Using New Shapes in Venn Diagram

Internal Shapes

The ggVennDiagram package has a set of built-in shapes that are used to plot Venn diagram. These internal data are stored as sys data as a tibble. It can be accessed with ggVennDiagram:::shapes and viewed by the function get_shapes(), and plotted with the function plot_shapes().

shape1 = ggVennDiagram:::shapes[[4]]
shape1
#> Class VennPlotData - '301f'
#>   Type: circle; No. sets: 3; No. regions: 7.
#>   To view this shape, use `plot_shape_edge(get_shape_by_id('301f'))`.
#>   To view its components, use `venn_setedge()`, `venn_setlabel()`, etc.

The format of these shapes data are defined in VennPlotData class. Use ?VennPlotData to view the document.

plot_shape_edge(shape1)

get_shapes() will extract the meta features of these shapes and output a tibble. These information can be used for sepecifying a shape either by its id, or type.

get_shapes()
#> # A tibble: 12 × 3
#>    shape_id nsets type    
#>    <chr>    <int> <chr>   
#>  1 101          1 circle  
#>  2 201f         2 circle  
#>  3 201          2 circle  
#>  4 301f         3 circle  
#>  5 301          3 circle  
#>  6 401f         4 ellipse 
#>  7 402          4 polygon 
#>  8 501          5 polygon 
#>  9 502          5 polygon 
#> 10 601t         6 triangle
#> 11 601          6 polygon 
#> 12 701          7 polygon

For example, if you want to extract the shape whose id is “401f”. This time we use ggplot2 functions to plot the set edge of it.

library(ggplot2)
shape2 = get_shape_by_id("401f")
plot_shape_edge(shape2)

The plot_shapes() function can be used to plot all the available shapes stored in this package. Please note that the shapes for this five sets diagram, as well as those for six and seven sets, are imported from the original package venn, authored by Adrian Dușa.

plot_shapes()

Among them, the shapes with less than four sets can be generated with circle or ellipses. For example, the parameters used to generate four-set ellipses were adopted from VennDiagram (https://CRAN.R-project.org/package=VennDiagram). Notably, those shapes of five or more sets, including 501, 502, 601, and 701, are created by Adrian Dușa and provided in his venn package (https://CRAN.R-project.org/package=venn). Besides, the 601t shape is imported from a WiKi entry (https://en.wikipedia.org/wiki/Venn_diagram).

Using alternative internal shapes

By default, only the most appropriate shape is used when calling the main function ggVennDiagram(). However, it may be specified in step wise plot which has been described in fully customed plot.

For example:

# Generate example data.
genes <- paste0("gene",1:1000)
set.seed(20210701)
gene_list <- list(A = sample(genes,100),
                  B = sample(genes,200),
                  C = sample(genes,300),
                  D = sample(genes,200))

# construct a Venn object
venn = Venn(gene_list)
data = process_data(venn, shape_id = "402")
plot_venn(data)

Using a novel shape

If user knows the coordinates of a novel shape, it may also be used to draw in ggVennDiagram. The functions of this part have been transfered to a new R package shapeMageR, which can be found in https://github.com/gaospecial/shapeMageR. To do this, the dependency of ggVennDiagram is very light, thus increase the accessibility of the package.

Reference

Adrian Dușa (2024) venn: Draw Venn Diagrams, R package version 1.12. https://CRAN.R-project.org/package=venn.