ChartDirector Ver 3.0 (Python Edition)

Dual Y-Axis




This example show demonstrates the dual independent y-axis feature of ChartDirector.

In ChartDirector, any data set can be binded to the primary y-axis or the secondary y-axis, controlled by DataSet.setUseYAxis2. The default is the primary y-axis.

The y-axes in this example are of different colors. This is achieved using Axis.setColors.

Source Code Listing

[File: pythondemo/dualyaxis.py] (The CGI version is available as "pythondemo_cgi/dualyaxis.py".)
#!/usr/bin/python from pychartdir import * #The data for the chart data0 = [0.05, 0.06, 0.48, 0.1, 0.01, 0.05] data1 = [100, 125, 265, 147, 67, 105] labels = ["Jan", "Feb", "Mar", "Apr", "May", "Jun"] #Create a XYChart object of size 300 x 180 pixels c = XYChart(300, 180) #Set the plot area at (50, 20) and of size 200 x 130 pixels c.setPlotArea(50, 20, 200, 130) #Add a title to the chart using 8 pts Arial Bold font c.addTitle("Independent Y-Axis Demo", "arialbd.ttf", 8) #Set the x axis labels using the given labels c.xAxis().setLabels(labels) #Add a title to the primary (left) y axis c.yAxis().setTitle("Packet Drop Rate (pps)") #Set the axis, label and title colors for the primary y axis to red (0xc00000) #to match the first data set c.yAxis().setColors(0xc00000, 0xc00000, 0xc00000) #Add a title to the secondary (right) y axis c.yAxis2().setTitle("Throughtput (MBytes)") #set the axis, label and title colors for the primary y axis to green (0x008000) #to match the second data set c.yAxis2().setColors(0x8000, 0x8000, 0x8000) #Add a line layer to for the first data set using red (0xc00000) color with a #line width to 3 pixels c.addLineLayer(data0, 0xc00000).setLineWidth(3) #Add a bar layer to for the second data set using green (0x00C000) color. Bind #the second data set to the secondary (right) y axis c.addBarLayer().addDataSet(data1, 0xc000).setUseYAxis2() #output the chart c.makeChart("dualyaxis.png")