|
| 1 | +import pandas as pd |
| 2 | +import polars as pl |
| 3 | +from typing import Union |
| 4 | +from pyindicators.exceptions import PyIndicatorException |
| 5 | + |
| 6 | +from .utils import pad_zero_values_pandas, pad_zero_values_polars |
| 7 | + |
| 8 | + |
| 9 | +def adx( |
| 10 | + data: Union[pd.DataFrame, pl.DataFrame], |
| 11 | + period=14, |
| 12 | + high_column="High", |
| 13 | + low_column="Low", |
| 14 | + close_column="Close", |
| 15 | + result_adx_column="ADX", |
| 16 | + result_pdi_column="+DI", |
| 17 | + result_ndi_column="-DI", |
| 18 | +) -> Union[pd.DataFrame, pl.DataFrame]: |
| 19 | + """ |
| 20 | + Calculate the Average Directional Index (ADX) for a given DataFrame. |
| 21 | +
|
| 22 | + Args: |
| 23 | + data (Union[pd.DataFrame, pl.DataFrame]): Input data containing |
| 24 | + the price series. |
| 25 | + period (int, optional): Period for the ADX calculation (default: 14). |
| 26 | + high_column (str, optional): Column name for the high price series. |
| 27 | + low_column (str, optional): Column name for the low price series. |
| 28 | + close_column (str, optional): Column name for the close price series. |
| 29 | + result_adx_column (str, optional): Column name to store the ADX. |
| 30 | + result_pdi_column (str, optional): Column name to store the +DI. |
| 31 | + result_ndi_column (str, optional): Column name to store the -DI. |
| 32 | +
|
| 33 | + Returns: |
| 34 | + Union[pd.DataFrame, pl.DataFrame]: DataFrame with ADX, +DI, and -DI. |
| 35 | + """ |
| 36 | + |
| 37 | + # Check if the high, low, and close columns are in the DataFrame |
| 38 | + if high_column not in data.columns: |
| 39 | + raise PyIndicatorException( |
| 40 | + f"Column '{high_column}' not found in DataFrame" |
| 41 | + ) |
| 42 | + |
| 43 | + if low_column not in data.columns: |
| 44 | + raise PyIndicatorException( |
| 45 | + f"Column '{low_column}' not found in DataFrame" |
| 46 | + ) |
| 47 | + |
| 48 | + if close_column not in data.columns: |
| 49 | + raise PyIndicatorException( |
| 50 | + f"Column '{close_column}' not found in DataFrame" |
| 51 | + ) |
| 52 | + |
| 53 | + if isinstance(data, pd.DataFrame): |
| 54 | + # Pandas version of the ADX calculation |
| 55 | + high = data[high_column] |
| 56 | + low = data[low_column] |
| 57 | + close = data[close_column] |
| 58 | + |
| 59 | + # Calculate True Range (TR) |
| 60 | + tr = pd.DataFrame({ |
| 61 | + 'TR': pd.concat([ |
| 62 | + high - low, |
| 63 | + (high - close.shift(1)).abs(), |
| 64 | + (low - close.shift(1)).abs() |
| 65 | + ], axis=1).max(axis=1) |
| 66 | + }) |
| 67 | + |
| 68 | + # Calculate Directional Movement (+DM and -DM) |
| 69 | + plus_dm = pd.DataFrame( |
| 70 | + {'+DM': (high.diff() > low.diff()).astype(int) |
| 71 | + * (high.diff().clip(lower=0))} |
| 72 | + ) |
| 73 | + minus_dm = pd.DataFrame( |
| 74 | + {'-DM': (low.diff() > high.diff()).astype(int) |
| 75 | + * (-low.diff().clip(upper=0))} |
| 76 | + ) |
| 77 | + |
| 78 | + # Smooth the TR, +DM, and -DM over the period |
