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).