Back to models
Transformer

PAAlegacy

Piecewise Aggregate Approximation Transformer (PAA).

(PAA) Piecewise Aggregate Approximation Transformer, as described in Eamonn Keogh, Kaushik Chakrabarti, Michael Pazzani, and Sharad Mehrotra. Dimensionality reduction for fast similarity search in large time series databases. Knowledge and information Systems, 3(3), 263-286, 2001. For each series reduce the dimensionality to num_intervals, where each value is the mean of values in the interval.

TO DO: pythonise it to make it more efficient. Maybe check vs this version

http://vigne.sh/posts/piecewise-aggregate-approx/

Could have: Tune the interval size in fit somehow?

Quickstart

python
from sktime.transformations.dictionary_based import PAAlegacy

estimator = PAAlegacy(num_intervals=8)

Tags

Capabilities

  • Multivariate
  • Unequal-length series
  • Inverse transform: Not supported
  • Missing values: Not supported
  • Removes missing values: Not supported
  • Equalizes series length: Not supported

Properties

Input typescitype:transform-input
Series
Output typescitype:transform-output
Series
Label typescitype:transform-labels
None
Fit is emptyfit_is_empty
Yes
Keeps the time indextransform-returns-same-time-index
No
Requires Xrequires_X
Yes
Requires yrequires_y
No
X and y need the same indexX-y-must-have-same-index
No

Parameters(1)

num_intervalsint, dimension of the transformed data (default 8)