chronaxis.extensions.TransformSpec

from chronaxis.extensions import TransformSpec

`TransformSpec`

Declare a stateful grid-transform factory, factory(resources). advance(time_ns, window_ns, values, weights_ns) calculates each window value.

python

TransformSpec(name: str, version: str, input: chronaxis.extensions.ValueSpec, output: chronaxis.extensions.ValueSpec, reference: object = None, numpy: object = None, state_bytes: int = 0, history_ns: int = 0, interval_modes: tuple[str, ...] = ('actual', 'fixed', 'dbc')) -> None

Name	Type	Required	Default	Purpose
`name`	str	Yes	No default	Expression identifier, unique in the registry and distinct from built-in operations.
`version`	str	Yes	No default	Nonempty implementation version; the host must change it when implementation behavior changes.
`input`	chronaxis.extensions.ValueSpec	Yes	No default	One ValueSpec numeric port with a registered unit; BOOL and ENUM are not accepted.
`output`	chronaxis.extensions.ValueSpec	Yes	No default	Output ValueSpec port declaring the callback result dtype and unit.
`reference`	object	No	None	State factory `factory(resources)`, creating one object per session with required advance(time_ns, window_ns, values, weights_ns), cancel() and close(). advance receives the actual output time, measured window width, valid ScalarValue tuple and corresponding duration weights, returning a ScalarValue matching output. Time values use ns. None disables reference; provide at least one backend.
`numpy`	object	No	None	State factory `factory(resources)`, with the same required methods as reference. advance receives a valid NumericArray as values and a matching duration array as weights_ns, and returns ScalarValue. None disables numpy; no reference factory fallback is used.
`state_bytes`	int	No	0	Nonnegative integer state reservation in bytes, declared by the host for actual state needs.
`history_ns`	int	No	0	Explicit positive int64 lookback width in ns, measured using the selected actual or periodic interval mode. The default 0 is not a valid declaration.
`interval_modes`	tuple[str, ...]	No	('actual', 'fixed', 'dbc')	Nonempty unique tuple drawn from actual/fixed/dbc. Declare only the weighting modes implemented correctly.

Returns

Immutable TransformSpec declaration.

Raises

ValueError/TypeError for invalid ports, resources, history width, or duplicate/unknown interval_modes. Both ports must be numeric.

Execution and resources

Creates state per session. advance receives valid zero-order-hold spans and weights and returns a ScalarValue at the grid time. History and state use the shared budget; close releases resources.

Declare ports with from chronaxis.extensions import ValueSpec and from chronaxis.core.types import SignalDType. For example, ValueSpec(SignalDType.FLOAT64, "A") declares a numeric current port.

`require_backend`

python

TransformSpec.require_backend(backend)

Inherited method: backend is required and must be reference or numpy. Returns that registered callback/factory; raises ValueError for an unknown or unsupported backend.

Worked host example

Source: src/chronaxis/extensions.py:117 (line at 8904c2f744951857659abd40aaa3535d57faf53c).