R: Return melted data for each token in a whitespace-separated...

melt_table {readr} | R Documentation

## Return melted data for each token in a whitespace-separated file

### Description

This function has been superseded in readr and moved to the meltr package.

For certain non-rectangular data formats, it can be useful to parse the data into a melted format where each row represents a single token.

`melt_table()` and `melt_table2()` are designed to read the type of textual data where each column is separated by one (or more) columns of space.

`melt_table2()` allows any number of whitespace characters between columns, and the lines can be of different lengths.

`melt_table()` is more strict, each line must be the same length, and each field is in the same position in every line. It first finds empty columns and then parses like a fixed width file.

### Usage

    melt_table(
      file,
      locale = default_locale(),
      na = "NA",
      skip = 0,
      n_max = Inf,
      guess_max = min(n_max, 1000),
      progress = show_progress(),
      comment = "",
      skip_empty_rows = FALSE
    )

    melt_table2(
      file,
      locale = default_locale(),
      na = "NA",
      skip = 0,
      n_max = Inf,
      progress = show_progress(),
      comment = "",
      skip_empty_rows = FALSE
    )

### Arguments

`file` | Either a path to a file, a connection, or literal data (either a single string or a raw vector). Files ending in `.gz`, `.bz2`, `.xz`, or `.zip` will be automatically uncompressed. Files starting with `http://`, `https://`, `ftp://`, or `ftps://` will be automatically downloaded. Remote gz files can also be automatically downloaded and decompressed. Literal data is most useful for examples and tests. To be recognised as a path, it must be wrapped with `I()`, be a string containing at least one new line, or be a vector containing at least one string with a new line. Using a value of `clipboard()` will read from the system clipboard.
`locale` | The locale controls defaults that vary from place to place. The default locale is US-centric (like R), but you can use `locale()` to create your own locale that controls things like the default time zone, encoding, decimal mark, big mark, and day/month names.
`na` | Character vector of strings to interpret as missing values. Set this option to `character()` to indicate no missing values.
`skip` | Number of lines to skip before reading data.
`n_max` | Maximum number of lines to read.
`guess_max` | Maximum number of lines to use for guessing column types.
`progress` | Display a progress bar? By default it will only display in an interactive session and not while knitting a document. The automatic progress bar can be disabled by setting option `readr.show_progress` to `FALSE`.
`comment` | A string used to identify comments. Any text after the comment characters will be silently ignored.
`skip_empty_rows` | Should blank rows be ignored altogether? i.e. If this option is `TRUE` then blank rows will not be represented at all. If it is `FALSE` then they will be represented by `NA` values in all the columns.

### See Also

`melt_fwf()` to melt fixed width files where each column is not separated by whitespace. `melt_fwf()` is also useful for reading tabular data with non-standard formatting. `read_table()` is the conventional way to read tabular data from whitespace-separated files.

### Examples

    # One corner from http://www.masseyratings.com/cf/compare.htm
    massey <- readr_example("massey-rating.txt")
    cat(read_file(massey))
    melt_table(massey)

    # Sample of 1978 fuel economy data from
    # http://www.fueleconomy.gov/feg/epadata/78data.zip
    epa <- readr_example("epa78.txt")
    cat(read_file(epa))
    melt_table(epa)

[Package readr version 2.0.2 Index]