ChartDirector 6.0 (Ruby Edition)

X Zone Coloring




This example demonstrates using x zone colors - colors that change at certain x value thresholds.

In this example, a x zone colors are used as the color of the line, and as the fill color of the band surrounding the line.

The x zone color for the line is configured to change from solid blue color to a red dash line color upon reaching a certain x value threshold. The x zone color for the band is configured to change from semi-transparent blue to semi-transparent red upon reaching the same threshold.

X zone colors are created using Layer.xZoneColor. You can use a x zone color in any ChartDirector API that expects a color. For instance, you can use a x zone color as background color, fill color of data sets, line color, etc.

A single x zone color can support one threshold value and change between two colors. The two colors can be any colors, including another x zone color. You may create x zone colors with multiple thresholds by cascading multiple x zone colors this way.

Source Code Listing

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

class XzonecolorController < ApplicationController

    def index()
        @title = "X Zone Coloring"
        @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 = [50, 55, 47, 34, 42, 49, 63, 62, 73, 59, 56, 50, 64, 60, 67, 67, 58, 59, 73, 77, 84,
            82, 80, 84, 89]

        # The error data representing the error band around the data points
        errData = [5, 6, 5.1, 6.5, 6.6, 8, 5.4, 5.1, 4.6, 5.0, 5.2, 6.0, 4.9, 5.6, 4.8, 6.2, 7.4,
            7.1, 6.5, 9.6, 12.1, 15.3, 18.5, 20.9, 24.1]

        # The timestamps for the data
        labels = [Time.mktime(2001, 1, 1), Time.mktime(2001, 2, 1), Time.mktime(2001, 3, 1),
            Time.mktime(2001, 4, 1), Time.mktime(2001, 5, 1), Time.mktime(2001, 6, 1), Time.mktime(
            2001, 7, 1), Time.mktime(2001, 8, 1), Time.mktime(2001, 9, 1), Time.mktime(2001, 10, 1),
            Time.mktime(2001, 11, 1), Time.mktime(2001, 12, 1), Time.mktime(2002, 1, 1),
            Time.mktime(2002, 2, 1), Time.mktime(2002, 3, 1), Time.mktime(2002, 4, 1), Time.mktime(
            2002, 5, 1), Time.mktime(2002, 6, 1), Time.mktime(2002, 7, 1), Time.mktime(2002, 8, 1),
            Time.mktime(2002, 9, 1), Time.mktime(2002, 10, 1), Time.mktime(2002, 11, 1),
            Time.mktime(2002, 12, 1), Time.mktime(2003, 1, 1)]

        # Create a XYChart object of size 550 x 220 pixels
        c = ChartDirector::XYChart.new(550, 220)

        # Set the plot area at (50, 10) and of size 480 x 180 pixels. Enabled both vertical and
        # horizontal grids by setting their colors to light grey (cccccc)
        c.setPlotArea(50, 10, 480, 180).setGridColor(0xcccccc, 0xcccccc)

        # Add a legend box (50, 10) (top of plot area) using horizontal layout. Use 8pt Arial font.
        # Disable bounding box (set border to transparent).
        legendBox = c.addLegend(50, 10, false, "", 8)
        legendBox.setBackground(ChartDirector::Transparent)

        # Add keys to the legend box to explain the color zones
        legendBox.addKey("Historical", 0x9999ff)
        legendBox.addKey("Forecast", 0xff9966)

        # Add a title to the y axis.
        c.yAxis().setTitle("Energy Consumption")

        # Set the labels on the x axis
        c.xAxis().setLabels2(labels)

        # Set multi-style axis label formatting. Use Arial Bold font for yearly labels and display
        # them as "yyyy". Use default font for monthly labels and display them as "mmm". Replace
        # some labels with minor ticks to ensure the labels are at least 3 units apart.
        c.xAxis().setMultiFormat(ChartDirector::StartOfYearFilter(),
            "<*font=arialbd.ttf*>{value|yyyy}", ChartDirector::StartOfMonthFilter(), "{value|mmm}",
            3)

        # Add a line layer to the chart
        layer = c.addLineLayer2()

        # Create the color to draw the data line. The line is blue (0x333399) to the left of x = 18,
        # and become a red (0xd04040) dash line to the right of x = 18.
        lineColor = layer.xZoneColor(18, 0x333399, c.dashLineColor(0xd04040, ChartDirector::DashLine
            ))

        # Add the data line
        layer.addDataSet(data, lineColor)

        # Create the color to draw the err zone. The color is semi-transparent blue (0x809999ff) to
        # the left of x = 18, and become semi-transparent red (0x80ff9966) to the right of x = 18.
        errColor = layer.xZoneColor(18, 0x809999ff, 0x80ff9966)

