Java Mean Calculation calculateMeanSD(double[] d)

Description

Calculate the mean and standard deviation for an array.

License

Apache License

Parameter

Parameter	Description
d	The data to calculate for.

Return

A string that shows the mean and standard dev.

Declaration

public static String calculateMeanSD(double[] d) 

Method Source Code

//package com.java2s;
/*/*www . j ava 2  s  .c  o m*/
 * Artificial Intelligence for Humans
 * Volume 3: Deep Learning and Neural Networks
 * Java Version
 * http://www.aifh.org
 * http://www.jeffheaton.com
 *
 * Code repository:
 * https://github.com/jeffheaton/aifh
 *
 * Copyright 2014-2015 by Jeff Heaton
 *
 * 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.
 *
 * For more information on Heaton Research copyrights, licenses
 * and trademarks visit:
 * http://www.heatonresearch.com/copyright
 */

public class Main {
    /**
     * Calculate the mean and standard deviation for an array.
     * @param d The data to calculate for.
     * @return A string that shows the mean and standard dev.
     */
    public static String calculateMeanSD(double[] d) {
        double sum = 0;
        for (int i = 0; i < d.length; i++) {
            sum += d[i];
        }
        double mean = sum / d.length;
        for (int i = 0; i < d.length; i++) {
            sum += Math.pow(d[i] - mean, 2);
        }
        double sd = Math.sqrt(mean / d.length);

        StringBuilder result = new StringBuilder();
        result.append("[mean=");
        result.append(mean);
        result.append(",sd=");
        result.append(sd);
        result.append("]");
        return result.toString();
    }
}

Related

1. calculateMean(float[] data)
2. calculateMeanAndStandardDeviation(float[] data)
3. calculateMeanAndStandardDeviationIgnoreNegatives( float[] data)
4. calculateMeanAndStandardDeviationVectors( float[][] vectors)
5. calculateMeanLevel(float[] distribution, int mid, int oldMid, float difference)