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tf_feature_similarity

Given a query input of entity keys, feature columns, and a metric column, and a second query input specifying a search vector of feature columns and metric, computes the similarity of each entity in the first input to the search vector based on their similarity. The score is computed as the cosine similarity of the feature column(s) for each entity with the feature column(s) for the search vector, which can optionally be TF/IDF weighted.

SELECT
  *
FROM
  TABLE(
    tf_feature_similarity(
      primary_features => CURSOR(
        SELECT
          primary_key,
          pivot_features,
          metric
        from
          table
        where
          ...
        group by
          primary_key,
          pivot_features
      ),
      comparison_features => CURSOR(
        SELECT
          comparison_metric
        from
          table
        where
          ...
        group by <column>
      ),
      use_tf_idf => <boolean>
    )
  )

Input Arguments

Output Columns

Example

/* Compute the similarity of US airline flight nums to a particular
Delta flight (DAL795) based on the cosine similarity of the overlap of
flight paths binned to a H3 Hex at zoom level 7 (roughly 5 sq km),  
and return the top 10 most similar flight nums */

SELECT
  *
FROM
  TABLE(
    tf_feature_similarity(
      primary_features => CURSOR(
        SELECT
          callsign,
          geotoh3(st_x(location), st_y(location), 7) as h3,
          count(*) as n
        from
          adsb_2021_03_01
        where
          operator in (
            'Delta Air Lines',
            'Alaska Airlines',
            'Southwest Airlines',
            'American Airlines',
            'United Airlines'
          )
          and altitude >= 1000
        group by
          callsign,
          h3
      ),
      comparison_features => CURSOR(
        SELECT
          geotoh3(st_x(location), st_y(location), 7) as h3,
          COUNT(*) as n
        from
          adsb_2021_03_01
        where
          callsign = 'DAL795'
          and altitude >= 1000
        group by
          h3
      ),
      use_tf_idf => false
    )
  )
ORDER BY
  similarity_score desc
limit
  10;
  
class|similarity_score
DAL795|1
DAL538|0.610889
DAL1192|0.3419932
DAL1185|0.3391671
SWA4346|0.3206964
DAL365|0.3037131
SWA953|0.2912168
UAL1559|0.2747431
SWA2098|0.2511763
DAL526|0.2473387

tf_feature_similarity

SELECT
  *
FROM
  TABLE(
    tf_feature_similarity(
      primary_features => CURSOR(
        SELECT
          primary_key,
          pivot_features,
          metric
        from
          table
        where
          ...
        group by
          primary_key,
          pivot_features
      ),
      comparison_features => CURSOR(
        SELECT
          comparison_metric
        from
          table
        where
          ...
        group by <column>
      ),
      use_tf_idf => <boolean>
    )
  )

Input Arguments

Parameter

Description

Data Type

Output Columns

Name

Description

Data Types

Example

/* Compute the similarity of US airline flight nums to a particular
Delta flight (DAL795) based on the cosine similarity of the overlap of
flight paths binned to a H3 Hex at zoom level 7 (roughly 5 sq km),  
and return the top 10 most similar flight nums */

SELECT
  *
FROM
  TABLE(
    tf_feature_similarity(
      primary_features => CURSOR(
        SELECT
          callsign,
          geotoh3(st_x(location), st_y(location), 7) as h3,
          count(*) as n
        from
          adsb_2021_03_01
        where
          operator in (
            'Delta Air Lines',
            'Alaska Airlines',
            'Southwest Airlines',
            'American Airlines',
            'United Airlines'
          )
          and altitude >= 1000
        group by
          callsign,
          h3
      ),
      comparison_features => CURSOR(
        SELECT
          geotoh3(st_x(location), st_y(location), 7) as h3,
          COUNT(*) as n
        from
          adsb_2021_03_01
        where
          callsign = 'DAL795'
          and altitude >= 1000
        group by
          h3
      ),
      use_tf_idf => false
    )
  )
ORDER BY
  similarity_score desc
limit
  10;
  
class|similarity_score
DAL795|1
DAL538|0.610889
DAL1192|0.3419932
DAL1185|0.3391671
SWA4346|0.3206964
DAL365|0.3037131
SWA953|0.2912168
UAL1559|0.2747431
SWA2098|0.2511763
DAL526|0.2473387

One or more columns constituting a compound feature. For example, two columns of visit hour and census block group would compare entities specified by primary_key based on whether they visited the same census block group in the same hour. If a single census block group feature column is used, the primary_key entities are compared only by the census block groups visited, regardless of time overlap.