Exhaustive (brute-force) index

Exact search: every query is compared to every indexed sample, SIMD accelerated and multi-threaded. The ground truth to measure the approximate indices against, and faster than you might think up to a few hundred thousand samples. Large query batches go through a blocked GEMM path, which on macOS runs on Apple Accelerate, so it can outrun the thread count set by ann_set_threads().

Super class

AnnIndex -> ExhaustiveIndex

Methods

Public methods

• ExhaustiveIndex$new()

• ExhaustiveIndex$clone()

Inherited methods

• AnnIndex$predict()
• AnnIndex$print()
• AnnIndex$query_self()
• AnnIndex$save()

---

ExhaustiveIndex$new()

Build the index.

Usage

ExhaustiveIndex$new(
  data,
  metric = c("euclidean", "sqeuclidean", "cosine", "manhattan"),
  precision = c("float", "double")
)

Arguments

data

Numeric matrix or data.frame. Samples x features. An index pointer is also accepted; load_ann_index() uses that path.

metric

String. One of c("euclidean", "sqeuclidean", "cosine", "manhattan").

precision

String. "float" stores the data as f32, "double" as f64.

---

ExhaustiveIndex$clone()

The objects of this class are cloneable with this method.

Usage

ExhaustiveIndex$clone(deep = FALSE)

Arguments

deep

Whether to make a deep clone.

Examples

x <- generate_clustered_data(1000L, 16L)$data
idx <- ExhaustiveIndex$new(x)
res <- idx$predict(x[1:5, ], k = 10L)