Histogram Chart Buckets


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Following is an example of a Histogram Chart with custom bucket size.

We have already seen the configurations used to draw a chart in Google Charts Configuration Syntax chapter. Now, let us see an example of a histogram chart with custom bucket size.

Configurations

We've used bucketSize configuration to change default bucket size of histogram chart.

options.setBucketSize(5);

Example

HelloWorld.java

package com.tutorialspoint.client;

import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.user.client.ui.RootPanel;

import com.googlecode.gwt.charts.client.ChartLoader;
import com.googlecode.gwt.charts.client.ChartPackage;
import com.googlecode.gwt.charts.client.DataTable;
import com.googlecode.gwt.charts.client.corechart.Histogram;
import com.googlecode.gwt.charts.client.corechart.HistogramOptions;
import com.googlecode.gwt.charts.client.options.Legend;
import com.googlecode.gwt.charts.client.options.LegendPosition;
import com.googlecode.gwt.charts.client.util.ChartHelper;

public class HelloWorld implements EntryPoint {
   private Histogram chart;

   private void initialize() {
      ChartLoader chartLoader = new ChartLoader(ChartPackage.CORECHART);
      chartLoader.loadApi(new Runnable() {
         public void run() {
            // Create and attach the chart
            chart = new Histogram();
            RootPanel.get().add(chart);
            draw();
         }
      });
   }
   private void draw() {
      // Prepare the data
      Object[][] data = new Object[][] { { "Student Roll No", "height" }, 
         {"1", 80},{"2", 55},{"3", 68},{"4", 80},{"5", 54},
         {"6", 70},{"7", 85},{"8", 78},{"9", 70},{"10", 58},
         {"11", 90},{"12", 65},{"13", 88},{"14", 82},{"15", 65},
         {"16", 86},{"17", 45},{"18", 62},{"19", 84},{"20", 75},
         {"21", 82},{"22", 75},{"23", 58},{"24", 70},{"25", 85}	
      };
      DataTable dataTable = ChartHelper.arrayToDataTable(data);
      
      // Set options
      HistogramOptions options = HistogramOptions.create();
      options.setTitle("Students height, in cm");
      options.setLegend(Legend.create(LegendPosition.NONE));
      options.setBucketSize(5);
      
      // Draw the chart
      chart.draw(dataTable,options);
      chart.setWidth("400px");
      chart.setHeight("400px");
   }
   public void onModuleLoad() {
      initialize();
   }
}

Result

Verify the result.

Histogram Chart Bucket Size
gwt_googlecharts_histogram_charts.htm
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