Stacked Rose Chart

This example demonstrates how to create a stacked rose chart.

This example employs the same approach as the previous Simple Rose Chart example. It creates a PolarChart object as the graph paper, and adding sector zones on it using AngularAxis.addZone. A transparent line layer is used for enabling auto-scaling.

In this example, multiple sectors are added for each angular direction, creating a "stacked" effect.

pythondemo\stackrose.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 *

# Data for the chart
data0 = [5, 3, 10, 4, 3, 5, 2, 5]
data1 = [12, 6, 17, 6, 7, 9, 4, 7]
data2 = [17, 7, 22, 7, 18, 13, 5, 11]

angles = [0, 45, 90, 135, 180, 225, 270, 315]
labels = ["North", "North\nEast", "East", "South\nEast", "South", "South\nWest", "West",
    "North\nWest"]

# Create a PolarChart object of size 460 x 500 pixels, with a grey (e0e0e0) background and a 1 pixel
# 3D border
c = PolarChart(460, 500, 0xe0e0e0, 0x000000, 1)

# Add a title to the chart at the top left corner using 15pt Arial Bold Italic font. Use white text
# on deep blue background.
c.addTitle("Wind Direction", "Arial Bold Italic", 15, 0xffffff).setBackground(0x000080)

legendBox = c.addLegend(230, 35, 0, "Arial Bold", 9)
legendBox.setAlignment(TopCenter)
legendBox.setBackground(Transparent, Transparent, 1)

legendBox.addKey("5 m/s or above", 0xff3333)
legendBox.addKey("1 - 5 m/s", 0x33ff33)
legendBox.addKey("less than 1 m/s", 0x3333ff)

# Set plot area center at (230, 280) with radius 180 pixels and white background
c.setPlotArea(230, 280, 180, 0xffffff)

# Set the grid style to circular grid
c.setGridStyle(0)

# Set angular axis as 0 - 360, with a spoke every 30 units
c.angularAxis().setLinearScale2(0, 360, labels)

for i in range(0, len(angles)) :
    c.angularAxis().addZone(angles[i] - 10, angles[i] + 10, 0, data0[i], 0x3333ff, 0)
    c.angularAxis().addZone(angles[i] - 10, angles[i] + 10, data0[i], data1[i], 0x33ff33, 0)
    c.angularAxis().addZone(angles[i] - 10, angles[i] + 10, data1[i], data2[i], 0xff3333, 0)

# Add an Transparent invisible layer to ensure the axis is auto-scaled using the data
c.addLineLayer(data2, Transparent)

# Output the chart
c.makeChart("stackrose.png")