        # Add the upper border of the err zone
        layer.addDataSet(ChartDirector::ArrayMath.new(data).add(errData).result(), errColor)

        # Add the lower border of the err zone
        layer.addDataSet(ChartDirector::ArrayMath.new(data).sub(errData).result(), errColor)

        # Set the default line width to 2 pixels
        layer.setLineWidth(2)

        # Color the region between the err zone lines
        c.addInterLineLayer(layer.getLine(1), layer.getLine(2), errColor)

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

# The data for the chart
data = [50, 55, 47, 34, 42, 49, 63, 62, 73, 59, 56, 50, 64, 60, 67, 67, 58, 59, 73, 77, 84, 82, 80,
    84, 89]

# The error data representing the error band around the data points
errData = [5, 6, 5.1, 6.5, 6.6, 8, 5.4, 5.1, 4.6, 5.0, 5.2, 6.0, 4.9, 5.6, 4.8, 6.2, 7.4, 7.1, 6.5,
    9.6, 12.1, 15.3, 18.5, 20.9, 24.1]

# The timestamps for the data
labels = [Time.mktime(2001, 1, 1), Time.mktime(2001, 2, 1), Time.mktime(2001, 3, 1), Time.mktime(
    2001, 4, 1), Time.mktime(2001, 5, 1), Time.mktime(2001, 6, 1), Time.mktime(2001, 7, 1),
    Time.mktime(2001, 8, 1), Time.mktime(2001, 9, 1), Time.mktime(2001, 10, 1), Time.mktime(2001,
    11, 1), Time.mktime(2001, 12, 1), Time.mktime(2002, 1, 1), Time.mktime(2002, 2, 1), Time.mktime(
    2002, 3, 1), Time.mktime(2002, 4, 1), Time.mktime(2002, 5, 1), Time.mktime(2002, 6, 1),
    Time.mktime(2002, 7, 1), Time.mktime(2002, 8, 1), Time.mktime(2002, 9, 1), Time.mktime(2002, 10,
    1), Time.mktime(2002, 11, 1), Time.mktime(2002, 12, 1), Time.mktime(2003, 1, 1)]

# Create a XYChart object of size 550 x 220 pixels
c = ChartDirector::XYChart.new(550, 220)

# Set the plot area at (50, 10) and of size 480 x 180 pixels. Enabled both vertical and horizontal
# grids by setting their colors to light grey (cccccc)
c.setPlotArea(50, 10, 480, 180).setGridColor(0xcccccc, 0xcccccc)

# Add a legend box (50, 10) (top of plot area) using horizontal layout. Use 8pt Arial font. Disable
# bounding box (set border to transparent).
legendBox = c.addLegend(50, 10, false, "", 8)
legendBox.setBackground(ChartDirector::Transparent)

# Add keys to the legend box to explain the color zones
legendBox.addKey("Historical", 0x9999ff)
legendBox.addKey("Forecast", 0xff9966)

# Add a title to the y axis.
c.yAxis().setTitle("Energy Consumption")

# Set the labels on the x axis
c.xAxis().setLabels2(labels)

# Set multi-style axis label formatting. Use Arial Bold font for yearly labels and display them as
# "yyyy". Use default font for monthly labels and display them as "mmm". Replace some labels with
# minor ticks to ensure the labels are at least 3 units apart.
c.xAxis().setMultiFormat(ChartDirector::StartOfYearFilter(), "<*font=arialbd.ttf*>{value|yyyy}",
    ChartDirector::StartOfMonthFilter(), "{value|mmm}", 3)

# Add a line layer to the chart
layer = c.addLineLayer2()

# Create the color to draw the data line. The line is blue (0x333399) to the left of x = 18, and
# become a red (0xd04040) dash line to the right of x = 18.
lineColor = layer.xZoneColor(18, 0x333399, c.dashLineColor(0xd04040, ChartDirector::DashLine))

# Add the data line
layer.addDataSet(data, lineColor)

# Create the color to draw the err zone. The color is semi-transparent blue (0x809999ff) to the left
# of x = 18, and become semi-transparent red (0x80ff9966) to the right of x = 18.
errColor = layer.xZoneColor(18, 0x809999ff, 0x80ff9966)

# Add the upper border of the err zone
layer.addDataSet(ChartDirector::ArrayMath.new(data).add(errData).result(), errColor)

# Add the lower border of the err zone
layer.addDataSet(ChartDirector::ArrayMath.new(data).sub(errData).result(), errColor)

# Set the default line width to 2 pixels
layer.setLineWidth(2)

# Color the region between the err zone lines
c.addInterLineLayer(layer.getLine(1), layer.getLine(2), errColor)

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