def sid_day_index(self, sid, day):
"""
Parameters
----------
sid : int
The asset identifier.
day : datetime64-like
Midnight of the day for which data is requested.
Returns
-------
int
Index into the data tape for the given sid and day.
Raises a NoDataOnDate exception if the given day and sid is before
or after the date range of the equity.
"""
try:
day_loc = self.sessions.get_loc(day)
except:
raise NoDataOnDate("day={0} is outside of calendar={1}".format(
day, self.sessions))
offset = day_loc - self._calendar_offsets[sid]
if offset < 0:
raise NoDataBeforeDate(
"No data on or before day={0} for sid={1}".format(day, sid))
ix = self._first_rows[sid] + offset
if ix > self._last_rows[sid]:
raise NoDataAfterDate(
"No data on or after day={0} for sid={1}".format(day, sid))
return ix
def get_value(self, sid, dt, field):
"""
Retrieve the pricing info for the given sid, dt, and field.
Parameters
----------
sid : int
Asset identifier.
dt : datetime-like
The datetime at which the trade occurred.
field : string
The type of pricing data to retrieve.
('open', 'high', 'low', 'close', 'volume')
Returns
-------
out : float|int
The market data for the given sid, dt, and field coordinates.
For OHLC:
Returns a float if a trade occurred at the given dt.
If no trade occurred, a np.nan is returned.
For volume:
Returns the integer value of the volume.
(A volume of 0 signifies no trades for the given dt.)
"""
if self._last_get_value_dt_value == dt.value:
minute_pos = self._last_get_value_dt_position
else:
try:
minute_pos = self._find_position_of_minute(dt)
except ValueError:
raise NoDataOnDate()
self._last_get_value_dt_value = dt.value
self._last_get_value_dt_position = minute_pos
# a patch for requesting non existing time frames
# due to the different candles labeling + wrong start dates
if minute_pos < 0:
return np.nan
try:
value = self._open_minute_file(field, sid)[minute_pos]
except IndexError:
value = 0
if value == 0:
if field == 'volume':
return 0
else:
return np.nan
# if field != 'volume':
value *= self._ohlc_ratio_inverse_for_sid(sid)
return value