R: Combine, transpose big matrices and change colnames

combineBigMatrices {bigstep} | R Documentation

## Combine, transpose big matrices and change colnames

### Description

Combine and/or transpose big matrices and write to a file with new names of columns

### Usage

    combineBigMatrices(X, Z = NULL, file.out = "XZ.txt", transX = FALSE,
      transZ = FALSE, new.names = NULL, maxp = 1e+07, verbose = TRUE)

### Arguments

`X` | an object of class big.matrix.
`Z` | an object of class big.matrix. Specify if you want to combine matrices.
`file.out` | a character string. The name of the output file.
`transX` | a logical. If `TRUE`, the matrix `X` will be transposed.
`transZ` | a logical. If `TRUE`, the matrix `Z` will be transposed.
`new.names` | a vector of strings. Specify if you want to change names of variables.
`maxp` | a numeric. If `X` is big, it will be splitted into parts with `maxp` elements. It will not change results, but it is necessary if your computer does not have enough RAM. Set to a lower value if you still have problems.
`verbose` | a logical. Set `FALSE` if you do not want to see any information during the selection procedure.

### Value

A numeric, a number of variables successfully written.

### Examples

    ## Not run:
    library(bigmemory)
    X <- matrix(sample(0:2, 20, replace=TRUE), 2, 10)
    Z <- matrix(sample(0:2, 20, replace=TRUE), 2, 10)
    write.table(X, "X.txt", col.names=FALSE, row.names=FALSE)
    write.table(Z, "Z.txt", col.names=FALSE, row.names=FALSE)
    X <- read.big.matrix("X.txt", sep=" ", type="char")
    Z <- read.big.matrix("Z.txt", sep=" ", type="char")
    # if it is possible, set type="char", reading will be quicker
    names <- c("X1", "X2", "Z1", "Z2")
    combineBigMatrices(X, Z, transX=TRUE, transZ=TRUE, new.names=names)

    ## End(Not run)

[Package bigstep version 0.7.4 Index]