Creae a simple plot showing a line segment.

## Arguments

- x
The endpoints of the interval. Values larger (smaller) than 999 (-999) will be interpreted as (negative) infinity.

- l
Indicate whether the left end point should be open (

`"o"`

) or closed (`"c"`

).- r
Indicate whether the right end point should be open (

`"o"`

) or closed (`"c"`

).- ticks
Indicate whether to show tick marks (

`TRUE`

) or not (`FALSE`

).- labs
The position for the point labels. Set to

`0`

if no labels should be shown.- add
Indicate whether the line segment should be added to an existing plot (

`TRUE`

) or a new plot should be created (`FALSE`

).- ylim
A vector of length 2 specifying the vertical plotting limits, which may be useful for fine-tuning plots. The default is

`c(-0.75,0.25)`

.