ChartDirector 6.0 (Ruby Edition)

Scatter Trend Chart




This example demonstrates linear regression trend line fitting together with scatter layers.

The chart in this example has 4 layers - 2 scatter layers created using XYChart.addScatterLayer to show the data points, and two trend layers created using XYChart.addTrendLayer2 for the two trend lines.

Source Code Listing

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

class ScattertrendController < ApplicationController

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

    #
    # Render and deliver the chart
    #
    def getchart()
        # The XY data of the first data series
        dataX0 = [50, 55, 37, 24, 42, 49, 63, 72, 83, 59]
        dataY0 = [3.6, 2.8, 2.5, 2.3, 3.8, 3.0, 3.8, 5.0, 6.0, 3.3]

        # The XY data of the second data series
        dataX1 = [50, 55, 37, 24, 42, 49, 63, 72, 83, 59]
        dataY1 = [1.6, 1.8, 0.8, 0.5, 1.3, 1.5, 2.3, 2.4, 2.9, 1.5]

        # Create a XYChart object of size 450 x 420 pixels
        c = ChartDirector::XYChart.new(450, 420)

        # Set the plotarea at (55, 65) and of size 350 x 300 pixels, with white background and a
        # light grey border (0xc0c0c0). Turn on both horizontal and vertical grid lines with light
        # grey color (0xc0c0c0)
        c.setPlotArea(55, 65, 350, 300, 0xffffff, -1, 0xc0c0c0, 0xc0c0c0, -1)

        # Add a legend box at (50, 30) (top of the chart) with horizontal layout. Use 12pt Times
        # Bold Italic font. Set the background and border color to Transparent.
        c.addLegend(50, 30, false, "timesbi.ttf", 12).setBackground(ChartDirector::Transparent)

        # Add a title to the chart using 18 point Times Bold Itatic font.
        c.addTitle("Server Performance", "timesbi.ttf", 18)

        # Add titles to the axes using 12pt Arial Bold Italic font
        c.yAxis().setTitle("Response Time (sec)", "arialbi.ttf", 12)
        c.xAxis().setTitle("Server Load (TPS)", "arialbi.ttf", 12)

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

        # Add a scatter layer using (dataX0, dataY0)
        c.addScatterLayer(dataX0, dataY0, "Server AAA", ChartDirector::DiamondSymbol, 11, 0x008000)

        # Add a trend line layer for (dataX0, dataY0)
        c.addTrendLayer2(dataX0, dataY0, 0x008000).setLineWidth(3)

        # Add a scatter layer for (dataX1, dataY1)
        c.addScatterLayer(dataX1, dataY1, "Server BBB", ChartDirector::TriangleSymbol, 9, 0x6666ff)

        # Add a trend line layer for (dataX1, dataY1)
        c.addTrendLayer2(dataX1, dataY1, 0x6666ff).setLineWidth(3)

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

# The XY data of the first data series
dataX0 = [50, 55, 37, 24, 42, 49, 63, 72, 83, 59]
dataY0 = [3.6, 2.8, 2.5, 2.3, 3.8, 3.0, 3.8, 5.0, 6.0, 3.3]

# The XY data of the second data series
dataX1 = [50, 55, 37, 24, 42, 49, 63, 72, 83, 59]
dataY1 = [1.6, 1.8, 0.8, 0.5, 1.3, 1.5, 2.3, 2.4, 2.9, 1.5]

# Create a XYChart object of size 450 x 420 pixels
c = ChartDirector::XYChart.new(450, 420)

# Set the plotarea at (55, 65) and of size 350 x 300 pixels, with white background and a light grey
# border (0xc0c0c0). Turn on both horizontal and vertical grid lines with light grey color
# (0xc0c0c0)
c.setPlotArea(55, 65, 350, 300, 0xffffff, -1, 0xc0c0c0, 0xc0c0c0, -1)

# Add a legend box at (50, 30) (top of the chart) with horizontal layout. Use 12pt Times Bold Italic
# font. Set the background and border color to Transparent.
c.addLegend(50, 30, false, "timesbi.ttf", 12).setBackground(ChartDirector::Transparent)

# Add a title to the chart using 18 point Times Bold Itatic font.
c.addTitle("Server Performance", "timesbi.ttf", 18)

# Add titles to the axes using 12pt Arial Bold Italic font
c.yAxis().setTitle("Response Time (sec)", "arialbi.ttf", 12)
c.xAxis().setTitle("Server Load (TPS)", "arialbi.ttf", 12)

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

# Add a scatter layer using (dataX0, dataY0)
c.addScatterLayer(dataX0, dataY0, "Server AAA", ChartDirector::DiamondSymbol, 11, 0x008000)

# Add a trend line layer for (dataX0, dataY0)
c.addTrendLayer2(dataX0, dataY0, 0x008000).setLineWidth(3)

# Add a scatter layer for (dataX1, dataY1)
c.addScatterLayer(dataX1, dataY1, "Server BBB", ChartDirector::TriangleSymbol, 9, 0x6666ff)

# Add a trend line layer for (dataX1, dataY1)
c.addTrendLayer2(dataX1, dataY1, 0x6666ff).setLineWidth(3)

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