This geom performs edge bundling using the edge path algorithm. This approach
uses the underlying graph structure to find shortest paths for each edge in
a graph the is gradually removed of it's edges. Since it is based on the
topology of the graph it should lead to less spurious bundling of unrelated
edges compared to `geom_edge_bundle_force()`

and also has a simpler parameter
space.

```
geom_edge_bundle_path(
mapping = NULL,
data = get_edges(),
position = "identity",
arrow = NULL,
n = 100,
directed = NULL,
max_distortion = 2,
weight_fac = 2,
tension = 1,
lineend = "butt",
linejoin = "round",
linemitre = 1,
label_colour = "black",
label_alpha = 1,
label_parse = FALSE,
check_overlap = FALSE,
angle_calc = "rot",
force_flip = TRUE,
label_dodge = NULL,
label_push = NULL,
show.legend = NA,
...
)
geom_edge_bundle_path2(
mapping = NULL,
data = get_edges("long"),
position = "identity",
arrow = NULL,
n = 100,
directed = NULL,
max_distortion = 2,
weight_fac = 2,
tension = 1,
lineend = "butt",
linejoin = "round",
linemitre = 1,
label_colour = "black",
label_alpha = 1,
label_parse = FALSE,
check_overlap = FALSE,
angle_calc = "rot",
force_flip = TRUE,
label_dodge = NULL,
label_push = NULL,
show.legend = NA,
...
)
geom_edge_bundle_path0(
mapping = NULL,
data = get_edges(),
position = "identity",
arrow = NULL,
directed = NULL,
max_distortion = 2,
weight_fac = 2,
tension = 1,
lineend = "butt",
show.legend = NA,
...
)
```

- mapping
Set of aesthetic mappings created by

`ggplot2::aes()`

or`ggplot2::aes_()`

. By default x, y, xend, yend, group and circular are mapped to x, y, xend, yend, edge.id and circular in the edge data.- data
The return of a call to

`get_edges()`

or a data.frame giving edges in correct format (see details for for guidance on the format). See`get_edges()`

for more details on edge extraction.- position
Position adjustment, either as a string naming the adjustment (e.g.

`"jitter"`

to use`position_jitter`

), or the result of a call to a position adjustment function. Use the latter if you need to change the settings of the adjustment.- arrow
Arrow specification, as created by

`grid::arrow()`

.- n
The number of points to create along the path.

- directed
Logical. Should the shortest paths be calculated using direction information of the graph. Setting this to

`TRUE`

can help split up bundles that flows in opposite directions. Ignored for undirected graphs- max_distortion
A multiplication factor to determine the maximum allowed distortion of the path during bundling. If the new edge is longer than

`max_distortion`

times the old length it is rejected.- weight_fac
The exponent used to assign weights to the graph when calculating the shortest path. The final weights are given as

`edge_length ^ weight_fac`

meaning that sorter edges are prioritised when calculating the weights.- tension
A loosening factor when calculating the b-spline of the edge based on the shortest path. Will move control points closer and closer to the direct line as it approaches 0

- lineend
Line end style (round, butt, square).

- linejoin
Line join style (round, mitre, bevel).

- linemitre
Line mitre limit (number greater than 1).

- label_colour
The colour of the edge label. If

`NA`

it will use the colour of the edge.- label_alpha
The opacity of the edge label. If

`NA`

it will use the opacity of the edge.- label_parse
If

`TRUE`

, the labels will be parsed into expressions and displayed as described in`grDevices::plotmath()`

.- check_overlap
If

`TRUE`

, text that overlaps previous text in the same layer will not be plotted.`check_overlap`

happens at draw time and in the order of the data. Therefore data should be arranged by the label column before calling`geom_text()`

. Note that this argument is not supported by`geom_label()`

.- angle_calc
Either 'none', 'along', or 'across'. If 'none' the label will use the angle aesthetic of the geom. If 'along' The label will be written along the edge direction. If 'across' the label will be written across the edge direction.

