Java stddev stdev(double... array)

Description

stdev

License

Apache License

Declaration

static public double stdev(double... array) 

Method Source Code

//package com.java2s;
/**/*  ww  w .j ava  2  s . c  o m*/
 * Copyright 2015, Emory University
 * 
 * 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 {
    static public double stdev(double... array) {
        return Math.sqrt(variance(array));
    }

    static public double variance(double... array) {
        double avg = average(array), sum = 0;

        for (double d : array)
            sum += sq(d - avg);

        return sum / (array.length - 1);
    }

    static public double average(double... array) {
        double sum = 0;

        for (double d : array)
            sum += d;

        return sum / array.length;
    }

    static public long sq(long l) {
        return l * l;
    }

    static public double sq(double d) {
        return d * d;
    }

    static public float sq(float f) {
        return f * f;
    }
}

Related

1. stddev(Number[] array, boolean isSample)
2. stdDev(T[] array)
3. stdDeviation(int[] data)
4. stdev(Collection values)
5. stdev(Collection values)
6. stdev(double[] array)
7. stdev(final double... values)
8. stdev(long[] vals, long average)