zarr_indexing.domain
zarr_indexing.domain ¶
Index domains — rectangular regions in N-dimensional integer space.
An IndexDomain represents the set of valid coordinates for an array or
array view. It is the cartesian product of per-dimension integer ranges::
IndexDomain(inclusive_min=(2, 5), exclusive_max=(10, 20))
# represents {(i, j) : 2 <= i < 10, 5 <= j < 20}
Unlike NumPy, domains can have non-zero origins. After slicing
arr[5:10], the result has origin 5 and shape 5 — coordinates 5 through
9 are valid. This follows the TensorStore convention.
IndexDomain
dataclass
¶
A rectangular region in N-dimensional index space.
The valid coordinates are the integers in
[inclusive_min[d], exclusive_max[d]) for each dimension d.
Examples:
Unlike a NumPy shape, a domain keeps literal coordinates: narrowing to
[5, 10) gives a region whose valid coordinates are 5 through 9, not
re-zeroed:
>>> view = IndexDomain.from_shape((10,)).narrow(slice(5, 10))
>>> view.origin, view.shape
((5,), (5,))
>>> view.contains((5,)), view.contains((0,))
(True, False)
Source code in src/zarr_indexing/domain.py
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exclusive_max
instance-attribute
¶
Each dimension's upper bound, excluded: valid coordinates end at exclusive_max - 1.
inclusive_min
instance-attribute
¶
The lower corner: each dimension's smallest literal coordinate. May be negative.
labels
class-attribute
instance-attribute
¶
Optional per-dimension names; carried through the wire format, never consulted by indexing.
origin
property
¶
The lower corner of the domain — an alias for inclusive_min, and may be negative.
shape
property
¶
Per-dimension extents: exclusive_max - inclusive_min for each dimension.
__init__ ¶
__init__(
inclusive_min: tuple[int, ...],
exclusive_max: tuple[int, ...],
labels: tuple[str, ...] | None = None,
) -> None
__post_init__ ¶
Source code in src/zarr_indexing/domain.py
contains ¶
Whether the literal coordinate index lies inside this domain.
Coordinates are literal, not NumPy-style offsets: a negative value is
the coordinate itself, valid only if the domain's bounds include it.
A tuple of the wrong length is simply not contained (returns False).
Source code in src/zarr_indexing/domain.py
contains_domain ¶
contains_domain(other: IndexDomain) -> bool
Whether every coordinate of other lies inside this domain.
An empty other within this domain's bounds is contained. A rank
mismatch returns False rather than raising.
Source code in src/zarr_indexing/domain.py
from_json
classmethod
¶
from_json(data: IndexDomainJSON) -> IndexDomain
Construct from the canonical ndsel JSON representation.
The document is validated by the message layer first, exactly as a
transform body is. Reading the keys directly would be a second,
undefended way into the same objects: int(value) alone accepts
3.9, "3" and True, and each of those builds a domain that is
not the document's.
Examples:
>>> domain = IndexDomain.from_json(
... {"input_inclusive_min": [1], "input_exclusive_max": [4], "input_labels": [""]}
... )
>>> (domain.inclusive_min, domain.exclusive_max, domain.shape)
((1,), (4,), (3,))
>>> IndexDomain.from_json(domain.to_json()) == domain
True
Source code in src/zarr_indexing/domain.py
from_shape
classmethod
¶
from_shape(shape: tuple[int, ...]) -> IndexDomain
intersect ¶
intersect(other: IndexDomain) -> IndexDomain | None
Return the overlap of this domain with other, or None if they are disjoint.
Raises:
-
ValueError–If the two domains have different ranks.
Source code in src/zarr_indexing/domain.py
narrow ¶
narrow(selection: Any) -> IndexDomain
Apply a basic selection and return a narrowed domain.
Indices are absolute coordinates, not NumPy-style offsets: -3 names
the coordinate -3, and is out of bounds unless the domain contains it.
Integer indices produce a length-1 extent. Strided slices are not
supported — use IndexTransform for strides.
Raises:
-
BoundsCheckError–If a bound lies outside this domain. A slice bound used to be clamped instead, so
narrow(slice(-3, None))on[0, 10)quietly returned the whole axis — reading as the NumPy spelling of "the last three" and answering with something else — andnarrow(slice(20, 30))returned a domain its own parent did not contain. The rest of the algebra states no clamping and no negative wrapping as an invariant and enforces it; this is the one place that did not.
Source code in src/zarr_indexing/domain.py
to_json ¶
to_json() -> IndexDomainJSON
Convert to the canonical ndsel JSON representation.
Examples:
>>> IndexDomain(inclusive_min=(0,), exclusive_max=(3,)).to_json()
{'input_inclusive_min': [0], 'input_exclusive_max': [3], 'input_labels': ['']}
Source code in src/zarr_indexing/domain.py
translate ¶
translate(offset: tuple[int, ...]) -> IndexDomain
Return this domain shifted by offset per dimension; the shape is unchanged.
Offsets may be negative, and the result may have a negative origin.
Raises:
-
ValueError–If
offsetdoes not have one entry per dimension.