Comments on: JRuby + JFreeChart = Sparklines

By: punk21

punk21 — Wed, 18 Jun 2008 04:22:31 +0000

Hey guys, Having problem while drawing Sparkline Charts then chk this out visifire an amazing charting component which is powered by silverlight offered under open source

By: slonkak

slonkak — Thu, 17 Apr 2008 18:40:02 +0000

Would you be so kind as to help our a Ruby/Java noob? Say I just created a default, blank rails app in my jRuby install. I have the jfreechart and jcommon JARs in my classpath. What all do I have to do to get your code to work and start producing charts. I don’t know Ruby (nor the MVC framework), I don’t know Java, and I most certainly don’t know how Java works with jRuby. I would like to learn, but since I learn by example, and most examples on the net are very incomplete, I’m having a hard time. Could you provide any assistance?

By: Keith

Keith — Thu, 12 Jul 2007 14:23:45 +0000

What's the actual error you're getting/can you post more of the code you're using? Hope this helps

By: mdweezer

mdweezer — Thu, 12 Jul 2007 12:28:26 +0000

Keith,

I appreciate the response, I kept getting “addValue” incorrect method errors… I’m building stacked bar charts with the data. I’m using data scraped from a database, I just used those values to figure out how to actually add data to the dataset. Not quite sure what I was doing wrong but I”ll see what I can do. Again, I appreciate it, thanks!

By: Keith

Keith — Wed, 11 Jul 2007 22:40:03 +0000

mdweezer: I haven't the foggiest idea what you're actually trying to do, but:

# Mostly inspired by http://left.subtree.org/2007/01/15/creating-sparklines-with-jfreechart/
# have JFreeChart in your classpath, obviously, as well as jcommon.jar
require 'java'

module Graph
  class Sparkline
    include_class 'java.io.File'
    include_class 'org.jfree.chart.ChartUtilities'
    include_class 'org.jfree.chart.JFreeChart'
    include_class 'org.jfree.data.category.DefaultCategoryDataset'
    include_class 'org.jfree.chart.ChartFactory'
    include_class 'org.jfree.chart.plot.PlotOrientation'

    def initialize(width=200, height=80, data=[])
      @width = width
      @height = height
      dataset = create_sample_data() if data.empty?
      @chart = create_chart(dataset)
    end

    def render_to_file(filename, format="png")
      javafile = java.io.File.new(filename)
      ChartUtilities.saveChartAsPNG(javafile, @chart, @width, @height)
    end

    private
    def create_sample_data
      dataset = DefaultCategoryDataset.new
      dataset.addValue(1, "Closed", "")
      dataset.addValue(1, "InVerfication", "")
      dataset.addValue(2, "Delivered", "")
      dataset.addValue(2, "On-hold", "")
      dataset.addValue(3, "In-work", "")
      dataset.addValue(3, "Rejected", "")
      dataset.addValue(3, "Duplicate", "")
      dataset.addValue(3, "Assigned", "")
      dataset.addValue(4, "Submitted", "")

      return dataset
    end

    def create_chart(dataset)
      chart = ChartFactory.createWaterfallChart("Phase","Name", "", dataset, PlotOrientation::VERTICAL, true, true, false)
      return chart    
    end
  end # class Sparkline  
end # class Graph

sp = Graph::Sparkline.new
puts "Rendering sparkline"
sp.render_to_file("sparkline.png")

By: mdweezer

mdweezer — Wed, 11 Jul 2007 17:58:34 +0000

Have you done anything with DefaultCategoryDatasets? I’m trying to build some stacked bar charts in JRuby and your code is excellent but I can’t seem to make things work with other types of datasets, grrrrr. But then again, my Ruby isn’t exactly sharp.

The following chunk of code is what I need to port over…

DefaultCategoryDataset result = new DefaultCategoryDataset();
result.addValue(0, “Closed”, “”);
result.addValue(0, “InVerfication”, “”);
result.addValue(0, “Delivered”, “”);
result.addValue(0, “On-hold”, “”);
result.addValue(0, “In-work”, “”);
result.addValue(0, “Rejected”, “”);
result.addValue(0, “Duplicate”, “”);
result.addValue(0, “Assigned”, “”);
result.addValue(0, “Submitted”, “”);