A sparkline is a small, condensed line chart designed to be embedded inline with text or in dashboard cells. It shows trends at a glance without axes, labels, or detailed scales - pure data visualization in minimal space. The defining characteristic is extreme minimalism: a single continuous line that conveys the shape of data without any chart chrome.
#' anyplot.ai
#' sparkline-basic: Basic Sparkline
#' Library: ggplot2 3.5.1 | R 4.4.1
#' Quality: 87/100 | Created: 2026-09-09
library(ggplot2)
library(ragg)
set.seed(42)
# --- Theme tokens ------------------------------------------------------------
THEME <- Sys.getenv("ANYPLOT_THEME", "light")
PAGE_BG <- if (THEME == "light") "#FAF8F1" else "#1A1A17"
INK <- if (THEME == "light") "#1A1A17" else "#F0EFE8"
# Imprint palette (see prompts/default-style-guide.md "Categorical Palette")
BRAND <- "#009E73" # position 1 — the trend line, ALWAYS first series
LOW_MARK <- "#AE3030" # position 5 — series minimum
HIGH_MARK <- "#4467A3" # position 3 — series maximum
# --- Data ---------------------------------------------------------------------
# Single stock's closing price over one trading quarter — the sparkline
# convention of embedding a trend inline (financial table cell) without any
# axes, ticks, or gridlines.
n_points <- 90
day <- 1:n_points
closing_price <- 142 + 14 * sin(2 * pi * day / 45 - 1) + cumsum(rnorm(n_points, mean = 0.12, sd = 1.3))
trend <- data.frame(day = day, closing_price = closing_price)
i_min <- which.min(closing_price)
i_max <- which.max(closing_price)
i_first <- 1
i_last <- n_points
# --- Plot -----------------------------------------------------------------
# geom_ribbon fills the area under the line for the classic sparkline look;
# geom_point marks the series extremes, the starting point, and the latest
# value — the only highlights the spec allows before it stops being "basic".
# Narrow side margins let the mark span nearly the full canvas width, and
# aspect.ratio ~0.18 keeps the panel a compact 5-6:1 band while still filling
# a healthy share of the fixed 3200x1800 canvas height.
p <- ggplot(trend, aes(x = day, y = closing_price)) +
geom_ribbon(aes(ymin = min(closing_price), ymax = closing_price), fill = BRAND, alpha = 0.12) +
geom_line(color = BRAND, linewidth = 1.9, lineend = "round") +
geom_point(data = trend[i_first, ], shape = 21, color = INK, fill = PAGE_BG, size = 3.2, stroke = 1.2) +
geom_point(data = trend[i_min, ], color = LOW_MARK, size = 3.8) +
geom_point(data = trend[i_max, ], color = HIGH_MARK, size = 3.8) +
geom_point(data = trend[i_last, ], color = BRAND, size = 4.2) +
scale_x_continuous(expand = expansion(mult = c(0.02, 0.02))) +
scale_y_continuous(expand = expansion(mult = c(0.12, 0.12))) +
labs(title = "sparkline-basic · r · ggplot2 · anyplot.ai") +
theme_void(base_size = 8) +
theme(
aspect.ratio = 0.18, # compact ~5.5:1 band — the sparkline's defining shape
plot.background = element_rect(fill = PAGE_BG, color = PAGE_BG),
panel.background = element_rect(fill = PAGE_BG, color = NA),
plot.title = element_text(color = INK, size = 15, hjust = 0.5, margin = margin(b = 24)),
plot.margin = margin(t = 30, r = 40, b = 30, l = 40)
)
# --- Save -------------------------------------------------------------------
ggsave(
filename = sprintf("plot-%s.png", THEME),
plot = p,
device = ragg::agg_png,
width = 8,
height = 4.5,
units = "in",
dpi = 400
)
Runnable source as JSON, for any HTTP client: https://api.anyplot.ai/specs/sparkline-basic/ggplot2/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": "sparkline-basic",
"language": "r",
"library": "ggplot2",
"page": "https://anyplot.ai/sparkline-basic/r/ggplot2",
"hub": "https://anyplot.ai/sparkline-basic",
"code_json": "https://api.anyplot.ai/specs/sparkline-basic/ggplot2/code",
"spec_json": "https://api.anyplot.ai/specs/sparkline-basic",
"render_light_png": "https://storage.googleapis.com/anyplot-images/plots/sparkline-basic/r/ggplot2/plot-light.png",
"render_dark_png": "https://storage.googleapis.com/anyplot-images/plots/sparkline-basic/r/ggplot2/plot-dark.png",
"quality_score": 87.0,
"license": "MIT",
"guide": "https://anyplot.ai/llms.txt"
}Part of Basic Sparkline on anyplot.ai.