feed.api.float.window.expanding module

expanding.py contains functions and classes for expanding stream operations.

class feed.api.float.window.expanding.Expanding(min_periods: int = 1)

Bases: feed.core.base.Stream

A stream that generates the entire history of a stream at each time step.

Parameters:min_periods (int, default 1) – The number of periods to wait before producing values from the aggregation function.

agg(func: Callable[[List[float]], float]) → feed.core.base.Stream[float][float]

Computes an aggregation of a stream’s history.

Parameters:func (Callable[[List[float]], float]) – A aggregation function. Returns:A stream producing aggregations of the stream history at each time step. Return type:Stream[float]

count() → feed.core.base.Stream[float][float]

Computes an expanding count fo the underlying stream.

Returns:An expanding count stream. Return type:Stream[float]

forward() → List[float]

Generates the next value from the underlying data streams.

Returns:The next value in the stream. Return type:T

generic_name = 'expanding'

has_next() → bool

Checks if there is another value.

Returns:If there is another value or not. Return type:bool

max() → feed.core.base.Stream[float][float]

Computes an expanding maximum fo the underlying stream.

Returns:An expanding maximum stream. Return type:Stream[float]

mean() → feed.core.base.Stream[float][float]

Computes an expanding mean fo the underlying stream.

Returns:An expanding mean stream. Return type:Stream[float]

median() → feed.core.base.Stream[float][float]

Computes an expanding median fo the underlying stream.

Returns:An expanding median stream. Return type:Stream[float]

min() → feed.core.base.Stream[float][float]

Computes an expanding minimum fo the underlying stream.

Returns:An expanding minimum stream. Return type:Stream[float]

reset() → None

Resets all the listeners of the stream.

std() → feed.core.base.Stream[float][float]

Computes an expanding standard deviation fo the underlying stream.

Returns:An expanding standard deviation stream. Return type:Stream[float]

sum() → feed.core.base.Stream[float][float]

Computes an expanding sum fo the underlying stream.

Returns:An expanding sum stream. Return type:Stream[float]

var() → feed.core.base.Stream[float][float]

Computes an expanding variance fo the underlying stream.

Returns:An expanding variance stream. Return type:Stream[float]

class feed.api.float.window.expanding.ExpandingCount

Bases: feed.api.float.window.expanding.ExpandingNode

A stream operator that counts the number of non-missing values.

forward() → float

Generates the next value from the underlying data streams.

Returns:The next value in the stream. Return type:T

class feed.api.float.window.expanding.ExpandingNode(func: Callable[[List[float]], float])

Bases: feed.core.base.Stream

A stream operator for aggregating an entire history of a stream.

Parameters:func (Callable[[List[float]], float]) – A function that aggregates the history of a stream.

forward() → float

Generates the next value from the underlying data streams.

Returns:The next value in the stream. Return type:T

has_next()

Checks if there is another value.

Returns:If there is another value or not. Return type:bool

feed.api.float.window.expanding.expanding(s: feed.core.base.Stream[float][float], min_periods: int = 1) → feed.core.base.Stream[typing.List[float]][List[float]]

Computes a stream that generates the entire history of a stream at each time step.

Parameters:

• s (Stream[float]) – A float stream.
• min_periods (int, default 1) – The number of periods to wait before producing values from the aggregation function.