度数分布図をJavaFXで描画

ソースコード

package practice;

import java.util.ArrayList;
import java.util.List;
import java.util.Random;

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.chart.BarChart;
import javafx.scene.chart.CategoryAxis;
import javafx.scene.chart.NumberAxis;
import javafx.scene.chart.XYChart;
import javafx.scene.chart.XYChart.Series;
import javafx.stage.Stage;

public class Hello20160806 extends Application {

	// 系列ラベル
	private static final String[] seriesNames = {
		"A",
		"B",
		"C"
	};

    // 項目ラベル
    private static final String[] dataLabels = {
            " 0～ 9点",
            "10～19点",
            "20～29点",
            "30～39点",
            "40～49点",
            "50～59点",
            "60～69点",
            "70～79点",
            "80～89点",
            "90～99点",
            "   100点",
    };

    // 人数を格納した配列を返却
    private int[] getCounts() {

        // 点数をランダムで格納
        int[] points = new int[1000];
        Random random = new Random();
        for (int i = 0; i < points.length; i++) {
            points[i] = random.nextInt(101);
        }

        // 集計
        int[] counts = new int[11];
        for (int point : points) {
            counts[ point / 10 ] ++;
        }

        return counts;
    }

    @Override
	public void start(Stage primaryStage) throws Exception {


        // 系列を生成
        List<Series<Number, String>> seriesList = new ArrayList<XYChart.Series<Number,String>>();

        for (String seriesName : seriesNames) {

        	int[] counts = getCounts();

            Series<Number, String> series = new Series<Number, String>();
            series.setName(seriesName);
            for (int i = 0; i < dataLabels.length; i ++) {
            	series.getData().add(new XYChart.Data<>(counts[i], dataLabels[i]));
            }
            seriesList.add(series);

        }

        // 軸を作成
        NumberAxis numberAxis = new NumberAxis();
        numberAxis.setLabel("人数");
        CategoryAxis categoryAxis = new CategoryAxis();
        categoryAxis.setLabel("点数");

        // 棒グラフを生成
        BarChart<Number, String> bc = new BarChart<>(numberAxis, categoryAxis);
        bc.setBarGap(2);
        bc.setCategoryGap(4);
        bc.getData().addAll(seriesList);

        // Scene
        Scene scene  = new Scene(bc, 400, 400);

        // Stage
		primaryStage.setTitle("得点分布図");
		primaryStage.setScene(scene);
		primaryStage.show();

	}

	public static void main(String[] args) {
        launch(args);
    }

}