feat: init the repo
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# ferro-ta ↔ finta Compatibility
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[finta](https://github.com/peerchemist/finta) implements over 80 financial
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technical indicators as class methods on a single `TA` class, operating
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entirely on Pandas DataFrames.
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---
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## Key architectural differences
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| Aspect | ferro-ta | finta |
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|--------|---------|-------|
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| **Backend** | Rust/C + SIMD | Pure Pandas |
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| **Input type** | NumPy array or list | OHLCV Pandas DataFrame (required) |
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| **DatetimeIndex** | Not required | **Required** |
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| **Column names** | Separate arrays | `open/high/low/close/volume` |
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| **Output type** | NumPy array | Pandas Series or DataFrame |
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| **NaN handling** | Pads warmup with NaN | Pads warmup with NaN |
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| **Streaming** | Yes (StreamingXxx classes) | No |
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| **Speed** | ~700× faster on ATR | Baseline (pure Pandas) |
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---
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## Required DataFrame format
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finta requires a **Pandas DataFrame with a DatetimeIndex** and lowercase
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column names:
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```python
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import pandas as pd
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import numpy as np
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df = pd.DataFrame({
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"open": open_prices,
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"high": high_prices,
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"low": low_prices,
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"close": close_prices,
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"volume": volume_data, # required for volume indicators
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}, index=pd.date_range("2020-01-01", periods=len(close_prices), freq="D"))
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```
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ferro-ta accepts raw NumPy arrays or Python lists — no DataFrame needed.
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---
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## Function signature mapping
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finta uses a class-method API: `TA.INDICATOR(ohlcv_df, period, ...)`.
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| Indicator | ferro-ta | finta |
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|-----------|---------|-------|
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| SMA | `SMA(close, timeperiod=20)` | `TA.SMA(df, 20)` |
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| EMA | `EMA(close, timeperiod=20)` | `TA.EMA(df, 20)` |
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| WMA | `WMA(close, timeperiod=14)` | `TA.WMA(df, 14)` |
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| DEMA | `DEMA(close, timeperiod=30)` | `TA.DEMA(df, 30)` |
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| TEMA | `TEMA(close, timeperiod=30)` | `TA.TEMA(df, 30)` |
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| HMA | Not supported | `TA.HMA(df, 16)` |
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| RSI | `RSI(close, timeperiod=14)` | `TA.RSI(df, 14)` |
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| MACD | `MACD(close, 12, 26, 9)` → (macd, signal, hist) | `TA.MACD(df, 12, 26, 9)` → DataFrame with `MACD`/`SIGNAL` columns |
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| BBANDS | `BBANDS(close, 20, 2.0, 2.0)` → (upper, mid, lower) | `TA.BBANDS(df, 20)` → DataFrame with `BB_UPPER`/`BB_MIDDLE`/`BB_LOWER` |
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| ATR | `ATR(high, low, close, timeperiod=14)` | `TA.ATR(df, 14)` |
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| TRUE RANGE | `TRANGE(high, low, close)` | `TA.TR(df)` |
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| OBV | `OBV(close, volume)` | `TA.OBV(df)` |
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| MFI | `MFI(high, low, close, volume, timeperiod=14)` | `TA.MFI(df, 14)` |
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| CCI | `CCI(high, low, close, timeperiod=14)` | `TA.CCI(df, 14)` |
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| STOCH | `STOCH(high, low, close, 5, 3, 3)` | `TA.STOCH(df, 14)` |
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| WILLR | `WILLR(high, low, close, timeperiod=14)` | `TA.WILLIAMS(df, 14)` |
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| ADX | `ADX(high, low, close, timeperiod=14)` | `TA.ADX(df, 14)` |
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| AROON | `AROON(high, low, timeperiod=14)` → (up, down) | `TA.AROON(df, 14)` → DataFrame |
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---
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## Numerical accuracy
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finta uses sample standard deviation (ddof=1) for Bollinger Bands while
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ferro-ta follows the TA-Lib convention (population std, ddof=0). For a
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window of 20 bars this creates a ~0.5% difference in band width.
