| read.fwf {utils} | R Documentation |
Read a “table” of fixed width formatted
data into a data.frame.
read.fwf(file, widths, header = FALSE, sep = "\t", as.is = FALSE,
skip = 0, row.names, col.names, n = -1, buffersize = 2000,
...)
file |
the name of the file which the data are to be read from.
Alternatively, file can be a connection, which
will be opened if necessary, and if so closed at the end of the
function call.
|
widths |
integer vector, giving the widths of the fixed-width fields (of one line), or list of integer vectors giving widths for multiline records. |
header |
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 sep. |
sep |
character; the separator used internally; should be a character that does not occur in the file (except in the header). |
as.is |
see read.table. |
skip |
number of initial lines to skip; see
read.table. |
row.names |
see read.table. |
col.names |
see read.table. |
n |
the maximum number of records (lines) to be read, defaulting to no limit. |
buffersize |
Maximum number of lines to read at one time |
... |
further arguments to be passed to
read.table. Useful further arguments include
na.strings, colClasses and strip.white. |
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
in file are replaced by NA.
Negative-width fields are used to indicate columns to be skipped, eg
-5 to skip 5 columns. These fields are not seen by
read.table and so should not be included in a col.names
or colClasses argument.
Reducing the buffersize argument may reduce memory use when
reading large files with long lines. Increasing buffersize may
result in faster processing when enough memory is available.
A data.frame as produced by read.table
which is called internally.
Brian Ripley for R version: original Perl by Kurt Hornik.
scan and read.table.
ff <- tempfile() cat(file=ff, "123456", "987654", sep="\n") read.fwf(ff, width=c(1,2,3)) #> 1 23 456 \ 9 87 654 read.fwf(ff, width=c(1,-2,3)) #> 1 456 \ 9 654 unlink(ff) cat(file=ff, "123", "987654", sep="\n") read.fwf(ff, width=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, width=list(c(1,0, 2,3), c(2,2,2))) #> 1 NA 23 456 98 76 54 unlink(ff)