| seq {base} | R Documentation |
Generate regular sequences. seq is a standard generic with a
default method. seq.int is an internal generic which can be
much faster but has a few restrictions. seq_along and
seq_len are very fast primitives for two common cases.
seq(...)
## Default S3 method:
seq(from = 1, to = 1, by = ((to - from)/(length.out - 1)),
length.out = NULL, along.with = NULL, ...)
seq.int(from, to, by, length.out, along.with, ...)
seq_along(along.with)
seq_len(length.out)
... |
arguments passed to or from methods. |
from, to |
the starting and (maximal) end value of the sequence. |
by |
number: increment of the sequence. |
length.out |
desired length of the sequence. A
non-negative number, which for seq and seq.int will be
rounded up if fractional. |
along.with |
take the length from the length of this argument. |
The interpretation of the unnamed arguments of seq and
seq.int is not standard, and it is recommended always to
name the arguments when programming.
Both seq are seq.int are generic, and only the default
method is described here. Typical usages are
seq(from, to) seq(from, to, by= ) seq(from, to, length.out= ) seq(along.with= ) seq(from) seq(length.out= )The first form generates the sequence
from, from+/-1, ..., to
(identical to from:to).
The second form generates from, from+by, ..., up to the
sequence value less than or equal to to. Specifying
to - from and by of opposite signs is an error.
The third generates a sequence of length.out equally spaced
values from from to to. (length.out is usually
abbreviated to length or len, and seq_len is much
faster.)
The fourth form generates the sequence 1, 2, ...,
length(along.with). (along.with is usually abbreviated to
along, and seq_along is much faster.)
The fifth form generates the sequence 1, 2, ..., length(from)
(as if argument along.with had been specified),
unless the argument is numeric of length 1 when it is
interpreted as 1:from (even for seq(0) for
compatibility with S).
The final form generates 1, 2, ..., length.out unless
length.out = 0, when it generates integer(0).
Very small sequences (with from - to of the order of 10^{-14}
times the larger of the ends) will return from.
For seq(only), up to two of from, to and by can
be supplied as complex values provided length.out or
along.with is specified.
Currently, the default method returns a result of type
"integer" if from is (numerically equal to an)
integer and, e.g., only to is specified, or also if only
length or only along.with is specified. Note:
this may change in the future and programmers should not rely on it.
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.
The methods seq.Date and seq.POSIXt.
seq(0, 1, length=11) seq(rnorm(20)) seq(1, 9, by = 2) # match seq(1, 9, by = pi)# stay below seq(1, 6, by = 3) seq(1.575, 5.125, by=0.05) seq(17) # same as 1:17