Log Scale Axis

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

require("chartdirector")

class LogaxisController < ApplicationController

    def index()
        @title = "Log Scale Axis"
        @ctrl_file = File.expand_path(__FILE__)
        @noOfCharts = 2
        render :template => "templates/chartview"
    end

    #
    # Render and deliver the chart
    #
    def getchart()
        # This script can draw different charts depending on the chartIndex
        chartIndex = (params["img"]).to_i

        # The data for the chart
        data = [100, 125, 260, 147, 67]
        labels = ["Mon", "Tue", "Wed", "Thu", "Fri"]

        # Create a XYChart object of size 200 x 180 pixels
        c = ChartDirector::XYChart.new(200, 180)

        # Set the plot area at (30, 10) and of size 140 x 130 pixels
        c.setPlotArea(30, 10, 140, 130)

        # Ise log scale axis if required
        if chartIndex == 1
            c.yAxis().setLogScale3()
        end

        # Set the labels on the x axis
        c.xAxis().setLabels(labels)

        # Add a color bar layer using the given data. Use a 1 pixel 3D border for the bars.
        c.addBarLayer3(data).setBorderColor(-1, 1)

        # 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/logaxis.rb

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

def createChart(chartIndex)

    # The data for the chart
    data = [100, 125, 260, 147, 67]
    labels = ["Mon", "Tue", "Wed", "Thu", "Fri"]

    # Create a XYChart object of size 200 x 180 pixels
    c = ChartDirector::XYChart.new(200, 180)

    # Set the plot area at (30, 10) and of size 140 x 130 pixels
    c.setPlotArea(30, 10, 140, 130)

    # Ise log scale axis if required
    if chartIndex == 1
        c.yAxis().setLogScale3()
    end

    # Set the labels on the x axis
    c.xAxis().setLabels(labels)

    # Add a color bar layer using the given data. Use a 1 pixel 3D border for the bars.
    c.addBarLayer3(data).setBorderColor(-1, 1)

    # Output the chart
    c.makeChart("logaxis%s.png" % chartIndex)
end

createChart(0)
createChart(1)