Construct a dgCMatrix whose x, i, p slots are ALTREP mmap views.

The three files must be the CSC component files of a sparse matrix: x_path stores nnz doubles, i_path stores nnz int32 row indices (0-based, matching dgCMatrix@i), p_path stores ncol+1 int32 column pointers (0-based, matching dgCMatrix@p).

Usage

mmap_dgCMatrix(x_path, i_path, p_path, nrow, ncol, nnz, dimnames = NULL)

Arguments

x_path, i_path, p_path

Paths to the .bin files.

nrow, ncol, nnz

Matrix shape + number of non-zeros.

dimnames

Optional list(rowname_character, colname_character).

Examples

# \donttest{
# Build a tiny CSC matrix: 3x2, 3 non-zeros
x_f <- tempfile(fileext = ".bin"); writeBin(c(1.0, 2.0, 3.0), x_f)
i_f <- tempfile(fileext = ".bin"); writeBin(c(0L, 1L, 2L), i_f)
p_f <- tempfile(fileext = ".bin"); writeBin(c(0L, 2L, 3L), p_f)
m <- mmap_dgCMatrix(x_f, i_f, p_f, nrow = 3L, ncol = 2L, nnz = 3L)
dim(m)
#> [1] 3 2
unlink(c(x_f, i_f, p_f))
# }