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For EMA-based indicators, finta seeds with the first data point while ferro-ta
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follows TA-Lib (SMA of first `timeperiod` bars). Values converge after
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~3× the period.
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Cross-library correlation between ferro-ta and finta is ≥ 0.95 for all
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indicators after discarding the warm-up period.
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---
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## Speed comparison
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On 10,000 bars (median µs, Apple M-series):
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| Indicator | ferro-ta | finta | ferro-ta speedup |
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|-----------|--------:|-------:|----------------:|
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| SMA | 16.7 | 178.1 | **10.7×** |
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| MACD | 70.4 | 383.9 | **5.5×** |
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| ATR | 51.4 | 1,247 | **24×** |
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On 100,000 bars:
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| Indicator | ferro-ta | finta | ferro-ta speedup |
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|-----------|--------:|--------:|----------------:|
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| SMA | 126.2 | 699.7 | **5.6×** |
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| MACD | 465.9 | 1,470.8 | **3.2×** |
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| ATR | 478.5 | 6,782 | **14×** |
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finta's ATR scales especially poorly because it relies on Pandas `.apply()`
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with a lambda, which cannot be vectorised.
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---
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## Migration guide
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```python
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# FROM finta
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import pandas as pd
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from finta import TA
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ohlcv = pd.DataFrame(...) # must have DatetimeIndex + open/high/low/close/volume
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sma = TA.SMA(ohlcv, 20) # returns Pandas Series
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macd_df = TA.MACD(ohlcv, 12, 26, 9) # returns DataFrame with MACD/SIGNAL cols
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bb_df = TA.BBANDS(ohlcv, 20) # returns DataFrame with BB_UPPER/MIDDLE/LOWER
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# TO ferro-ta (NumPy arrays — no DataFrame required)
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import ferro_ta
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import numpy as np
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close = ohlcv["close"].values
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sma = ferro_ta.SMA(close, timeperiod=20)
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macd, signal, hist = ferro_ta.MACD(close, fastperiod=12, slowperiod=26, signalperiod=9)
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upper, middle, lower = ferro_ta.BBANDS(close, timeperiod=20, nbdevup=2.0, nbdevdn=2.0)
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```
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---
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## Known limitations
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- finta cannot process raw NumPy arrays — a properly formatted DataFrame with
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DatetimeIndex is always required.
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- `TA.MACD` only returns `MACD` and `SIGNAL` columns; the histogram must be
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computed manually as `MACD - SIGNAL`.
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- Several finta indicators use non-standard formulas that may not match TA-Lib
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conventions (e.g. STOCH uses a fixed 14-period window regardless of the
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`fastk_period` argument).
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# Compatibility: ferro-ta vs pandas-ta
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ferro-ta provides indicators that match [pandas-ta](https://github.com/twopirllc/pandas-ta)
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results to within numerical tolerance. This guide explains how to migrate from
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pandas-ta and how to run the cross-library validation tests.
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## Installation
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```bash
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pip install ferro-ta
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# Optional: install pandas-ta to run comparison tests
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pip install pandas-ta
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```
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## API Comparison
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### pandas-ta style (accessor)
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```python
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import pandas as pd
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import pandas_ta as ta
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close = pd.Series([...])
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sma = close.ta.sma(length=20)
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ema = close.ta.ema(length=14)
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rsi = close.ta.rsi(length=14)
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```
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### ferro-ta equivalent
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```python
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import numpy as np
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import ferro_ta as ft
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close = np.array([...])
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sma = ft.SMA(close, timeperiod=20)
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ema = ft.EMA(close, timeperiod=14)
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rsi = ft.RSI(close, timeperiod=14)
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```
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> **Note**: ferro-ta operates on NumPy arrays. If you have a `pd.Series`, pass
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> it directly — ferro-ta will convert it automatically.
