spatstat.geom (version 3.7-0)

plot.psp: plot a Spatial Line Segment Pattern

Description

Plot a two-dimensional line segment pattern

Usage

# S3 method for psp
plot(x, ..., main, add=FALSE,
                     show.all=!add, show.window=show.all, do.plot=TRUE,
                     use.marks=TRUE,
                     which.marks=1,
                     style=c("colour", "width", "none"),
                     col=NULL, 
                     ribbon=show.all,
                     ribsep=0.15, ribwid=0.05, ribn=1024,
                     scale=NULL, adjust=1,
                     legend=TRUE,
                     leg.side=c("right", "left", "bottom", "top"),
                     leg.sep=0.1,
                     leg.wid=0.1,
                     leg.args=list(),
                     leg.scale=1,
                     negative.args=list(col=2),
                     background=NULL,
                     scramble.cols=FALSE)

Value

If style="colour", the result is a colourmap

object specifying the association between marks and colours, if any.

If style="width", the result is a numeric value giving the scaling between the mark values and the physical widths.

In all cases, the return value also has an attribute

"bbox" giving a bounding box for the plot.

Details

This is the plot method for line segment pattern datasets (of class "psp", see psp.object). It plots both the observation window Window(x) and the line segments themselves.

Plotting of the window Window(x) is performed by plot.owin. This plot may be modified through the ... arguments.

Plotting of the segments themselves is performed by the standard R function segments. Its plotting behaviour may also be modified through the ... arguments.

There are three different styles of plotting which apply when the segments have marks (i.e. when marks(x) is not null):

style="colour" (the default):

Segments are plotted with different colours depending on their mark values. The colour map, associating mark values with colours, is determined by the argument col. The colour map will be displayed as a vertical colour ribbon to the right of the plot, if ribbon=TRUE (the default).

style="width":

Segments are plotted with different widths depending on their mark values. The expanded segments are plotted using the base graphics function polygon. The width map, associating mark values with line widths, can be specified by giving the physical scale factor scale. There is a sensible default scale, which can be adjusted using the adjustment factor adjust. The width map will be displayed as a vertical stack of lines to the right of the plot, if legend=TRUE (the default).

style="none" or use.marks=FALSE:

Mark information is ignored and the segments are plotted as thin lines using segments.

If marks(x) is a data frame, the default is to use the first column of marks(x) to determine the colours or widths. To specify another column, use the argument which.marks.

See Also

psp.object, plot, par, plot.owin, text.psp, symbols

Examples

  X <- psp(runif(20), runif(20), runif(20), runif(20), window=owin())
  plot(X)
  plot(X, lwd=3)
  lettuce <- sample(letters[1:4], 20, replace=TRUE)
  marks(X) <- data.frame(A=1:20, B=factor(lettuce))
  plot(X)
  plot(X, which.marks="B")
  plot(X, style="width", col="grey")
  marks(X) <- factor(letters[1:20])
  plot(X)
  plot(X, scramble.cols=TRUE)