Read/Write Sparse Data — read.matrix.csr • e1071

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

David Meyer
David.Meyer@R-project.org

See also

Examples

if (FALSE) { # \dontrun{
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!")
}
} # }