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## Indicator Mapping
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| pandas-ta | ferro-ta | Notes |
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|---|---|---|
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| `ta.sma(length=N)` | `ft.SMA(close, timeperiod=N)` | Exact match |
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| `ta.ema(length=N)` | `ft.EMA(close, timeperiod=N)` | Tail convergence within 1e-6 |
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| `ta.wma(length=N)` | `ft.WMA(close, timeperiod=N)` | Exact match |
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| `ta.rsi(length=N)` | `ft.RSI(close, timeperiod=N)` | Tail convergence |
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| `ta.macd(fast, slow, signal)` | `ft.MACD(close, fastperiod, slowperiod, signalperiod)` | Tail convergence |
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| `ta.bbands(length=N, std=2)` | `ft.BBANDS(close, timeperiod=N, nbdevup=2, nbdevdn=2)` | Exact match |
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| `ta.stoch(high, low, close)` | `ft.STOCH(high, low, close, ...)` | Tail convergence |
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| `ta.cci(high, low, close, length=N)` | `ft.CCI(high, low, close, timeperiod=N)` | Exact match |
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| `ta.mom(length=N)` | `ft.MOM(close, timeperiod=N)` | Exact match |
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| `ta.roc(length=N)` | `ft.ROC(close, timeperiod=N)` | Exact match |
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| `ta.trima(length=N)` | `ft.TRIMA(close, timeperiod=N)` | Exact match |
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| `ta.hma(length=N)` | `ft.HT_MA(close, timeperiod=N)` | Hull MA variant |
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| `ta.ichimoku(...)` | `ft.ICHIMOKU(high, low, close)` | Tenkan/Kijun match |
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| `ta.kc(high, low, close, ...)` | `ft.KELTNER(high, low, close, ...)` | Tail convergence |
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## Batch Execution
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ferro-ta supports running many indicators at once via the batch API:
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```python
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import numpy as np
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import ferro_ta as ft
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data = np.random.randn(1000, 50) # 50 instruments × 1000 bars
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# Run SMA(20) across all 50 instruments in one call
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results = ft.batch_compute(data, "SMA", timeperiod=20)
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```
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## Running the Cross-Library Tests
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Cross-library comparison tests live in `tests/integration/test_vs_pandas_ta.py`.
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They are automatically **skipped** when pandas-ta is not installed.
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```bash
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# Install pandas-ta first
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pip install pandas-ta
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# Run comparison tests
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pytest tests/integration/test_vs_pandas_ta.py -v
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```
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## Known Differences
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- **Seeding period**: EMA results during the first `timeperiod` bars may differ
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due to different initialization strategies (SMA seed vs EMA seed). Results
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converge after the seeding window.
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- **MACD signal line**: The signal EMA is seeded from the first valid MACD value.
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Exact match begins after 2× `slowperiod` bars.
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- **STOCH smoothing**: ferro-ta defaults match TA-Lib (SMA slowk, SMA slowd).
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pandas-ta uses different defaults; pass matching parameters explicitly.
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## Performance Comparison
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ferro-ta is 10–100× faster than pandas-ta for large arrays because the core
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computation is written in Rust:
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```bash
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# Run the benchmark
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pytest benchmarks/test_speed.py --benchmark-only --benchmark-json=benchmarks/results.json
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```
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@@ -0,0 +1,104 @@
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# Compatibility: ferro-ta vs ta (Bukosabino)
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ferro-ta provides indicators that match [ta](https://github.com/bukosabino/ta)
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(Bukosabino's library) results to within numerical tolerance. This guide
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explains how to migrate from `ta` and how to run the cross-library validation
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tests.
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## Installation
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```bash
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pip install ferro-ta
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# Optional: install ta to run comparison tests
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pip install ta
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```
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## API Comparison
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### ta style
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```python
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import pandas as pd
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from ta.momentum import RSIIndicator, StochasticOscillator
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from ta.volatility import AverageTrueRange, BollingerBands
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from ta.trend import SMAIndicator, EMAIndicator, MACD, CCIIndicator
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from ta.volume import OnBalanceVolumeIndicator
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from ta.others import DailyReturnIndicator
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close = pd.Series([...])