| 79 | + tr_smooth = tr['TR'].rolling(window=period).mean() |
| 80 | + plus_dm_smooth = plus_dm['+DM'].rolling(window=period).mean() |
| 81 | + minus_dm_smooth = minus_dm['-DM'].rolling(window=period).mean() |
| 82 | + |
| 83 | + # Calculate +DI and -DI |
| 84 | + pdi = 100 * (plus_dm_smooth / tr_smooth) |
| 85 | + ndi = 100 * (minus_dm_smooth / tr_smooth) |
| 86 | + |
| 87 | + # Smooth the difference to get ADX |
| 88 | + adx = pd.DataFrame({ |
| 89 | + result_adx_column: (pdi - ndi).abs().rolling(window=period).mean() |
| 90 | + }) |
| 91 | + |
| 92 | + # Add columns to the original dataframe |
| 93 | + data[result_adx_column] = adx |
| 94 | + data[result_pdi_column] = pdi |
| 95 | + data[result_ndi_column] = ndi |
| 96 | + |
| 97 | + pad_zero_values_pandas(data, result_adx_column, period) |
| 98 | + pad_zero_values_pandas(data, result_pdi_column, period - 1) |
| 99 | + pad_zero_values_pandas(data, result_ndi_column, period - 1) |
| 100 | + return data |
| 101 | + |
| 102 | + elif isinstance(data, pl.DataFrame): |
| 103 | + # Polars version of the ADX calculation |
| 104 | + high = data[high_column] |
| 105 | + low = data[low_column] |
| 106 | + close = data[close_column] |
| 107 | + |
| 108 | + # Calculate True Range (TR) |
| 109 | + tr = pl.max_horizontal([ |
| 110 | + high - low, |
| 111 | + (high - close.shift(1)).abs(), |
| 112 | + (low - close.shift(1)).abs() |
| 113 | + ]) |
| 114 | + |
| 115 | + # Calculate Directional Movement (+DM and -DM) |
| 116 | + plus_dm = high.diff().clip_min(0) |
| 117 | + minus_dm = (-low.diff()).clip_min(0).abs() |
| 118 | + |
| 119 | + # Smooth the TR, +DM, and -DM over the period |
| 120 | + # (use rolling sum, not mean) |
| 121 | + tr_smooth = tr.rolling_sum(window_size=period, min_periods=1) |
| 122 | + plus_dm_smooth = plus_dm.rolling_sum(window_size=period, min_periods=1) |
| 123 | + minus_dm_smooth = minus_dm.rolling_sum( |
| 124 | + window_size=period, min_periods=1 |
| 125 | + ) |
| 126 | + |
| 127 | + # Calculate +DI and -DI |
| 128 | + pdi = 100 * (plus_dm_smooth / tr_smooth) |
| 129 | + ndi = 100 * (minus_dm_smooth / tr_smooth) |
| 130 | + |
| 131 | + # Calculate ADX (average of the absolute difference |
| 132 | + # between +DI and -DI) |
| 133 | + |
| 134 | + di_diff = (pdi - ndi).abs() |
| 135 | + # Smooth the difference to get ADX |
| 136 | + adx = di_diff.rolling_mean(window_size=period) |
| 137 | + |
| 138 | + # Add columns to the original dataframe |
| 139 | + data = data.with_columns([ |
| 140 | + adx.alias(result_adx_column), |
| 141 | + pdi.alias(result_pdi_column), |
| 142 | + ndi.alias(result_ndi_column) |
| 143 | + ]) |
| 144 | + |
| 145 | + # Pad the first `period` rows with zero values |
| 146 | + data = pad_zero_values_polars(data, result_adx_column, period) |
| 147 | + data = pad_zero_values_polars(data, result_pdi_column, period - 1) |
| 148 | + data = pad_zero_values_polars(data, result_ndi_column, period - 1) |
| 149 | + |
| 150 | + return data |
| 151 | + else: |
| 152 | + raise PyIndicatorException( |
