ChartDirector Ver 5.0 (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

[Standalone Version] pythondemo\rotatedline.py
#!/usr/bin/python
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", "timesbi.ttf", 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")

[CGI Version] pythondemo_cgi\rotatedline.py
#!/usr/bin/python
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", "timesbi.ttf", 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
print("Content-type: image/png\n")
binaryPrint(c.makeChart2(PNG))