[R] How to draw a line in plot when I know the start point(x1, y1) and end point(x2, y2)?

[Marc Schwartz]

On Jun 25, 2009, at 1:30 PM, Lesandro wrote:

> Hello all,
>
> How to draw a line in plot when I know the start point(x1,y1) and  
> end point(x2,y2)? I need make this as additional information in the  
> graph:
>
> plot(wl2[[1]],wl2[[2]])
>
> I think that is possible make this with the function abline(), is  
> possible? I looked the function lines() too, but don't understand as  
> make.
>
>
> Thanks!
> Lesandro


See ?segments which does just what you are looking for.

lines() is more designed for a series of connected lines (eg. a  
polygon) rather than a single line segment.

abline() can draw a straight line, at a given vertical or horizontal  
position, or if given a linear model object, the fitted line.

HTH,

Marc Schwartz