| 153 | + "Input data must be either a pandas or polars DataFrame." |
| 154 | + ) |
| 155 | + |
| 156 | + |
| 157 | +def adx_v2( |
| 158 | + data: Union[pd.DataFrame, pl.DataFrame], |
| 159 | + period=14, |
| 160 | + high_column="High", |
| 161 | + low_column="Low", |
| 162 | + close_column="Close", |
| 163 | + result_adx_column="ADX", |
| 164 | + result_pdi_column="+DI", |
| 165 | + result_ndi_column="-DI", |
| 166 | +) -> Union[pd.DataFrame, pl.DataFrame]: |
| 167 | + """ |
| 168 | + Calculate the Average Directional Index (ADX) using Wilder's smoothing. |
| 169 | + Matches Tulipy's ADX calculation. |
| 170 | +
|
| 171 | + Args: |
| 172 | + data: Input DataFrame (Pandas or Polars). |
| 173 | + period: Period for the ADX calculation (default: 14). |
| 174 | + high_column, low_column, close_column: Column names for price data. |
| 175 | + result_adx_column, result_pdi_column, |
| 176 | + result_ndi_column: Output column names. |
| 177 | +
|
| 178 | + Returns: |
| 179 | + DataFrame with ADX, +DI, and -DI. |
| 180 | + """ |
| 181 | + if high_column not in data.columns \ |
| 182 | + or low_column not in data.columns \ |
| 183 | + or close_column not in data.columns: |
| 184 | + raise PyIndicatorException( |
| 185 | + "High, Low, or Close column not found in DataFrame." |
| 186 | + ) |
| 187 | + |
| 188 | + if isinstance(data, pd.DataFrame): |
| 189 | + # Pandas version |
| 190 | + high, low, close = data[high_column], data[low_column], \ |
| 191 | + data[close_column] |
| 192 | + |
| 193 | + tr = pd.concat([ |
| 194 | + high - low, |
| 195 | + (high - close.shift(1)).abs(), |
| 196 | + (low - close.shift(1)).abs() |
| 197 | + ], axis=1).max(axis=1) |
| 198 | + |
| 199 | + plus_dm = high.diff().clip(lower=0) |
| 200 | + minus_dm = -low.diff().clip(upper=0) |
| 201 | + |
| 202 | + # Wilder’s smoothing with EMA |
| 203 | + tr_smooth = tr.ewm(span=period, adjust=False).mean() |
| 204 | + plus_dm_smooth = plus_dm.ewm(span=period, adjust=False).mean() |
| 205 | + minus_dm_smooth = minus_dm.ewm(span=period, adjust=False).mean() |
| 206 | + |
| 207 | + pdi = 100 * (plus_dm_smooth / tr_smooth) |
| 208 | + ndi = 100 * (minus_dm_smooth / tr_smooth) |
| 209 | + adx = (100 * (pdi - ndi).abs().ewm(span=period, adjust=False).mean()) |
| 210 | + |
| 211 | + # Add results to DataFrame |
| 212 | + data[result_adx_column] = adx |
| 213 | + data[result_pdi_column] = pdi |
| 214 | + data[result_ndi_column] = ndi |
| 215 | + |
| 216 | + # Pad with zeros |
| 217 | + pad_zero_values_pandas(data, result_adx_column, period) |
| 218 | + pad_zero_values_pandas(data, result_pdi_column, period - 1) |
| 219 | + pad_zero_values_pandas(data, result_ndi_column, period - 1) |
| 220 | + |
| 221 | + return data |
| 222 | + |
| 223 | + elif isinstance(data, pl.DataFrame): |
| 224 | + # Polars version |
| 225 | + high, low, close = data[high_column], data[low_column], \ |
| 226 | + data[close_column] |
| 227 | + |
| 228 | + tr = pl.max_horizontal([ |
| 229 | + high - low, |
| 230 | + (high - close.shift(1)).abs(), |