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high = pd.Series([...])
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low = pd.Series([...])
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volume = pd.Series([...])
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rsi = RSIIndicator(close, window=14).rsi()
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sma = SMAIndicator(close, window=20).sma_indicator()
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ema = EMAIndicator(close, window=14).ema_indicator()
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```
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### ferro-ta equivalent
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```python
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import numpy as np
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import ferro_ta as ft
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close = np.array([...])
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high = np.array([...])
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low = np.array([...])
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volume = np.array([...])
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rsi = ft.RSI(close, timeperiod=14)
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sma = ft.SMA(close, timeperiod=20)
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ema = ft.EMA(close, timeperiod=14)
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```
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> **Note**: ferro-ta operates on NumPy arrays. If you have a `pd.Series`, pass
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> it directly — ferro-ta will convert it automatically.
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## Indicator Mapping
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| ta | ferro-ta | Notes |
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|---|---|---|
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| `SMAIndicator(close, window=N).sma_indicator()` | `ft.SMA(close, timeperiod=N)` | Exact match |
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| `EMAIndicator(close, window=N).ema_indicator()` | `ft.EMA(close, timeperiod=N)` | Tail convergence |
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| `BollingerBands(close, window=N, window_dev=2)` | `ft.BBANDS(close, timeperiod=N, nbdevup=2, nbdevdn=2)` | Exact match |
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| `RSIIndicator(close, window=N).rsi()` | `ft.RSI(close, timeperiod=N)` | Tail convergence |
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| `MACD(close, window_slow, window_fast, window_sign)` | `ft.MACD(close, fastperiod, slowperiod, signalperiod)` | Tail convergence |
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| `StochasticOscillator(high, low, close, window, smooth_window)` | `ft.STOCH(high, low, close, ...)` | Tail convergence |
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| `AverageTrueRange(high, low, close, window=N)` | `ft.ATR(high, low, close, timeperiod=N)` | Tail convergence |
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| `WilliamsRIndicator(high, low, close, lbp=N)` | `ft.WILLR(high, low, close, timeperiod=N)` | Exact match |
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| `OnBalanceVolumeIndicator(close, volume)` | `ft.OBV(close, volume)` | Exact match |
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| `CCIIndicator(high, low, close, window=N)` | `ft.CCI(high, low, close, timeperiod=N)` | Exact match |
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## Running the Cross-Library Tests
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Cross-library comparison tests live in `tests/integration/test_vs_ta.py`.
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They are automatically **skipped** when `ta` is not installed.
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```bash
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# Install ta first
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pip install ta
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# Run comparison tests
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pytest tests/integration/test_vs_ta.py -v
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```
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## Known Differences
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- **EMA seeding**: `ta` uses pandas `ewm` with `adjust=True` by default, which
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produces different warm-up values. Results converge after `2 × timeperiod` bars.
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- **ATR**: `ta` uses a simple rolling mean for ATR by default; ferro-ta uses
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Wilder's smoothing (same as TA-Lib). Values converge after the warm-up window.
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- **STOCH**: `ta` and ferro-ta use different default smoothing periods. Pass
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matching `window` / `smooth_window` values to get tail convergence.
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|
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## Performance Comparison
|
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|
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ferro-ta is significantly faster than `ta` for large arrays because the core
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computation is written in Rust:
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|
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```bash
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pytest benchmarks/test_speed.py --benchmark-only --benchmark-json=benchmarks/results.json
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```
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`ta` is a pure-Python/pandas library; ferro-ta processes 100k-bar arrays
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in microseconds vs milliseconds for pandas-based implementations.
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@@ -0,0 +1,27 @@
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# Compatibility: ferro-ta vs TA-Lib
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See the full migration guide at [docs/migration_talib.rst](../migration_talib.rst).
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ferro-ta is designed as a **drop-in replacement** for TA-Lib (`talib` Python package) for the most commonly used indicators.
