code: public Histogram newMaxDiffHistogram(int numBkts, int numPcts) {
  		Map<String, BucketBuilder> initBbs = new HashMap<String, BucketBuilder>();
  		for (String fld : schema.fields()) {
  			if (schema.type(fld).isNumeric()) {
  				initBbs.put(fld, new MaxDiffAreaBucketBuilder(frequencies(fld),
  						null));
  			} else
  				initBbs.put(fld, new MaxDiffFreqBucketBuilder(frequencies(fld),
  						numPcts));
  		}
  		return newMaxDiffHistogram(numBkts, initBbs);
  	}
docs: Constructs a histogram with the "MaxDiff(V, A)" buckets for numeric field
  values and "MaxDiff(V, F)" buckets for other types of field values
  respectively.
  
  @param numBkts
  the number of buckets to construct for each field
  @param numPcts
  the number of value percentiles in each bucket of the
  non-numeric fields
  @return a "MaxDiff(V, A/F)" histogram