ChartDirector 6.0 (Ruby Edition)

Pareto Chart



This example demonstrates the pareto chart style.

A pareto chart is a bar chart with the data sorted in descending order, together with a line chart showing the same data in accumulated form. In the current example, the data is shown as both percentages and values on the two y-axes.

The chart in this example is composed of two layers - a BarLayer created using XYChart.addBarLayer, and a LineLayer created using XYChart.addLineLayer.

This example employs the ArrayMath utility class for computing the accumulated line, obtaining the scaling factor between the two y-axes, and re-scaling the line data as percentages.

The two y-axes are synchronized using Axis.syncAxis.

Source Code Listing

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

class ParetoController < ApplicationController

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

    #
    # Render and deliver the chart
    #
    def getchart()
        # The data for the chart
        data = [40, 15, 7, 5, 2]

        # The labels for the chart
        labels = ["Hard Disk", "PCB", "Printer", "CDROM", "Keyboard"]

        # In the pareto chart, the line data are just the accumulation of the raw data, scaled to a
        # range of 0 - 100%
        lineData = ChartDirector::ArrayMath.new(data)
        lineData.acc()
        scaleFactor = lineData.max() / 100
        if scaleFactor == 0
            # Avoid division by zero error for zero data
            scaleFactor = 1
        end
        lineData.div2(scaleFactor)

        # Create a XYChart object of size 480 x 300 pixels. Set background color to brushed silver,
        # with a grey (bbbbbb) border and 2 pixel 3D raised effect. Use rounded corners. Enable soft
        # drop shadow.
        c = ChartDirector::XYChart.new(400, 300, ChartDirector::brushedSilverColor(), 0xbbbbbb, 2)
        c.setRoundedFrame()
        c.setDropShadow()

        # Add a title to the chart using 15 points Arial Italic. Set top/bottom margins to 12
        # pixels.
        title = c.addTitle("Pareto Chart Demonstration", "ariali.ttf", 15)
        title.setMargin2(0, 0, 12, 12)

        # Tentatively set the plotarea at (50, 40). Set the width to 100 pixels less than the chart
        # width, and the height to 80 pixels less than the chart height. Use pale grey (f4f4f4)
        # background, transparent border, and dark grey (444444) dotted grid lines.
        c.setPlotArea(50, 40, c.getWidth() - 100, c.getHeight() - 80, 0xf4f4f4, -1,
            ChartDirector::Transparent, c.dashLineColor(0x444444, ChartDirector::DotLine))

        # Add a line layer for the pareto line
        lineLayer = c.addLineLayer2()

        # Add the pareto line using deep blue (0000ff) as the color, with circle symbols
        lineLayer.addDataSet(lineData.result(), 0x0000ff).setDataSymbol(ChartDirector::CircleShape,
            9, 0x0000ff, 0x0000ff)

        # Set the line width to 2 pixel
        lineLayer.setLineWidth(2)

        # Bind the line layer to the secondary (right) y-axis.
        lineLayer.setUseYAxis2()

        # Add a multi-color bar layer using the given data.
        barLayer = c.addBarLayer3(data)

        # Set soft lighting for the bars with light direction from the right
        barLayer.setBorderColor(ChartDirector::Transparent, ChartDirector::softLighting(
            ChartDirector::Right))

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

        # Set the secondary (right) y-axis scale as 0 - 100 with a tick every 20 units
        c.yAxis2().setLinearScale(0, 100, 20)

        # Set the format of the secondary (right) y-axis label to include a percentage sign
        c.yAxis2().setLabelFormat("{value}%")

        # Set the relationship between the two y-axes, which only differ by a scaling factor
        c.yAxis().syncAxis(c.yAxis2(), scaleFactor)

        # Set the format of the primary y-axis label foramt to show no decimal point
        c.yAxis().setLabelFormat("{value|0}")

        # Add a title to the primary y-axis
        c.yAxis().setTitle("Frequency")

        # Set all axes to transparent
        c.xAxis().setColors(ChartDirector::Transparent)
        c.yAxis().setColors(ChartDirector::Transparent)
        c.yAxis2().setColors(ChartDirector::Transparent)

