| seq {base} | R Documentation |
Generate regular sequences.
from:to seq(from, to) seq(from, to, by=) seq(from, to, length=) seq(along)
from |
starting value of sequence. |
to |
(maximal) end value of the sequence. |
by |
increment of the sequence. |
length |
desired length of the sequence. |
along |
take the length from the length of this argument. |
The operator : and the first seq(.) form generate the
sequence from, from+1, ..., to.
seq is a generic function.
The second form generates from, from+by, ..., to.
The third generates a sequence of length equally spaced values
from from to to.
The last generates the sequence 1, 2, ...,
length(along).
If from and to are factors of the same length, then
from : to returns the ``cross'' of the two.
The result is of mode "integer" if from is
(numerically equal to an) integer and by is not specified.
1:4
pi:6 # float
6:pi # integer
seq(0,1, length=11)
str(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)
stopifnot(
3 == seq(3,3, by=pi),
3 == seq(3,3.1,by=pi),
seq(1,6,by=3) == c(1,4),
seq(10,4.05,by=-3) == c(10,7)
)
for (x in list(NULL, letters[1:6], list(1,pi)))
cat("x=",deparse(x),"; seq(along = x):",seq(along = x),"\n")
f1 <- gl(2,3); f1
f2 <- gl(3,2); f2
f1:f2 # a factor, the ``cross'' f1 x f2