piker/piker/fsp/_volume.py

94 lines
2.5 KiB
Python

# piker: trading gear for hackers
# Copyright (C) 2018-present Tyler Goodlet (in stewardship of piker0)
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Affero General Public License for more details.
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.
from typing import AsyncIterator, Optional
import numpy as np
from ..data._normalize import iterticks
def wap(
signal: np.ndarray,
weights: np.ndarray,
) -> np.ndarray:
"""Weighted average price from signal and weights.
"""
cum_weights = np.cumsum(weights)
cum_weighted_input = np.cumsum(signal * weights)
# cum_weighted_input / cum_weights
# but, avoid divide by zero errors
avg = np.divide(
cum_weighted_input,
cum_weights,
where=cum_weights != 0
)
return (
avg,
cum_weighted_input,
cum_weights,
)
async def _tina_vwap(
source, #: AsyncStream[np.ndarray],
ohlcv: np.ndarray, # price time-frame "aware"
anchors: Optional[np.ndarray] = None,
) -> AsyncIterator[np.ndarray]: # maybe something like like FspStream?
"""Streaming volume weighted moving average.
Calling this "tina" for now since we're using HLC3 instead of tick.
"""
if anchors is None:
# TODO:
# anchor to session start of data if possible
pass
a = ohlcv.array
chl3 = (a['close'] + a['high'] + a['low']) / 3
v = a['volume']
h_vwap, cum_wp, cum_v = wap(chl3, v)
# deliver historical output as "first yield"
yield h_vwap
w_tot = cum_wp[-1]
v_tot = cum_v[-1]
# vwap_tot = h_vwap[-1]
async for quote in source:
for tick in iterticks(quote, types=['trade']):
# c, h, l, v = ohlcv.array[-1][
# ['closes', 'high', 'low', 'volume']
# ]
# this computes tick-by-tick weightings from here forward
size = tick['size']
price = tick['price']
v_tot += size
w_tot += price * size
# yield ((((o + h + l) / 3) * v) weights_tot) / v_tot
yield w_tot / v_tot