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About the package

This package aims to make network visualisation easier, succinct, and consistent. Visualisation is a key part of the research process, from the initial exploration of data to the analysis of results and the presentation of findings in publications. However, it is often a tedious and time-consuming task. Trying to wrangle these into a consistent style for publication or presentation can be frustrating and requires a lot of code. While there are a number of excellent packages for network analysis in R, they each face several of the following challenges when it comes to visualisation:

{autograph} aims to solve these problems by providing automatic graph drawing for networks in any of the {manynet} formats, and automatic plotting for results from {stocnet} packages, including {migraph}, {RSiena}, and {MoNAn}, and more.

All you need to do is install the package (loading it last will make sure its plotting methods are the default), use set_stocnet_theme() (once) to set your preferred theme, and then use graphr() to graph your networks, or plot() to plot your results. That’s it!

Drawing graphs

{autograph} includes three one-line graphing functions with sensible defaults based on the network’s properties.

First, graphr() is used to graph networks in any of the {manynet} formats. Because it builds upon {manynet}, it can graph networks in any of the {manynet} formats, including network, igraph, sna, tidygraph, and more.

Second, it includes sensible defaults so that researchers can view their network’s structure or distribution quickly with a minimum of fuss. Compare the output from {autograph} with a similar default from {igraph}:

Example illustrating differences in default igraph and autograph graphs

{igraph} requires the bipartite layout to be specified, has cumbersome node size defaults for all but the smallest graphs, and labels also very often need resizing and adjustment to avoid overlap. Getting this default plot to look good can take a lot of trial and error, and time. By contrast, graphr() recognises the network as two-mode and uses a bipartite layout by default. It also recognises that the network contains names for the nodes and prints them vertically so that they are legible in this layout. Other ‘clever’ features include automatic node sizing and more.

This inference matters for more than tidiness. Where a default does not recognise a property of the network, that property is usually dropped silently. Compare the same signed network drawn by each package:

Example illustrating that igraph's default draws positive and negative ties identically

irps_tribes records both alliance and antagonism between sixteen tribes, in equal number. {igraph} draws all of these ties identically, so the distinction that motivates the data is not visible. graphr() recognises the network as signed and maps the sign to both colour and linetype, with a legend. The same applies to weights, to self-ties, and to direction: graphr() reads these from the network rather than requiring you to know to ask for them.

More options

All of graphr()’s adjustments can be overridden, however… Changing the size and colors of nodes and ties is as easy as specifying the function’s relevant argument with a replacement, e.g. node_color = "darkblue" or node_size = 6, or indicating from which attribute it should inherit this information, e.g. node_color = "Office" or node_size = "Seniority".

Graph illustrating automatic and manual use of node color and size

Legends are added by default when node or tie aesthetics are mapped to attributes, but can be removed with show_legend = FALSE. Since the {autograph} builds upon {ggplot2}, titles, subtitles and, for plotting, axis labels can all be added on easily, or other elements (e.g. font size) can be tweaked for a particular output.

More layouts

graphr() can use all the layout algorithms offered by packages such as {igraph}, {ggraph}, and {graphlayouts}. {autograph} also offers some additional layout algorithms for visualising layers horizontally, vertically, or concentrically, conforming to configurational coordinates, or for snapping these layouts to a grid.

Graphs illustrating different layouts

More networks

The second graph drawing function included, graphs(), is used to graph multiple networks together. This can be useful for ego networks or network panels. {patchwork} is used to help arrange individual plots together, and is used throughout the package to help arrange plots together informatively.

graphs() computes one layout and holds it across every panel. Plotting each network separately gives each panel its own layout, so a node can appear in a different position in each panel even where nothing about that node has changed. Holding the layout constant makes the panels comparable, so that what moves on the page is what changed in the data. graphs() also collects a single legend for the whole set.

Example of graphs() used on longitudinal data

More time

The third graph drawing function, grapht(), is used to visualise dynamic networks. It uses {gganimate} and {gifski} to create a gif that visualises network changes over time, with node positions transitioning smoothly between waves and nodes fading in and out as they enter and exit the network. It really couldn’t be easier.

Example of grapht() on longitudinal data

Generating plots

Since network analysis involves not just drawing graphs, {autograph} also provides a function for plotting results from the analysis or modelling of those networks. To keep things simple, all users need to remember is a single, generic function: plot(). Method dispatching takes care of the rest, so you can concentrate on exploring and interpreting your results.

Dispatching works because the results carry a class. igraph::degree() and sna::degree() each return a bare numeric vector, so plot() falls back to a scatterplot of the values against their index, and that index is not meaningful. netrics::node_by_degree() returns a node_measure, which {autograph} plots as a themed distribution:

Example illustrating that plotting a bare vector of degree scores gives an index scatterplot, where plotting a node_measure gives a distribution

The same holds for the other result classes. Here are some further examples, using goodness-of-fit results from fitting a SAOM in {RSiena} and an ERGM in {ergm}. (Note that neither the data nor the model are similar; this is just for illustrative purposes.)

