Sequence Generation

Usage

from:to
seq(from, to)
seq(from, to, by=)
seq(from, to, length=)
seq(along)

Description

The : and the first seq(.) form above generate the sequence from, from+1, ..., to. seq is a generic function.

The second, 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, the ``cross'' of the two is returned.

Value

The result is of mode "integer" if from is (numerically equal to an) integer.

See Also

rep, sequence, row, col.

Examples

1:4
pi:6 # float
6:pi # integer

seq(0,1, length=11)
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)

1:4
pi:6 # float
6:pi # integer

seq(0,1, length=11)
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)


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


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

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