@ Override public double getStdDev ( ) { // two-pass algorithm for variance, avoids numeric overflow if ( values . length <= 1 ) { return 0 ; } final double mean = getMean ( ) ; double variance = 0 ; for ( int i = 0 ; i < values . length ; i ++ ) { final double diff = values [ i ] - mean ; variance += normWeights [ i ] * diff * diff ; } return Math . sqrt ( variance ) ; }
Returns the weighted standard deviation of the values in the snapshot .