Goodness-of-fit plots for a SAOM fitted in RSiena and an ERGM fitted in ergmGoodness-of-fit plots for a SAOM fitted in RSiena and an ERGM fitted in ergm

Setting a theme

Note that in the above plots, the same colour scheme and fonts were used. They can be easily changed though. {autograph} includes a number of themes that can be used to style all graphs and plots consistently. And it is very easy to set a theme. Just type stocnet_theme() to see which is the theme currently set, and to get a list of available themes. Then enter the chosen theme name in the function to set it. All plots created using {autograph} functions will then use this theme, until you change it again.

stocnet_theme()
(plot(netrics::node_by_degree(ison_karateka)) + 
plot(netrics::tie_by_betweenness(ison_karateka)))/
(plot(netrics::node_in_regular(ison_southern_women, "e")) + 
plot(as_matrix(ison_southern_women),
     membership = netrics::node_in_regular(ison_southern_women, "e")))
stocnet_theme("ethz")
(plot(netrics::node_by_degree(ison_karateka)) + 
plot(netrics::tie_by_betweenness(ison_karateka)))/
(plot(netrics::node_in_regular(ison_southern_women, "e")) + 
plot(as_matrix(ison_southern_women),
     membership = netrics::node_in_regular(ison_southern_women, "e")))

Themed figuresThemed figures

There are a range of institutional and topical themes available, including default, bw, crisp, neon, clay, iheid, ethz, uzh, rug, unibe, oxf, unige, cmu, iast, hwu, rainbow, with more on the way.

Institutional themesInstitutional themes

Colours everyone can read

About one man in twelve, and one woman in two hundred, sees colour differently. A palette that separates its categories for most readers can collapse for them, and the classic offender is the red-green pair that so many palettes hold.

{autograph} does something about this without asking you to give up a palette. Every theme’s categorical palette is reordered when the theme is set, so that the colours a graph reaches for first are those that stay distinct under each type of colour blindness, and each divergent palette pairs a warm pole with a cool one.

simulate_colorblind() shows a set of colours as another viewer sees them, so mapping the simulated colours back onto a graph shows you their view of it. Here is the same network four times: in {autograph}’s default palette as most readers see it, then as a reader with deuteranopia does, then as a photocopier renders it, and then in the palette {ggraph} falls back on when {autograph} is not setting the colours, as that same reader with deuteranopia sees it.

set_stocnet_theme("default")
as_seen <- function(colours, type, title){
  graphr(fict_lotr, node_colour = "Race", node_size = 3, labels = FALSE) +
    ggplot2::scale_fill_manual(values = simulate_colorblind(colours, type)) +
    ggtitle(title)
}
as_seen(ag_qualitative(6), "normal", "autograph") |
  as_seen(ag_qualitative(6), "deutan", "autograph, deuteranopia") |
  as_seen(ag_qualitative(6), "grey", "autograph, greyscale") |
  as_seen(scales::hue_pal()(6), "deutan", "ggraph default, deuteranopia")

The same network seen with normal vision, with deuteranopia, and in greyscale, in autograph's palette, and with deuteranopia in ggraph's

The six races remain tellable apart in the second panel, its closest pair being Hobbits and Maiar. In the right-hand one, Elves and Ents have become the same olive. The third panel is the harder case, and it is not one reordering can fix: a greyscale device keeps only the luminance of a colour, so two colours of the same lightness merge however different their hues. check_separation() reports that view beside its own score; where a figure has to print in black and white, use the "bw" theme or add a second channel such as node_shape. check_separation() puts a number on it, scoring how far apart colours are at their worst across normal vision and each type of colour blindness:

round(min(check_separation(ag_qualitative(6)), na.rm = TRUE), 1)             # autograph
#> [1] 13.5
round(min(check_separation(scales::hue_pal()(6)), na.rm = TRUE), 1)          # ggraph
#> [1] 5.5
round(min(check_separation(igraph::categorical_pal(6)), na.rm = TRUE), 1)    # igraph
#> [1] 16.2

Below 10 two colours are easily confused, above 25 they are comfortably distinct. {igraph}’s categorical palette is the Okabe-Ito scheme, which was designed for this and scores accordingly: where you are free to choose any colours at all, such a scheme is hard to beat, and graphr() will happily take it. The harder case is the one {autograph} is built for — colours chosen by somebody else, for reasons that were not legibility — and there the ordering is what stands between a brand palette and an unreadable graph. A palette with more colours to draw on has more room to gain: six categories score 29 under the "hwu" theme and 26 under "oxf".

Marks are only half of it. Text has to be read rather than told apart, which is a matter of contrast rather than of hue, and check_contrast() scores it against the thresholds of WCAG 2.1: 4.5 for body text, 3 for large text and for graphical objects. Every theme’s ink clears 4.5 on that theme’s own ground, and the test suite holds it there.

Each theme's name written in that theme's ink on that theme's ground, annotated with its WCAG contrast ratio

The medium is a separate question again. stocnet_medium() sizes the text for where the figure will be seen — "screen", "presentation", "mobile" — and "print" draws on white whatever ground the theme prefers, since a tinted ground costs ink and is often not reproduced. The theme is untouched by it, so one institutional palette carries from the desk to the slide to the page.

If your institution or organisation is not included and you would like it to be, please just raise an issue on Github, along with a link to your corporate branding or style guide if available, and we will attempt to add it at the next opportunity.

In sum, while there is a lot of clever defaults and customisation available, all it takes is three simple functions for your

Installation

Stable

The easiest way to install the latest stable version of {autograph} is via CRAN. Simply open the R console and enter:

install.packages('autograph')

library(autograph) will then load the package and make the data and tutorials (see below) contained within the package available.

Development

For the latest development version, for slightly earlier access to new features or for testing, you may wish to download and install the binaries from Github or install from source locally. The latest binary releases for all major OSes – Windows, Mac, and Linux – can be found here. Download the appropriate binary for your operating system, and install using an adapted version of the following commands:

To install from source the latest main version of {autograph} from Github, please install the {remotes} package from CRAN and then:

Other sources

Those using Mac computers may also install using Macports:

sudo port install R-autograph

Funding details

Development on this package has been funded by the Swiss National Science Foundation (SNSF) Grant Number 188976: “Power and Networks and the Rate of Change in Institutional Complexes” (PANARCHIC).