plot.shp {fastshp}

R Documentation

Plot shape files

Description

plot.shp plots a list of shapes

Usage

plot.shp(x, xlim, ylim, asp = 1/cos(sum(ylim)/360 * pi), add = FALSE,
         axes = FALSE, full = TRUE, hold = FALSE,
         col = "#e0e0e0", border = "#808080", ...)

Arguments

x	"shp" object as returned from read.shp
xlim	range to plot in x direction; defaults to the range of all bounding boxes
ylim	range to plot in x direction; defaults to the range of all bounding boxes
asp	aspect ratio; the default ensures least distortion in the center of the image
add	logical; if TRUE polygons are added to the existing plot and xlim, ylim, asp, axes, full are ignored. Otherwise a new plot is created.
axes	logical; passed to plot

.

full	logical; if TRUE then margins are removed for full-size plot, otherwise margins are not touched.
hold	logical; if TRUE then the drawing code is wrapped in dev.hold()/dev.flush()
col	colors for the shapes; each shape (possibly consisting of multiple polygons) consumes one element
border	borders for the shapes; consumer and recycled jsut like col
...	additional arguments

Value

NULL invisibly

Note

It is most efficient to plot the result of read.shp(..., format="list"). All other types are converted into that type before plotting. It is most inefficient to use format="table".

Author(s)

Simon Urbanek

See Also

read.shp

Examples

Run examples

  # Census 2010 TIGER/Line(TM) state shapefile
  fn <- system.file("shp", "tl_2010_us_state10.shp.xz", package="fastshp")
  # contrary to the advice above we use the table format, because
  # it is a huge file with many points, so we use constrained thinning
  # which works on tables
  s <- read.shp(xzfile(fn, "rb"), "table")
  # substantially reduce the number of points
  s <- s[thin.shp(s, 0.01),]
  # focus on continental US only
  q <- list(x=c(-127.35, -65), y = c(51.5, 22.23))
  plot.shp(s, q$x, q$y)

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