A histogram showing multiple groups stacked on top of each other within each bin. The total bar height represents the combined frequency, while colored segments show individual group contributions.
""" anyplot.ai
histogram-stacked: Stacked Histogram
Library: bokeh 3.9.0 | Python 3.13.13
Quality: 84/100 | Updated: 2026-05-12
"""
import os
import time
from pathlib import Path
import numpy as np
from bokeh.io import output_file, save
from bokeh.models import ColumnDataSource
from bokeh.plotting import figure
from selenium import webdriver
from selenium.webdriver.chrome.options import Options
THEME = os.getenv("ANYPLOT_THEME", "light")
PAGE_BG = "#FAF8F1" if THEME == "light" else "#1A1A17"
ELEVATED_BG = "#FFFDF6" if THEME == "light" else "#242420"
INK = "#1A1A17" if THEME == "light" else "#F0EFE8"
INK_SOFT = "#4A4A44" if THEME == "light" else "#B8B7B0"
IMPRINT = ["#009E73", "#C475FD", "#4467A3"]
# Data - Simulating test scores from three different study groups
np.random.seed(42)
group_a = np.random.normal(loc=75, scale=8, size=150)
group_b = np.random.normal(loc=82, scale=10, size=120)
group_c = np.random.normal(loc=65, scale=12, size=100)
# Cap test scores at realistic range (0-100)
group_a = np.clip(group_a, 0, 100)
group_b = np.clip(group_b, 0, 100)
group_c = np.clip(group_c, 0, 100)
# Create consistent bin edges for all groups
all_data = np.concatenate([group_a, group_b, group_c])
bin_edges = np.linspace(0, 100, 16)
# Compute histograms with same bins
hist_a, _ = np.histogram(group_a, bins=bin_edges)
hist_b, _ = np.histogram(group_b, bins=bin_edges)
hist_c, _ = np.histogram(group_c, bins=bin_edges)
bin_centers = (bin_edges[:-1] + bin_edges[1:]) / 2
bin_width = bin_edges[1] - bin_edges[0]
# Create figure
p = figure(
width=4800,
height=2700,
title="histogram-stacked · bokeh · anyplot.ai",
x_axis_label="Test Score (points)",
y_axis_label="Frequency (count)",
)
# Prepare data for stacking
source_c = ColumnDataSource(
data={
"x": bin_centers,
"top": hist_c,
"bottom": np.zeros_like(hist_c),
"width": [bin_width * 0.85] * len(bin_centers),
}
)
source_a = ColumnDataSource(
data={"x": bin_centers, "top": hist_c + hist_a, "bottom": hist_c, "width": [bin_width * 0.85] * len(bin_centers)}
)
source_b = ColumnDataSource(
data={
"x": bin_centers,
"top": hist_c + hist_a + hist_b,
"bottom": hist_c + hist_a,
"width": [bin_width * 0.85] * len(bin_centers),
}
)
# Plot stacked bars using ColumnDataSource
p.vbar(
x="x",
top="top",
bottom="bottom",
width="width",
source=source_c,
fill_color=IMPRINT[2],
line_color="white",
line_width=2,
alpha=0.9,
legend_label="Group C",
)
p.vbar(
x="x",
top="top",
bottom="bottom",
width="width",
source=source_a,
fill_color=IMPRINT[0],
line_color="white",
line_width=2,
alpha=0.9,
legend_label="Group A",
)
p.vbar(
x="x",
top="top",
bottom="bottom",
width="width",
source=source_b,
fill_color=IMPRINT[1],
line_color="white",
line_width=2,
alpha=0.9,
legend_label="Group B",
)
# Text sizing for 4800x2700 canvas
p.title.text_font_size = "28pt"
p.xaxis.axis_label_text_font_size = "22pt"
p.yaxis.axis_label_text_font_size = "22pt"
p.xaxis.major_label_text_font_size = "18pt"
p.yaxis.major_label_text_font_size = "18pt"
# Theme-adaptive chrome
p.background_fill_color = PAGE_BG
p.border_fill_color = PAGE_BG
p.outline_line_color = INK_SOFT
p.title.text_color = INK
p.xaxis.axis_label_text_color = INK
p.yaxis.axis_label_text_color = INK
p.xaxis.major_label_text_color = INK_SOFT
p.yaxis.major_label_text_color = INK_SOFT
p.xaxis.axis_line_color = INK_SOFT
p.yaxis.axis_line_color = INK_SOFT
p.xaxis.major_tick_line_color = INK_SOFT
p.yaxis.major_tick_line_color = INK_SOFT
p.xgrid.grid_line_color = INK
p.ygrid.grid_line_color = INK
p.xgrid.grid_line_alpha = 0.10
p.ygrid.grid_line_alpha = 0.10
# Legend styling
p.legend.background_fill_color = ELEVATED_BG
p.legend.border_line_color = INK_SOFT
p.legend.label_text_color = INK_SOFT
p.legend.label_text_font_size = "18pt"
p.legend.location = "top_right"
p.y_range.start = 0
# Save HTML
output_file(f"plot-{THEME}.html")
save(p)
# Screenshot with Selenium
W, H = 4800, 2700
opts = Options()
for arg in (
"--headless=new",
"--no-sandbox",
"--disable-dev-shm-usage",
"--disable-gpu",
f"--window-size={W},{H}",
"--hide-scrollbars",
):
opts.add_argument(arg)
driver = webdriver.Chrome(options=opts)
driver.set_window_size(W, H)
driver.get(f"file://{Path(f'plot-{THEME}.html').resolve()}")
time.sleep(3)
driver.save_screenshot(f"plot-{THEME}.png")
driver.quit()
Part of Stacked Histogram on anyplot.ai.