1.1 - 8.10 - ShapeletUnsupervised Troubleshooting - Teradata Vantage

Teradata Vantage™ - Machine Learning Engine Analytic Function Reference

Product
Teradata Vantage
Release Number
1.1
8.10
Release Date
October 2019
Content Type
Programming Reference
Publication ID
B700-4003-079K
Language
English (United States)

Problem: The function runs slowly for large input data sets.

For a large input data set, the function runs slowly, spending much time on one step, or it terminates with a failure message. Consult the logs for error messages and troubleshooting information.

Workarounds:

  • Improve the execution time of the saxification step, in any of the following ways:
    • Increase SAXWindowSize syntax element value.
    • Increase the SAXOutputFrequency syntax element value.
    • Decrease the SAXSymbolsPerWindow syntax element value.
  • Decrease the number of masking operations by decreasing the RandomProjections syntax element value.
  • Decrease the number of iterations by decreasing the MaxIterNum syntax element value.
  • Decrease the number of u_shapelets for clustering by decreasing the ShapeletCutOff syntax element value.
  • Increase the StopThreshold syntax element value.

Problem: Clustering accuracy is not good enough.

The function completes successfully, but the clustering accuracy is low.

Workarounds:

  • Improve the accuracy of the saxification step, in any of the following ways:
    • Decrease the SAXWindowSize syntax element value.
    • Decrease the SAXOutputFrequency syntax element value.
    • Increase the SAXSymbolsPerWindow syntax element value.
  • Increase the number of masking operations by increasing the RandomProjections syntax element value.
  • Increase the number of iterations by decreasing the MaxIterNum syntax element value.
  • Increase the number of u_shapelets for clustering by decreasing the ShapeletCutOff syntax element value.
  • Decrease the StopThreshold syntax element value.