SparseM.hb: Harwell-Boeing Format Sparse Matrices

Description

Read, write and extract components of data in Harwell-Boeing sparse matrix format.

Usage

read.matrix.hb(filename)
write.matrix.hb(filename = "hb.out", X, title, key, mxtype, 
rhs = NULL, guess = FALSE, xsol = FALSE, ptrfmt, indfmt,
valfmt = "(1P,5D16.9)", rhsfmt = "(1P,5D16.9)")
model.matrix(object, ...)
model.response(data,type)

Arguments

filename

file name to read from or write to

data, object

an object of either matrix.csc.hb or matrix.ssc.hb class

type

One of `"any"', `"numeric"', `"double"'. Using the either of latter two coerces the result to have storage mode `"double"'

coefficient matrix stored in csc (for unsymmetric and rectangular matrix) or ssc (for symmetric matrix) format

title

72-character title for the matrix

key

8-character identifier for the matrix

mxtype

3-character identifier for type of the coefficient matrix; First character: currently only "R" for real matrix is supported; second character: "S" for symmetric, "U" for unsymmetric" and "R" for rectangular matrix; third character: curr

rhs

vector or matrix of right-hand-side(s) including starting guesses and solution vectors if present stored in full storage mode

guess

logical flag for the presence of initial guess of the solutions; if TRUE, the values of initial guess are appended to the end of rhs

xsol

logical flag for the presence of exact solutions; if TRUE, the values of the exact solutions are appended to the end of rhs

ptrfmt

printing format for the column pointers

indfmt

printing format for the row indices

valfmt

printing format for the values

rhsfmt

printing format for the right-hand-sides

...

additional arguments

Value

The function read.matrix.hb returns a list of class matrix.csc.hb or matrix.ssc.hb depending on how the coefficient matrix is stored in the file.
rara component of the csc or ssc format of the coefficient matrix, X.
jaja component of the csc or ssc format of the coefficient matrix, X.
iaia component of the csc or ssc format of the coefficient matrix, X.
rhs.rara component of the right-hand-side, y, if stored in csc or ssc format; right-hand-side stored in dense vector or matrix otherwise.
rhs.jaja component of the right-hand-side, y, if stored in csc or ssc format; a null vector otherwise.
rhs.iaia component of the right-hand-side, y, if stored in csc or ssc format; a null vector otherwise.
xexactvector of the exact solutions, b, if they exist; a null vector otherwise.
guessvector of the initial guess of the solutions if they exist; a null vector otherwise.
dimensiondimenson of the coefficient matrix, X.
rhs.dimdimenson of the right-hand-side, y.
rhs.modestorage mode of the right-hand-side; can be full storage or same format as the coefficient matrix.
The function model.matrix returns the X matrix of class matrix.csr. The function model.response returns the y vector (or matrix).

Details

Sparse coefficient matrices in the Harwell-Boeing format are stored in 80-column records. Each file begins with a multiple line header block followed by two, three or four data blocks. The header block contains summary information on the storage formats and storage requirements. The data blocks contain information of the sparse coefficient matrix and data for the right-hand-side of the linear system of equations, initial guess of the solution and the exact solutions if they exist. The function model.matrix extracts the X matrix component. The function model.response extracts the y vector (or matrix). NOTE: The HB read and write functions have been temporarily purged due to a memory bug in iohb.c. We hope to restore this functionality in the near future.

References