\HeaderA{pscontinuous}{Position: continuous}{pscontinuous}
\keyword{hplot}{pscontinuous}
\begin{Description}\relax
Add a continuous position scale to the plot
\end{Description}
\begin{Usage}
\begin{verbatim}pscontinuous(plot = .PLOT, variable="x", transform=trans_none, range=c(NA,NA), expand=c(0.05, 0), breaks=NULL)\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{plot}] plot
\item[\code{variable}] variable ("x" or "y")
\item[\code{transform}] transform function and it's inverse in a vector
\item[\code{range}] range, or leave missing to automatically determine
\item[\code{expand}] expansion vector (numeric vector, multiplicative and additive expansion)
\item[\code{breaks}] set breaks manually
\end{ldescription}
\end{Arguments}
\begin{Details}\relax
There are a few useful things that you can do with \code{pscontinuous}:

\item set plot limits explicitly (with \code{range})
\item transform the scale (with \code{transform})
\item explicitly set where the axis labels (and grid lines) should appear (with \code{breaks})

Note, that if you explicitly set the axis range, you may want to use
\code{\LinkA{expand\_range}{expand.Rul.range}} to add a little extra room on each side.

When transforming an axes, you need to supply the transforming function
and it's inverse (used to create pretty axis labels).  I have created
a few common ones for you:

\item \code{trans\_log10}: log base 10
\item \code{trans\_log10}: log base 2
\item \code{trans\_inverse}: inverse
\item \code{trans\_sqrt}: square root
\end{Details}
\begin{Value}
modified plot object
\end{Value}
\begin{Author}\relax
Hadley Wickham <h.wickham@gmail.com>
\end{Author}
\begin{Examples}
\begin{ExampleCode}p <- ggpoint(ggplot(mtcars, aesthetics=list(x=mpg, y=disp)))
pscontinuous(p, "x", range=c(20,30))
pscontinuous(p, "y", breaks=seq(100, 400, 50)) 
pscontinuous(p, "y", transform=trans_inverse)
pscontinuous(p, "x", transform=trans_sqrt)
pscontinuous(p, "x", transform=trans_log10)
pscontinuous(p, "x", transform=trans_log10, breaks=seq(10,30, 5))\end{ExampleCode}
\end{Examples}

