Assemble an nd-array from nested lists of blocks. Blocks in the innermost lists are concatenated along the last dimension (-1), then these are concatenated along the second-last dimension (-2), and so on until the outermost list is reached Blocks can be of any dimension, but w
(arrays, allow_unknown_chunksizes=False)
| 4449 | |
| 4450 | |
| 4451 | def block(arrays, allow_unknown_chunksizes=False): |
| 4452 | """ |
| 4453 | Assemble an nd-array from nested lists of blocks. |
| 4454 | |
| 4455 | Blocks in the innermost lists are concatenated along the last |
| 4456 | dimension (-1), then these are concatenated along the second-last |
| 4457 | dimension (-2), and so on until the outermost list is reached |
| 4458 | |
| 4459 | Blocks can be of any dimension, but will not be broadcasted using the normal |
| 4460 | rules. Instead, leading axes of size 1 are inserted, to make ``block.ndim`` |
| 4461 | the same for all blocks. This is primarily useful for working with scalars, |
| 4462 | and means that code like ``block([v, 1])`` is valid, where |
| 4463 | ``v.ndim == 1``. |
| 4464 | |
| 4465 | When the nested list is two levels deep, this allows block matrices to be |
| 4466 | constructed from their components. |
| 4467 | |
| 4468 | Parameters |
| 4469 | ---------- |
| 4470 | arrays : nested list of array_like or scalars (but not tuples) |
| 4471 | If passed a single ndarray or scalar (a nested list of depth 0), this |
| 4472 | is returned unmodified (and not copied). |
| 4473 | |
| 4474 | Elements shapes must match along the appropriate axes (without |
| 4475 | broadcasting), but leading 1s will be prepended to the shape as |
| 4476 | necessary to make the dimensions match. |
| 4477 | |
| 4478 | allow_unknown_chunksizes: bool |
| 4479 | Allow unknown chunksizes, such as come from converting from dask |
| 4480 | dataframes. Dask.array is unable to verify that chunks line up. If |
| 4481 | data comes from differently aligned sources then this can cause |
| 4482 | unexpected results. |
| 4483 | |
| 4484 | Returns |
| 4485 | ------- |
| 4486 | block_array : ndarray |
| 4487 | The array assembled from the given blocks. |
| 4488 | |
| 4489 | The dimensionality of the output is equal to the greatest of: |
| 4490 | * the dimensionality of all the inputs |
| 4491 | * the depth to which the input list is nested |
| 4492 | |
| 4493 | Raises |
| 4494 | ------ |
| 4495 | ValueError |
| 4496 | * If list depths are mismatched - for instance, ``[[a, b], c]`` is |
| 4497 | illegal, and should be spelt ``[[a, b], [c]]`` |
| 4498 | * If lists are empty - for instance, ``[[a, b], []]`` |
| 4499 | |
| 4500 | See Also |
| 4501 | -------- |
| 4502 | concatenate : Join a sequence of arrays together. |
| 4503 | stack : Stack arrays in sequence along a new dimension. |
| 4504 | hstack : Stack arrays in sequence horizontally (column wise). |
| 4505 | vstack : Stack arrays in sequence vertically (row wise). |
| 4506 | dstack : Stack arrays in sequence depth wise (along third dimension). |
| 4507 | vsplit : Split array into a list of multiple sub-arrays vertically. |
| 4508 |
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