R: Repulsive textual annotations.

geom_label_repel {ggrepel} | R Documentation

## Repulsive textual annotations.

### Description

`geom_text_repel` adds text directly to the plot. `geom_label_repel` draws a rectangle underneath the text, making it easier to read. The text labels repel away from each other and away from the data points.

### Usage

    geom_label_repel(mapping = NULL, data = NULL, stat = "identity",
      parse = FALSE, ..., box.padding = 0.25, label.padding = 0.25,
      point.padding = 1e-06, label.r = 0.15, label.size = 0.25,
      segment.colour = NULL, segment.color = NULL, segment.size = 0.5,
      segment.alpha = NULL, min.segment.length = 0.5, arrow = NULL,
      force = 1, max.iter = 2000, nudge_x = 0, nudge_y = 0, xlim = c(NA,
      NA), ylim = c(NA, NA), na.rm = FALSE, show.legend = NA,
      direction = c("both", "y", "x"), seed = NA, inherit.aes = TRUE)

    geom_text_repel(mapping = NULL, data = NULL, stat = "identity",
      parse = FALSE, ..., box.padding = 0.25, point.padding = 1e-06,
      segment.colour = NULL, segment.color = NULL, segment.size = 0.5,
      segment.alpha = NULL, min.segment.length = 0.5, arrow = NULL,
      force = 1, max.iter = 2000, nudge_x = 0, nudge_y = 0, xlim = c(NA,
      NA), ylim = c(NA, NA), na.rm = FALSE, show.legend = NA,
      direction = c("both", "y", "x"), seed = NA, inherit.aes = TRUE)

### Arguments

`mapping` | Set of aesthetic mappings created by `aes` or `aes_`. If specified and `inherit.aes = TRUE` (the default), is combined with the default mapping at the top level of the plot. You only need to supply `mapping` if there isn't a mapping defined for the plot.
`data` | A data frame. If specified, overrides the default data frame defined at the top level of the plot.
`stat` | The statistical transformation to use on the data for this layer, as a string.
`parse` | If TRUE, the labels will be parsed into expressions and displayed as described in ?plotmath
`...` | other arguments passed on to `layer`. There are three types of arguments you can use here: Aesthetics: to set an aesthetic to a fixed value, like `colour = "red"` or `size = 3`. Other arguments to the layer, for example you override the default `stat` associated with the layer. Other arguments passed on to the stat.
`box.padding` | Amount of padding around bounding box, as unit or number. Defaults to 0.25. (Default unit is lines, but other units can be specified by passing `unit(x, "units")`).
`label.padding` | Amount of padding around label, as unit or number. Defaults to 0.25. (Default unit is lines, but other units can be specified by passing `unit(x, "units")`).
`point.padding` | Amount of padding around labeled point, as unit or number. Defaults to 0. (Default unit is lines, but other units can be specified by passing `unit(x, "units")`).
`label.r` | Radius of rounded corners, as unit or number. Defaults to 0.15. (Default unit is lines, but other units can be specified by passing `unit(x, "units")`).
`label.size` | Size of label border, in mm.
`segment.colour, segment.color` | Colour of the line segment. Defaults to the same colour as the text. In the unlikely event you specify both US and UK spellings of colour, the US spelling will take precedence.
`segment.size` | Width of line segment connecting the data point to the text label, in mm.
`segment.alpha` | Transparency of the line segment. Defaults to the same transparency as the text.
`min.segment.length` | Skip drawing segments shorter than this, as unit or number. Defaults to 0.5. (Default unit is lines, but other units can be specified by passing `unit(x, "units")`).
`arrow` | specification for arrow heads, as created by `arrow`
`force` | Force of repulsion between overlapping text labels. Defaults to 1.
`max.iter` | Maximum number of iterations to try to resolve overlaps. Defaults to 2000.
`nudge_x, nudge_y` | Horizontal and vertical adjustments to nudge the starting position of each text label.
`xlim, ylim` | Limits for the x and y axes. Text labels will be constrained to these limits. By default, text labels are constrained to the entire plot area.
`na.rm` | If `FALSE` (the default), removes missing values with a warning. If `TRUE` silently removes missing values.
`show.legend` | logical. Should this layer be included in the legends? `NA`, the default, includes if any aesthetics are mapped. `FALSE` never includes, and `TRUE` always includes.
`direction` | "both", "x", or "y" – direction in which to adjust position of labels
`seed` | Random seed passed to `set.seed`. Defaults to `NA`, which means that `set.seed` will not be called.
`inherit.aes` | If `FALSE`, overrides the default aesthetics, rather than combining with them. This is most useful for helper functions that define both data and aesthetics and shouldn't inherit behaviour from the default plot specification, e.g. `borders`.

