`Identity`#

Description#

The Identity function returns each input unchanged. It is a no-op transform whose only purpose is to act as a placeholder in pipelines: a slot that has the same call signature as any other transform but does nothing to the data.

Equation:

\[ y[t] = x[t] \]

Parameters: Identity takes no parameters.

NaN handling: Inputs pass through bit-for-bit, including NaN and infinities.

NaN handling#

Policy: ignore. A NaN in any input at index t causes the function to skip that step: output at t is NaN and internal state is unchanged. Subsequent finite samples are processed as if step t had not occurred.

Examples#

Usage example#

from screamer import Identity, RollingMean

# A pipeline slot that can later be swapped for a real transform.
preproc = Identity()
smoother = RollingMean(10)

stream = (smoother(preproc(v)) for v in source)

Reference#

Conceptually equivalent to the identity function lambda x: x. It exists as a class so it can be slotted in anywhere a ScreamerBase is expected.

Identity#