Seeing Through grid Graphics

R Graphics

An Example Plot

library(lattice)
plot <- xyplot(mpg ~ disp | trans, data=mtcars)

An Example Plot

What can I do with this plot AFTER it has been drawn ?

Not Interested

     xyplot(x,
            data,
            allow.multiple = is.null(groups) || outer,
            outer = !is.null(groups),
            auto.key = FALSE,
            aspect = "fill",
            panel = lattice.getOption("panel.xyplot"),
            prepanel = NULL,
            scales = list(),
            strip = TRUE,
            groups = NULL,
            xlab,
            xlim,
            ylab,
            ylim,
            drop.unused.levels = lattice.getOption("drop.unused.levels"),
            ...,

Allow More Drawing

print(plot)
grid.rect()

Allow More Drawing

An Example Plot

What can I do with this plot AFTER it has been drawn ?

Remember the Drawing Context

print(plot)
showViewport()

Allow Access to the Drawing Context

print(plot)
downViewport("plot_01.panel.1.2.vp")
grid.text("Ferrari Dino", x=155, y=19.7, just="left", default="native")

Allow Access to the Drawing Context

+ →

Remember What was Drawn

print(plot)
showGrob()

Allow Access to What was Drawn

print(plot)
grid.edit("plot_01.xlab", label="Engine Displacement")

Allow Access to What was Drawn

 → 

Allow Labels and Structure

grid.roundrect(gp=gpar(col=NA, fill=rgb(1,0,0,.5)), name="box")
grid.text("Ferrari Dino", name="label")

grid.ls()

box
label

Allow Labels and Structure

gTree(children=gList(roundrectGrob(gp=gpar(col=NA, fill=rgb(1,0,0,.5)), 
                                   name="box"),
                     textGrob("Ferrari Dino", name="label")),
      name="boxedLabel")

grid.ls()

boxedLabel
  box
  label

The Example Plot

Provide Labels and Structure

print(plot)
grid.ls(viewports=TRUE)

viewport[ROOT]
  rect[plot_01.background]
  viewport[plot_01.toplevel.vp]
    viewport[plot_01.xlab.vp]
      text[plot_01.xlab]
    viewport[plot_01.ylab.vp]
      text[plot_01.ylab]
    viewport[plot_01.figure.vp]

Export Labels and Structure

Export Labels and Structure

R code ...

library(gridSVG)
print(plot)
grid.export()

SVG code ...

<svg>
  <rect id="plot_01.background.1.1"/>
  <g id="plot_01.toplevel.vp.1">
    <g id="plot_01.toplevel.vp::plot_01.xlab.vp.1">
      <text id="plot_01.xlab.1">
...

Export Labels and Structure

The Royal Society of New Zealand: Languages in Aotearoa New Zealand

Export Labels and Structure

Export Labels and Structure

R code ...

pushViewport(viewport(name="viewport"))
grid.polygon("ID:1")
grid.polygon("ID:2")
...

SVG code ...

<svg>
  <g id="viewport">
    <polygon id="ID:1" .../>
    <polygon id="ID:2" .../>
...

Javascript code ...

svgRoot = root.getElementById("viewport");
...

Don't be a Dead End

The Royal Society of New Zealand: Languages in Aotearoa New Zealand (original)

Don't be a Dead End

The Royal Society of New Zealand: Languages in Aotearoa New Zealand (recycled)

Don't be a Dead End

Summary

Don't be a Dead End

• grid
  • Allow more drawing
  • Record the drawing context
  • Allow access to the drawing context
  • Record what was drawn
  • Allow access to what was drawn
  • Allow labels and structure
• lattice
  • Provide a naming scheme
  • Provide structure
• gridSVG
  • Export labels and structure

Acknowledgements

• The plot with lots of extra drawing was adapted from Felgate, Bickler, and Murrell (2013) "Estimating parent population of pottery vessels from a sample of fragments: a case study from inter-tidal surface collections, Roviana Lagoon, Solomon Islands", Journal of Archaeological Science, 40 (2013) 1319-1328.

• The raster map plot used NASA light data from Steve Mosher and a Google Map tile (copyright 2011 Google, Map Data and copyright 2011 Tele Atlas).

• The forest plot was generated using the 'metaplot' package by Murrell, Scott, and Lu

• The map of Multilingualism in New Zealand was created by Paul Behrens for the Royal Society of New Zealand