XY#

class lsst.images.XY(x: T, y: T)#

Bases: NamedTuple, Generic

A pair of per-dimension objects, ordered (x, y).

Notes#

XY is used for points and other 2-d pairs when the most natural ordering is (x, y). Because it is a tuple, however, arithmetic operations behave as they would on a collections.abc.Sequence, not a mathematical vector (e.g. adding concatenates).

In Pydantic models XY is serialized as a JSON object with x and y keys rather than an array, so the dimension order is explicit in the serialized form. Validation also accepts a two-element [x, y] array, the form emitted before the object form was introduced and still present in files that cannot be rewritten. Pydantic only invokes the schema hooks that provide this for bare XY annotations, however, because it handles parameterized named tuples specially; model fields that need a member type (e.g. XY[float]) must be annotated with SerializableXY instead.

See Also#

Attributes Summary

`x`	The x / column object.
`y`	The y / row object.
`yx`	A tuple of the same objects in the opposite order.

Methods Summary

`count`(value, /)	Return number of occurrences of value.
`index`(value[, start, stop])	Return first index of value.
`map`(func)	Apply a function to both objects.
`to_legacy_float_extent`()	Convert to a legacy `lsst.geom.Extent2D` object.
`to_legacy_float_point`()	Convert to a legacy `lsst.geom.Point2D` object.
`to_legacy_int_extent`()	Convert to a legacy `lsst.geom.Extent2I` object.
`to_legacy_int_point`()	Convert to a legacy `lsst.geom.Point2I` object.

Attributes Documentation

x: T#: The x / column object.

y: T#: The y / row object.

yx#: A tuple of the same objects in the opposite order.

Methods Documentation

count(value, /)#: Return number of occurrences of value.

index(value, start=0, stop=9223372036854775807, /)#

Return first index of value.

Raises ValueError if the value is not present.

map(func: Callable[[T], U]) → XY#

Apply a function to both objects.

Parameters#

func: Callable applied to each of the two objects in turn.

to_legacy_float_extent() → LegacyExtent2D#: Convert to a legacy lsst.geom.Extent2D object.

to_legacy_float_point() → LegacyPoint2D#: Convert to a legacy lsst.geom.Point2D object.

to_legacy_int_extent() → LegacyExtent2I#: Convert to a legacy lsst.geom.Extent2I object.

to_legacy_int_point() → LegacyPoint2I#: Convert to a legacy lsst.geom.Point2I object.