rfwtools.extractor.down_sample.lttb_extractor
- rfwtools.extractor.down_sample.lttb_extractor(example, signals, n_out, query=None)[source]
Extract features via lttb on individual signals from a set. Loads/unloads data.
LTTB is not a fixed time step method, but produces good graphical results. It uses a Largest Triangle Three Bucket approach which picks points based on which would maximize the size of triangles created but points in adjacent buckets.
- Parameters:
example (
Example) – The example on which to operatesignals (
List[str]) – A list of the example’s columns to be down sampled (e.g., “1_GMES”).n_out (
int) – The number of points to be returnedquery (
Optional[str]) – Argument passed to the ex.event_df to filter data prior to feature extraction, e.g. “Time <= 0”.
- Return type:
DataFrame- Returns:
A DataFrame with a single row containing the the down sampled and concatenated signals.