geom_glowpath: Connect Observations

In ggshadow: Shadow and Glow Geoms for 'ggplot2'

Connect Observations

Description

Plot a glow beneath the connected lines to make it easier to read a chart with several overlapping observations. 'geom_glowpath()' connects the observations in the order in which they appear in the data. 'geom_glowline()' connects them in order of the variable on the x axis. 'geom_glowstep()' creates a stairstep plot, highlighting exactly when changes occur.

Usage

geom_glowpath(
  mapping = NULL,
  data = NULL,
  stat = "identity",
  position = "identity",
  ...,
  lineend = "butt",
  linejoin = "round",
  linemitre = 10,
  arrow = NULL,
  na.rm = FALSE,
  show.legend = NA,
  inherit.aes = TRUE
)

geom_glowline(
  mapping = NULL,
  data = NULL,
  stat = "identity",
  position = "identity",
  na.rm = FALSE,
  orientation = NA,
  show.legend = NA,
  inherit.aes = TRUE,
  ...
)

geom_glowstep(
  mapping = NULL,
  data = NULL,
  stat = "identity",
  position = "identity",
  direction = "hv",
  na.rm = FALSE,
  show.legend = NA,
  inherit.aes = TRUE,
  ...
)

Arguments

mapping	Set of aesthetic mappings created by [aes()] or [aes_()]. If specified and 'inherit.aes = TRUE' (the default), it is combined with the default mapping at the top level of the plot. You must supply 'mapping' if there is no plot mapping.
data	The data to be displayed in this layer. There are three options: If 'NULL', the default, the data is inherited from the plot data as specified in the call to [ggplot()]. A 'data.frame', or other object, will override the plot data. All objects will be fortified to produce a data frame. See [fortify()] for which variables will be created. A 'function' will be called with a single argument, the plot data. The return value must be a 'data.frame', and will be used as the layer data. A 'function' can be created from a 'formula' (e.g. '~ head(.x, 10)').
stat	The statistical transformation to use on the data for this layer, as a string.
position	Position adjustment, either as a string, or the result of a call to a position adjustment function.
...	Other arguments passed on to [layer()]. These are often aesthetics, used to set an aesthetic to a fixed value, like 'colour = "red"' or 'size = 3'. They may also be parameters to the paired geom/stat.
lineend	Line end style (round, butt, square).
linejoin	Line join style (round, mitre, bevel).
linemitre	Line mitre limit (number greater than 1).
arrow	Arrow specification, as created by [grid::arrow()].
na.rm	If 'FALSE', the default, missing values are removed with a warning. If 'TRUE', missing values are silently removed.
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. It can also be a named logical vector to finely select the aesthetics to display.
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()].
orientation	The orientation of the layer. The default ('NA') automatically determines the orientation from the aesthetic mapping. In the rare event that this fails it can be given explicitly by setting 'orientation' to either '"x"' or '"y"'. See the *Orientation* section for more detail.
direction	direction of stairs: 'vh' for vertical then horizontal, 'hv' for horizontal then vertical, or 'mid' for step half-way between adjacent x-values.

Details

The 'group' aesthetic determines which cases are connected together. These functions are designed as a straight replacement to the [geom_path()], [geom_line()] and [geom_step()] functions. To set the order of drawing, make the 'colour' aesthetic a factor, and set the order from bottom to top.

Value

a 'ggplot2' layer to add to a plot.

Functions

• geom_glowpath(): Connects observations in the order in which they appear in the data.

• geom_glowline(): Connects observations in order of the variable on the x axis.

• geom_glowstep(): Creates a stairstep plot, highlighting exactly when changes occur.

Missing value handling

'geom_glowpath()', 'geom_glowline()', and 'geom_glowstep()' handle 'NA' as follows:

* If an 'NA' occurs in the middle of a line, it breaks the line. No warning is shown, regardless of whether 'na.rm' is 'TRUE' or 'FALSE'. * If an 'NA' occurs at the start or the end of the line and 'na.rm' is 'FALSE' (default), the 'NA' is removed with a warning. * If an 'NA' occurs at the start or the end of the line and 'na.rm' is 'TRUE', the 'NA' is removed silently, without warning.

Aesthetics

Adds 3 new aesthetics to [geom_path()]: * shadowcolour defaults to path color, controls the color of the shadow. * shadowsize defaults to size, controls the size of the shadow. * shadowalpha defaults to 0.06 * alpha or 0.06, controls the alpha of the glow.

See Also

[ggplot::geom_path()], [ggplot::geom_line()], [ggplot::geom_step()]: Filled paths (polygons);

Examples

# geom_glowline() is suitable for time series
library(ggplot2)
ggplot(economics_long, aes(date, value01, colour = variable)) + geom_glowline()

ggshadow documentation built on Nov. 21, 2022, 1:07 a.m.