Java Program to Calculate Standard Deviation


In this program we are going to use an individual series using arrays to calculates the Standard Deviation.


 Program to Calculate Standard Deviation in Java


public class Main {

    

    public static double standard_deviation(double array1[])
    {
        double sum = 0.0, standard_Deviation = 0.0;
        int len = array1.length;

        for(double num : array1) {
            sum += num;
        }

        double mean = sum/len;

        for(double num: array1) {
            standard_Deviation += Math.pow(num - mean, 2);
        }

        return Math.sqrt(standard_Deviation/len);
    }

    static double calculate_variance(double array1[])
    {
        // Compute mean (average of elements)
        int len = array1.length;
        double sum = 0;
         
        for (int i = 0; i < len; i++)
            sum += array1[i];
        double mean = (double)sum/(double)len;
     
        // Compute sum squared differences with
        // mean.
        double square_Diff = 0;
        for (int i = 0; i < len; i++) 
            square_Diff += (array1[i] - mean) * (array1[i] - mean);
         
        return (double)square_Diff/len;
    }

      public static void main(String[] args) {
        double[] arr = { 30,35,36,40,41,42,55,60,61 };
        double Standard_Deviation = standard_deviation(arr);
        System.out.printf("Standard Deviation is = %.6f", Standard_Deviation);
        System.out.println();
        double variance =calculate_variance(arr);
        System.out.printf("Varience is = %.6f", variance);
    }

}

Output:-

Standard Deviation is = 147.322775
Varience is = 21704.000000

 

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