Fixed warning

README.md

@@ -777,7 +777,6 @@ Function | Description | Added
 cosine_distance(halfvec, halfvec) → double precision | cosine distance | unreleased
 inner_product(halfvec, halfvec) → double precision | inner product | unreleased
 l2_distance(halfvec, halfvec) → double precision | Euclidean distance | unreleased
-l2_norm(halfvec) → double precision | Euclidean norm | unreleased
 l1_distance(halfvec, halfvec) → double precision | taxicab distance | unreleased
 quantize_binary(halfvec) → bit | quantize | unreleased
 subvector(halfvec, integer, integer) → halfvec | subvector | unreleased
@@ -819,7 +818,6 @@ Function | Description | Added
 cosine_distance(sparsevec, sparsevec) → double precision | cosine distance | unreleased
 inner_product(sparsevec, sparsevec) → double precision | inner product | unreleased
 l2_distance(sparsevec, sparsevec) → double precision | Euclidean distance | unreleased
-l2_norm(sparsevec) → double precision | Euclidean norm | unreleased
 l1_distance(sparsevec, sparsevec) → double precision | taxicab distance | unreleased
 
 ## Installation Notes - Linux and Mac

sql/vector--0.6.2--0.7.0.sql

@@ -71,8 +71,8 @@ CREATE FUNCTION cosine_distance(halfvec, halfvec) RETURNS float8
 CREATE FUNCTION l1_distance(halfvec, halfvec) RETURNS float8
 	AS 'MODULE_PATHNAME', 'halfvec_l1_distance' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
 
-CREATE FUNCTION l2_norm(halfvec) RETURNS float8
-	AS 'MODULE_PATHNAME', 'halfvec_l2_norm' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+CREATE FUNCTION halfvec_norm(halfvec) RETURNS float8
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
 
 CREATE FUNCTION quantize_binary(halfvec) RETURNS bit
 	AS 'MODULE_PATHNAME', 'halfvec_quantize_binary' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
@@ -151,7 +151,7 @@ CREATE OPERATOR CLASS halfvec_cosine_ops
 	FOR TYPE halfvec USING hnsw AS
 	OPERATOR 1 <=> (halfvec, halfvec) FOR ORDER BY float_ops,
 	FUNCTION 1 halfvec_negative_inner_product(halfvec, halfvec),
-	FUNCTION 2 l2_norm(halfvec);
+	FUNCTION 2 halfvec_norm(halfvec);
 
 CREATE FUNCTION halfvec_to_vector(halfvec, integer, boolean) RETURNS vector
 	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
@@ -200,8 +200,11 @@ CREATE FUNCTION inner_product(sparsevec, sparsevec) RETURNS float8
 CREATE FUNCTION cosine_distance(sparsevec, sparsevec) RETURNS float8
 	AS 'MODULE_PATHNAME', 'sparsevec_cosine_distance' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
 
-CREATE FUNCTION l2_norm(sparsevec) RETURNS float8
-	AS 'MODULE_PATHNAME', 'sparsevec_l2_norm' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+CREATE FUNCTION sparsevec_norm(sparsevec) RETURNS float8
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION subvector(sparsevec, int, int) RETURNS sparsevec
+	AS 'MODULE_PATHNAME', 'sparsevec_subvector' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
 
 CREATE FUNCTION sparsevec_l2_squared_distance(sparsevec, sparsevec) RETURNS float8
 	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
@@ -256,4 +259,4 @@ CREATE OPERATOR CLASS sparsevec_cosine_ops
 	FOR TYPE sparsevec USING hnsw AS
 	OPERATOR 1 <=> (sparsevec, sparsevec) FOR ORDER BY float_ops,
 	FUNCTION 1 sparsevec_negative_inner_product(sparsevec, sparsevec),
-	FUNCTION 2 l2_norm(sparsevec);
+	FUNCTION 2 sparsevec_norm(sparsevec);

sql/vector.sql

@@ -364,8 +364,8 @@ CREATE FUNCTION cosine_distance(halfvec, halfvec) RETURNS float8
 CREATE FUNCTION l1_distance(halfvec, halfvec) RETURNS float8
 	AS 'MODULE_PATHNAME', 'halfvec_l1_distance' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
 
