A Venn diagram visualizes the logical relationships between two or three sets using overlapping circles. Each circle represents a set, and overlapping regions show elements shared between sets. This classic visualization is ideal for showing intersections, unions, and exclusive memberships, making abstract set relationships immediately intuitive.
# anyplot.ai
# venn-basic: Venn Diagram
# Library: makie 0.21.9 | Julia 1.11.9
# Quality: 94/100 | Created: 2026-09-09
using CairoMakie
using Colors
# --- Theme tokens -------------------------------------------------------------
const THEME = get(ENV, "ANYPLOT_THEME", "light")
const PAGE_BG = THEME == "light" ? colorant"#FAF8F1" : colorant"#1A1A17"
const ELEVATED_BG = THEME == "light" ? colorant"#FFFDF6" : colorant"#242420"
const INK = THEME == "light" ? colorant"#1A1A17" : colorant"#F0EFE8"
const INK_SOFT = THEME == "light" ? colorant"#4A4A44" : colorant"#B8B7B0"
const IMPRINT_PALETTE = [
colorant"#009E73", colorant"#C475FD", colorant"#4467A3",
]
# --- Data: developer skill survey (n = 270 engineers) --------------------------
set_labels = ["Python", "SQL", "JavaScript"]
size_python, size_sql, size_js = 145, 120, 95
overlap_py_sql, overlap_py_js, overlap_sql_js = 45, 35, 25
overlap_all = 15
only_python = size_python - overlap_py_sql - overlap_py_js + overlap_all
only_sql = size_sql - overlap_py_sql - overlap_sql_js + overlap_all
only_js = size_js - overlap_py_js - overlap_sql_js + overlap_all
only_py_sql = overlap_py_sql - overlap_all
only_py_js = overlap_py_js - overlap_all
only_sql_js = overlap_sql_js - overlap_all
total = only_python + only_sql + only_js + only_py_sql + only_py_js + only_sql_js + overlap_all
# --- Circle geometry: radii scaled by sqrt(set size) for an area-proportional
# impression; centers pulled in toward the largest circle by the same
# ratio so the three circles keep overlapping cleanly. ---------------------
base_radius = 1.6
radius_python = base_radius * sqrt(size_python / size_python)
radius_sql = base_radius * sqrt(size_sql / size_python)
radius_js = base_radius * sqrt(size_js / size_python)
center_python = Point2f(-0.65, 0.55)
center_sql = Point2f(0.65, 0.55) * (radius_sql / base_radius)
center_js = Point2f(0.0, -0.55) * (radius_js / base_radius)
# --- Plot -----------------------------------------------------------------------
fig = Figure(
size = (1200, 1200),
fontsize = 14,
backgroundcolor = PAGE_BG,
)
ax = Axis(
fig[1, 1];
title = "venn-basic · julia · makie · anyplot.ai",
titlesize = 20,
titlecolor = INK,
backgroundcolor = PAGE_BG,
aspect = DataAspect(),
)
hidedecorations!(ax)
hidespines!(ax)
xlims!(ax, -2.5, 2.5)
ylims!(ax, -2.3, 2.5)
fill_alpha = 0.55
poly!(ax, Circle(center_python, radius_python);
color = (IMPRINT_PALETTE[1], fill_alpha), strokecolor = INK_SOFT, strokewidth = 2)
poly!(ax, Circle(center_sql, radius_sql);
color = (IMPRINT_PALETTE[2], fill_alpha), strokecolor = INK_SOFT, strokewidth = 2)
poly!(ax, Circle(center_js, radius_js);
color = (IMPRINT_PALETTE[3], fill_alpha), strokecolor = INK_SOFT, strokewidth = 2)
# Set name labels, placed outside each circle
text!(ax, -1.55, 2.05; text = set_labels[1], color = INK, fontsize = 22,
font = :bold, align = (:center, :center))
text!(ax, 1.41, 1.86; text = set_labels[2], color = INK, fontsize = 22,
font = :bold, align = (:center, :center))
text!(ax, 0.0, -1.78; text = set_labels[3], color = INK, fontsize = 22,
font = :bold, align = (:center, :center))
# Region count labels (count + percentage, inline — no helper functions)
text!(ax, -1.35, 1.05; text = "$(only_python)\n($(round(Int, 100 * only_python / total))%)",
color = INK, fontsize = 17, align = (:center, :center))
text!(ax, 1.23, 0.96; text = "$(only_sql)\n($(round(Int, 100 * only_sql / total))%)",
color = INK, fontsize = 17, align = (:center, :center))
text!(ax, 0.0, -1.25; text = "$(only_js)\n($(round(Int, 100 * only_js / total))%)",
color = INK, fontsize = 17, align = (:center, :center))
text!(ax, -0.04, 0.88; text = "$(only_py_sql)\n($(round(Int, 100 * only_py_sql / total))%)",
color = INK, fontsize = 17, align = (:center, :center))
text!(ax, -0.59, -0.08; text = "$(only_py_js)\n($(round(Int, 100 * only_py_js / total))%)",
color = INK, fontsize = 17, align = (:center, :center))
text!(ax, 0.56, -0.12; text = "$(only_sql_js)\n($(round(Int, 100 * only_sql_js / total))%)",
color = INK, fontsize = 17, align = (:center, :center))
# Focal point: the triple overlap is the rarest — and most interesting —
# combination, so it gets a soft halo backdrop plus a bolder, larger label.
poly!(ax, Circle(Point2f(0.0, 0.20), 0.32);
color = (ELEVATED_BG, 0.9), strokecolor = INK_SOFT, strokewidth = 1)
text!(ax, 0.0, 0.20; text = "$(overlap_all)\n($(round(Int, 100 * overlap_all / total))%)",
color = INK, fontsize = 19, font = :bold, align = (:center, :center))
# Makie-distinctive touch: a grid-layout callout row (not axis text) that
# turns the triple-overlap number into a short data story.
Label(
fig[2, 1],
"$(overlap_all) engineers ($(round(Int, 100 * overlap_all / total))%) are full-stack — fluent in Python, SQL, and JavaScript alike, the rarest combination in the survey.";
fontsize = 15,
color = INK_SOFT,
tellwidth = false,
)
rowgap!(fig.layout, 10)
# --- Save -------------------------------------------------------------------
save("plot-$(THEME).png", fig; px_per_unit = 2)
Runnable source as JSON, for any HTTP client: https://api.anyplot.ai/specs/venn-basic/makie/code. Any spec id and library id listed in llms-full.txt fit the same URL shape; every URL below is complete and callable.
{
"spec_id": "venn-basic",
"language": "julia",
"library": "makie",
"page": "https://anyplot.ai/venn-basic/julia/makie",
"hub": "https://anyplot.ai/venn-basic",
"code_json": "https://api.anyplot.ai/specs/venn-basic/makie/code",
"spec_json": "https://api.anyplot.ai/specs/venn-basic",
"render_light_png": "https://storage.googleapis.com/anyplot-images/plots/venn-basic/julia/makie/plot-light.png",
"render_dark_png": "https://storage.googleapis.com/anyplot-images/plots/venn-basic/julia/makie/plot-dark.png",
"quality_score": 94.0,
"license": "MIT",
"guide": "https://anyplot.ai/llms.txt"
}Part of Venn Diagram on anyplot.ai.