Pie Charts

Build pies, donuts, and nested rings with centered labels and contrast so proportions stay legible.

import matplotlib.colors as mcolors
import matplotlib.pyplot as plt

import dartwork_mpl as dm

# Apply scientific style preset
# Default: font.size=7.5, lines.linewidth=0.5, axes.linewidth=0.3
dm.style.use("scientific")

# Sample data
sizes1 = [30, 25, 20, 15, 10]
labels1 = ["Category A", "Category B", "Category C", "Category D", "Category E"]
# Convert dartwork-mpl color strings to RGB tuples for pie() function
colors1 = [
    mcolors.to_rgb("oc.blue5"),
    mcolors.to_rgb("oc.red5"),
    mcolors.to_rgb("oc.green5"),
    mcolors.to_rgb("oc.orange5"),
    mcolors.to_rgb("oc.violet5"),
]

sizes2 = [35, 25, 20, 20]
labels2 = ["Group 1", "Group 2", "Group 3", "Group 4"]
colors2 = [
    mcolors.to_rgb("oc.blue5"),
    mcolors.to_rgb("oc.red5"),
    mcolors.to_rgb("oc.green5"),
    mcolors.to_rgb("oc.orange5"),
]

# Explode values
explode1 = (0.05, 0, 0, 0, 0)
explode2 = (0.1, 0, 0, 0)

# Create figure
# Square layout for even slices
fig = plt.figure(figsize=(dm.cm2in(17), dm.cm2in(12.5)), dpi=300)

# Create GridSpec for 3 subplots
gs = fig.add_gridspec(
    nrows=2,
    ncols=2,
    left=0.06,
    right=0.96,
    top=0.94,
    bottom=0.10,
    wspace=0.12,
    hspace=0.34,
)

# Panel A: Basic pie chart
ax1 = fig.add_subplot(gs[0, 0])
# Explicit parameters: startangle=90, autopct='%1.1f%%', textprops fontsize
wedges1, texts1, autotexts1 = ax1.pie(
    sizes1,
    labels=labels1,
    colors=colors1,
    autopct="%1.1f%%",
    startangle=90,
    labeldistance=1.04,
    pctdistance=0.72,
    textprops={"fontsize": dm.fs(-1)},
)
# Set autopct text color and size
for autotext in autotexts1:
    autotext.set_color("white")
    autotext.set_fontweight("bold")
    autotext.set_fontsize(dm.fs(-1))
ax1.set_title("Basic Pie Chart", fontsize=dm.fs(1))

# Panel B: Donut chart (pie with hole)
ax2 = fig.add_subplot(gs[0, 1])
# Explicit parameters: startangle=90, autopct='%1.1f%%', wedgeprops for donut
wedges2, texts2, autotexts2 = ax2.pie(
    sizes2,
    labels=labels2,
    colors=colors2,
    autopct="%1.1f%%",
    startangle=90,
    labeldistance=1.04,
    pctdistance=0.72,
    textprops={"fontsize": dm.fs(-1)},
    wedgeprops={"width": 0.5, "edgecolor": "white", "linewidth": 0.5},
)
# Set autopct text color and size
for autotext in autotexts2:
    autotext.set_color("white")
    autotext.set_fontweight("bold")
    autotext.set_fontsize(dm.fs(-1))
ax2.set_title("Donut Chart", fontsize=dm.fs(1))

# Panel C: Exploded pie chart
ax3 = fig.add_subplot(gs[1, 0])
# Explicit parameters: explode, shadow=True, startangle=90
wedges3, texts3, autotexts3 = ax3.pie(
    sizes2,
    labels=labels2,
    colors=colors2,
    explode=explode2,
    shadow=True,
    autopct="%1.1f%%",
    startangle=90,
    labeldistance=1.04,
    pctdistance=0.72,
    textprops={"fontsize": dm.fs(-1)},
)
# Set autopct text color and size
for autotext in autotexts3:
    autotext.set_color("white")
    autotext.set_fontweight("bold")
    autotext.set_fontsize(dm.fs(-1))
ax3.set_title("Exploded Pie Chart", fontsize=dm.fs(1))


# Panel D: Nested donut comparison
ax4 = fig.add_subplot(gs[1, 1])
outer_sizes = [0.5, 0.3, 0.2]
inner_sizes = [0.6, 0.4]
colors_outer = ["oc.blue5", "oc.orange5", "oc.gray3"]
colors_inner = ["oc.purple5", "oc.purple2"]
ax4.pie(
    outer_sizes,
    radius=1.0,
    colors=colors_outer,
    wedgeprops={"width": 0.4, "edgecolor": "white"},
    startangle=60,
)
ax4.pie(
    inner_sizes,
    radius=0.6,
    colors=colors_inner,
    wedgeprops={"width": 0.4, "edgecolor": "white"},
    startangle=-30,
)
ax4.set_title("Nested Donut Variations", fontsize=dm.fs(1))
ax4.axis("equal")

# Keep all pies perfectly circular and visible
for ax in (ax1, ax2, ax3, ax4):
    ax.set_aspect("equal", adjustable="box")

# Optimize layout
dm.simple_layout(fig, gs=gs, margins=(0.08, 0.08, 0.08, 0.12))

# Show plot
plt.show()