Draw a scale bar as an arrow, labelled with its length in plot units.

Draw a scale bar as an arrow, labelled with its length in plot units.

panel.scaleArrow(x = unit(0:1, "npc"), y = unit(0:1, "npc"),
                 default.units = "npc",
                 digits = 0, append = "", label = NULL,
                 angle = 30, length = 0.5, unit = "char",
                 type = "open", ends = "both",
                 ...,
                 col = add.line$col, fill = col, alpha = add.line$alpha,
                 lty = add.line$lty, lwd = add.line$lwd,
                 col.text = add.text$col, alpha.text = add.text$alpha)

Arguments

x, y, default.units

coordinates of the line ends as grid units or otherwise interpreted in default.units.

digits

number of decimal places to keep for the distance measure.

append

a string to append to the distance for the label.

label

label to place on the mid point of the scale, over-riding the default.

angle, length, unit, type, ends

specification of the arrow style; see panel.arrows.

...

further arguments passed to panel.text. You will need at least the pos or adj arguments.

col, fill, alpha, lty, lwd

graphical parameters relevant to the line.

col.text, alpha.text

graphical parameters relevant to the text label. Others like cex and font can be passed though ....

Author

Felix Andrews felix@nfrac.org

See also

panel.abline, grid.text

Examples

xyplot(EuStockMarkets) +
  layer(panel.scaleArrow(x = 0.99, append = " units",
          col = "grey", srt = 90, cex = 0.8))