Histogram.java Histogram.java Below is the syntax highlighted version of Histogram.java from §3.2 Creating Data Types. /******************************************************************************
* Compilation: javac Histogram.java
* Execution: java Histogram n trials
*
* 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).
*
* % java Histogram 50 1000000
*
******************************************************************************/
public class Histogram {
private final double[] freq; // freq[i] = # occurences of value i
private double max; // max frequency of any value
// Create a new histogram.
public Histogram(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(-1, max + 1); // to leave a little border
StdStats.plotBars(freq);
}
// See Program 2.2.6.
public static void main(String[] args) {
int n = Integer.parseInt(args[0]); // number of coins
int trials = Integer.parseInt(args[1]); // number of trials
// create the histogram
Histogram histogram = new Histogram(n+1);
for (int t = 0; t < trials; t++) {
histogram.addDataPoint(Bernoulli.binomial(n));
}
// display using standard draw
StdDraw.setCanvasSize(500, 100);
histogram.draw();
}
}
Copyright © 2000–2017, Robert Sedgewick and Kevin Wayne. Last updated: Fri Oct 20 14:12:12 EDT 2017.
