Java Variance variance(double... array)

Description

variance

License

Apache License

Declaration

static public double variance(double... array) 

Method Source Code

//package com.java2s;
/**/*w  w w . ja va 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 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. variance(double[] a)
2. variance(double[] a, int from, int to)
3. variance(double[] arr)
4. variance(double[] arr)