Quickstart: R

eulerr is the R binding: the original package, now backed by the eunoia engine. You hand euler() a named vector of set sizes, it fits an area-proportional diagram, and plot() draws it with grid graphics.

Install

install.packages("eulerr")

CRAN ships binary builds, so no Rust toolchain is needed. (Installing from source does require rustc ≥ 1.88; see the package README.)

Fit a diagram

library(eulerr)

fit <- euler(c(A = 5, B = 3, "A&B" = 1.5))
fit        # prints the residual table and goodness-of-fit metrics
plot(fit)

The input is a named numeric vector. Names are combination expressions: a single set (A) or sets joined with & ("A&B"). Values are disjoint (exclusive) by default: the part of A outside B is 5, the overlap is 1.5. Pass input = "union" if your numbers are full set sizes instead.

fit carries the fitted geometry and fit statistics:

fit$shapes       # data frame of fitted circle/ellipse parameters
fit$stress       # goodness-of-fit (venneuler-style)
fit$diagError    # largest single-region error

Pick a different shape

fit <- euler(c(A = 5, B = 3, "A&B" = 1.5), shape = "ellipse")
plot(fit)

shape is one of "circle" (default), "ellipse", "square", or "rectangle". Ellipses are more flexible and often fit three or more sets noticeably better; see Shapes.

Customize the plot

plot() takes styling arguments for fills, edges, labels, and quantities:

plot(
  fit,
  quantities = TRUE,
  fills = c("#e41a1c", "#377eb8"),
  labels = list(fontsize = 14)
)

Venn diagrams

For a fixed, non-proportional Venn template (every intersection shown regardless of size), use venn():

plot(venn(c("A", "B", "C")))  # three-set Venn
plot(venn(3))                 # same, by set count

Next steps

Read the introductory vignette and the full reference on the eulerr website. For how the fit works across all bindings, see the Fitter pipeline and Goodness of fit chapters.