R: Read Fixed-Format Data in a Fortran-like Style

read.fortran {utils} | R Documentation

## Read Fixed-Format Data in a Fortran-like Style

### Description

Read fixed-format data files using Fortran-style format specifications.

### Usage

    read.fortran(file, format, ..., as.is = TRUE, colClasses = NA)

### Arguments

`file` | File or connection to read from.
`format` | Character vector or list of vectors. See ‘Details’ below.
`...` | Other arguments for `read.fwf`.
`as.is` | Keep characters as characters?
`colClasses` | Variable classes to override defaults. See `read.table` for details.

### Details

The format for a field is of one of the following forms: `rFl.d`, `rDl.d`, `rXl`, `rAl`, `rIl`, where `l` is the number of columns, `d` is the number of decimal places, and `r` is the number of repeats. `F` and `D` are numeric formats, `A` is character, `I` is integer, and `X` indicates columns to be skipped. The repeat code `r` and decimal place code `d` are always optional. The length code `l` is required except for `X` formats when `r` is present.

For a single-line record, `format` should be a character vector. For a multiline record it should be a list with a character vector for each line.

Skipped (`X`) columns are not passed to `read.fwf`, so `colClasses`, `col.names`, and similar arguments passed to `read.fwf` should not reference these columns.

### Value

A data frame

### Note

`read.fortran` does not use actual Fortran input routines, so the formats are at best rough approximations to the Fortran ones. In particular, specifying `d > 0` in the `F` or `D` format will shift the decimal `d` places to the left, even if it is explicitly specified in the input file.

### See Also

`read.fwf`, `read.table`, `read.csv`

### Examples

    ff <- tempfile()
    cat(file = ff, "123456", "987654", sep = "\n")
    read.fortran(ff, c("F2.1","F2.0","I2"))
    read.fortran(ff, c("2F1.0","2X","2A1"))
    unlink(ff)
    cat(file = ff, "123456AB", "987654CD", sep = "\n")
    read.fortran(ff, list(c("2F3.1","A2"), c("3I2","2X")))
    unlink(ff)
    # Note that the first number is read differently than Fortran would
    # read it:
    cat(file = ff, "12.3456", "1234567", sep = "\n")
    read.fortran(ff, "F7.4")
    unlink(ff)

[Package utils version 3.1.2 Index]