cosine_similarity

cosine_similarity [WhereOS, SQL, Spark, Hive]

Class hivemall.knn.similarity.CosineSimilarityUDF
Usage cosine_similarity(ftvec1, ftvec2) - Returns a cosine similarity of the given two vectors

WITH docs as (
select 1 as docid, array('apple:1.0', 'orange:2.0', 'banana:1.0', 'kuwi:0') as features
union all
select 2 as docid, array('apple:1.0', 'orange:0', 'banana:2.0', 'kuwi:1.0') as features
union all
select 3 as docid, array('apple:2.0', 'orange:0', 'banana:2.0', 'kuwi:1.0') as features
)
select
l.docid as doc1,
r.docid as doc2,
cosine_similarity(l.features, r.features) as similarity
from
docs l
CROSS JOIN docs r
where
l.docid != r.docid
order by
doc1 asc,
similarity desc;

doc1 doc2 similarity
1 3 0.5443311
1 2 0.5
2 3 0.9525793
2 1 0.5
3 2 0.9525793
3 1 0.5443311

More functions can be added to WhereOS via Python or R bindings or as Java & Scala UDF (user-defined function), UDAF (user-defined aggregation function) and UDTF (user-defined table generating function) extensions. Custom libraries can be added on via Settings-page or installed from WhereOS Store.

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