Histogram

[Altug Altintas]

I developed a histogram graph by using Jfreechart. You can watch this graph from :

http://www.riskturk.com/chart/histogram.jpeg

As you see, i have got problem on X axis legend values (Category). Category values are like this (-1789, -1637). It seems long but there are no ways no cut this value

How can i solve this problem ? Any idea

Regards
Altug.

[Dave Gilbert]

Hi Altug,

If I was creating histograms, I would use the vertical XY bar chart:

ChartFactory.createVerticalXYBarChart(...)

For this you need your data accessible via the IntervalXYDataset. In this dataset, you can specify start and end x-values for each item in the series.

What is required is some utility methods to take a set of data and create an IntervalXYDataset with definable 'buckets' for the histogram.

Regards,

DG.

[Altug Altintas]

Hi Dave

I did what u said. i use vertical XY bar chart and i wrote a class which is impements IntervalXYDataset . Everything seems ok but if you look at Histogram graph :

http://www.riskturk.com/chart/histogram2.jpeg

The x values are in date/hour format.

My x axis values must be in number format like 236, 1234 or 1234.
I tried to use ValueAxis class to solve this problem but i doesn't effect anything.

How can i solve this ?

Regards
Altug.

[Altug Altintas]

I found the solution. The problem is in ChartFactory.createVerticalXYBarChart(...) method. It creates DateAxis obkject automatically. I changed it to NumberAxis object and then it was solved.


Regards
Altug.

[Dave Gilbert]

Hi Altug,

Glad you found it. I'm using the XY bar chart for price-volume charts, so that is why it uses a date axis by default. It is probably sensible to create another method createHistogram(...) in the ChartFactory class that sets the chart up with a number axis.

Regards,

DG

[Altug Altintas]

Thanks for your help Dave

By the way if you want, i try to write a generic Histogram chart

Regards
Altug.

[Dave Gilbert]

That would be great.

Regards,

DG