/*
 *  Copyright 2006-2007 Columbia University.
 *
 *  This file is part of MEAPsoft.
 *
 *  MEAPsoft is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 *
 *  MEAPsoft is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with MEAPsoft; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 *  02110-1301 USA
 *
 *  See the file "COPYING" for the text of the license.
 */

package com.meapsoft;


/** A simple histogram class to count the frequency of
  * values of a parameter of interest.
 **/
public class BasicHist
{
  int [] bins;
  int numBins;
  int underflows;
  int overflows;

  double lo;
  double hi;
  double range;

  /** The constructor will create an array of a given
    * number of bins. The range of the histogram given 
    * by the upper and lower limt values. 
   **/
  public BasicHist (int numBins, double lo, double hi) {
    this.numBins = numBins;

    bins = new int[numBins];

    this.lo = lo;
    this.hi = hi;
    range = hi - lo;
  }

  /**
    * Add an entry to a bin.
    * Include if value is in the range
    * lo <= x < hi
   **/
  public void add(double x) {
    if( x >= hi) overflows++;
    else if( x < lo) underflows++;
    else {
      double val = x - lo;

      // Casting to int will round off to lower
      // integer value.
     int bin = (int)(numBins * (val/range) );

      // Increment the corresponding bin.
      bins[bin]++;
    }
  }

  /** Clear the histogram bins. **/
  public void clear() {
    for (int i=0; i < numBins; i++) {
        bins[i] = 0;
        overflows = 0;
        underflows= 0;
    }
  }

  /** Provide access to the bin values. **/
  public int getValue(int bin) {
    if (bin < 0)
        return underflows;
    else if( bin >= numBins)
        return overflows;
    else
        return bins[bin];
  }
}