import {spam} | R Documentation |
Read matrices stored in the Harwell-Boeing or MatrixMarket formats.
read.HB(file) read.MM(file)
file |
the name of the file to read, as a character scalar.
Alternatively, read.HB and read.MM accept connection
objects. |
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"
.
Currently, only real assembled Harwell-Boeing can be read with
read.HB
. Reading MatrixMarket formats is more flexible.
However, as entries of spam
matrices are of mode double
,
integers matrices are coerced to doubles, patterns lead to matrices
containing ones and complex are coerced to the real part thereof. In
these aforementioned cases, a warning is issued.
MatrixMarket also defines an array format, in which case a (possibly)
dense spam
object is return (retaining only elements which are
larger than spam.options('eps')
. A warning is issued.
A sparse matrix of class spam
.
The functions are based on readHB
and readMM
from
the library Matrix
to build the connection and read the raw
data.
At present, read.MM
is more flexible than readMM
.
Reinhard Furrer based on Matrix
functions by
Douglas Bates bates@stat.wisc.edu and Martin Maechler maechler@stat.math.ethz.ch
http://math.nist.gov/MatrixMarket
http://www.cise.ufl.edu/research/sparse/matrices
## Not run: image(read.MM(gzcon(url( "ftp://math.nist.gov/pub/MatrixMarket2/Harwell-Boeing/bcspwr/bcspwr01.mtx.gz")))) ## End(Not run) ## Not run: ## Datasets supplied within Matrix str(read.MM(system.file("external/pores_1.mtx",package = "Matrix"))) str(read.HB(system.file("external/utm300.rua", package = "Matrix"))) str(read.MM(system.file("external/lund_a.mtx", package = "Matrix"))) str(read.HB(system.file("external/lund_a.rsa", package = "Matrix"))) ## End(Not run)