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);
	}
}