spatstat.geom (version 3.3-6)

plot.yardstick: Plot a Yardstick or Scale Bar

Description

Plots an object of class "yardstick".

Usage

# S3 method for yardstick
plot(x, ...,
        style=c("arrows", "zebra"),
        angle = 20, frac = 1/8, 
        split = FALSE, shrink = 1/4,
        zebra.step=NULL, zebra.width=NULL, zebra.col="black",
        pos = NULL,
        txt.args=list(),
        txt.shift=c(0,0),
        do.plot = TRUE)

Value

A window (class "owin") enclosing the plotted graphics.

Arguments

x

Object of class "yardstick" to be plotted. This object is created by the command yardstick.

...

Additional graphics arguments passed to segments to control the appearance of the line.

style

Character string (partially matched) specifying the style of plot. See Details.

angle

Angle between the arrows and the line segment, in degrees. Applies when style="arrows".

frac

Length of arrow as a fraction of total length of the line segment. Applies when style="arrows".

split

Logical. If TRUE, then the line will be broken in the middle, and the text will be placed in this gap. If FALSE, the line will be unbroken, and the text will be placed beside the line. Applies when style="arrows".

shrink

Fraction of total length to be removed from the middle of the line segment, if split=TRUE. Applies when style="arrows".

zebra.step

Length of each bar in the zebra pattern. Applies when style="zebra".

zebra.width

Width of each bar in the zebra pattern. Applies when style="zebra".

zebra.col

Colour of each bar in the zebra pattern. Applies when style="zebra".

pos

Integer (passed to text) determining the position of the annotation text relative to the line segment, if split=FALSE. Values of 1, 2, 3 and 4 indicate positions below, to the left of, above and to the right of the line, respectively.

txt.args

Optional list of additional arguments passed to text controlling the appearance of the text. Examples include adj, srt, col, cex, font.

txt.shift

Optional numeric vector of length 2 specifying displacement of the text position relative to the centre of the yardstick.

do.plot

Logical. Whether to actually perform the plot (do.plot=TRUE).

Author

Adrian Baddeley , Rolf Turner and Ege Rubak .

Details

A yardstick or scale bar is a line segment, drawn on any spatial graphics display, indicating the scale of the plot.

• If style="arrows", the line segment is drawn as a pair of arrows pointing from the middle of the line to the ends of the line. This style is often used in architectural drawings. If angle=0, the arrow heads are replaced by parallel bars marking the two ends of the line.

• If style="zebra", the line segment is divided into block of length zebra.step and width zebra.width units. Blocks are drawn alternately as filled rectangles and outlined rectangles, so that the result resembles a zebra crossing. This style is often used in maps and charts. There are sensible defaults for zebra.step and zebra.width.

The argument x should be an object of class "yardstick" created by the command yardstick.

See Also

yardstick

Examples

  plot(owin(), main="Yardsticks")
  ys <- yardstick(as.psp(list(xmid=0.5, ymid=0.1, length=0.4, angle=0),
                         window=owin(c(0.2, 0.8), c(0, 0.2))),
                  txt="1 km")
  plot(ys)
  ys <- shift(ys, c(0, 0.3))
  plot(ys, angle=90, frac=0.08)
  ys <- shift(ys, c(0, 0.3))
  plot(ys, split=TRUE)

  yt <- shift(ys, c(0, 0.2))
  plot(yt, style="z", pos=3, zebra.step=0.1, txt.args=list(offset=0.1))