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## Quick Reference
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```python
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# TA-Lib
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import talib
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result = talib.SMA(close, timeperiod=14)
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# ferro-ta (identical API)
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import ferro_ta
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result = ferro_ta.SMA(close, timeperiod=14)
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```
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Full migration guide including all indicator mappings, known differences, and step-by-step migration: [migration_talib.rst](../migration_talib.rst)
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## Running Cross-Library Tests
|
||||
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```bash
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# Requires TA-Lib C library + talib Python package
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pip install TA-Lib
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pytest tests/integration/test_vs_talib.py -v
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```
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@@ -0,0 +1,140 @@
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# ferro-ta ↔ Tulipy Compatibility
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[Tulipy](https://github.com/cirla/tulipy) is the Python binding for
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[Tulip Indicators](https://tulipindicators.org/) — 104 technical analysis
|
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functions written in pure ANSI C99, designed for absolute speed with zero
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||||
external dependencies.
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|
||||
---
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## Key architectural differences
|
||||
|
||||
| Aspect | ferro-ta | Tulipy |
|
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|--------|---------|--------|
|
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| **Backend** | Rust/C + SIMD | ANSI C99 |
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| **Input type** | NumPy array or list | `np.float64` contiguous array |
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| **Output length** | Same as input (NaN-padded) | Truncated (lookback bars shorter) |
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| **NaN handling** | Pads warmup with NaN | Strips warmup entirely |
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| **Multi-output** | Returns tuple | Returns tuple |
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| **Pandas support** | Yes (via `ArrayLike`) | No |
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| **Streaming** | Yes (StreamingXxx classes) | No |
|
||||
|
||||
---
|
||||
|
||||
## Output length difference
|
||||
|
||||
Tulipy **truncates** output instead of NaN-padding. When comparing results
|
||||
you must align by the **trailing** elements:
|
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```python
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import tulipy as ti
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import ferro_ta
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import numpy as np
|
||||
|
||||
close = np.ascontiguousarray(np.random.randn(100).cumsum() + 100, dtype=np.float64)
|
||||
|
||||
ti_sma = ti.sma(close, period=20) # len = 81
|
||||
ft_sma = ferro_ta.SMA(close, timeperiod=20) # len = 100 (19 leading NaN)
|
||||
|
||||
# Align: compare last 81 values
|
||||
n = len(ti_sma)
|
||||
assert np.allclose(ti_sma, ft_sma[-n:][np.isfinite(ft_sma[-n:])], atol=1e-8)
|
||||
```
|
||||
|
||||
---
|
||||
|
||||
## Function signature mapping
|
||||
|
||||
Tulipy uses lowercase function names. The `period` argument is always a
|
||||
positional-or-keyword integer.
|
||||
|
||||
| Indicator | ferro-ta | Tulipy |
|
||||
|-----------|---------|--------|
|
||||
| SMA | `SMA(close, timeperiod=20)` | `sma(close, period=20)` |
|
||||
| EMA | `EMA(close, timeperiod=20)` | `ema(close, period=20)` |
|
||||
| WMA | `WMA(close, timeperiod=14)` | `wma(close, period=14)` |
|
||||
| RSI | `RSI(close, timeperiod=14)` | `rsi(close, period=14)` |
|
||||
| MACD | `MACD(close, 12, 26, 9)` | `macd(close, short_period=12, long_period=26, signal_period=9)` |
|
||||
| BBANDS | `BBANDS(close, timeperiod=20, nbdevup=2.0, nbdevdn=2.0)` → (upper, mid, lower) | `bbands(close, period=20, stddev=2.0)` → (lower, mid, upper) ⚠️ reversed! |
|
||||
| ATR | `ATR(high, low, close, timeperiod=14)` | `atr(high, low, close, period=14)` |
|
||||
| OBV | `OBV(close, volume)` | `obv(close, volume)` |
|
||||
| CCI | `CCI(high, low, close, timeperiod=14)` | `cci(high, low, close, period=14)` |
|
||||
| WILLR | `WILLR(high, low, close, timeperiod=14)` | `willr(high, low, close, period=14)` |
|
||||
| STOCH | `STOCH(high, low, close, 5, 3, 3)` | `stoch(high, low, close, ...)` |
|
||||
| HMA | Not supported | `hma(close, period=14)` |
|
||||
| DEMA | `DEMA(close, timeperiod=30)` | `dema(close, period=30)` |
|
||||
| TEMA | `TEMA(close, timeperiod=30)` | `tema(close, period=30)` |
|
||||
| AROON | `AROONOSC(high, low, timeperiod=14)` | `aroonosc(high, low, period=14)` |
|
||||
| MFI | `MFI(high, low, close, volume, timeperiod=14)` | `mfi(high, low, close, volume, period=14)` |
|
||||
| TRANGE | `TRANGE(high, low, close)` | `tr(high, low, close)` |
|
||||
|
||||
⚠️ **BBANDS tuple order**: Tulipy returns `(lower, middle, upper)`;
|
||||
ferro-ta and TA-Lib return `(upper, middle, lower)`.
