deepcopy {bigmemory}R Documentation

Produces a physical copy of a “big.matrix”

Description

This is needed to make a duplicate of a big.matrix, with the new copy optionally filebacked.

Usage

deepcopy(x, cols = NULL, type = NULL, separated = NULL,
  backingfile = NULL, backingpath = NULL, descriptorfile = NULL,
  shared=TRUE)

Arguments

x a big.matrix.
cols possible subset of columns for the deepcopy; could be numeric, named, or logical.
type preferably specified, "integer" for example.
separated use separated column organization of the data instead of column-major organization; use with caution if the number of columns is large.
backingfile the root name for the file(s) for the cache of x.
backingpath the path to the directory containing the file-backing cache.
descriptorfile we recommend specifying this for file-backing.
shared TRUE by default, and always TRUE if the big.matrix is file-backed. For a non-filebacked big.matrix, shared=FALSE uses non-shared memory, which can be more stable for large (say, >50% of RAM) objects. Shared memory allocation can sometimes fail in such cases due to exhausted shared-memory resources in the system.

Details

This is needed to make a duplicate of a big.matrix, because traditional R syntax would only copy the R object (the pointer to the big.matrix rather than the big.matrix itself). It can also make a copy of only a subset of columns.

Value

a big.matrix.

See Also

big.matrix

Examples


x <- as.big.matrix(matrix(1:30, 10, 3))
y <- deepcopy(x, -1)    # Don't include the first column.
x
y
head(x)
head(y)


[Package bigmemory version 4.2.3 Index]