# ReadHBSparse

read a Harwell-Boeing sparse format file

## Calling Sequence

    [A, description, ref, mtype] = ReadHBSparse([filename])

## Arguments

filename

  (optional) a string given the filename (eventually preceeding by the path), if filename is not given then the function use uigetfile to get filename interactively

A

  the sparse matrix

description

  a string given some information about the matrix

ref

  a string given the reference of the matrix

mtype

  a string given the type of the matrix

## Description

An utility to read the Harwell-Boeing sparse matrix format. Currently do not work for unassembled matrix. Also the eventual rhs vectors of the file are not returned. Generally the file name is of the form ref.mtype where mtype is a 3 letters word abc given some information (already inside the file) on the matrix :

    a = R|C|P   for real|complex|pattern (no values given)
    b = S|H|Z|U for symmetric|hermitian|skew symmetric|asymmetric
    c = A|E     for assembled|unassembled matrix
                (case E is not treated by this func)

## References

Users' Guide for the Harwell-Boeing Sparse Matrix Collection Iain S. Duff, Roger G. Grimes, John G. Lewis. You may found this guide and numerous sparse matrices (in the Harwell-Boeing format) at the University of Florida Sparse Matrix Collection

web site : http://www.cise.ufl.edu/research/sparse/matrices/

maintained by Tim Davis (http://www.cise.ufl.edu/~davis/)

## Examples

    [A] = ReadHBSparse(SCI+"/modules/umfpack/examples/arc130.rua");

## See Also

- PlotSparse