4.6.1 Example

The following example (invoked in a Nokia N95 device) demonstrates how to use the Python positioning module to obtain information about the positioning technologies in the device:

>>> import positioning
>>> positioning.modules()
[{'available': 0, 'id': 270526873, 'name': u'Bluetooth GPS'}, {'available': 1, '
id': 270526858, 'name': u'Integrated GPS'}, {'available': 1, 'id': 270559509, 'n
ame': u'Network based'}]
>>> positioning.default_module()
270526858
>>> positioning.module_info(270526858)
{'available': 1, 'status': {'data_quality': 3, 'device_status': 7}, 'version': u
'1.00(0)', 'name': u'Integrated GPS', 'position_quality': {'vertical_accuracy':
10.0, 'time_to_first_fix': 1000000L, 'cost': 1, 'time_to_next_fix': 1000000L, 'h
orizontal_accuracy': 10.0, 'power_consumption': 3}, 'technology': 1, 'id': 27052
6858, 'capabilities': 127, 'location': 1}
>>>

# information about available positioning modules
print "***available modules***"
print positioning.modules()
print ""

# id of the default positioning module
print "***default module***"
print positioning.default_module()
print ""

# detailed information about the default positioning module
print "***detailed module info***"
print positioning.module_info(positioning.default_module())
print ""

# select a module (in practise, selecting default module has no 
# relevance.). 
positioning.select_module(positioning.default_module())

# set requestors.
# at least one requestor must be set before requesting the 
# current position or last position.
# the last requestor must always be service requestor 
# (whether or not there are other requestors). 
positioning.set_requestors([{"type":"service",
                             "format":"application",
                             "data":"test_app"}])
                            
# get the last position.
print positioning.last_position()

An example dictionary returned/printed from the above call to last_position function could be as follows

{'vertical_accuracy':59.0,'time':1206530248.329,'latitude':12.956741,'altitude':
811.0,'horizontal_accuracy':41.77254404,'longitude':77.715568724}

# get the last position if the device's position has not previously been 
# discovered.
print positioning.last_position()

An example dictionary returned/printed from the above call to last_position function could be as follows

{'vertical_accuracy':NaN,'time':1206530248.329,'latitude':NaN,'altitude':NaN,
'horizontal_accuracy':NaN,'longitude':NaN}

# Example 1. Blocking call

# get the position. 
# note that the first position()-call may take a long time
# (because of gps technology).
print "***position info***"                         
print positioning.position()
print ""

# re-get the position.
# this call should be much quicker.
# ask also course and satellite information.
print "***course and satellites***" 
print positioning.position(course=1,satellites=1)
print ""

# Example 2. Non-blocking call

def cb(event):
    print "---"
    print event
    print "---"

print "***starts the position feed***" 
print positioning.position(course=1,satellites=1,
                           callback=cb, interval=500000,
                           partial=0)

An example dictionary returned/printed from the above example script could be as follows:

{'satellites': {'horizontal_dop': 2.34999990463257, 'used_satellites': 5, 'verti
cal_dop': 2.29999995231628, 'time': 1187167353.0, 'satellites': 11, 'time_dop':
1.26999998092651}, 'position': {'latitude': 60.217033666473, 'altitude': 42.0, '
vertical_accuracy': 58.0, 'longitude': 24.878942093007, 'horizontal_accuracy': 4
7.531005859375}, 'course': {'speed': 0.0500000007450581, 'heading': 68.959999084
4727, 'heading_accuracy': 359.989990234375, 'speed_accuracy': NaN}}

To run the script in the emulator you must configure PSY emulation from your emulator (SimPSYConfigurator $\rightarrow$ Select Config File $\rightarrow$ <some config files>or Tools $\rightarrow$ Position).