Matrix (version 0.99-3)

externalFormats: Read and write external matrix formats

Description

Read matrices stored in the Harwell-Boeing or MatrixMarket formats or write sparseMatrix objects to one of these formats.

Usage

readHB(file)
readMM(file)
writeHB(obj, file, ...)
writeMM(obj, file, ...)

Arguments

obj

a real sparse matrix

file

for writeHB and writeMM - the name of the file to be written. For readHB and readMM the name of the file to read, as a character scalar. The names of files storing matrices in the Harwell-Boein

...

optional additional arguments. Currently none are used in any methods.

Value

• The readHB and readMM functions return an object that inherits from the "Matrix" class. Methods for the writeHB and writeMM generic functions usually return NULL and, as a side effect, the matrix obj is written to file in the Harwell-Boeing format (writeHB) or the MatrixMarket format (writeMM).

References

http://math.nist.gov/MatrixMarket

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

Examples

str(pores <- readMM(system.file("external/pores_1.mtx",
                                package = "Matrix")))
str(utm <- readHB(system.file("external/utm300.rua",
                               package = "Matrix")))
str(lundA <- readMM(system.file("external/lund_a.mtx",
                                package = "Matrix")))
str(lundA <- readHB(system.file("external/lund_a.rsa",
                                package = "Matrix")))
## NOTE: The following examples take quite some time
## ----  even on a fast internet connection:
str(sm <-
 readHB(gzcon(url("http://www.cise.ufl.edu/research/sparse/HBformat/Boeing/msc00726.rsa.gz"))))
str(jgl009 <-
 readMM(gzcon(url("ftp://math.nist.gov/pub/MatrixMarket2/Harwell-Boeing/counterx/jgl009.mtx.gz"))))
writeHB(mm, "mmHB.rua")
writeMM(mm, "mmMM.mtx")