| 231 | + (low - close.shift(1)).abs() |
| 232 | + ]) |
| 233 | + |
| 234 | + plus_dm = high.diff().clip_min(0) |
| 235 | + minus_dm = (-low.diff()).clip_min(0).abs() |
| 236 | + |
| 237 | + # Wilder’s smoothing (manual EMA for Polars) |
| 238 | + def wilder_ema(series, period): |
| 239 | + alpha = 1 / period |
| 240 | + return series.cumsum() * alpha |
| 241 | + |
| 242 | + tr_smooth = wilder_ema(tr, period) |
| 243 | + plus_dm_smooth = wilder_ema(plus_dm, period) |
| 244 | + minus_dm_smooth = wilder_ema(minus_dm, period) |
| 245 | + |
| 246 | + pdi = 100 * (plus_dm_smooth / tr_smooth) |
| 247 | + ndi = 100 * (minus_dm_smooth / tr_smooth) |
| 248 | + adx = (100 * (pdi - ndi).abs()).cumsum() / period |
| 249 | + |
| 250 | + # Add results to DataFrame |
| 251 | + data = data.with_columns([ |
| 252 | + adx.alias(result_adx_column), |
| 253 | + pdi.alias(result_pdi_column), |
| 254 | + ndi.alias(result_ndi_column) |
| 255 | + ]) |
| 256 | + |
| 257 | + # Pad with zeros |
| 258 | + data = pad_zero_values_polars(data, result_adx_column, period) |
| 259 | + data = pad_zero_values_polars(data, result_pdi_column, period - 1) |
| 260 | + data = pad_zero_values_polars(data, result_ndi_column, period - 1) |
| 261 | + |
| 262 | + return data |
| 263 | + |
| 264 | + else: |
| 265 | + raise PyIndicatorException( |
| 266 | + "Input data must be either a pandas or polars DataFrame." |
| 267 | + ) |
| 268 | + |
| 269 | + |
| 270 | +def di( |
| 271 | + data: Union[pd.DataFrame, pl.DataFrame], |
| 272 | + period=14, |
| 273 | + high_column="High", |
| 274 | + low_column="Low", |
| 275 | + close_column="Close", |
| 276 | + result_pdi_column="+DI", |
| 277 | + result_ndi_column="-DI", |
| 278 | +) -> Union[pd.DataFrame, pl.DataFrame]: |
| 279 | + """ |
| 280 | + Calculate the +DI and -DI indicators exactly like Tulipy, |
| 281 | + supporting both Pandas and Polars. |
| 282 | +
|
| 283 | + Args: |
| 284 | + data (Union[pd.DataFrame, pl.DataFrame]): Input data |
| 285 | + containing the price series. |
| 286 | + period (int, optional): Period for the DI calculation (default: 14). |
| 287 | + high_column (str, optional): Column name for the high price series. |
| 288 | + low_column (str, optional): Column name for the low price series. |
| 289 | + close_column (str, optional): Column name for the close price series. |
| 290 | + result_pdi_column (str, optional): Column name to store the +DI. |
| 291 | + result_ndi_column (str, optional): Column name to store the -DI. |
| 292 | +
|
| 293 | + Returns: |
| 294 | + Union[pd.DataFrame, pl.DataFrame]: DataFrame with +DI and -DI. |
| 295 | + """ |
| 296 | + |
| 297 | + if isinstance(data, pd.DataFrame): |
| 298 | + high = data[high_column] |
| 299 | + low = data[low_column] |
| 300 | + close = data[close_column] |
| 301 | + |
| 302 | + # True Range |
| 303 | + tr = pd.concat([ |
| 304 | + high - low, |
| 305 | + (high - close.shift(1)).abs(), |
| 306 | + (low - close.shift(1)).abs() |
| 307 | + ], axis=1).max(axis=1) |
| 308 | + |
| 309 | + # Directional Movement |
