Java Square Calculate squareRoot(Number num)

Description

Compute an approximate square root of num.

License

LGPL

Declaration

public static double squareRoot(Number num) 

Method Source Code

//package com.java2s;
//License from project: LGPL 

public class Main {
    /**// w w w  .ja v a2  s .co m
     * Compute an approximate square root of num.
     * 
     * @pre num > 1.0
     * @post the square of the result is within .01 of num.
     */
    public static double squareRoot(Number num) {
        double n = num.doubleValue();
        double lower = 1.0;
        double upper = n;
        while (upper - lower > 0.0001) {
            double mid = upper / 2.0 + lower / 2.0;
            if (mid * mid < n)
                lower = mid;
            else
                upper = mid;
        } // while
        return (upper + lower) / 2.0;
    }
}

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3. squareEntries(double[][] m)
4. squarenessRatio(final double w, final double h)
5. squareOfSumFirstN(long n)
6. squareSign(double value)
7. squareSum(double... doubles)