row/colnames {base} | R Documentation

## Row and Columnn Names

### Description

Retrieve or set the row or column names of an object (the first or second component of its `dimnames`).

### Usage

    rownames(x, do.NULL = TRUE, prefix = "row")
    rownames(x) <- namevector

    colnames(x, do.NULL = TRUE, prefix = "col")
    colnames(x) <- namevector

### Details

If `do.NULL` is `FALSE`, a character vector (of length `NROW(x)` or `NCOL(x)` is returned in any case, prepending `prefix` to simple numbers, if `dimnames(x)[[i]]` (`i =` 1 or 2) is `NULL`.

### See Also

`dimnames`, `case.names`, `variable.names`.

### Examples

    m0 <- matrix(NA, 4, 0)
    m2 <- cbind(1,1:4)
    rownames(m0)

    colnames(m2, do.NULL = FALSE)
    colnames(m2) <- c("x","Y")
    rownames(m2) <- rownames(m2, do.NULL = FALSE, prefix = "Obs.")
    m2