-CREATE FUNCTION l2_norm(halfvec) RETURNS float8
-	AS 'MODULE_PATHNAME', 'halfvec_l2_norm' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+CREATE FUNCTION halfvec_norm(halfvec) RETURNS float8
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
 
 CREATE FUNCTION quantize_binary(halfvec) RETURNS bit
 	AS 'MODULE_PATHNAME', 'halfvec_quantize_binary' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
@@ -454,7 +454,7 @@ CREATE OPERATOR CLASS halfvec_cosine_ops
 	FOR TYPE halfvec USING hnsw AS
 	OPERATOR 1 <=> (halfvec, halfvec) FOR ORDER BY float_ops,
 	FUNCTION 1 halfvec_negative_inner_product(halfvec, halfvec),
-	FUNCTION 2 l2_norm(halfvec);
+	FUNCTION 2 halfvec_norm(halfvec);
 
 -- extension casts
 
@@ -509,8 +509,11 @@ CREATE FUNCTION inner_product(sparsevec, sparsevec) RETURNS float8
 CREATE FUNCTION cosine_distance(sparsevec, sparsevec) RETURNS float8
 	AS 'MODULE_PATHNAME', 'sparsevec_cosine_distance' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
 
-CREATE FUNCTION l2_norm(sparsevec) RETURNS float8
-	AS 'MODULE_PATHNAME', 'sparsevec_l2_norm' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+CREATE FUNCTION sparsevec_norm(sparsevec) RETURNS float8
+	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
+
+CREATE FUNCTION subvector(sparsevec, int, int) RETURNS sparsevec
+	AS 'MODULE_PATHNAME', 'sparsevec_subvector' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;
 
 -- sparsevec private functions
 
@@ -575,4 +578,4 @@ CREATE OPERATOR CLASS sparsevec_cosine_ops
 	FOR TYPE sparsevec USING hnsw AS
 	OPERATOR 1 <=> (sparsevec, sparsevec) FOR ORDER BY float_ops,
 	FUNCTION 1 sparsevec_negative_inner_product(sparsevec, sparsevec),
-	FUNCTION 2 l2_norm(sparsevec);
+	FUNCTION 2 sparsevec_norm(sparsevec);

src/halfvec.c

@@ -950,9 +950,9 @@ halfvec_l1_distance(PG_FUNCTION_ARGS)
 /*
  * Get the L2 norm of a half vector
  */
-PGDLLEXPORT PG_FUNCTION_INFO_V1(halfvec_l2_norm);
+PGDLLEXPORT PG_FUNCTION_INFO_V1(halfvec_norm);
 Datum
-halfvec_l2_norm(PG_FUNCTION_ARGS)
+halfvec_norm(PG_FUNCTION_ARGS)
 {
 	HalfVector *a = PG_GETARG_HALFVEC_P(0);
 	half	   *ax = a->x;

src/sparsevec.c

@@ -762,9 +762,9 @@ sparsevec_cosine_distance(PG_FUNCTION_ARGS)
 /*
  * Get the L2 norm of a sparse vector
  */
-PGDLLEXPORT PG_FUNCTION_INFO_V1(sparsevec_l2_norm);
+PGDLLEXPORT PG_FUNCTION_INFO_V1(sparsevec_norm);
 Datum
-sparsevec_l2_norm(PG_FUNCTION_ARGS)
+sparsevec_norm(PG_FUNCTION_ARGS)
 {
 	SparseVector *a = PG_GETARG_SPARSEVEC_P(0);
 	float	   *ax = SPARSEVEC_VALUES(a);
@@ -776,3 +776,55 @@ sparsevec_l2_norm(PG_FUNCTION_ARGS)
 
