collect: Materialise a delayed matrix

In delarr: Lazy Delayed Arrays with Fused Execution

Materialise a delayed matrix

Description

Streams column chunks from the backing seed, applying deferred operations and optional reductions on the fly. By default the result is returned as a base matrix or vector; alternatively, supply a writer via into to stream the output elsewhere (e.g., hdf5_writer()).

Usage

collect(
  x,
  into = NULL,
  chunk_size = NULL,
  chunk_margin = c("cols", "rows"),
  target_bytes = NULL,
  parallel = FALSE,
  workers = NULL,
  optimize = TRUE
)

Arguments

x	A delarr object.
into	Optional writer or callback used to receive streamed chunks.
chunk_size	Optional chunk size along chunk_margin.
chunk_margin	Chunking axis for non-reduction collection.
target_bytes	Optional memory budget (bytes) used to adapt chunk size.
parallel	Logical; attempt parallel chunk execution when safe.
workers	Number of worker processes when parallel = TRUE.
optimize	Logical; run lightweight DAG optimizations before evaluation.

Value

A realised matrix/vector, or NULL invisibly when writing to into.

Examples

# Basic materialization
mat <- matrix(1:12, nrow = 3, ncol = 4)
darr <- delarr(mat)
collect(darr)

# Collect after lazy operations
result <- darr |>
  d_map(~ .x^2) |>
  collect()
result

delarr documentation built on July 1, 2026, 1:06 a.m.