### Details

These geoms are based on `geom_text` and `geom_label`. See the documentation for those functions for more details. Differences from those functions are noted here.

Text labels have height and width, but they are physical units, not data units. The amount of space they occupy on that plot is not constant in data units: when you resize a plot, labels stay the same size, but the size of the axes changes. The text labels are repositioned after resizing a plot.

### `geom_label_repel`

Currently `geom_label_repel` does not support the `rot` parameter and is considerably slower than `geom_text_repel`. The `fill` aesthetic controls the background colour of the label.

### Alignment

The repulsive geoms reposition text labels to avoid overlap, so the following parameters are not supported:

- `hjust`

- `vjust`

- `position`

- `check_overlap`

### Examples

    p <- ggplot(mtcars,
      aes(wt, mpg, label = rownames(mtcars), colour = factor(cyl))) +
      geom_point()

    # Avoid overlaps by repelling text labels
    p + geom_text_repel()
    # Labels with background
    p + geom_label_repel()

    ## Not run:
    p + geom_text_repel(family = "Times New Roman",
      box.padding = 0.5)

    # Add aesthetic mappings
    p + geom_text_repel(aes(alpha=wt, size=mpg))
    p + geom_label_repel(aes(fill=factor(cyl)), colour="white", segment.colour="black")

    # Draw all line segments
    p + geom_text_repel(min.segment.length = 0)

    # Omit short line segments (default behavior)
    p + geom_text_repel(min.segment.length = 0.5)

    # Omit all line segments
    p + geom_text_repel(segment.colour = NA)

    # Repel just the labels and totally ignore the data points
    p + geom_text_repel(point.padding = NA)

    # Hide some of the labels, but repel from all data points
    mtcars$label <- rownames(mtcars)
    mtcars$label[1:15] <- ""
    p + geom_text_repel(data = mtcars, aes(wt, mpg, label = label))

    # Nudge the starting positions
    p + geom_text_repel(nudge_x = ifelse(mtcars$cyl == 6, 1, 0),
                        nudge_y = ifelse(mtcars$cyl == 6, 8, 0))

    # Change the text size
    p + geom_text_repel(aes(size = wt))
    # Scale height of text, rather than sqrt(height)
    p + geom_text_repel(aes(size = wt)) + scale_radius(range = c(3,6))

    # You can display expressions by setting parse = TRUE.  The
    # details of the display are described in ?plotmath, but note that
    # geom_text_repel uses strings, not expressions.
    p + geom_text_repel(aes(label = paste(wt, "^(", cyl, ")", sep = "")),
      parse = TRUE)

    # Add a text annotation
    p +
      geom_text_repel() +
      annotate(
        "text", label = "plot mpg vs. wt",
        x = 2, y = 15, size = 8, colour = "red"
      )

    # Add arrows
    p +
      geom_point(colour = "red") +
      geom_text_repel(
        arrow = arrow(length = unit(0.02, "npc")),
        box.padding = 1
      )

    ## End(Not run)

[Package ggrepel version 0.7.0 Index]