A 'ggplot2' geom to add text labels to point genetic features

geom_feature_label() adds text labels to features drawn with geom_feature().

geom_feature_label(
  mapping = NULL,
  data = NULL,
  stat = "identity",
  position = "identity",
  na.rm = FALSE,
  show.legend = FALSE,
  inherit.aes = FALSE,
  feature_height = unit(4, "mm"),
  label_height = unit(3, "mm"),
  ...
)

Arguments

mapping, data, stat, position, na.rm, show.legend, inherit.aes, ...

As standard for ggplot2. inherit.aes is set to FALSE by default, as features are not likely to share any plot aesthetics other than y.

feature_height

grid::unit() object giving the height of the feature being labelled, and hence the distance of the label above or below the molecule line. Can be set as a negative value for features drawn below the line. Defaults to 4 mm, to align labels with the default height of geom_feature().

label_height

grid::unit() object giving the height of the label text. Defaults to 3 mm.

Details

Standard 'ggplot2' aesthetics for text are supported (see Aesthetics).

Aesthetics

• x (required; position of the feature)

• y (required; molecule)

• label (required; the label text)

• forward (optional; will draw text in the appropriate location for features with angled arrowheads)

• colour

• size

• alpha

• family

• fontface

• angle

See also

geom_feature()

Examples

ggplot2::ggplot(example_genes, ggplot2::aes(xmin = start, xmax = end,
                                            y = molecule, fill = gene)) +
  geom_gene_arrow() +
  geom_feature(data = example_features, ggplot2::aes(x = position, y = molecule, 
                                                     forward = forward)) +
  geom_feature_label(data = example_features,
                     ggplot2::aes(x = position, y = molecule, label = name, 
                                  forward = forward)) + 
  ggplot2::facet_wrap(~ molecule, scales = "free")