guide_axis_mark ¶

Axis guide that labels the scale's breaks with leader lines (ComplexHeatmap anno_mark).

Pick the breaks to label with the scale's breaks= (for example a few genes of a heatmap's rows), and its limits= to keep the axis order (without limits a discrete axis moves its breaks to the front, as in lets-plot). Their labels are spread along the axis so they never overlap, and a line links each break's true position to its label: straight out for a third of the link, slanted over the middle third, straight into the label. Works on any axis side (position=), under coord_flip(), and on side panel axes (scale_xsidey_*(), scale_ysidex_*()). Labels take the axis text theme (axis_text_y=element_text(face="italic")); on top and bottom axes they read upwards, and the theme's text angle is not applied. The link takes the axis ticks' line (the label colour when ticks are blank). A ggrust guide: lets-plot and ggplot2 have no equivalent.

In HTML output with zoom (ggtb()), zoomed labels sit at their breaks without links; resetting the zoom restores the spread layout.

Parameters:

• spread ((nearest, even), default: "nearest" ) –

  "nearest": each label at its break when there is room, pushed apart only as far as needed (anno_mark). "even": equal slots over the whole axis, in break order.

• link_width (float, default: 20 ) –

  Pixels across the axis the link takes past the ticks (anno_mark's 5 mm).

• padding (float, default: 4 ) –

  Pixels kept between neighbouring labels (anno_mark's 1 mm).

Returns:

• FeatureSpec –

  Guide specification for scale_*(guide=...) or guides(x=...).

Raises:

• SpecError –

  If spread is unknown.

• UnsupportedValueError –

  If spread is not a string, or link_width or padding is not a number of 0 or more.

Examples:

>>> from ggrust import *
>>> data = {"fruit": ["apple", "banana", "cherry", "date", "fig", "grape"],
...         "month": ["Jan"] * 6, "sales": [3, 5, 2, 8, 6, 4]}
>>> plot = (
...     ggplot(data, aes("month", "fruit", fill="sales"))
...     + geom_tile()
...     + scale_y_discrete(
...         breaks=["banana", "cherry", "grape"],
...         limits=data["fruit"],
...         guide=guide_axis_mark(),
...     )
... )