A span plot highlights a specific region of interest on a chart using a shaded rectangular area that spans the full height or width of the plot. Vertical spans mark ranges along the x-axis (e.g., time periods), while horizontal spans mark ranges along the y-axis (e.g., value thresholds). The semi-transparent fill allows underlying data to remain visible while drawing attention to the highlighted region.
# anyplot.ai
# span-basic: Basic Span Plot (Highlighted Region)
# Library: makie 0.21.9 | Julia 1.11.9
# Quality: 91/100 | Created: 2026-07-25
using CairoMakie
using Colors
using Random
Random.seed!(42)
# --- Theme tokens -----------------------------------------------------------
const THEME = get(ENV, "ANYPLOT_THEME", "light")
const PAGE_BG = THEME == "light" ? colorant"#FAF8F1" : colorant"#1A1A17"
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", colorant"#BD8233",
colorant"#AE3030", colorant"#2ABCCD", colorant"#954477", colorant"#99B314",
]
const ANYPLOT_AMBER = colorant"#DDCC77" # warning / caution — outside the categorical pool
const ANYPLOT_MUTED = THEME == "light" ? colorant"#6B6A63" : colorant"#A8A79F"
const ANYPLOT_ALERT = colorant"#AE3030" # bad / breach — semantic-red anchor
# --- Data ---------------------------------------------------------------
# Daily API response latency (ms) over a 90-day monitoring window, with two
# operational events overlaid: an incident-driven spike and a planned
# maintenance bump.
days = 1:90
latency = fill(120.0, 90) .+ randn(90) .* 8.0
incident_days = 35:41
latency[incident_days] .+= 55.0 .+ randn(length(incident_days)) .* 5.0
maintenance_days = 65:70
latency[maintenance_days] .+= 18.0 .+ randn(length(maintenance_days)) .* 3.0
sla_threshold = 160.0 # ms — response times above this breach the SLA
# --- Plot -----------------------------------------------------------------
fig = Figure(
size = (1600, 900),
fontsize = 14,
backgroundcolor = PAGE_BG,
)
ax = Axis(
fig[1, 1];
title = "span-basic · julia · makie · anyplot.ai",
titlesize = 20,
titlecolor = INK,
xlabel = "Day of Monitoring Window",
ylabel = "API Response Latency (ms)",
xlabelsize = 14,
ylabelsize = 14,
xlabelcolor = INK,
ylabelcolor = INK,
xticklabelsize = 12,
yticklabelsize = 12,
xticklabelcolor = INK_SOFT,
yticklabelcolor = INK_SOFT,
xtickcolor = INK_SOFT,
ytickcolor = INK_SOFT,
backgroundcolor = PAGE_BG,
topspinevisible = false,
rightspinevisible = false,
leftspinecolor = INK_SOFT,
bottomspinecolor = INK_SOFT,
xgridvisible = false,
ygridcolor = RGBAf(INK.r, INK.g, INK.b, 0.15),
)
vspan!(ax, 34.5, 41.5; color = (ANYPLOT_AMBER, 0.25), label = "Incident: Database Failover")
vspan!(ax, 64.5, 70.5; color = (ANYPLOT_MUTED, 0.2), label = "Scheduled Maintenance")
hspan!(ax, sla_threshold, 200; color = (ANYPLOT_ALERT, 0.09), label = "SLA Threshold (>160ms)")
# Thin edge strokes give each span a crisper boundary against the grid,
# without adding duplicate legend entries.
vlines!(ax, [34.5, 41.5]; color = ANYPLOT_AMBER, linewidth = 1.5, linestyle = :dash)
vlines!(ax, [64.5, 70.5]; color = ANYPLOT_MUTED, linewidth = 1.5, linestyle = :dash)
hlines!(ax, [sla_threshold]; color = ANYPLOT_ALERT, linewidth = 1.5, linestyle = :dash)
lines!(ax, days, latency; color = IMPRINT_PALETTE[1], linewidth = 3, label = "Response Latency")
# Fix y-limits to the data's natural range; the SLA hspan's upper bound (200)
# is intentionally past the visible area so the "breach zone" reads as
# extending to the top of the chart, without dragging the autolimits along.
ylims!(ax, 95, 195)
axislegend(
ax;
position = :lt,
framevisible = false,
backgroundcolor = :transparent,
labelcolor = INK_SOFT,
)
# --- Save -------------------------------------------------------------------
save("plot-$(THEME).png", fig; px_per_unit = 2)
Runnable source as JSON, for any HTTP client: https://api.anyplot.ai/specs/span-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": "span-basic",
"language": "julia",
"library": "makie",
"page": "https://anyplot.ai/span-basic/julia/makie",
"hub": "https://anyplot.ai/span-basic",
"code_json": "https://api.anyplot.ai/specs/span-basic/makie/code",
"spec_json": "https://api.anyplot.ai/specs/span-basic",
"render_light_png": "https://storage.googleapis.com/anyplot-images/plots/span-basic/julia/makie/plot-light.png",
"render_dark_png": "https://storage.googleapis.com/anyplot-images/plots/span-basic/julia/makie/plot-dark.png",
"quality_score": 91.0,
"license": "MIT",
"guide": "https://anyplot.ai/llms.txt"
}Part of Basic Span Plot (Highlighted Region) on anyplot.ai.