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:

Initially, the x-axis is horizontal from left to right at the bottom of the plot area, while the y-axis is vertical from bottom to top at the left side of the plot area.
Swap the x and y axes using XYChart.swapXY. Now the x-axis is vertical from bottom to top at the left side of the chart, while the y-axis is horizontal from left to right at the bottom of the chart.
Use XYChart.setYAxisOnRight to move the y-axis to the opposite side of the plot area, so that the y-axis is at the top of the plot area. (Note: the "right" word on setYAxisOnRight means the "right" side before "swapXY" rotation. After rotation, the right side will become to top side.)
Use Axis.setReverse to reverse the direction of the x-axis, so that the x-axis is vertical from top to bottom (instead of from bottom to top).

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.

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")