def moving_window(x):
msec = datetime.timedelta(milliseconds=1)
zero = datetime.timedelta(seconds=0)
half_span = datetime.timedelta(seconds=window / 2)
start = utils.normalize_time(data.index[0])
stop = utils.normalize_time(data.index[-1] +
datetime.timedelta(seconds=min_grain))
# min_grain addition necessary since each bin of rolled-up data
# is indexed by leftmost timestamp of bin.
left = half_span if center else zero
right = 2 * half_span - left - msec
# msec subtraction is so we don't include right endpoint in slice.
x = utils.normalize_time(x)
if x - left >= start and x + right <= stop:
dslice = data[x - left:x + right]
if center and dslice.size % 2 == 0:
return func([
func(data[x - msec - left:x - msec + right]),
func(data[x + msec - left:x + msec + right])
])
# (NOTE) atmalagon: the msec shift here is so that we have two
# consecutive windows; one centered at time x - msec,
# and one centered at time x + msec. We then average the
# aggregates from the two windows; this result is centered
# at time x. Doing this double average is a way to return a
# centered average indexed by a timestamp that existed in
# the input data (which wouldn't be the case for an even number
# of points if we did only one centered average).
else:
return numpy.nan
if dslice.size < min_size:
return numpy.nan
return func(dslice)
def process_result_value(self, value, dialect):
if dialect.name == 'mysql':
value = self._decimal_to_dt(value)
if value is not None:
return utils.normalize_time(value).replace(
tzinfo=iso8601.iso8601.UTC)
def process_bind_param(self, value, dialect):
if value is not None:
value = utils.normalize_time(value)
if dialect.name == 'mysql':
return self._dt_to_decimal(value)
return value
def process_bind_param(self, value, dialect):
if value is not None:
return utils.normalize_time(value)
def process_result_value(self, value, dialect):
if dialect.name == 'mysql':
value = self._decimal_to_dt(value)
if value is not None:
return utils.normalize_time(value).replace(
tzinfo=iso8601.iso8601.UTC)
def process_bind_param(self, value, dialect):
if value is not None:
value = utils.normalize_time(value)
if dialect.name == 'mysql':
return self._dt_to_decimal(value)
return value
def process_bind_param(self, value, dialect):
if value is not None:
return utils.normalize_time(value)