        # Adjust the plot area size, such that the bounding box (inclusive of axes) is 10 pixels
        # from the left edge, just below the title, 10 pixels from the right edge, and 20 pixels
        # from the bottom edge.
        c.packPlotArea(10, title.getHeight(), c.getWidth() - 10, c.getHeight() - 20)

        # Output the chart
        send_data(c.makeChart2(ChartDirector::JPG), :type => "image/jpeg", :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/pareto.rb 
#!/usr/bin/env ruby
require("chartdirector")

# The data for the chart
data = [40, 15, 7, 5, 2]

# The labels for the chart
labels = ["Hard Disk", "PCB", "Printer", "CDROM", "Keyboard"]

# In the pareto chart, the line data are just the accumulation of the raw data, scaled to a range of
# 0 - 100%
lineData = ChartDirector::ArrayMath.new(data)
lineData.acc()
scaleFactor = lineData.max() / 100
if scaleFactor == 0
    # Avoid division by zero error for zero data
    scaleFactor = 1
end
lineData.div2(scaleFactor)

# Create a XYChart object of size 480 x 300 pixels. Set background color to brushed silver, with a
# grey (bbbbbb) border and 2 pixel 3D raised effect. Use rounded corners. Enable soft drop shadow.
c = ChartDirector::XYChart.new(400, 300, ChartDirector::brushedSilverColor(), 0xbbbbbb, 2)
c.setRoundedFrame()
c.setDropShadow()

# Add a title to the chart using 15 points Arial Italic. Set top/bottom margins to 12 pixels.
title = c.addTitle("Pareto Chart Demonstration", "ariali.ttf", 15)
title.setMargin2(0, 0, 12, 12)

# Tentatively set the plotarea at (50, 40). Set the width to 100 pixels less than the chart width,
# and the height to 80 pixels less than the chart height. Use pale grey (f4f4f4) background,
# transparent border, and dark grey (444444) dotted grid lines.
c.setPlotArea(50, 40, c.getWidth() - 100, c.getHeight() - 80, 0xf4f4f4, -1,
    ChartDirector::Transparent, c.dashLineColor(0x444444, ChartDirector::DotLine))

# Add a line layer for the pareto line
lineLayer = c.addLineLayer2()

# Add the pareto line using deep blue (0000ff) as the color, with circle symbols
lineLayer.addDataSet(lineData.result(), 0x0000ff).setDataSymbol(ChartDirector::CircleShape, 9,
    0x0000ff, 0x0000ff)

# Set the line width to 2 pixel
lineLayer.setLineWidth(2)

# Bind the line layer to the secondary (right) y-axis.
lineLayer.setUseYAxis2()

# Add a multi-color bar layer using the given data.
barLayer = c.addBarLayer3(data)

# Set soft lighting for the bars with light direction from the right
barLayer.setBorderColor(ChartDirector::Transparent, ChartDirector::softLighting(ChartDirector::Right
    ))

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

# Set the secondary (right) y-axis scale as 0 - 100 with a tick every 20 units
c.yAxis2().setLinearScale(0, 100, 20)

# Set the format of the secondary (right) y-axis label to include a percentage sign
c.yAxis2().setLabelFormat("{value}%")

# Set the relationship between the two y-axes, which only differ by a scaling factor
c.yAxis().syncAxis(c.yAxis2(), scaleFactor)

# Set the format of the primary y-axis label foramt to show no decimal point
c.yAxis().setLabelFormat("{value|0}")

# Add a title to the primary y-axis
c.yAxis().setTitle("Frequency")

# Set all axes to transparent
c.xAxis().setColors(ChartDirector::Transparent)
c.yAxis().setColors(ChartDirector::Transparent)
c.yAxis2().setColors(ChartDirector::Transparent)

# Adjust the plot area size, such that the bounding box (inclusive of axes) is 10 pixels from the
# left edge, just below the title, 10 pixels from the right edge, and 20 pixels from the bottom
# edge.
c.packPlotArea(10, title.getHeight(), c.getWidth() - 10, c.getHeight() - 20)

# Output the chart
c.makeChart("pareto.jpg")

© 2017 Advanced Software Engineering Limited. All rights reserved.