Y-axis data in Histogram is not correct

[Ananthareddyn4]

i am trying to use Xchart for generating Histogram in java, i am using the below code

 Histogram histogram = new Histogram(myData, 3);
CategoryChart chart = new CategoryChartBuilder().width(800).height(600).title("Xchart Histogram").xAxisTitle("Mean").yAxisTitle("Count").build();
 chart.addSeries("histogram ", histogram.getxAxisData(), histogram.getyAxisData());

but the Y-axis data(that is, the frequency) is not the correct data(i am comparing wrt histogram chart generated in excel sheet using frequency formula)

[timmolter]

Please past a full working example class with a main method, and I'll take a look at it.

[Ananthareddyn4]

public static void main(String[] args) throws IOException {
		
		List<Double> myData = new ArrayList<>();
		myData.add(10.0);
		myData.add(20.0);
		myData.add(10.0);
		myData.add(30.0);
		myData.add(40.0);
		myData.add(20.0);
		myData.add(30.0);
		myData.add(10.0);
		myData.add(40.0);
		myData.add(50.0);
		myData.add(10.0);
		myData.add(10.0);
		
		int numBins = 3;
		 Histogram histogram = new Histogram(myData, numBins);
		 CategoryChart chart = new CategoryChartBuilder().width(800).height(600).title("Xchart Histogram").xAxisTitle("Mean").yAxisTitle("Count").build();
		  chart.getStyler().setAvailableSpaceFill(.96);
		  chart.getStyler().setOverlapped(false);
		  chart.addSeries("histogram ", histogram.getxAxisData(), histogram.getyAxisData());
		  BitmapEncoder.saveBitmap(chart, "\\MyHistogram", BitmapFormat.JPG);
		  
		  System.out.println("Bins :"+histogram.getxAxisData());//Bins :[16.666666666666668, 30.000000000000004, 43.333333333333336]
		  System.out.println("frequency :"+histogram.getyAxisData());//frequency :[7.0, 2.0, 3.0]

	}

in the above list frequency(16.6666) is only 5, but is 7 according to Xchart
frequency(30) is 4 while its 2 for Xchart
frequency(43.333) is 2 but its 3 for Xchart.

[timmolter]

In the 16.67 bin the range is from between 10 and 23.26. Looking at the data there are 7 that fall in this range: 5x10 and 2x20, which is 7 total. I think XChart is correct.

[Mr14huashao]

@timmolter
Results calculated on MATLAB:

[Mr14huashao]

@timmolter
The caculated yData is not wrong, this is not a bug.