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Fixed out of range results for cosine distance - fixes #196

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This commit is contained in:
Andrew Kane
2023-07-25 14:54:13 -07:00
parent f210791846
commit 47e5a86b63
4 changed files with 25 additions and 1 deletions
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1
CHANGELOG.md
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@@ -5,6 +5,7 @@
- Added element-wise multiplication for vectors
- Added `sum` aggregate
- Improved performance of distance functions
- Fixed out of range results for cosine distance
## 0.4.4 (2023-06-12)

11
src/vector.c
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@@ -630,6 +630,7 @@ cosine_distance(PG_FUNCTION_ARGS)
float distance = 0.0;
float norma = 0.0;
float normb = 0.0;
double similarity;
CheckDims(a, b);
@@ -642,7 +643,15 @@ cosine_distance(PG_FUNCTION_ARGS)
}
/* Use sqrt(a * b) over sqrt(a) * sqrt(b) */
PG_RETURN_FLOAT8(1.0 - ((double) distance / sqrt((double) norma * (double) normb)));
similarity = (double) distance / sqrt((double) norma * (double) normb);
/* Keep in range */
if (similarity > 1)
similarity = 1.0;
else if (similarity < -1)
similarity = -1.0;
PG_RETURN_FLOAT8(1.0 - similarity);
}
/*

12
test/expected/functions.out
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@@ -96,6 +96,18 @@ SELECT cosine_distance('[1,1]', '[-1,-1]');
SELECT cosine_distance('[1,2]', '[3]');
ERROR: different vector dimensions 2 and 1
SELECT cosine_distance(array_fill(0.1, ARRAY[1536])::vector, array_fill(0.111, ARRAY[1536])::vector);
cosine_distance
-----------------
0
(1 row)
SELECT cosine_distance(array_fill(0.1, ARRAY[1536])::vector, array_fill(-0.111, ARRAY[1536])::vector);
cosine_distance
-----------------
2
(1 row)
SELECT l1_distance('[0,0]', '[3,4]');
l1_distance
-------------

2
test/sql/functions.sql
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@@ -24,6 +24,8 @@ SELECT cosine_distance('[1,2]', '[0,0]');
SELECT cosine_distance('[1,1]', '[1,1]');
SELECT cosine_distance('[1,1]', '[-1,-1]');
SELECT cosine_distance('[1,2]', '[3]');
SELECT cosine_distance(array_fill(0.1, ARRAY[1536])::vector, array_fill(0.111, ARRAY[1536])::vector);
SELECT cosine_distance(array_fill(0.1, ARRAY[1536])::vector, array_fill(-0.111, ARRAY[1536])::vector);
SELECT l1_distance('[0,0]', '[3,4]');
SELECT l1_distance('[0,0]', '[0,1]');