code: public void setStrategy( double median,
                               double standardDeviation,
                               int sigma ) {
          this.bucketingStrategy = new StandardDeviationBucketingStrategy(median, standardDeviation, sigma);
          this.bucketWidth = null;
      }
docs: Set the histogram to use the standard deviation to determine the bucket sizes.
  
  @param median
  @param standardDeviation
  @param sigma