# lines: Add Connected Line Segments to a Plot

## Description

A generic function taking coordinates given in various ways and joining the corresponding points with line segments.

## Usage

 ```1 2 3 4``` ```lines(x, ...) ## Default S3 method: lines(x, y = NULL, type = "l", ...) ```

## Arguments

 `x, y` coordinate vectors of points to join. `type` character indicating the type of plotting; actually any of the `type`s as in `plot.default`. `...` Further graphical parameters (see `par`) may also be supplied as arguments, particularly, line type, `lty`, line width, `lwd`, color, `col` and for `type = "b"`, `pch`. Also the line characteristics `lend`, `ljoin` and `lmitre`.

## Details

The coordinates can be passed in a plotting structure (a list with `x` and `y` components), a two-column matrix, a time series, .... See `xy.coords`. If supplied separately, they must be of the same length.

The coordinates can contain `NA` values. If a point contains `NA` in either its `x` or `y` value, it is omitted from the plot, and lines are not drawn to or from such points. Thus missing values can be used to achieve breaks in lines.

For `type = "h"`, `col` can be a vector and will be recycled as needed.

`lwd` can be a vector: its first element will apply to lines but the whole vector to symbols (recycled as necessary).

## References

Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.

`lines.formula` for the formula method; `points`, particularly for `type %in% c("p","b","o")`, `plot`, and the workhorse function `plot.xy`.
`abline` for drawing (single) straight lines.
`par` for line type (`lty`) specification and how to specify colors.
 ```1 2 3``` ```# draw a smooth line through a scatter plot plot(cars, main = "Stopping Distance versus Speed") lines(stats::lowess(cars)) ```