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",
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, |
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 |
character; the separator used internally; should be a character that does not occur in the file (except in the header). |
skip |
number of initial lines to skip; see
|
row.names |
see |
col.names |
see |
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
|
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 (nor in the header line, if present).
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, 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)