ChartDirector 7.0 (Python Edition)

Rotated Line Chart




This example demonstrates swapping the x and y axes to produce a rotated line chart in which the line goes from top to bottom (instead of left to right).

The x and y axes in the example are configured as follows:

For demo purposes, this example uses RanTable to simulate a database table with 4 columns, in which one is a date/time column and the remaining three are data columns. The date/time column is passed to ChartDirector as the x values using Layer.setXData, while the data columns are passed to ChartDirector as y values using Layer.addDataSet.

Source Code Listing

pythondemo\rotatedline.py
#!/usr/bin/python # The ChartDirector for Python module is assumed to be in "../lib" import sys, os sys.path.insert(0, os.path.join(os.path.abspath(sys.path[0]), "..", "lib")) from pychartdir import * # # We use a random table to simulate generating 12 months of data # # Create the random table object with 4 cols * 12 rows, using 3 as seed rantable = RanTable(3, 4, 12) # Set the 1st column to be the 12 months of year 2002 rantable.setDateCol(0, chartTime(2002, 1, 1), 86400 * 30) # Set the 2nd, 3rd and 4th columns to be random numbers starting from 125, 75, and 100 respectively. # The change between rows is set to -35 to + 35. The minimum value of any cell is 0. rantable.setCol(1, 125, -35, 35, 0) rantable.setCol(2, 75, -35, 35, 0) rantable.setCol(3, 100, -35, 35, 0) # Get the 1st column (time) as the x data dataX = rantable.getCol(0) # Get the 2nd, 3rd and 4th columns as 3 data sets dataY0 = rantable.getCol(1) dataY1 = rantable.getCol(2) dataY2 = rantable.getCol(3) # Create a XYChart object of size 360 x 400 pixels c = XYChart(360, 400) # Add a title to the chart c.addTitle("<*underline=2*>Rotated Line Chart Demo", "Times New Roman Bold Italic", 14) # Set the plotarea at (60, 75) and of size 190 x 320 pixels. Turn on both horizontal and vertical # grid lines with light grey color (0xc0c0c0) c.setPlotArea(60, 75, 190, 320).setGridColor(0xc0c0c0, 0xc0c0c0) # Add a legend box at (270, 75) c.addLegend(270, 75) # Swap the x and y axis to become a rotated chart c.swapXY() # Set the y axis on the top side (right + rotated = top) c.setYAxisOnRight() # Add a title to the y axis c.yAxis().setTitle("Throughput (MBytes)") # Reverse the x axis so it is pointing downwards c.xAxis().setReverse() # Add a line chart layer using the given data layer = c.addLineLayer2() layer.setXData(dataX) layer.addDataSet(dataY0, 0xff0000, "Server A") layer.addDataSet(dataY1, 0x338033, "Server B") layer.addDataSet(dataY2, 0x0000ff, "Server C") # Set the line width to 2 pixels layer.setLineWidth(2) # Output the chart c.makeChart("rotatedline.png")