|
||||
|
||||
---
|
||||
|
||||
## Memory requirements
|
||||
|
||||
Tulipy requires **strictly contiguous** `np.float64` arrays. Passing a
|
||||
Pandas Series slice or a non-contiguous array causes an error:
|
||||
|
||||
```python
|
||||
# Wrong — may be a non-contiguous view
|
||||
close = df["close"].values
|
||||
ti.sma(close, period=20) # may raise ValueError
|
||||
|
||||
# Correct — explicit contiguous cast
|
||||
close = np.ascontiguousarray(df["close"].values, dtype=np.float64)
|
||||
ti.sma(close, period=20) # always works
|
||||
```
|
||||
|
||||
ferro-ta accepts any `ArrayLike` and handles the conversion internally.
|
||||
|
||||
---
|
||||
|
||||
## Numerical accuracy
|
||||
|
||||
Tulipy and ferro-ta agree closely for SMA, WMA, and other non-recursive
|
||||
indicators (differences < 1e-8). For EMA-based indicators the first
|
||||
`timeperiod` values differ due to initialisation seed choice:
|
||||
|
||||
- **Tulipy**: uses the first data value as the EMA seed.
|
||||
- **ferro-ta**: follows TA-Lib convention (SMA of first `timeperiod` bars).
|
||||
|
||||
Values converge after approximately 2–3× the `timeperiod`.
|
||||
|
||||
---
|
||||
|
||||
## Speed comparison
|
||||
|
||||
On 10,000 bars (median µs, Apple M-series):
|
||||
|
||||
| Indicator | ferro-ta | Tulipy | Winner |
|
||||
|-----------|--------:|-------:|--------|
|
||||
| SMA | 16.7 | 21.2 | ferro-ta |
|
||||
| MACD | 70.4 | 30.2 | Tulipy |
|
||||
| ATR | 51.4 | 27.6 | Tulipy |
|
||||
|
||||
Tulipy's C99 implementation excels for recursive indicators (ATR, MACD).
|
||||
ferro-ta is faster for sliding-window indicators (SMA) thanks to SIMD
|
||||
vectorisation.
|
||||
|
||||
---
|
||||
|
||||
## Migration guide
|
||||
|
||||
```python
|
||||
# FROM Tulipy
|
||||
import tulipy as ti
|
||||
import numpy as np
|
||||
|
||||
close = np.ascontiguousarray(close_series.values, dtype=np.float64)
|
||||
sma_values = ti.sma(close, period=20) # length: n - 19
|
||||
|
||||
# TO ferro-ta (drop-in, same numeric result in the tail)
|
||||
import ferro_ta
|
||||
|
||||
sma_values = ferro_ta.SMA(close, timeperiod=20) # length: n (19 leading NaN)
|
||||
# Strip warmup if needed:
|
||||
sma_values = sma_values[~np.isnan(sma_values)]
|
||||
```
|
||||
Reference in New Issue
Block a user