liuyu/pgvector
1
0
Fork 0
mirror of https://github.com/pgvector/pgvector.git synced 2026-07-01 02:02:10 +08:00
Code Issues Packages Projects Releases Wiki Activity

Added l1_distance function for sparsevec [skip ci]

Browse Source
This commit is contained in:
Andrew Kane
2024-04-14 22:59:28 -07:00
parent b70fb2b3f4
commit 4f6c4850d9
5 changed files with 80 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

49
src/sparsevec.c
View File

@@ -781,6 +781,55 @@ sparsevec_cosine_distance(PG_FUNCTION_ARGS)
PG_RETURN_FLOAT8(1.0 - similarity);
}
/*
* Get the L1 distance between two sparse vectors
*/
PGDLLEXPORT PG_FUNCTION_INFO_V1(sparsevec_l1_distance);
Datum
sparsevec_l1_distance(PG_FUNCTION_ARGS)
{
SparseVector *a = PG_GETARG_SPARSEVEC_P(0);
SparseVector *b = PG_GETARG_SPARSEVEC_P(1);
float *ax = SPARSEVEC_VALUES(a);
float *bx = SPARSEVEC_VALUES(b);
double distance = 0.0;
int bpos = 0;
CheckDims(a, b);
for (int i = 0; i < a->nnz; i++)
{
int ai = a->indices[i];
int bi = -1;
for (int j = bpos; j < b->nnz; j++)
{
bi = b->indices[j];
if (ai == bi)
distance += fabs(ax[i] - bx[j]);
else if (ai > bi)
distance += fabs(bx[j]);
/* Update start for next iteration */
if (ai >= bi)
bpos = j + 1;
/* Found or passed it */
if (bi >= ai)
break;
}
if (ai != bi)
distance += fabs(ax[i]);
}
for (int j = bpos; j < b->nnz; j++)
distance += fabs(bx[j]);
PG_RETURN_FLOAT8(distance);
}
/*
* Get the L2 norm of a sparse vector
*/