| externalFormats {Matrix} | R Documentation |
Read matrices stored in the Harwell-Boeing or MatrixMarket formats or write sparseMatrix objects to one of these formats.
readHB(file) readMM(file) writeMM(obj, file, ...)
obj |
a real sparse matrix |
file |
for 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-Boeing format usually end in ".rua" or ".rsa".
Those storing matrices in the MatrixMarket format usually end in
".mtx".
Alternatively, readHB and readMM accept connection objects. |
... |
optional additional arguments. Currently none are used in any methods. |
The readHB and readMM functions return an object that
inherits from the "Matrix" class. Methods for the
writeMM generic functions usually return
NULL and, as a side effect, the matrix obj is
written to file in the MatrixMarket format (writeMM).
The Harwell-Boeing format is older and less flexible than the
MatrixMarket format. The function writeHB was deprecated and
has now been removed. Please use writeMM instead.
http://math.nist.gov/MatrixMarket
http://www.cise.ufl.edu/research/sparse/matrices
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")))
## Not run:
## NOTE: The following examples take quite some time
## ---- even on a fast internet connection:
if(FALSE) # the URL has been corrected, but we need an un-tar step!
str(sm <-
readHB(gzcon(url("http://www.cise.ufl.edu/research/sparse/RB/Boeing/msc00726.tar.gz"))))
str(jgl009 <-
readMM(gzcon(url("ftp://math.nist.gov/pub/MatrixMarket2/Harwell-Boeing/counterx/jgl009.mtx.gz"))))
## End(Not run)
data(KNex)
writeMM(KNex$mm, "mmMM.mtx")