# sequence: Create A Vector of Sequences

## Description

The default method for `sequence` generates the sequence `seq(from[i], by = by[i], length.out = nvec[i])` for each element `i` in the parallel (and recycled) vectors `from`, `by` and `nvec`. It then returns the result of concatenating those sequences.

## Usage

 ```1 2 3``` ```sequence(nvec, ...) ## Default S3 method: sequence(nvec, from = 1L, by = 1L, ...) ```

## Arguments

 `nvec` coerced to a non-negative integer vector each element of which specifies the length of a sequence. `from` coerced to an integer vector each element of which specifies the first element of a sequence. `by` coerced to an integer vector each element of which specifies the step size between elements of a sequence. `...` additional arguments passed to methods.

## Details

Negative values are supported for `from` and `by`. `sequence(nvec, from, by=0L)` is equivalent to `rep(from, each=nvec)`.

This function was originally implemented in R with fewer features, but it has since become more flexible, and the default method is implemented in C for speed.

## Author(s)

Of the current version, Michael Lawrence based on code from the S4Vectors Bioconductor package

`gl`, `seq`, `rep`.
 ```1 2 3 4 5 6 7 8``` ```sequence(c(3, 2)) # the concatenated sequences 1:3 and 1:2. #> [1] 1 2 3 1 2 sequence(c(3, 2), from=2L) #> [1] 2 3 4 2 3 sequence(c(3, 2), from=2L, by=2L) #> [1] 2 4 6 2 4 sequence(c(3, 2), by=c(-1L, 1L)) #> [1] 1 0 -1 1 2 ```