ChartDirector Ver 3.0 (Python Edition)

Custom Scatter Labels




This example demonstrates adding custom labels to data points.

Source Code Listing

[File: pythondemo/scatterlabels.py] (The CGI version is available as "pythondemo_cgi/scatterlabels.py".)
#!/usr/bin/python from pychartdir import * #The XY points for the scatter chart dataX = [150, 400, 300, 1500, 800] dataY = [0.6, 8, 5.4, 2, 4] #The labels for the points labels = ["Nano\n100", "SpeedTron\n200 Lite", "SpeedTron\n200", "Marathon\nExtra", "Marathon\n2000"] #Create a XYChart object of size 450 x 400 pixels c = XYChart(450, 400) #Set the plotarea at (55, 40) and of size 350 x 300 pixels, with a light grey #border (0xc0c0c0). Turn on both horizontal and vertical grid lines with light #grey color (0xc0c0c0) c.setPlotArea(55, 40, 350, 300, 0xffffff, -1, 0xc0c0c0, 0xc0c0c0, -1) #Add a title to the chart using 18 pts Times Bold Itatic font. c.addTitle("Product Comparison Chart", "timesbi.ttf", 18) #Add a title to the y axis using 12 pts Arial Bold Italic font c.yAxis().setTitle("Capacity (tons)", "arialbi.ttf", 12) #Add a title to the x axis using 12 pts Arial Bold Italic font c.xAxis().setTitle("Range (miles)", "arialbi.ttf", 12) #Set the axes line width to 3 pixels c.xAxis().setWidth(3) c.yAxis().setWidth(3) #Add the data as a scatter chart layer, using a 15 pixel circle as the symbol layer = c.addScatterLayer(dataX, dataY, "Server BBB", CircleSymbol, 15, 0xff3333, 0xff3333) #Add labels to the chart as an extra field layer.addExtraField(labels) #Set the data label format to display the extra field layer.setDataLabelFormat("{field0}") #Use 8pts Arial Bold to display the labels textbox = layer.setDataLabelStyle("arialbd.ttf", 8) #Set the background to purple with a 1 pixel 3D border textbox.setBackground(0xcc99ff, Transparent, 1) #Put the text box 4 pixels to the right of the data point textbox.setAlignment(Left) textbox.setPos(4, 0) #output the chart c.makeChart("scatterlabels.png")