read.matrix.csr {e1071}

Read/Write Sparse Data

Description

reads and writes a file in sparse data format.

Usage

read.matrix.csr(file, fac = TRUE, ncol = NULL)
write.matrix.csr(x, file = "out.dat", y = NULL, fac = TRUE)

Arguments

x

An object of class matrix.csr

y

A vector (either numeric or a factor)

file

The filename.

fac

If TRUE, the y-values (if any) are interpreted as factor levels.

ncol

Number of columns, detected automatically. Can be used to add empty columns (possibly not stored in the sparse format).

Value

If the data file includes no y variable, read.matrix.csr returns an object of class matrix.csr, else a list with components:

x

object of class matrix.csr

y

vector of numeric values or factor levels, depending on fac.

Author(s)

David Meyer
[e-mail]

See Also

matrix.csr

Examples

## Not run: 
library(methods)
if (require(SparseM)) {
    data(iris)
    x <- as.matrix(iris[,1:4])
    y <- iris[,5]
    xs <- as.matrix.csr(x)
    write.matrix.csr(xs, y = y, file = "iris.dat")
    xs2 <- read.matrix.csr("iris.dat")$x
    if (!all(as.matrix(xs) == as.matrix(xs2)))
        stop("Error: objects are not equal!")
}

## End(Not run)