warp.tile_view#

warp.tile_view( t: Tile[Any, tuple[int, ...]], offset: tuple, shape: tuple[int, ...] = ..., ) → Tile[Any, tuple[int, ...]]#

Kernel: true
Python: false
Differentiable: false

Return a view of a tile.

The view aliases the source tile: writing through it modifies t. Taking a view requires shared storage, but the view itself is non-owning and allocates no additional storage.

Two forms are supported:

When shape is omitted, entries in offset map from left to right to the dimensions of t. Integer entries select and remove dimensions; for example, wp.tile_view(t, offset=(i,)) on an (M, N) tile returns row i with shape=(N,). Python slice entries select ranges and retain dimensions, with each extent determined by its slice. Omitted trailing dimensions are retained in full. Tile subscript syntax such as t[2:4, ::-1] produces this form.
When shape is provided, offset gives the origin of a rectangular view and shape gives its extent. In this form, supplied offset entries must be integers; slices are not allowed.

Parameters:

t – Input tile to take a view of
offset – Integer indices, Python slice objects, or a mix describing the part of t to view. Integer entries may be runtime values; constant integer entries must lie within the corresponding dimension of t. Runtime integer bounds are checked in debug mode; in all modes, out-of-range values are invalid. Slice bounds and steps must be compile-time constants; negative bounds and steps are supported. Use subscript syntax such as t[-1, :] for negative integer indexing.
shape – Extent of the view, with one entry per dimension of t. Entries must be compile-time constants, and for every dimension d, offset[d] + shape[d] must not exceed t.shape[d]. Only valid when offset contains no slices.

Returns:

A non-owning tile that aliases t, with dimensions given by shape, by the inferred slice extents, or by the source dimensions that offset did not name.

Example

@wp.kernel
def replace_rows(a: wp.array2d[float], out: wp.array2d[float]):
    t = wp.tile_load(a, shape=(4, 4))

    # the view aliases t, so writing through it updates t
    rows = wp.tile_view(t, offset=(2, 0), shape=(2, 4))
    values = wp.tile_arange(100.0, 108.0, 1.0, dtype=float)
    wp.tile_assign(rows, wp.tile_reshape(values, shape=(2, 4)))

    wp.tile_store(out, t)

a = wp.array(np.arange(16, dtype=np.float32).reshape(4, 4), dtype=float)
out = wp.zeros((4, 4), dtype=float)

wp.launch_tiled(replace_rows, dim=1, inputs=[a], outputs=[out], block_dim=8)

print(out.numpy())

[[  0.   1.   2.   3.]
 [  4.   5.   6.   7.]
 [100. 101. 102. 103.]
 [104. 105. 106. 107.]]