ChartDirector Ver 4.1 (Ruby Edition)

Pie Chart with Legend




This example demonstrates how to add a legend box to a pie chart. It also demonstrates the use of alternative sector label format.

Source Code Listing

[Ruby On Rails Version - Controller] app/controllers/legendpie_controller.rb
require("chartdirector")

class LegendpieController < ApplicationController

    def index()
        @title = "Pie Chart with Legend"
        @ctrl_file = File.expand_path(__FILE__)
        @noOfCharts = 1
        render :template => "templates/chartview"
    end

    #
    # Render and deliver the chart
    #
    def getchart()
        # The data for the pie chart
        data = [25, 18, 15, 12, 8, 30, 35]

        # The labels for the pie chart
        labels = ["Labor", "Licenses", "Taxes", "Legal", "Insurance", "Facilities",
            "Production"]

        # Create a PieChart object of size 450 x 240 pixels
        c = ChartDirector::PieChart.new(450, 240)

        # Set the center of the pie at (150, 100) and the radius to 80 pixels
        c.setPieSize(150, 100, 80)

        # Add a title at the bottom of the chart using Arial Bold Italic font
        c.addTitle2(ChartDirector::Bottom, "Project Cost Breakdown", "arialbi.ttf")

        # Draw the pie in 3D
        c.set3D()

        # add a legend box where the top left corner is at (330, 40)
        c.addLegend(330, 40)

        # modify the label format for the sectors to $nnnK (pp.pp%)
        c.setLabelFormat("{label} ${value}K\n({percent}%)")

        # Set the pie data and the pie labels
        c.setData(data, labels)

        # Explode the 1st sector (index = 0)
        c.setExplode(0)

        # output the chart
        send_data(c.makeChart2(ChartDirector::PNG), :type => "image/png",
            :disposition => "inline")
    end

end

[Ruby On Rails Version - View] app/views/templates/chartview.rhtml
<html>
<body style="margin:5px 0px 0px 5px">

<!-- Title -->
<div style="font-size:18pt; font-family:verdana; font-weight:bold">
    <%= @title %>
</div>
<hr style="border:solid 1px #000080" />

<!-- Source Code Listing Link -->
<div style="font-size:9pt; font-family:verdana; margin-bottom:1.5em">
    <%= link_to "Source Code Listing", 
        :controller => "cddemo", :action => "viewsource",
        :ctrl_file => @ctrl_file, :view_file => File.expand_path(__FILE__) %>
</div>

<!-- Create one or more IMG tags to display the demo chart(s) -->
<% 0.upto(@noOfCharts - 1) do |i| %>
    <img src="<%= url_for(:action => "getchart", :img => i) %>">
<% end %>

</body>
</html>

[Command Line Version] rubydemo/legendpie.rb
#!/usr/bin/env ruby
require("chartdirector")

# The data for the pie chart
data = [25, 18, 15, 12, 8, 30, 35]

# The labels for the pie chart
labels = ["Labor", "Licenses", "Taxes", "Legal", "Insurance", "Facilities",
    "Production"]

# Create a PieChart object of size 450 x 240 pixels
c = ChartDirector::PieChart.new(450, 240)

# Set the center of the pie at (150, 100) and the radius to 80 pixels
c.setPieSize(150, 100, 80)

# Add a title at the bottom of the chart using Arial Bold Italic font
c.addTitle2(ChartDirector::Bottom, "Project Cost Breakdown", "arialbi.ttf")

# Draw the pie in 3D
c.set3D()

# add a legend box where the top left corner is at (330, 40)
c.addLegend(330, 40)

# modify the label format for the sectors to $nnnK (pp.pp%)
c.setLabelFormat("{label} ${value}K\n({percent}%)")

# Set the pie data and the pie labels
c.setData(data, labels)

# Explode the 1st sector (index = 0)
c.setExplode(0)

# output the chart
c.makeChart("legendpie.png")