Draw grouped axis labels

Draw grouped axis labels given a character vector.

groupedAxis(
  side = 1,
  x,
  group_style = c("partial_grouped", "grouped", "centered"),
  las = 2,
  returnFractions = TRUE,
  nudge = 0.2,
  do_abline = FALSE,
  abline_lty = "solid",
  abline_col = "grey40",
  do_plot = TRUE,
  ...
)

Arguments

side

integer indicating the axis side, passed to axis(). 1=bottom, 2=left, 3=top, 4=right.

x

character vector of axis labels

group_style

character string indicating the style of label:

• "partial_grouped" - uses square bracket to bound 2+ repeated entries, and single line tick mark for non-repeated entries.

• "grouped" - uses square bracket to bound each set of repeated entries including non-repeated entries.

• "centered" - only labels the center of each group of repeated entries with no bracket bounding the entries.

las

integer indicating whether labels should be perpendicular, see par("las").

returnFractions

logical passed to breaksByVector() to calculate label positions. Set returnFractions=FALSE and all labels will only appear at integer locations on the axis.

nudge

numeric adjustment for labels away from the plot border.

do_abline

logical indicating whether to draw abline() lines inside the plot to indicate the exact breakpoints between each group of labels.

abline_lty

line type compatible with par("lty"), used when do_abline=TRUE.

abline_col

character color used when do_abline=TRUE.

do_plot

logical whether to plot the resulting axis, as an option to suppress the output and do something else with the data.frame of coordinates returned by this function.

...

additional arguments are passed to breaksByVector(), and/or to axis().

Value

data.frame invisibly, which contains the relevant axis coordinates, labels, and whether the coordinate should appear with a tick mark.

Details

This function extends breaksByVector() specifically for axis labels. It is intended where character labels are spaced at integer steps, and some labels are expected to be repeated.

See also

Other jam plot functions: adjustAxisLabelMargins(), coordPresets(), decideMfrow(), drawLabels(), getPlotAspect(), imageByColors(), imageDefault(), minorLogTicksAxis(), nullPlot(), plotPolygonDensity(), plotRidges(), plotSmoothScatter(), shadowText_options(), shadowText(), showColors(), smoothScatterJam(), sqrtAxis(), usrBox()

Examples

par("mar"=c(4,4,6,6));
b <- rep(LETTERS[1:5], c(2,3,5,4,3));
b2 <- c(b[1:2], makeNames(b[3:5]), b[6:16]);
nullPlot(doBoxes=FALSE,
   doUsrBox=TRUE,
   xlim=c(0,18),
   ylim=c(0,18));

groupedAxis(1, b);
groupedAxis(2, b, group_style="grouped");
groupedAxis(2, b, group_style="centered");
groupedAxis(3, b2, do_abline=TRUE);
groupedAxis(4, b2, group_style="grouped");
mtext(side=1, "group_style='partial_grouped'", line=2, las=0);
mtext(side=2, "group_style='grouped'", line=2, las=0);
mtext(side=3, "group_style='partial_grouped'", line=2, las=0);
mtext(side=4, "group_style='grouped'", line=2, las=0);