1.1 - 8.10 - LoopyBeliefPropagation Example: Equally Weighted Edges - Teradata Vantage

Teradata Vantage™ - Machine Learning Engine Analytic Function Reference

Teradata Vantage
Release Number
October 2019
Content Type
Programming Reference
Publication ID
English (United States)

In this example, the probability of hepatitis depends on all symptoms equally; therefore, the Edges table does not include edge weights.


Vertices: lbp_vertices
id vertex
1 Jaundice
2 Internal bleeding
3 Loss of appetite
4 Fatigue
5 Fever
6 Dark urine
7 Stupor
8 Nausea/vomiting
9 Hepatitis
Edges: lbp_edges
id source target
1 Jaundice Hepatitis
2 Internal bleeding Hepatitis
3 Loss of appetite Hepatitis
4 Fatigue Hepatitis
5 Fever Hepatitis
6 Dark urine Hepatitis
7 Stupor Hepatitis
8 Nausea/vomiting Hepatitis

In the ObservationTable, 't' means that the symptom is present and 'f' means that it is absent.

ObservationTable: lbp_observation
id vertex obs
1 Jaundice t
2 Internal bleeding t
3 Loss of appetite t
4 Fatigue t
5 Fever f
6 Dark urine t
7 Stupor f
8 Nausea/vomiting f

SQL Call

SELECT * FROM LoopyBeliefPropagation (
  ON lbp_edges AS Edges PARTITION BY source
  ON lbp_vertices AS Vertices PARTITION BY vertex
  ON lbp_observation AS ObservationTable PARTITION BY vertex
  TargetKey ('target')
  ObservationColumn ('obs')
  Accumulate ('vertex')
  MaxIterNum (20)
  StopThreshold (1E-10)
) AS dt ORDER BY vertex;


In the output table, 1 means that the symptom is present and 0 means that it is absent. Five of the eight symptoms are present, so the conditional probability of hepatitis is 5/8 (0.625).

 vertex            prob_true 
 ----------------- --------- 
 dark urine              1.0
 fatigue                 1.0
 fever                   0.0
 hepatitis             0.625
 internal bleeding       1.0
 jaundice                1.0
 loss of appetite        1.0
 nausea/vomiting         0.0
 stupor                  0.0

Download a zip file of all examples and a SQL script file that creates their input tables from the attachment in the left sidebar.