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ferro-ta/python/ferro_ta/analysis/resample.py
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Pratik Bhadane 436954138f chore: prepare v1.1.0 release
Update version numbers across Rust, Python, and documentation files to 1.1.0. Enhance the .gitignore to include macOS dSYM files and plans directory. Introduce new dependencies in the Rust core library and update the README to reflect recent performance benchmarks and backtesting engine capabilities. Add new artifacts to the benchmarks manifest and improve documentation for the backtesting engine API.
2026-03-30 12:45:52 +05:30

140 lines
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Python

"""
OHLCV bar aggregation utilities.
resample_ohlcv(open, high, low, close, volume, factor)
Aggregate every `factor` bars into one OHLCV bar.
open = first bar's open
high = max of highs
low = min of lows
close = last bar's close
volume = sum of volumes
resample_ohlcv_labels(n_bars, factor)
Return an integer label array of length n_bars where label[i] = i // factor.
Useful for aligning fine-bar signals with coarse-bar indicators.
align_to_coarse(coarse_values, factor, n_fine_bars)
Broadcast a coarse-bar array back to fine-bar length by repeating each value `factor` times.
Handles the case where n_fine_bars % factor != 0 (last group may be partial).
"""
import numpy as np
from numpy.typing import ArrayLike, NDArray
__all__ = ["resample_ohlcv", "resample_ohlcv_labels", "align_to_coarse"]
def resample_ohlcv(
open_: ArrayLike,
high: ArrayLike,
low: ArrayLike,
close: ArrayLike,
volume: ArrayLike,
factor: int,
) -> tuple[NDArray, NDArray, NDArray, NDArray, NDArray]:
"""Aggregate fine-bar OHLCV into coarser bars.
Parameters
----------
open_ : array-like
Fine-bar open prices.
high : array-like
Fine-bar high prices.
low : array-like
Fine-bar low prices.
close : array-like
Fine-bar close prices.
volume : array-like
Fine-bar volume.
factor : int
Number of fine bars per coarse bar (e.g. 5 for 1-min -> 5-min).
Returns
-------
(open, high, low, close, volume) arrays of length ceil(n / factor).
Only complete groups are returned — if n % factor != 0, trailing bars are dropped.
"""
if factor < 1:
raise ValueError(f"factor must be >= 1, got {factor}")
o = np.asarray(open_, dtype=np.float64)
h = np.asarray(high, dtype=np.float64)
low_arr = np.asarray(low, dtype=np.float64)
c = np.asarray(close, dtype=np.float64)
v = np.asarray(volume, dtype=np.float64)
n = len(o)
n_complete = (n // factor) * factor # truncate to complete bars
o = o[:n_complete].reshape(-1, factor)
h = h[:n_complete].reshape(-1, factor)
low_arr = low_arr[:n_complete].reshape(-1, factor)
c = c[:n_complete].reshape(-1, factor)
v = v[:n_complete].reshape(-1, factor)
return (
o[:, 0], # open = first bar's open
h.max(axis=1), # high = max of highs
low_arr.min(axis=1), # low = min of lows
c[:, -1], # close = last bar's close
v.sum(axis=1), # volume = sum of volumes
)
def resample_ohlcv_labels(n_bars: int, factor: int) -> NDArray:
"""Return coarse-bar index for each fine bar (i // factor).
Parameters
----------
n_bars : int
Number of fine-resolution bars.
factor : int
Number of fine bars per coarse bar.
Returns
-------
NDArray of int64, shape (n_bars,), where label[i] = i // factor.
"""
if factor < 1:
raise ValueError(f"factor must be >= 1, got {factor}")
return np.arange(n_bars, dtype=np.int64) // factor
def align_to_coarse(coarse_values: ArrayLike, factor: int, n_fine_bars: int) -> NDArray:
"""Broadcast coarse-bar array back to fine-bar resolution.
Each coarse value is repeated `factor` times. If n_fine_bars % factor != 0,
the last coarse value covers the partial group at the end.
Parameters
----------
coarse_values : array-like
Values at coarse resolution, shape (n_coarse,).
factor : int
Number of fine bars per coarse bar.
n_fine_bars : int
Total number of fine bars to produce.
Returns
-------
NDArray of shape (n_fine_bars,).
"""
if factor < 1:
raise ValueError(f"factor must be >= 1, got {factor}")
coarse = np.asarray(coarse_values, dtype=np.float64)
n_coarse = len(coarse)
# Build the full repeated array (may be longer than n_fine_bars if partial group exists)
repeated = np.repeat(coarse, factor)
# If repeated is shorter than n_fine_bars (shouldn't happen with correct n_coarse,
# but handle defensively), pad with last value
if len(repeated) < n_fine_bars:
pad = np.full(
n_fine_bars - len(repeated), coarse[-1] if n_coarse > 0 else np.nan
)
repeated = np.concatenate([repeated, pad])
return repeated[:n_fine_bars]