/*

 *     def stats(self,r):
        #returns the average, standard deviation, and min of a sequence
        tot = sum(r)
        ave = tot/len(r)
        sdsq = sum([(i-ave)**2 for i in r])
        s = list(r)
        s.sort()
        #median = s[len(s)//2]
        return ave, (sdsq/(len(r)-1 or 1))**.5

    def zscore(self,pop_mean,pop_std,raw_goid):
        return (raw_goid - pop_mean)/pop_std
 */

/**
 *
 * @author DTian
 */
public class Stats {

    /**
     *
     * @param data the double array
     * @return the stand deviation of the array
     */
    public static double getStdDev(double[] data) {
        double result = 0.0;
        double ave = getMean(data);
        for (double d : data) {
            result += Math.pow((d-ave), 2);
        }
        if (data.length>1) {
        	return Math.sqrt(result/(data.length-1));
        } else {
        	return Math.sqrt(result/1);
        }
    }

    /**
     *
     * @param data the double array
     * @return the mean of the double array.
     */
    public static double getMean(double[] data) {
        double result = 0.0;
        for (double d : data) {
            result += d;
        }
        return (result/data.length);
    }

    /**
     *
     * @param size  the size of ori cluster File
     * @return the mean of the double array.
     */
    public static double getMeanFromFunc(int size) {
        return ( -4.8616 + 71.1806/Math.pow(size, 0.33511));
    }

    /**
     *
     * @param size  the size of ori cluster File
     * @return the mean of the double array.
     */
    public static double getStdDevFromFunc(int size) {
        return ( -0.04943 + 56.634/Math.pow(size, 0.89384));
    }

    public static double getZscore(double popMean, double popStd, double rawGoid) {
      return (rawGoid - popMean)/popStd;
    }
}