### Features

For now, only a few features are implemented:

convert a dgCMatrix or a dsCMatrix to an SFBM, a Sparse Filebacked Big Matrix

grow an SFBM using `$add_columns()`

(similar to ‘cbind’ or ‘bdiag’)

compute the product and crossproduct of an SFBM with a vector

solve Ax=b, where A is a symmetric SFBM and b is a vector

access the subset of an SFBM as a dgCMatrix (matrix accessor, since v0.6.1)

A **new compact format** is available (since v0.5), which is useful when non-zero values in columns are contiguous (or almost).

### Installation