R: plot a Spatial Line Segment Pattern

plot.psp {spatstat} | R Documentation

## plot a Spatial Line Segment Pattern

### Description

Plot a two-dimensional line segment pattern

### Usage

      ## S3 method for class 'psp'
    plot(x, ..., main, add=FALSE,
                         show.all=!add, show.window=show.all,
                         which.marks=1, ribbon=show.all,
                         ribsep=0.15, ribwid=0.05, ribn=1024,
                         do.plot=TRUE)

### Arguments

`x` | The line segment pattern to be plotted. An object of class `"psp"`, or data which can be converted into this format by `as.psp()`.
`...` | extra arguments that will be passed to the plotting functions `segments` (to plot the segments) and `plot.owin` (to plot the observation window).
`main` | Character string giving a title for the plot.
`add` | Logical. If `TRUE`, the current plot is not erased; the segments are plotted on top of the current plot, and the window is not plotted (by default).
`show.all` | Logical value specifying whether to plot everything including the window, main title, and colour ribbon.
`show.window` | Logical value specifying whether to plot the window.
`which.marks` | Index determining which column of marks to use, if the marks of `x` are a data frame. A character string or an integer. Defaults to `1` indicating the first column of marks.
`ribbon` | Logical flag indicating whether to display a ribbon showing the colour map (in which mark values are associated with colours).
`ribsep` | Factor controlling the space between the ribbon and the image.
`ribwid` | Factor controlling the width of the ribbon.
`ribn` | Number of different values to display in the ribbon.
`do.plot` | Logical value indicating whether to actually perform 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.

For a marked line segment pattern (i.e. if `marks(x)` is not `NULL`) the line segments are plotted in colours determined by the mark values. If `marks(x)` is a data frame, the default is to use the first column of `marks(x)` to determine the colours. To specify another column, use the argument `which.marks`. The colour map (associating mark values with colours) will be displayed as a vertical colour ribbon to the right of the plot, if `ribbon=TRUE`.

### Value

(Invisibly) a colour map object specifying the association between marks and colours, if any. The return value also has an attribute `"bbox"` giving a bounding box for the plot.

### Author(s)

Adrian Baddeley Adrian.Baddeley@curtin.edu.au

and Rolf Turner r.turner@auckland.ac.nz

### 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")

[Package spatstat version 1.54-0 Index]