Custom Scatter Labels

[Ruby On Rails Version - Controller] app/controllers/scatterlabels_controller.rb

require("chartdirector")

class ScatterlabelsController < ApplicationController

    def index()
        @title = "Custom Scatter Labels"
        @ctrl_file = File.expand_path(__FILE__)
        @noOfCharts = 1
        render :template => "templates/chartview"
    end

    #
    # Render and deliver the chart
    #
    def getchart()
        # The XY points for the scatter chart
        dataX = [150, 400, 300, 1500, 800]
        dataY = [0.6, 8, 5.4, 2, 4]

        # The labels for the points
        labels = ["Nano\n100", "SpeedTron\n200 Lite", "SpeedTron\n200", "Marathon\nExtra",
            "Marathon\n2000"]

        # Create a XYChart object of size 450 x 400 pixels
        c = ChartDirector::XYChart.new(450, 400)

        # Set the plotarea at (55, 40) and of size 350 x 300 pixels, with a light grey border
        # (0xc0c0c0). Turn on both horizontal and vertical grid lines with light grey color
        # (0xc0c0c0)
        c.setPlotArea(55, 40, 350, 300, 0xffffff, -1, 0xc0c0c0, 0xc0c0c0, -1)

        # Add a title to the chart using 18pt Times Bold Itatic font.
        c.addTitle("Product Comparison Chart", "timesbi.ttf", 18)

        # Add a title to the y axis using 12pt Arial Bold Italic font
        c.yAxis().setTitle("Capacity (tons)", "arialbi.ttf", 12)

        # Add a title to the x axis using 12pt Arial Bold Italic font
        c.xAxis().setTitle("Range (miles)", "arialbi.ttf", 12)

        # Set the axes line width to 3 pixels
        c.xAxis().setWidth(3)
        c.yAxis().setWidth(3)

        # Add the data as a scatter chart layer, using a 15 pixel circle as the symbol
        layer = c.addScatterLayer(dataX, dataY, "", ChartDirector::GlassSphereShape, 15, 0xff3333,
            0xff3333)

        # Add labels to the chart as an extra field
        layer.addExtraField(labels)

        # Set the data label format to display the extra field
        layer.setDataLabelFormat("{field0}")

        # Use 8pt Arial Bold to display the labels
        textbox = layer.setDataLabelStyle("arialbd.ttf", 8)

        # Set the background to purple with a 1 pixel 3D border
        textbox.setBackground(0xcc99ff, ChartDirector::Transparent, 1)

        # Put the text box 4 pixels to the right of the data point
        textbox.setAlignment(ChartDirector::Left)
        textbox.setPos(4, 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.html.erb

<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/scatterlabels.rb

#!/usr/bin/env ruby
require("chartdirector")

# The XY points for the scatter chart
dataX = [150, 400, 300, 1500, 800]
dataY = [0.6, 8, 5.4, 2, 4]

# The labels for the points
labels = ["Nano\n100", "SpeedTron\n200 Lite", "SpeedTron\n200", "Marathon\nExtra", "Marathon\n2000"]

# Create a XYChart object of size 450 x 400 pixels
c = ChartDirector::XYChart.new(450, 400)

# Set the plotarea at (55, 40) and of size 350 x 300 pixels, with a light grey border (0xc0c0c0).
# Turn on both horizontal and vertical grid lines with light grey color (0xc0c0c0)
c.setPlotArea(55, 40, 350, 300, 0xffffff, -1, 0xc0c0c0, 0xc0c0c0, -1)

# Add a title to the chart using 18pt Times Bold Itatic font.
c.addTitle("Product Comparison Chart", "timesbi.ttf", 18)

# Add a title to the y axis using 12pt Arial Bold Italic font
c.yAxis().setTitle("Capacity (tons)", "arialbi.ttf", 12)

# Add a title to the x axis using 12pt Arial Bold Italic font
c.xAxis().setTitle("Range (miles)", "arialbi.ttf", 12)

# Set the axes line width to 3 pixels
c.xAxis().setWidth(3)
c.yAxis().setWidth(3)

# Add the data as a scatter chart layer, using a 15 pixel circle as the symbol
layer = c.addScatterLayer(dataX, dataY, "", ChartDirector::GlassSphereShape, 15, 0xff3333, 0xff3333)

# Add labels to the chart as an extra field
layer.addExtraField(labels)

# Set the data label format to display the extra field
layer.setDataLabelFormat("{field0}")

# Use 8pt Arial Bold to display the labels
textbox = layer.setDataLabelStyle("arialbd.ttf", 8)

# Set the background to purple with a 1 pixel 3D border
textbox.setBackground(0xcc99ff, ChartDirector::Transparent, 1)

# Put the text box 4 pixels to the right of the data point
textbox.setAlignment(ChartDirector::Left)
textbox.setPos(4, 0)

# Output the chart
c.makeChart("scatterlabels.png")