seq {base} R Documentation

## Sequence Generation

### Description

Generate regular sequences.

### Usage

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

### Details

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.

### Value

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

`rep`, `sequence`, `row`, `col`.

### Examples

```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)

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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