Brute Force (Flat)
This page describes the brute force (flat) index parameters as part of AI libs.
.ai.flat.normalize
The .ai.flat.normalize function normalizes vectors.
Cosine similarity is mathematically equivalent to the inner product metric performed on normalized vectors. By normalizing your vectors before inserting them into hnsw or flat, and also normalizing incoming search vectors, you can use the inner product metric instead of cosine similarity, thus yielding identical results. This significantly reduces search and insert times, as it removes repeated normalization.
You can use this function, however, note that it is optimized for speed, not memory utilization. If you're converting large vector stores, it's best to do them in smaller chunks using the formula {8h$x%sqrt sum x*x}.
Parameters
|
Name |
Type(s) |
Description |
|---|---|---|
|
embs |
real[][] |
The original un-normalized vector embeddings |
Returns
|
Type |
Description |
|---|---|
|
real[][] |
Returns normalized vector embeddings |
Example
q
q).ai:use`kx.ai
q)vecs:{(x;y)#(x*y)?1e}[100000;10];
q)\ts:1000 res1:.ai.flat.search[vecs;first vecs;5;`CS]
676 2099232
q)nvecs:.ai.flat.normalize vecs;
q)\ts:1000 res2:.ai.flat.search[nvecs;first nvecs;5;`IP]
544 2099232
q)res1[1]~res2[1]
1b.ai.flat.search
The .ai.flat.search function conducts a parallelized flat search, returning k nearest neighbors under the provided metric.
Parameters
|
Name |
Type(s) |
Description |
|---|---|---|
|
embs |
real[][] |
The set of vectors to conduct kNN search against |
|
q |
real[] | float[] |
The query vector |
|
k |
short | int | long |
The number of nearest neighbors to return |
|
metric |
symbol |
A metric for search, one of (L2;CS;IP) |
Returns
|
Type |
Description |
|---|---|
|
(real[]; long[]) |
The nearest points and the corresponding distance under the given metric |
Example
q
q).ai:use`kx.ai
q)vecs:{(x;y)#(x*y)?1e}[1000;10];
q).ai.flat.search[vecs;first vecs;5;`L2]
0 0.2658583 0.3118592 0.3484065 0.3911282
0 404 631 93 241