tff.templates.EstimationProcess

A stateful process that can compute an estimate of some value.

Inherits From: IterativeProcess

tff.templates.EstimationProcess(
    initialize_fn: tff.Computation,
    next_fn: tff.Computation,
    report_fn: tff.Computation,
    next_is_multi_arg: Optional[bool] = None
)

This class inherits the constraints documented by tff.templates.IterativeProcess.

A tff.templates.EstimationProcess is an tff.templates.IterativeProcess that in addition to the initialize and next functions, has a report function that returns the result of some computation based on the state of the process. The argument of report must be of the same type as the state, that is, the type of object returned by initialize.

initialize_fn A no-arg tff.Computation that returns the initial state of the estimation process. Let the type of this state be called S.
next_fn A tff.Computation that represents the iterated function. The first or only argument must match the state type S. The first or only return value must also match state type S.
report_fn A tff.Computation that represents the estimation based on state. Its input argument must match the state type S.
next_is_multi_arg An optional boolean indicating that next_fn will receive more than just the state argument (if True) or only the state argument (if False). This parameter is primarily used to provide better error messages.

TypeError If initialize_fn, next_fn and report_fn are not instances of tff.Computation.
TemplateInitFnParamNotEmptyError If initialize_fn has any input arguments.
TemplateStateNotAssignableError If the state returned by either initialize_fn or next_fn is not assignable to the first input argument of next_fn and report_fn.

initialize A no-arg tff.Computation that returns the initial state.
next A tff.Computation that produces the next state.

Its first argument should always be the current state (originally produced by tff.templates.IterativeProcess.initialize), and the first (or only) returned value is the updated state.

report A tff.Computation that computes the current estimate from state.

Given a state controlled by this process, computes and returns the most recent estimate of the estimated value.

state_type The tff.Type of the state of the process.

Methods

map

View source

map(
    map_fn: tff.Computation
)

Applies map_fn to the estimate function of the process.

This method will return a new instance of EstimationProcess with the same initailize and next functions, and its report function replaced by map_fn(report(state)).

Args
map_fn A tff.Computation to apply to the result of the report function of the process. Must accept the return type of report.

Returns
An EstimationProcess.

Raises
EstimateNotAssignableError If the return type of report is not assignable to the expected input type of map_fn.