A Simple Moving Average (SMA) chart displays price or value data with one or more SMA overlays, typically showing short, medium, and long-term periods (e.g., 20, 50, 200-day). Each SMA line smooths out price fluctuations by averaging the last N data points, revealing underlying trends at different time scales. This multi-period overlay is fundamental to technical analysis, helping traders identify trend direction, support/resistance levels, and potential crossover signals.
# anyplot.ai
# indicator-sma: Simple Moving Average (SMA) Indicator Chart
# Library: makie 0.21.9 | Julia 1.11.9
# Quality: 92/100 | Created: 2026-09-02
using CairoMakie
using Colors
using Dates
using Random
using Statistics
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",
]
# --- Data ---------------------------------------------------------------
n = 300
daily_returns = 0.0004 .+ 0.013 .* randn(n)
close = 180.0 .* cumprod(1.0 .+ daily_returns)
trading_day = 1:n
start_date = Date(2024, 1, 2)
window_short = 20
window_medium = 50
window_long = 200
sma_short = [i < window_short ? NaN : mean(close[(i - window_short + 1):i]) for i in 1:n]
sma_medium = [i < window_medium ? NaN : mean(close[(i - window_medium + 1):i]) for i in 1:n]
sma_long = [i < window_long ? NaN : mean(close[(i - window_long + 1):i]) for i in 1:n]
# Golden-cross / death-cross detection (SMA 20 vs. SMA 50) — the crossover
# signal that is the entire analytical point of a multi-period SMA overlay.
diff_ma = sma_short .- sma_medium
crossovers = Tuple{Int,Symbol}[]
for i in (window_medium + 1):n
if sign(diff_ma[i]) != sign(diff_ma[i - 1])
push!(crossovers, (i, diff_ma[i] > 0 ? :golden : :death))
end
end
# Annotate only well-separated crossovers so the callouts stay a focal point
# rather than clutter.
featured_crossovers = Tuple{Int,Symbol}[]
last_i = -Inf
for (i, kind) in crossovers
if i - last_i >= 40
push!(featured_crossovers, (i, kind))
global last_i = i
end
end
featured_crossovers = first(featured_crossovers, min(2, length(featured_crossovers)))
# --- Plot -----------------------------------------------------------------
fig = Figure(
size = (1600, 900),
fontsize = 14,
backgroundcolor = PAGE_BG,
)
ax = Axis(
fig[1, 1];
title = "indicator-sma · julia · makie · anyplot.ai",
titlesize = 23,
titlecolor = INK,
xlabel = "Date",
ylabel = "Closing Price (\$)",
xlabelsize = 14,
ylabelsize = 14,
xlabelcolor = INK,
ylabelcolor = INK,
xticklabelsize = 12,
yticklabelsize = 12,
xticklabelcolor = INK_SOFT,
yticklabelcolor = INK_SOFT,
xtickcolor = INK_SOFT,
ytickcolor = INK_SOFT,
xtickformat = xs -> [Dates.format(start_date + Day(round(Int, x) - 1), "u yyyy") for x in xs],
backgroundcolor = PAGE_BG,
topspinevisible = false,
rightspinevisible = false,
leftspinecolor = INK_SOFT,
bottomspinecolor = INK_SOFT,
ygridcolor = RGBAf(INK.r, INK.g, INK.b, 0.15),
xgridvisible = false,
)
lines!(ax, trading_day, close; color = IMPRINT_PALETTE[1], linewidth = 2.0, label = "Close")
lines!(ax, trading_day, sma_short; color = IMPRINT_PALETTE[2], linewidth = 2.0, label = "SMA 20")
lines!(ax, trading_day, sma_medium; color = IMPRINT_PALETTE[3], linewidth = 2.0, label = "SMA 50")
lines!(ax, trading_day, sma_long; color = IMPRINT_PALETTE[4], linewidth = 2.5, label = "SMA 200")
# Golden-cross / death-cross callouts — a Makie-distinctive `scatter!` +
# `text!` + dotted leader-line annotation combo that gives the overlay its
# analytical focal point. The label is placed clear of every series' local
# extremum (not just the marker itself) so it never sits on top of a line.
margin = 0.05 * (maximum(close) - minimum(close))
for (i, kind) in featured_crossovers
is_golden = kind == :golden
marker_color = is_golden ? IMPRINT_PALETTE[1] : IMPRINT_PALETTE[5]
marker_glyph = is_golden ? :utriangle : :dtriangle
label_text = is_golden ? "Golden Cross" : "Death Cross"
window = max(1, i - 15):min(n, i + 15)
local_values = vcat(close[window], filter(!isnan, sma_short[window]),
filter(!isnan, sma_medium[window]), filter(!isnan, sma_long[window]))
label_y = is_golden ? maximum(local_values) + margin : minimum(local_values) - margin
scatter!(
ax, [trading_day[i]], [sma_short[i]];
marker = marker_glyph,
markersize = 22,
color = marker_color,
strokecolor = INK,
strokewidth = 1.5,
)
lines!(
ax, [trading_day[i], trading_day[i]], [sma_short[i], label_y];
color = (marker_color, 0.6),
linewidth = 1.2,
linestyle = :dot,
)
text!(
ax, trading_day[i], label_y;
text = label_text,
align = (:center, is_golden ? :bottom : :top),
color = marker_color,
fontsize = 13,
font = :bold,
)
end
axislegend(ax; position = :lt, labelcolor = INK, framevisible = false, labelsize = 13)
# --- Save -------------------------------------------------------------------
save("plot-$(THEME).png", fig; px_per_unit = 2)
Runnable source as JSON, for any HTTP client: https://api.anyplot.ai/specs/indicator-sma/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": "indicator-sma",
"language": "julia",
"library": "makie",
"page": "https://anyplot.ai/indicator-sma/julia/makie",
"hub": "https://anyplot.ai/indicator-sma",
"code_json": "https://api.anyplot.ai/specs/indicator-sma/makie/code",
"spec_json": "https://api.anyplot.ai/specs/indicator-sma",
"render_light_png": "https://storage.googleapis.com/anyplot-images/plots/indicator-sma/julia/makie/plot-light.png",
"render_dark_png": "https://storage.googleapis.com/anyplot-images/plots/indicator-sma/julia/makie/plot-dark.png",
"quality_score": 92.0,
"license": "MIT",
"guide": "https://anyplot.ai/llms.txt"
}Part of Simple Moving Average (SMA) Indicator Chart on anyplot.ai.