require("chartdirector")
class ContourlegendController < ApplicationController
def index()
@title = "Contour Color Legend"
@ctrl_file = File.expand_path(__FILE__)
@noOfCharts = 1
render :template => "templates/chartview"
end
#
# Render and deliver the chart
#
def getchart()
# The x and y coordinates of the grid
dataX = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
dataY = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
# Use random numbers for the z values on the XY grid
r = ChartDirector::RanSeries.new(999)
dataZ = r.get2DSeries(dataX.length, dataY.length, -0.9, 1.15)
# Create a XYChart object of size 640 x 460 pixels
c = ChartDirector::XYChart.new(640, 460)
# Set the plotarea at (30, 25) and of size 400 x 400 pixels. Use semi-transparent grey
# (0xdd000000) horizontal and vertical grid lines
c.setPlotArea(50, 25, 400, 400, -1, -1, ChartDirector::Transparent, 0xdd000000, -1)
# Set the x and y axis stems to transparent and the label font to 12pt Arial
c.xAxis().setColors(ChartDirector::Transparent)
c.yAxis().setColors(ChartDirector::Transparent)
c.xAxis().setLabelStyle("arial.ttf", 12)
c.yAxis().setLabelStyle("arial.ttf", 12)
# Set the x-axis and y-axis scale
c.xAxis().setLinearScale(0, 10, 1)
c.yAxis().setLinearScale(0, 10, 1)
# Add a contour layer using the given data
layer = c.addContourLayer(dataX, dataY, dataZ)
# Move the grid lines in front of the contour layer
c.getPlotArea().moveGridBefore(layer)
# Define the color scale
colorScale = [-0.8, 0x0066ff, -0.5, 0x66ccff, -0.3, 0x66ffff, 0, 0x88ff88, 0.4, 0x00ff00,
0.7, 0xffff00, 0.9, 0xff6600, 1.0, 0xcc0000, 1.1]
# Apply the color scale, and specify the underflow and overflow colors for regions exceeding
# the color scale
layer.colorAxis().setColorScale(colorScale, 0x0000cc, 0x000000)
#
# Instead of displaying the color axis, we use a legend box to display the colors. This is
# useful for colors that are unevenly spaced on the color axis.
#
# Add a legend box at (460, 25) with vertical layout, with 12pt Arial font, transparent
# background and border, icon size of 15 x 15 pixels, and line spacing of 8 pixels.
b = c.addLegend(460, 25, true, "arial.ttf", 12)
b.setBackground(ChartDirector::Transparent, ChartDirector::Transparent)
b.setKeySize(15, 15)
b.setKeySpacing(0, 8)
# Add the legend box entries
b.addKey("> 1.1 (Critical)", 0x000000)
b.addKey("1.0 to 1.1 (Alert)", 0xcc0000)
b.addKey("0.9 to 1.0", 0xff6600)
b.addKey("0.7 to 0.9", 0xffff00)
b.addKey("0.4 to 0.7", 0x00ff00)
b.addKey("0.0 to 0.4", 0x88ff88)
b.addKey("-0.3 to 0.0", 0x66ffff)
b.addKey("-0.5 to -0.3", 0x66ccff)
b.addKey("-0.8 to -0.5", 0x0066ff)
b.addKey("< -0.8", 0x0000cc)
# Output the chart
send_data(c.makeChart2(ChartDirector::PNG), :type => "image/png", :disposition => "inline")
end
end |