- force_flip
Logical. If

`angle_calc`

is either 'along' or 'across' should the label be flipped if it is on it's head. Default to`TRUE`

.- label_dodge
A

`grid::unit()`

giving a fixed vertical shift to add to the label in case of`angle_calc`

is either 'along' or 'across'- label_push
A

`grid::unit()`

giving a fixed horizontal shift to add to the label in case of`angle_calc`

is either 'along' or 'across'- 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.- ...
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.

`geom_edge_force_path`

and `geom_edge_force_path0`

understand the following
aesthetics. Bold aesthetics are automatically set, but can be overwritten.

**x****y****xend****yend****edge_id**(should not be overwritten)edge_colour

edge_width

edge_linetype

edge_alpha

filter

`geom_edge_force_path2`

understand the following aesthetics. Bold aesthetics are
automatically set, but can be overwritten.

**x****y****group****edge_id**(should not be overwritten)edge_colour

edge_width

edge_linetype

edge_alpha

filter

`geom_edge_force_path`

and `geom_edge_force_path2`

furthermore takes the following
aesthetics.

start_cap

end_cap

label

label_pos

label_size

angle

hjust

vjust

family

fontface

lineheight

- index
The position along the path (not computed for the *0 version)

Many geom_edge_* layers comes in 3 flavors depending on the level of control
needed over the drawing. The default (no numeric postfix) generate a number
of points (`n`

) along the edge and draws it as a path. Each point along
the line has a numeric value associated with it giving the position along the
path, and it is therefore possible to show the direction of the edge by
mapping to this e.g. `colour = after_stat(index)`

. The version postfixed with a
"2" uses the "long" edge format (see `get_edges()`

) and makes it
possible to interpolate node parameter between the start and end node along
the edge. It is considerable less performant so should only be used if this
is needed. The version postfixed with a "0" draws the edge in the most
performant way, often directly using an appropriate grob from the grid
package, but does not allow for gradients along the edge.

Often it is beneficial to stop the drawing of the edge before it reaches the
node, for instance in cases where an arrow should be drawn and the arrowhead
shouldn't lay on top or below the node point. geom_edge_* and geom_edge_*2
supports this through the start_cap and end_cap aesthetics that takes a
`geometry()`

specification and dynamically caps the termini of the
edges based on the given specifications. This means that if
`end_cap = circle(1, 'cm')`

the edges will end at a distance of 1cm even
during resizing of the plot window.

All `geom_edge_*`

and `geom_edge_*2`

have the ability to draw a
label along the edge. The reason this is not a separate geom is that in order
for the label to know the location of the edge it needs to know the edge type
etc. Labels are drawn by providing a label aesthetic. The label_pos can be
used to specify where along the edge it should be drawn by supplying a number
between 0 and 1. The label_size aesthetic can be used to control the size of
the label. Often it is needed to have the label written along the direction
of the edge, but since the actual angle is dependent on the plot dimensions
this cannot be calculated beforehand. Using the angle_calc argument allows
you to specify whether to use the supplied angle aesthetic or whether to draw
the label along or across the edge.

In order to avoid excessive typing edge aesthetic names are
automatically expanded. Because of this it is not necessary to write
`edge_colour`

within the `aes()`

call as `colour`

will
automatically be renamed appropriately.

Wallinger, M., Archambault, D., Auber, D., Nöllenburg, M., and Peltonen, J.
(2022). *Edge-Path Bundling: A Less Ambiguous Edge Bundling Approach.* IEEE
Transactions on Visualization and Computer Graphics 28(1) 313-323.
https://doi.org/10.1109/TVCG.2021.3114795

Other geom_edge_*:
`geom_edge_arc()`

,
`geom_edge_bend()`

,
`geom_edge_bundle_force()`

,
`geom_edge_bundle_minimal()`

,
`geom_edge_density()`

,
`geom_edge_diagonal()`

,
`geom_edge_elbow()`

,
`geom_edge_fan()`

,
`geom_edge_hive()`

,
`geom_edge_link()`

,
`geom_edge_loop()`

,
`geom_edge_parallel()`

,
`geom_edge_point()`

,
`geom_edge_sf()`

,
`geom_edge_span()`

,
`geom_edge_tile()`