && n <= 0)
            throw new IllegalArgumentException("x is zero and n=" + n);
        else if (n == 0)
            return 1;
        else if (n > 0)
            return x * pow2(x, n - 1);
        else
            // x is nonzero, and n is negative.
            return 1 / pow2(x, -n);
    }
}

Related

1. pow10(int degree)
2. pow10(int n)
3. pow16(float a)
4. pow2(double base, double power)
5. pow2(double num)
6. pow2(final int a)
7. pow2(final int n)
8. pow2(final int x)
9. pow2(int c)