match_sampling_rate

MatchSamplingRate(reference_timestamps, feature_columns_with_timestamps)

Bases: Transform

Matches the sampling rate of all time series in the DataFrame.

Interpolates the time series to match the sampling rate of the reference time series. The below example shows the usage of a MatchSamplingRate transform in a run.py file. Assuming the loaded data is represented by the table:

feature_a	feature_b	const
list[struct[datetime[us],struct[]]	list[struct[datetime[us],struct[]]	int
-----------------------------------	-----------------------------------	-----
[{2024-06-25 12:26:01.0,{1.2}]},	[{2024-06-25 12:26:00.0,{1.0}},	1
{2024-06-25 12:26:02.0,{2.4}]},	{2024-06-25 12:26:05.0,{2}}]
{2024-06-25 12:26:03.0,{3.6}]},
{2024-06-25 12:26:04.0,{4.8}]}]

The following transform can be used to match the sampling rate of the time series feature_b to the sampling rate of the time series feature_a.

    ...
    environment.load()
    data = environment.get_data()
    transform = MatchSamplingRate(
        reference_timestamps="time_feature_a",
        feature_columns_with_timestamps={
            "feature_b": "time_feature_b"
        },
    )
    transformed_data = transform.transform(data)
    ...

The resulting Dataframe after the transform is:

time_feature_a	feature_a	time_feature_b	feature_b	constant
[0, 1, 2]	[2, 1, 7]	[0, 1, 2]	[10, 15, 20]	1
[0, 1, 2]	[4, 1, 0]	[0, 1, 2]	[20, 30, 40]	2

Note that the used feature time_feature_b is still present in the DataFrame. To remove it use the select transform.

Initialize the MatchSamplingRate transform.

Parameters:

Name	Type	Description	Default
reference_timestamps	str	Timestamps of the reference feature.	required
feature_columns_with_timestamps	dict[str, str]	Names of the features that are getting interpolated with their respective original timestamp feature names.	required

Source code in src/flowcean/transforms/match_sampling_rate.py

def __init__(
    self,
    reference_timestamps: str,
    feature_columns_with_timestamps: dict[str, str],
) -> None:
    """Initialize the MatchSamplingRate transform.

    Args:
        reference_timestamps: Timestamps of the reference feature.
        feature_columns_with_timestamps: Names of the features that are
            getting interpolated with their respective original timestamp
            feature names.
    """
    self.reference_timestamps = reference_timestamps
    self.feature_columns_with_timestamps = feature_columns_with_timestamps