R: Read in random lines from a text file

sample_lines {LaF} | R Documentation

## Read in random lines from a text file

### Description

Read in random lines from a text file

### Usage

    sample_lines(filename, n, nlines = NULL)

### Arguments

`filename` | character containing the filename of the file from which the lines should be read.
`n` | The number of lines that should be sampled from the file.
`nlines` | The total number of lines in the file. If not specified or `NULL` the number of lines is first determined using `determine_nlines`.

### Details

When `nlines` is not specified, the total number of lines is first determined. This can take quite some time. Therefore, specifying the number of lines can cause a significant speed up. It can also be used to sample lines from the first `nlines` line by specifying a value for `nlines` that is smaller than the number of lines in the file.

### Value

Returns a character vector with the sampled lines.

### See Also

See `readLines` to read in all lines a text file; `get_lines` can be used to read in specified lines.

### Examples

    # Create temporary filename
    tmpcsv  <- tempfile(fileext="csv")

    writeLines(letters[1:20], con=tmpcsv)
    sample_lines(tmpcsv, 10)

    # Cleanup
    file.remove(tmpcsv)

[Package LaF version 0.8.4 Index]