def setUp(self):
self.base_time = tz.datetime(2012, 5, 2, 20, 10, 2, 0)
if settings.USE_TZ:
self.base_time = self.base_time.replace(tzinfo=tz.utc)
self.dimension = TimeDimension(
key='fake',
name='fake',
description='fake',
field_name='fake',
default_bins=self.DEFAULT_BINS,
min_bin_size=self.MIN_BIN_SIZE
)
class TestTimeBinning(TestCase):
MIN_BIN_SIZE = 1
DEFAULT_BINS = 50
def setUp(self):
self.base_time = tz.datetime(2012, 5, 2, 20, 10, 2, 0)
if settings.USE_TZ:
self.base_time = self.base_time.replace(tzinfo=tz.utc)
self.dimension = TimeDimension(
key='fake',
name='fake',
description='fake',
field_name='fake',
default_bins=self.DEFAULT_BINS,
min_bin_size=self.MIN_BIN_SIZE
)
def test_narrow_distribution(self):
min_val = self.base_time
max_val = min_val + timedelta(minutes=30)
bin_size = self.dimension._get_bin_size(min_val, max_val, 2000)
self.assertEquals(bin_size, 1)
self.assertEquals(self.dimension._bin_value(min_val, bin_size), min_val)
self.assertEquals(self.dimension._bin_value(max_val, bin_size), max_val)
def test_wide_distribution(self):
min_val = self.base_time
max_val = min_val + timedelta(days=4)
# Remove the time parts
day1 = min_val.replace(hour=0, minute=0, second=0, microsecond=0)
day2 = min_val.replace(hour=0, minute=0, second=0, microsecond=0)
bin_size = self.dimension._get_bin_size(min_val, max_val, 4)
self.assertEquals(bin_size, 24 * 60 * 60)
self.assertEquals(self.dimension._bin_value(min_val, bin_size), day1)
self.assertEquals(self.dimension._bin_value(min_val, bin_size), day2)
# These are just some extra time binning tests
def run_time_bin_test(self, delta, desired_bins, expected_bin_size):
"""Run a generic time bin test."""
t0 = self.base_time
t1 = t0 + delta
dimension = registry.get_dimension('time')
self.assertEquals(dimension._get_bin_size(t0, t1, desired_bins), expected_bin_size)
def test_time_bin_min_size(self):
"""Returns minimum bin size of 1 second."""
self.run_time_bin_test(
delta=tz.timedelta(seconds=4),
desired_bins=10,
expected_bin_size=1)
def test_time_bin_max_size(self):
"""Returns a max bin size of 1 year."""
self.run_time_bin_test(
delta=tz.timedelta(days=10*365),
desired_bins=5,
expected_bin_size=31536e3) # 1 year in seconds
def test_time_bin_even_split(self):
"""Split evenly when the desired bins is perfect"""
self.run_time_bin_test(
delta=tz.timedelta(minutes=4),
desired_bins=8,
expected_bin_size=30,
)
def test_time_bin_at_least_desired(self):
"""Continues to deliver at least the desired bins"""
self.run_time_bin_test(
delta=tz.timedelta(minutes=4),
desired_bins=7,
expected_bin_size=30,
)
def test_time_bin_bumps_up(self):
"""If you ask for more bins, increases granularity"""
self.run_time_bin_test(
delta=tz.timedelta(minutes=4),
desired_bins=9,
expected_bin_size=30,
) # 4 minutes / 9 is 26.6 seconds, so it should go up
def test_time_bin_special(self):
self.run_time_bin_test(
delta=tz.timedelta(minutes=4, seconds=11),
desired_bins=50,
expected_bin_size=5,
)
