Read Fixed Width Format Files
Read a table of fixed width formatted
data into a
read.fwf(file, widths, header = FALSE, sep = "\t", skip = 0, row.names, col.names, n = -1, buffersize = 2000, fileEncoding = "", …)
the name of the file which the data are to be read from.
filecan be a connection, which will be opened if necessary, and if so closed at the end of the function call.
- integer vector, giving the widths of the fixed-width fields (of one line), or list of integer vectors giving widths for multiline records.
- a logical value indicating whether the file contains the
names of the variables as its first line. If present, the names
must be delimited by
- character; the separator used internally; should be a character that does not occur in the file (except in the header).
- number of initial lines to skip; see
- the maximum number of records (lines) to be read, defaulting to no limit.
- Maximum number of lines to read at one time
- character string: if non-empty declares the
encoding used on a file (not a connection) so the character data can
be re-encoded. See the ‘Encoding’ section of the help for
file, the ‘R Data Import/Export Manual’ and ‘Note’.
- further arguments to be passed to
read.table. Useful such arguments include
Multiline records are concatenated to a single line before processing.
Fields that are of zero-width or are wholly beyond the end of the line
file are replaced by
NA. Negative-width fields are used to indicate columns to be skipped, e.g.,
-5 to skip 5 columns. These fields are not seen by
read.table and so should not be included in a
colClasses argument (nor in the header line, if present). Reducing the
buffersize argument may reduce memory use when
reading large files with long lines. Increasing
result in faster processing when enough memory is available. Note that
read.table) reads the supplied
file, so the latter's argument
encoding will not be useful.
ff <- tempfile() cat(file = ff, "123456", "987654", sep = "\n") read.fwf(ff, widths = c(1,2,3)) #> 1 23 456 \ 9 87 654 read.fwf(ff, widths = c(1,-2,3)) #> 1 456 \ 9 654 unlink(ff) cat(file = ff, "123", "987654", sep = "\n") read.fwf(ff, widths = c(1,0, 2,3)) #> 1 NA 23 NA \ 9 NA 87 654 unlink(ff) cat(file = ff, "123456", "987654", sep = "\n") read.fwf(ff, widths = list(c(1,0, 2,3), c(2,2,2))) #> 1 NA 23 456 98 76 54 unlink(ff)