Fully Customed Venn Diagram

Comprehensive customization by using helper functions

The main function ggVennDiagram() accepts a list input, and output a ggplot object. By measuring the length of input list, it automatically applies internal functions to build a plot in two steps: data preparation and visualization.

Data preparation was packaged into one function process_data(). Its output is a S4 VennPlotData class object, which contains three slots, setEdge, setLabel and region. These slot data then can be further plotted with ggplot functions.

See below for a better understanding.

Generate example data.

genes <- paste0("gene",1:1000)
set.seed(20231214)
gene_list <- list(A = sample(genes,100),
                  B = sample(genes,200),
                  C = sample(genes,300),
                  D = sample(genes,200))

library(ggVennDiagram)
library(ggplot2)

Then we can reproduce the plot of ggVennDiagram() with several lines.

venn <- Venn(gene_list)
data <- process_data(venn)
ggplot() +
  # 1. region count layer
  geom_polygon(aes(X, Y, fill = count, group = id), 
          data = venn_regionedge(data)) +
  # 2. set edge layer
  geom_path(aes(X, Y, color = id, group = id), 
          data = venn_setedge(data), 
          show.legend = FALSE) +
  # 3. set label layer
  geom_text(aes(X, Y, label = name), 
               data = venn_setlabel(data)) +
  # 4. region label layer
  geom_label(aes(X, Y, label = count), 
                data = venn_regionlabel(data)) +
  coord_equal() +
  theme_void()
#> Joining with `by = join_by(id)`

The variable data is a structured list that has three slots.

data
#> Class VennPlotData - '401f'
#>   Type: ellipse; No. sets: 4; No. regions: 15.
#>   To view this shape, use `plot_shape_edge()`.
#>   To view its components, use `venn_setedge()`, `venn_setlabel()`, etc.

ggVennDiagram export functions to get these data, and they can be used for comprehensive customization in user-side.

Venn(): Venn object constructor, use this to construct a Venn object from list.
process_data(): process data with a Venn object
venn_regionedge(): get region edge data to plot
venn_regionlabel(): get region label position to plot
venn_setedge(): get setedge data to plot
venn_setlabel(): get setlabel data to plot

For example, you may change edge/fill/label properties as you will.

ggplot() +
  # change mapping of color filling
  geom_polygon(aes(X, Y, fill = id, group = id), 
          data = venn_regionedge(data),
          show.legend = FALSE) +
  # adjust edge size and color
  geom_path(aes(X, Y, color = id, group = id), 
          data = venn_setedge(data), 
          linewidth = 3,
          show.legend = FALSE) +
  # show set label in bold
  geom_text(aes(X, Y, label = name), 
            fontface = "bold",
            data = venn_setlabel(data)) +
  # add a alternative region name
  geom_label(aes(X, Y, label = id), 
             data = venn_regionlabel(data),
             alpha = 0.5) +
  coord_equal() +
  theme_void()
#> Joining with `by = join_by(id)`