scan {base} | R Documentation |
Read data into a vector or list from the console or file.
scan(file = "", what = double(0), nmax = -1, n = -1, sep = "", quote = "", dec = ".", skip = 0, nlines = 0, na.strings = "NA", flush = FALSE, strip.white = FALSE, quiet = FALSE)
file |
the name of a file to read data values from. If the
specified file is "" , then input is taken from the keyboard
(in this case input can be terminated by a blank line).
Otherwise, the file name is relative to the current working
directory, |
what |
the type of what gives the type of data to be
read. If what is a list, it is assumed that the lines of the
data file are records each containing length(what) items
(``fields''). |
nmax |
the maximum number of data values to be read, or if
what is a list, the maximum number of records to be read. If
omitted, scan will read to the end of file . |
n |
the maximum number of data values to be read, defaulting to no limit. |
sep |
by default, scan expects to read white-space delimited
input fields. Alternatively, sep can be used to specify a
character which delimits fields. |
quote |
the set of quoting characters as a single character string. |
dec |
decimal point character. |
skip |
this many lines of the input file should be skipped before starting to read data values. |
nlines |
the maximum number of lines of data to be read. |
na.strings |
character string, indicating which character
fields in the file should translate to missing (NA )
values. |
flush |
logical; if TRUE , scan will flush to the
end of the line after reading the last of the fields requested.
This allows putting comments after the last field. |
strip.white |
vector of logical value(s) corresponding to items
in the what argument. It is used only when sep has
been specified, and allows to strip leading and trailing white space
from character fields (numeric fields are always
stripped).
If |
quiet |
logical; if FALSE (default), scan(.) will print a
line, telling what fields have been read. |
The value of what
can be a list of types, in which case
scan
returns a list of vectors with the types given by the
types of the elements in what
. This provides a way of reading
columnar data.
If sep
is nondefault, the fields may be quoted in the style of
.csv format files where separators inside quotes (''
or
""
) are ignored and quotes may be put inside strings by
doubling them.
Keyboard entry is terminated by typing a blank line.
read.table
for more user-friendly reading of data
matrices;
write
.
cat("TITLE extra line", "2 3 5 7", "11 13 17", file="ex.data", sep="\n") pp <- scan("ex.data", skip = 1, quiet= TRUE) scan("ex.data", skip = 1) scan("ex.data", skip = 1, nlines=1)# only 1 line after the skipped one str(scan("ex.data", what = list("","",""))) # flush is F -> read "7" str(scan("ex.data", what = list("","",""), flush = TRUE)) unlink("ex.data") # tidy up