ChartDirector Ver 5.0 (Python Edition)

Start Angle and Direction


  

This example demonstrates different sector layout angles and directions.

By default, ChartDirector positions sectors starting from the upward pointing position, and in clockwise direction.

The start angle and layout direction can be changed using PieChart.setStartAngle.

One common application for PieChart.setStartAngle is to facilitate layout of pie charts containing many small sectors. Please refer to Side Label Layout for an example.

Source Code Listing

[Standalone Version] pythondemo\anglepie.py
#!/usr/bin/python
from pychartdir import *

def createChart(img) :

    # Determine the starting angle and direction based on input parameter
    angle = 0
    clockwise = 1
    if img != "0" :
        angle = 90
        clockwise = 0

    # The data for the pie chart
    data = [25, 18, 15, 12, 8, 30, 35]

    # The labels for the pie chart
    labels = ["Labor", "Licenses", "Taxes", "Legal", "Insurance", "Facilities",
        "Production"]

    # Create a PieChart object of size 280 x 240 pixels
    c = PieChart(280, 240)

    # Set the center of the pie at (140, 130) and the radius to 80 pixels
    c.setPieSize(140, 130, 80)

    # Add a title to the pie to show the start angle and direction
    if clockwise :
        c.addTitle("Start Angle = %s degrees\nDirection = Clockwise" % (angle))
    else :
        c.addTitle("Start Angle = %s degrees\nDirection = AntiClockwise" % (angle))

    # Set the pie start angle and direction
    c.setStartAngle(angle, clockwise)

    # Draw the pie in 3D
    c.set3D()

    # Set the pie data and the pie labels
    c.setData(data, labels)

    # Explode the 1st sector (index = 0)
    c.setExplode(0)

    # Output the chart
    c.makeChart("anglepie%s.png" % img)


createChart("0")
createChart("1")

[CGI Version] pythondemo_cgi\anglepie.py
#!/usr/bin/python
from pychartdir import *
import cgi

# Get HTTP query parameters
query = cgi.FieldStorage()

# Determine the starting angle and direction based on input parameter
angle = 0
clockwise = 1
if query["img"].value != "0" :
    angle = 90
    clockwise = 0

# The data for the pie chart
data = [25, 18, 15, 12, 8, 30, 35]

# The labels for the pie chart
labels = ["Labor", "Licenses", "Taxes", "Legal", "Insurance", "Facilities",
    "Production"]

# Create a PieChart object of size 280 x 240 pixels
c = PieChart(280, 240)

# Set the center of the pie at (140, 130) and the radius to 80 pixels
c.setPieSize(140, 130, 80)

# Add a title to the pie to show the start angle and direction
if clockwise :
    c.addTitle("Start Angle = %s degrees\nDirection = Clockwise" % (angle))
else :
    c.addTitle("Start Angle = %s degrees\nDirection = AntiClockwise" % (angle))

# Set the pie start angle and direction
c.setStartAngle(angle, clockwise)

# Draw the pie in 3D
c.set3D()

# Set the pie data and the pie labels
c.setData(data, labels)

# Explode the 1st sector (index = 0)
c.setExplode(0)

# Output the chart
print("Content-type: image/png\n")
binaryPrint(c.makeChart2(PNG))