Returns the probability density function of a double with mean 0 variance 1. - Java java.lang

Java examples for java.lang:Math Function

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Description

Returns the probability density function of a double with mean 0 variance 1.

Demo Code

/*/* www.  ja  v  a2s. c om*/
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//package com.java2s;

public class Main {
    /**
     * Returns the probability density function of a double with mean 0 variance
     * 1.
     * 
     * @param x
     *            A double value.
     * @return Returns the probability density function of a double with mean 0
     *         variance 1.
     */
    static public double pdf(double x) {
        double ans;
        ans = Math.exp(-(x * x) / 2.) / Math.sqrt(2 * Math.PI);

        return ans;
    }

    /**
     * Returns the probability density function of a double.
     * 
     * @param x
     *            A double value.
     * @param mean
     *            The mean of the gaussian distribution.
     * @param variance
     *            The variance of the gaussian distribution.
     * @return Returns the probability density function of a double.
     */
    static public double pdf(double x, double mean, double variance) {
        double ans;
        ans = Math.exp(-(x - mean) * (x - mean) / (2. * variance))
                / Math.sqrt(2 * Math.PI * variance);

        return ans;
    }
}

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