filematrix-package {filematrix}

File-backed numeric matrix.

Description

File-Backed Matrix Class with Convenient Read and Write Access

Details

Interface for working with large matrices stored in files, not in computer memory. Supports multiple non-character data types (double, integer, logical and raw) of various sizes (e.g. 8 and 4 byte real values). Access to parts of the matrix is done by indexing (e.g. fm[,1]), exactly as with usual R matrices. Supports very large matrices. Tested on multi-terabyte matrices. Allows for more than 2^32 rows or columns. Allows for quick addition of extra columns to a filematrix. Cross-platform as the package has R code only.

A new file.matrix object can be created with fm.create and fm.create.from.matrix. Existing file.matrix files can be opened with fm.open.

Once a file.matrix is created or opened it can be accessed as a regular matrix object in R. All changes to file.matrix object are written to the data files without extra buffering.

Note

Due to lack of 64 bit integer data type in R, the package uses double values for calculation of indices. The precision of double data type is sufficient for indexing matrices up to 8,192 terabytes in size.

Author(s)

Andrey A Shabalin [e-mail]

See Also

See fm.create and filematrix for reference.

Run browseVignettes("filematrix") for the list of vignettes.