Description
This is a library for representing sparse matrices in Erlang using a modified
triplet representation. On the face of it, Erlang is not the first language of
choice for working with matrices. However, the representation is usefully
compact for certain cases, such as configuration or bit masks. This is the
primary use case for the library, although a rudimentary summation operation
is defined. Additional mathematical operations may be included later if there
is interest.
One nice feature of the library is that coordinates are arbitrary. If integer
indices are used, then the dimensions of the matrix are based on the maximum
index for each dimension. If the indices are specified by atoms, then the
dimensions are determined by the number of populated entries per dimension.
Creating sparse matrices can be accomplished by using the from_triplets
function which takes a list of triplet tuples and produces a sparse_matrix
record.
Examples
> A = sparse_matrix:from_triplets([
{albany,new_york,180}, {new_york,buffalo,360},
{new_york,montreal,325}, {boston,new_york,250} ]).
> sparse_matrix:value({new_york,montreal}, A).
325
> sparse_matrix:value({montreal,new_york}, A).
0
Author
Brian Lee Yung Rowe