lattice (version 0.20-21)

G_panel.axis: Panel Function for Drawing Axis Ticks and Labels

Description

panel.axis is the function used by lattice to draw axes. It is typically not used by users, except those wishing to create advanced annotation. Keep in mind issues of clipping when trying to use it as part of the panel function. current.panel.limits can be used to retrieve a panel's x and y limits.

Usage

panel.axis(side = c("bottom", "left", "top", "right"),
           at,
           labels = TRUE,
           draw.labels = TRUE,
           check.overlap = FALSE,
           outside = FALSE,
           ticks = TRUE,
           half = !outside,
           which.half,
           tck = as.numeric(ticks),
           rot = if (is.logical(labels)) 0 else c(90, 0),
           text.col, text.alpha, text.cex, text.font,
           text.fontfamily, text.fontface, text.lineheight,
           line.col, line.lty, line.lwd, line.alpha)
current.panel.limits(unit = "native")

Arguments

side

A character string indicating which side axes are to be drawn on. Partial specification is allowed.

at

Numeric vector giving location of labels.

labels

The labels to go along with at. The labels can be a character vector or a vector of expressions. Alternatively, at can be a logical flag: If TRUE, the labels are derived from at, otherwise,

draw.labels

A logical indicating whether labels are to be drawn.

check.overlap

A logical, whether to check for overlapping of labels. This also has the effect of removing at values that are too close to the limits.

outside

A logical flag, indicating whether to draw the labels outside the panel or inside. Note that outside=TRUE will only have a visible effect if clipping is disabled for the viewport (panel).

ticks

Logical flag, whether to draw the tickmarks.

half

Logical flag, indicating whether only around half the scales will be drawn for each side. This is primarily used for axis labeling in splom.

which.half

Character string, either "lower" or "upper", indicating which half is to be used for tick locations if half = TRUE. Defaults to whichever is suitable for splom.

tck

A numeric scalar multiplier for tick length. Can be negative, in which case the ticks point inwards.

rot

Rotation angle(s) for labels in degrees. Can be a vector of length 2 for x- and y-axes.

text.col

Color for the axis label text. See gpar for more details on this and the other graphical parameters listed below.

text.alpha

Alpha-transparency value for the axis label text.

text.cex

Size multiplier for the axis label text.

text.font, text.fontfamily, text.fontface

Font for the axis label text.

text.lineheight

Line height for the axis label text.

line.col

Color for the axis label text.

line.lty

Color for the axis.

line.lwd

Color for the axis.

line.alpha

Alpha-transparency value for the axis.

unit

Which grid unit the values should be in.

Value

• current.panel.limits returns a list with components xlim and ylim, which are both numeric vectors of length 2, giving the scales of the current panel (viewport). The values correspond to the unit system specified by unit, by default "native".

Details

panel.axis can draw axis tick marks inside or outside a panel (more precisely, a grid viewport). It honours the (native) axis scales. Used in panel.pairs for splom, as well as for all the usual axis drawing by the print method for "trellis" objects. It can also be used to enhance plots after the fact by adding axes.

See Also

Lattice, xyplot, trellis.focus, unit