| % File src/library/grid/vignettes/sharing.Rnw |
| % Part of the R package, https://www.R-project.org |
| % Copyright 2001-13 Paul Murrell and the R Core Team |
| % Distributed under GPL 2 or later |
| |
| \documentclass[a4paper]{article} |
| %\VignetteIndexEntry{Modifying multiple grobs simultaneously} |
| \newcommand{\code}[1]{\texttt{#1}} |
| \newcommand{\pkg}[1]{{\normalfont\fontseries{b}\selectfont #1}} |
| \newcommand{\grid}{\pkg{grid}} |
| \newcommand{\R}{{\sffamily R}} |
| \setlength{\parindent}{0in} |
| \setlength{\parskip}{.1in} |
| \title{An Example of ``Linking'' Graphical Objects in \grid{}} |
| \author{Paul Murrell} |
| |
| \begin{document} |
| \maketitle |
| |
| <<echo=FALSE, results=hide>>= |
| library(grDevices) |
| library(graphics) |
| library(stats) # for rnorm |
| library(grid) |
| ps.options(pointsize = 12) |
| options(width = 60) |
| @ |
| Suppose that I am drawing two graphs on a page, which are the results |
| from two subjects in an experiment. I want the graphs to have the same |
| axes to aid in comparison of the subjects. |
| |
| First of all, I will split the page up into two bits for the two graphs. |
| |
| <<axes1, eval=FALSE, results=hide>>= |
| pushViewport(viewport(layout = grid.layout(1, 2, respect = TRUE))) |
| @ |
| Now I generate some data and draw the first plot. |
| |
| <<axes2, eval=FALSE, results=hide>>= |
| x <- 1:10 |
| y1 <- rnorm(10) |
| vp1a <- viewport(layout.pos.col = 1) |
| vp1b <- viewport(width = 0.6, height = 0.6, |
| xscale = c(0, 11), yscale = c(-4, 4)) |
| pushViewport(vp1a, vp1b) |
| grid.xaxis(name = "xaxis") |
| grid.yaxis(name = "yaxis") |
| grid.points(x, y1) |
| popViewport(2) |
| @ |
| Notice that I have named the graphical objects for the axes. |
| When I draw the second plot I will use the same names for the |
| axis objects. |
| |
| <<axes3, eval=FALSE, results=hide>>= |
| y2 <- rnorm(10) |
| vp2a <- viewport(layout.pos.col = 2) |
| vp2b <- viewport(width = 0.6, height = 0.6, |
| xscale = c(0, 11), yscale = c(-4, 4)) |
| pushViewport(vp2a, vp2b) |
| grid.xaxis |
| grid.xaxis(name = "xaxis") |
| grid.yaxis(name = "yaxis") |
| grid.points(x, y2) |
| popViewport(2) |
| @ |
| The output looks like the figure below. |
| |
| <<shared, results=hide, fig=TRUE, echo=FALSE, width=4, height=2, include=FALSE>>= |
| <<axes1>> |
| <<axes2>> |
| <<axes3>> |
| |
| @ |
| \begin{center} |
| \includegraphics[width=4in, height=2in]{sharing-shared} |
| \end{center} |
| @ |
| |
| Because I have used the same name for the axis objects in both plots, |
| I can edit the axes for both plots |
| simultaneously rather than having to edit each one in turn. |
| For example ... |
| |
| <<axesedit, eval=FALSE, results=hide>>= |
| grid.edit("xaxis", at = c(1, 5, 9), global = TRUE) |
| |
| @ |
| The output now looks like the figure below. |
| |
| <<shared2, results=hide, echo=FALSE>>= |
| postscript("shared2-%02d.eps", onefile = FALSE, paper = "special", |
| width = 4, height = 2) |
| <<axes1>> |
| <<axes2>> |
| <<axes3>> |
| <<axesedit>> |
| dev.off() |
| |
| pdf("shared2-%02d.pdf", onefile = FALSE, width = 4, height = 2) |
| <<axes1>> |
| <<axes2>> |
| <<axes3>> |
| <<axesedit>> |
| dev.off() |
| @ |
| \begin{center} |
| \includegraphics[width=4in, height=2in]{shared2-02} |
| \end{center} |
| @ |
| |
| This might seem a very small gain in this example, but it is |
| potentially of great use in, for example, the implementation of a scatterplot |
| matrix. |
| \end{document} |
