Return a new array with the same shape and type as a given array. Parameters ---------- a : array_like The shape and data-type of `a` define these same attributes of the returned array. dtype : data-type, optional Overrides the data type of the result.
(a, dtype=None, order="C", chunks=None, name=None, shape=None)
| 287 | |
| 288 | |
| 289 | def empty_like(a, dtype=None, order="C", chunks=None, name=None, shape=None): |
| 290 | """ |
| 291 | Return a new array with the same shape and type as a given array. |
| 292 | |
| 293 | Parameters |
| 294 | ---------- |
| 295 | a : array_like |
| 296 | The shape and data-type of `a` define these same attributes of the |
| 297 | returned array. |
| 298 | dtype : data-type, optional |
| 299 | Overrides the data type of the result. |
| 300 | order : {'C', 'F'}, optional |
| 301 | Whether to store multidimensional data in C- or Fortran-contiguous |
| 302 | (row- or column-wise) order in memory. |
| 303 | chunks : sequence of ints |
| 304 | The number of samples on each block. Note that the last block will have |
| 305 | fewer samples if ``len(array) % chunks != 0``. |
| 306 | name : str, optional |
| 307 | An optional keyname for the array. Defaults to hashing the input |
| 308 | keyword arguments. |
| 309 | shape : int or sequence of ints, optional. |
| 310 | Overrides the shape of the result. |
| 311 | |
| 312 | Returns |
| 313 | ------- |
| 314 | out : ndarray |
| 315 | Array of uninitialized (arbitrary) data with the same |
| 316 | shape and type as `a`. |
| 317 | |
| 318 | See Also |
| 319 | -------- |
| 320 | ones_like : Return an array of ones with shape and type of input. |
| 321 | zeros_like : Return an array of zeros with shape and type of input. |
| 322 | empty : Return a new uninitialized array. |
| 323 | ones : Return a new array setting values to one. |
| 324 | zeros : Return a new array setting values to zero. |
| 325 | |
| 326 | Notes |
| 327 | ----- |
| 328 | This function does *not* initialize the returned array; to do that use |
| 329 | `zeros_like` or `ones_like` instead. It may be marginally faster than |
| 330 | the functions that do set the array values. |
| 331 | """ |
| 332 | |
| 333 | a = asarray(a, name=False) |
| 334 | shape, chunks = _get_like_function_shapes_chunks(a, chunks, shape) |
| 335 | |
| 336 | # if shape is nan we cannot rely on regular empty function, we use |
| 337 | # generic map_blocks. |
| 338 | if np.isnan(shape).any(): |
| 339 | return a.map_blocks(partial(np.empty_like, dtype=(dtype or a.dtype))) |
| 340 | |
| 341 | return empty( |
| 342 | shape, |
| 343 | dtype=(dtype or a.dtype), |
| 344 | order=order, |
| 345 | chunks=chunks, |
| 346 | name=name, |
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