| 310 | + plus_dm = ( |
| 311 | + (high.diff() > low.shift(1) - low) & (high.diff() > 0) |
| 312 | + ) * high.diff() |
| 313 | + minus_dm = ( |
| 314 | + (low.shift(1) - low > high.diff()) & (low.shift(1) - low > 0) |
| 315 | + ) * (low.shift(1) - low) |
| 316 | + |
| 317 | + # Smoothed values |
| 318 | + tr_smooth = tr.rolling(window=period).sum() |
| 319 | + plus_dm_smooth = plus_dm.rolling(window=period).sum() |
| 320 | + minus_dm_smooth = minus_dm.rolling(window=period).sum() |
| 321 | + |
| 322 | + # Calculate +DI and -DI |
| 323 | + pdi = 100 * (plus_dm_smooth / tr_smooth) |
| 324 | + ndi = 100 * (minus_dm_smooth / tr_smooth) |
| 325 | + |
| 326 | + # Add to DataFrame |
| 327 | + data[result_pdi_column] = pdi |
| 328 | + data[result_ndi_column] = ndi |
| 329 | + |
| 330 | + # Pad initial values with zero |
| 331 | + # (replace NaN values for first `period-1` rows) |
| 332 | + data[result_pdi_column].iloc[:period-1] = 0 |
| 333 | + data[result_ndi_column].iloc[:period-1] = 0 |
| 334 | + |
| 335 | + return data |
| 336 | + |
| 337 | + elif isinstance(data, pl.DataFrame): |
| 338 | + high = data[high_column] |
| 339 | + low = data[low_column] |
| 340 | + close = data[close_column] |
| 341 | + |
| 342 | + # True Range |
| 343 | + tr = pl.max_horizontal([ |
| 344 | + high - low, |
| 345 | + (high - close.shift(1)).abs(), |
| 346 | + (low - close.shift(1)).abs() |
| 347 | + ]) |
| 348 | + |
| 349 | + # Directional Movement |
| 350 | + plus_dm = (high.diff() > low.shift(1) - low) & (high.diff() > 0) |
| 351 | + plus_dm = plus_dm * high.diff() |
| 352 | + |
| 353 | + minus_dm = ( |
| 354 | + low.shift(1) - low > high.diff() |
| 355 | + ) & (low.shift(1) - low > 0) |
| 356 | + minus_dm = minus_dm * (low.shift(1) - low) |
| 357 | + |
| 358 | + # Smoothed values |
| 359 | + tr_smooth = tr.rolling_sum(window_size=period) |
| 360 | + plus_dm_smooth = plus_dm.rolling_sum(window_size=period) |
| 361 | + minus_dm_smooth = minus_dm.rolling_sum(window_size=period) |
| 362 | + |
| 363 | + # Calculate +DI and -DI |
| 364 | + pdi = 100 * (plus_dm_smooth / tr_smooth) |
| 365 | + ndi = 100 * (minus_dm_smooth / tr_smooth) |
| 366 | + |
| 367 | + # Add to DataFrame |
| 368 | + data = data.with_columns([ |
| 369 | + pdi.alias(result_pdi_column), |
| 370 | + ndi.alias(result_ndi_column) |
| 371 | + ]) |
| 372 | + |
| 373 | + # Pad initial values with zero |
| 374 | + # (replace NaN values for first `period-1` rows) |
| 375 | + data = data.with_columns([ |
| 376 | + pl.when(pl.col(result_pdi_column).is_null()).then(0) |
| 377 | + .otherwise(pl.col(result_pdi_column)).alias(result_pdi_column), |
| 378 | + pl.when(pl.col(result_ndi_column).is_null()).then(0) |
| 379 | + .otherwise(pl.col(result_ndi_column)).alias(result_ndi_column) |
| 380 | + ]) |
| 381 | + |
| 382 | + return data |
| 383 | + |
| 384 | + else: |
| 385 | + raise ValueError( |
| 386 | + "Input data must be either a pandas or polars DataFrame." |
| 387 | + ) |
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