package stdlib;

/* ***********************************************************************
 *  This data type supports simple client code to create dynamic
 *  histograms of the frequency of occurrence of values in [0, N).
 *  The frequencies are kept in an instance-variable array, and
 *  an instance variable max tracks the maximum frequency (for scaling).
 *************************************************************************/

public class XHistogram {
  private final double[] freq;   // freq[i] = # occurences of value i
  private double max;            // max frequency of any value

  // Create a new histogram.
  public XHistogram(int N) {
    freq = new double[N];
  }

  // Add one occurrence of the value i.
  public void addDataPoint(int i) {
    freq[i]++;
    if (freq[i] > max) max = freq[i];
  }

  // draw (and scale) the histogram.
  public void draw() {
    StdDraw.setYscale(0, max);
    StdStats.plotBars(freq);
  }
}