ChartDirector 5.1 (Python Edition)

Wide Angular Meters


          

This example demonstrates angular meters of which the width is large compared to the height. It also demonstrates various background effects.

The meters in this example are created by using large meter radii, but small angular spans. The center (pivot for the pointer) can then be put outside the meter region and the meters can be reduced in height.

This example also demonstrates metallic background effects and background patterns. The backgrounds are configured using BaseChart.setBackground. The metallic colors are created using pychartdir.goldColor, pychartdir.silverColor and pychartdir.metalColor. The background patterns are created by loading image files as pattern colors using BaseChart.patternColor2.

This example also shows the effect of the semi-transparent pointers, which can avoid blocking the labels on the meter.

Source Code Listing

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

def createChart(img) :

    # The value to display on the meter
    value = 6.5

    # Create an AugularMeter object of size 200 x 100 pixels with rounded corners
    m = AngularMeter(200, 100)
    m.setRoundedFrame()

    # Set meter background according to a parameter
    if img == "0" :
        # Use gold background color
        m.setBackground(goldColor(), 0x000000, -2)
    elif img == "1" :
        # Use silver background color
        m.setBackground(silverColor(), 0x000000, -2)
    elif img == "2" :
        # Use metallic blue (9898E0) background color
        m.setBackground(metalColor(0x9898e0), 0x000000, -2)
    elif img == "3" :
        # Use a wood pattern as background color
        m.setBackground(m.patternColor2("wood.png"), 0x000000, -2)
    elif img == "4" :
        # Use a marble pattern as background color
        m.setBackground(m.patternColor2("marble.png"), 0x000000, -2)
    else :
        # Use a solid light purple (EEBBEE) background color
        m.setBackground(0xeebbee, 0x000000, -2)

    # Set the meter center at (100, 235), with radius 210 pixels, and span from -24
    # to +24 degress
    m.setMeter(100, 235, 210, -24, 24)

    # Meter scale is 0 - 100, with a tick every 1 unit
    m.setScale(0, 10, 1)

    # Set 0 - 6 as green (99ff99) zone, 6 - 8 as yellow (ffff00) zone, and 8 - 10 as
    # red (ff3333) zone
    m.addZone(0, 6, 0x99ff99, 0x808080)
    m.addZone(6, 8, 0xffff00, 0x808080)
    m.addZone(8, 10, 0xff3333, 0x808080)

    # Add a title at the bottom of the meter using 10 pts Arial Bold font
    m.addTitle2(Bottom, "OUTPUT POWER LEVEL\n", "arialbd.ttf", 10)

    # Add a semi-transparent black (80000000) pointer at the specified value
    m.addPointer(value, 0x80000000)

    # Output the chart
    m.makeChart("wideameter%s.png" % img)


createChart("0")
createChart("1")
createChart("2")
createChart("3")
createChart("4")
createChart("5")

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

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

# The value to display on the meter
value = 6.5

# Create an AugularMeter object of size 200 x 100 pixels with rounded corners
m = AngularMeter(200, 100)
m.setRoundedFrame()

# Set meter background according to a parameter
if query["img"].value == "0" :
    # Use gold background color
    m.setBackground(goldColor(), 0x000000, -2)
elif query["img"].value == "1" :
    # Use silver background color
    m.setBackground(silverColor(), 0x000000, -2)
elif query["img"].value == "2" :
    # Use metallic blue (9898E0) background color
    m.setBackground(metalColor(0x9898e0), 0x000000, -2)
elif query["img"].value == "3" :
    # Use a wood pattern as background color
    m.setBackground(m.patternColor2(os.path.join(os.path.dirname(sys.argv[0]),
        "wood.png")), 0x000000, -2)
elif query["img"].value == "4" :
    # Use a marble pattern as background color
    m.setBackground(m.patternColor2(os.path.join(os.path.dirname(sys.argv[0]),
        "marble.png")), 0x000000, -2)
else :
    # Use a solid light purple (EEBBEE) background color
    m.setBackground(0xeebbee, 0x000000, -2)

# Set the meter center at (100, 235), with radius 210 pixels, and span from -24 to
# +24 degress
m.setMeter(100, 235, 210, -24, 24)

# Meter scale is 0 - 100, with a tick every 1 unit
m.setScale(0, 10, 1)

# Set 0 - 6 as green (99ff99) zone, 6 - 8 as yellow (ffff00) zone, and 8 - 10 as red
# (ff3333) zone
m.addZone(0, 6, 0x99ff99, 0x808080)
m.addZone(6, 8, 0xffff00, 0x808080)
m.addZone(8, 10, 0xff3333, 0x808080)

# Add a title at the bottom of the meter using 10 pts Arial Bold font
m.addTitle2(Bottom, "OUTPUT POWER LEVEL\n", "arialbd.ttf", 10)

# Add a semi-transparent black (80000000) pointer at the specified value
m.addPointer(value, 0x80000000)

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