\HeaderA{grid.lines}{Draw Lines in a Grid Viewport}{grid.lines}
\aliasA{linesGrob}{grid.lines}{linesGrob}
\keyword{dplot}{grid.lines}
\begin{Description}\relax
These functions create and draw a series of lines.
\end{Description}
\begin{Usage}
\begin{verbatim}
grid.lines(x = unit(c(0, 1), "npc", units.per.obs),
       y = unit(c(0, 1), "npc", units.per.obs), 
       default.units = "npc", units.per.obs = FALSE, name = NULL,
       gp=gpar(), draw = TRUE, vp = NULL)
linesGrob(x = unit(c(0, 1), "npc", units.per.obs),
       y = unit(c(0, 1), "npc", units.per.obs), 
       default.units = "npc", units.per.obs = FALSE, name = NULL,
       gp=gpar(), vp = NULL)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{x}] A numeric vector or unit object specifying x-values.
\item[\code{y}] A numeric vector or unit object specifying y-values.
\item[\code{default.units}] A string indicating the default units to use
if \code{x} or \code{y} are only given as numeric vectors.
\item[\code{units.per.obs}] A logical value to indicate whether each
individual (x, y) location has its own unit(s) specified.
\item[\code{name}] A character identifier. 
\item[\code{gp}] An object of class \code{gpar}, typically the output
from a call to the function \code{gpar}.  This is basically
a list of graphical parameter settings.
\item[\code{draw}] A logical value indicating whether graphics output
should be produced.
\item[\code{vp}] A Grid viewport object (or NULL).
\end{ldescription}
\end{Arguments}
\begin{Details}\relax
Both functions create a lines grob (a graphical object describing
lines), but only \code{grid.lines}
draws the lines (and then only if \code{draw} is \code{TRUE}).
\end{Details}
\begin{Value}
A lines grob.  \code{grid.lines} returns the value invisibly.
\end{Value}
\begin{Author}\relax
Paul Murrell
\end{Author}
\begin{SeeAlso}\relax
\LinkA{Grid}{Grid},
\code{\LinkA{viewport}{viewport}}
\end{SeeAlso}

