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JavaFX – Scatter Chart ”; Previous Next A scatterplot is a type of graph which uses values from two variables plotted in a Cartesian plane. It is usually used to find out the relationship between two variables. Following is a Scatter chart plotted between area and weight. Scatter Chart in JavaFX In JavaFX, a Scatter chart is represented by a class named ScatterChart. This class belongs to the package javafx.scene.chart. By instantiating this class, you can create a ScatterChart node in JavaFX. To generate an area chart in JavaFX, follow the steps given below. Step 1: Defining the Axis Define the X and Y axis of the area chart and set labels to them in start() method of Application class. In our example, X axis represents area and the Y axis represents weights. public class ClassName extends Application { @Override public void start(Stage primaryStage) throws Exception { //Defining the x axis NumberAxis xAxis = new NumberAxis(0, 12, 3); xAxis.setLabel(“Area”); //Defining the y axis NumberAxis yAxis = new NumberAxis(0, 16, 4); yAxis.setLabel(“Weight”); } } Step 2: Creating the Scatter Chart Create a line chart by instantiating the class named ScatterChart of the package javafx.scene.chart. To the constructor of this class, pass the objects representing the X and Y axis created in the previous step. //Creating the Scatter chart ScatterChart<String, Number> scatterChart = new ScatterChart(xAxis, yAxis); Step 3: Preparing the Data Instantiate the XYChart.Series class and add the data (a series of, x and y coordinates) to the Observable list of this class as follows − //Prepare XYChart.Series objects by setting data XYChart.Series series = new XYChart.Series(); series.getData().add(new XYChart.Data(8, 12)); series.getData().add(new XYChart.Data(4, 5.5)); series.getData().add(new XYChart.Data(11, 14)); series.getData().add(new XYChart.Data(4, 5)); series.getData().add(new XYChart.Data(3, 3.5)); series.getData().add(new XYChart.Data(6.5, 7)); Step 4: Add Data to the Scatter Chart Add the data series prepared in the previous step to the scatter chart as follows − //Setting the data to scatter chart scatterChart.getData().addAll(series); Step 5: Creating a Group Object In the start() method, create a group object by instantiating the class named Group. This belongs to the package javafx.scene. Pass the ScatterChart (node) object created in the previous step as a parameter to the constructor of the Group class. This should be done in order to add it to the group as follows − Group root = new Group(scatterChart); Step 6: Launching Application Lastly, follow the given steps below to launch the application properly − Firstly, instantiate the class named Scene by passing the Group object as a parameter value to its constructor. To this constructor, you can also pass dimensions of the application screen as optional parameters. Then, set the title to the stage using the setTitle() method of the Stage class. Now, a Scene object is added to the stage using the setScene() method of the class named Stage. Display the contents of the scene using the method named show(). Lastly, the application is launched with the help of the launch() method. Example The following table contains sample data plotted between area and weight. Area Weight 8 12 4 5.5 11 14 4 5 3 3.5 6.5 7 Following is a Java program which generates a scatter chart depicting the above data using JavaFX. Save this code in a file with the name ScatterChartExample.java. import javafx.application.Application; import static javafx.application.Application.launch; import javafx.scene.Group; import javafx.scene.Scene; import javafx.stage.Stage; import javafx.scene.chart.NumberAxis; import javafx.scene.chart.ScatterChart; import javafx.scene.chart.XYChart; public class ScatterChartExample extends Application { @Override public void start(Stage stage) { //Defining the axes NumberAxis xAxis = new NumberAxis(0, 12, 3); xAxis.setLabel(“Area”); NumberAxis yAxis = new NumberAxis(0, 16, 4); yAxis.setLabel(“Weight”); //Creating the Scatter chart ScatterChart<String, Number> scatterChart = new ScatterChart(xAxis, yAxis); //Prepare XYChart.Series objects by setting data XYChart.Series series = new XYChart.Series(); series.getData().add(new XYChart.Data(8, 12)); series.getData().add(new XYChart.Data(4, 5.5)); series.getData().add(new XYChart.Data(11, 14)); series.getData().add(new XYChart.Data(4, 5)); series.getData().add(new XYChart.Data(3, 3.5)); series.getData().add(new XYChart.Data(6.5, 7)); //Setting the data to scatter chart scatterChart.getData().addAll(series); //Creating a Group object Group root = new Group(scatterChart); //Creating a scene object Scene scene = new Scene(root, 600, 400); //Setting title to the Stage stage.setTitle(“Scatter Chart”); //Adding scene to the stage stage.setScene(scene); //Displaying the contents of the stage stage.show(); } public static void main(String args[]){ launch(args); } } Compile and execute the saved java file from the command prompt using the following commands. javac –module-path %PATH_TO_FX% –add-modules javafx.controls ScatterChartExample.java java –module-path %PATH_TO_FX% –add-modules javafx.controls ScatterChartExample Output On executing, the above program generates a JavaFX window displaying a scatter chart as shown below. Example The following table illustrates the number of electronic items that were in sold per month. Item Number of Sales (Per Month) Laptop 176 TV 30 Mobile 540 Smart Watch 250 MacBook 60 Following is a Java program which generates a scatter chart depicting the above data using JavaFX. Save this code in a file with the name ScatterChartSales.java. import javafx.application.Application; import static javafx.application.Application.launch; import javafx.scene.Group; import javafx.scene.Scene; import javafx.stage.Stage; import javafx.scene.chart.NumberAxis; import javafx.scene.chart.CategoryAxis; import javafx.scene.chart.ScatterChart; import javafx.scene.chart.XYChart; public class ScatterChartExample extends Application { @Override public void start(Stage stage) { //Defining the axes CategoryAxis xAxis = new CategoryAxis(); xAxis.setLabel(“Items”); NumberAxis yAxis = new NumberAxis(); yAxis.setLabel(“Sales (per month)”); //Creating the Scatter chart ScatterChart scatterChart = new ScatterChart(xAxis, yAxis); //Prepare XYChart.Series objects by setting data XYChart.Series series = new XYChart.Series(); series.setName(“Items sold per month”); series.getData().add(new XYChart.Data(“Laptop”, 176)); series.getData().add(new XYChart.Data(“TV”, 30)); series.getData().add(new XYChart.Data(“Mobile”, 540)); series.getData().add(new XYChart.Data(“Smart Watch”, 250)); series.getData().add(new XYChart.Data(“MacBook”, 60)); //Setting the data to scatter chart scatterChart.getData().addAll(series); //Creating a Group object Group root = new Group(scatterChart); //Creating a scene object Scene scene = new Scene(root, 600, 400); //Setting title to the Stage stage.setTitle(“Scatter Chart”); //Adding scene to the stage stage.setScene(scene); //Displaying the contents of the stage stage.show(); } public static void main(String args[]){ launch(args); } } Compile and execute the saved java file from the command prompt using the following commands. javac –module-path %PATH_TO_FX% –add-modules javafx.controls ScatterChartSales.java java –module-path %PATH_TO_FX% –add-modules javafx.controls ScatterChartSales Output On executing, the above program generates a JavaFX window displaying a scatter chart as shown below. 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