Read HB-format file.
file : str-like or file-like
If a string-like object, file is the name of the file to read. If a file-like object, the data are read from it.
data : scipy.sparse.csc_matrix instance
The data read from the HB file as a sparse matrix.
At the moment not the full Harwell-Boeing format is supported. Supported features are:
- assembled, non-symmetric, real matrices
- integer for pointer/indices
- exponential format for float values, and int format