 	PG_RETURN_FLOAT8(sqrt(norm));
 }
+
+/*
+ * Get a subvector
+ */
+PGDLLEXPORT PG_FUNCTION_INFO_V1(sparsevec_subvector);
+Datum
+sparsevec_subvector(PG_FUNCTION_ARGS)
+{
+	SparseVector *a = PG_GETARG_SPARSEVEC_P(0);
+	int32		start = PG_GETARG_INT32(1);
+	int32		count = PG_GETARG_INT32(2);
+	int32		end = start + count;
+	float	   *ax = SPARSEVEC_VALUES(a);
+	SparseVector *result;
+	float	   *rx;
+	int			dim;
+	int			nnz = 0;
+	int			startIndex;
+
+	/* Indexing starts at 1, like substring */
+	if (start < 1)
+		start = 1;
+
+	if (end > a->dim)
+		end = a->dim + 1;
+
+	dim = end - start;
+	CheckDim(dim);
+
+	for (startIndex = 0; startIndex < a->nnz; startIndex++)
+	{
+		if (a->indices[startIndex] >= start - 1)
+			break;
+	}
+
+	for (int i = startIndex; i < a->nnz; i++)
+	{
+		if (a->indices[i] < end - 1)
+			nnz++;
+	}
+
+	result = InitSparseVector(dim, nnz);
+	rx = SPARSEVEC_VALUES(result);
+
+	for (int i = 0; i < nnz; i++)
+	{
+		result->indices[i] = a->indices[startIndex + i];
+		rx[i] = ax[startIndex + i];
+	}
+
+	PG_RETURN_POINTER(result);
+}

test/expected/sparsevec_functions.out

@@ -60,3 +60,33 @@ SELECT cosine_distance('{}/1'::sparsevec, '{}/1');
 
 SELECT cosine_distance('{0:1}/2'::sparsevec, '{0:1}/3');
 ERROR:  different sparsevec dimensions 2 and 3
+SELECT subvector('{0:1,1:2,2:3,3:4,4:5}/5'::sparsevec, 1, 3);
+    subvector    
+-----------------
+ {0:1,1:2,2:3}/3
+(1 row)
+
+SELECT subvector('{0:1,1:2,2:3,3:4,4:5}/5'::sparsevec, 3, 2);
+  subvector  
+-------------
+ {2:3,3:4}/2
+(1 row)
+
+SELECT subvector('{0:1,1:2,2:3,3:4,4:5}/5'::sparsevec, -1, 3);
+ subvector 
+-----------
+ {0:1}/1
+(1 row)
+
+SELECT subvector('{0:1,1:2,2:3,3:4,4:5}/5'::sparsevec, 3, 9);
+    subvector    
+-----------------
+ {2:3,3:4,4:5}/3
+(1 row)
+
+SELECT subvector('{0:1,1:2,2:3,3:4,4:5}/5'::sparsevec, 1, 0);
+ERROR:  sparsevec must have at least 1 dimension
+SELECT subvector('{0:1,1:2,2:3,3:4,4:5}/5'::sparsevec, 3, -1);
+ERROR:  sparsevec must have at least 1 dimension
+SELECT subvector('{0:1,1:2,2:3,3:4,4:5}/5'::sparsevec, -1, 2);
+ERROR:  sparsevec must have at least 1 dimension

test/sql/sparsevec_functions.sql

@@ -11,3 +11,11 @@ SELECT cosine_distance('{0:1,1:1}/2'::sparsevec, '{0:-1,1:-1}/2');
 SELECT cosine_distance('{0:1}/2'::sparsevec, '{1:2}/2');
 SELECT cosine_distance('{}/1'::sparsevec, '{}/1');
 SELECT cosine_distance('{0:1}/2'::sparsevec, '{0:1}/3');
+
+SELECT subvector('{0:1,1:2,2:3,3:4,4:5}/5'::sparsevec, 1, 3);
+SELECT subvector('{0:1,1:2,2:3,3:4,4:5}/5'::sparsevec, 3, 2);
+SELECT subvector('{0:1,1:2,2:3,3:4,4:5}/5'::sparsevec, -1, 3);
+SELECT subvector('{0:1,1:2,2:3,3:4,4:5}/5'::sparsevec, 3, 9);
+SELECT subvector('{0:1,1:2,2:3,3:4,4:5}/5'::sparsevec, 1, 0);
+SELECT subvector('{0:1,1:2,2:3,3:4,4:5}/5'::sparsevec, 3, -1);
+SELECT subvector('{0:1,1:2,2:3,3:4,4:5}/5'::sparsevec, -1, 2);