Stem Plots

Use stem plots for impulses, grouped spikes, and categorical events with careful labeling.

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

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")

# Generate sample data
x = np.arange(0, 10)
y1 = np.sin(x)
y2 = np.cos(x)
y3 = 0.5 * np.sin(2 * x)

# Create figure (square-ish): 16 cm wide, 12 cm tall
fig = plt.figure(figsize=(dm.cm2in(16), dm.cm2in(12)), dpi=300)

# Create GridSpec for 4 subplots (2x2)
gs = fig.add_gridspec(
    nrows=2,
    ncols=2,
    left=0.08,
    right=0.98,
    top=0.92,
    bottom=0.12,
    wspace=0.25,
    hspace=0.5,
)

# Panel A: Basic stem plot
ax1 = fig.add_subplot(gs[0, 0])
# Explicit parameters: linefmt, markerfmt, basefmt
# Note: stem() doesn't accept dartwork-mpl color strings in format strings,
# so we use standard format strings and set colors separately
markerline1, stemlines1, baseline1 = ax1.stem(
    x, y1, linefmt="-", markerfmt="o", basefmt="-", label="Data"
)
# Set colors and line widths: lw=0.7 for stem lines
plt.setp(stemlines1, linewidth=0.7, color=mcolors.to_rgb("oc.blue5"))
plt.setp(baseline1, linewidth=0.5, color=mcolors.to_rgb("oc.gray5"))
plt.setp(
    markerline1,
    markersize=4,
    markeredgewidth=0.3,
    markerfacecolor=mcolors.to_rgb("oc.blue7"),
    markeredgecolor=mcolors.to_rgb("oc.blue7"),
)
ax1.set_xlabel("Index", fontsize=dm.fs(0))
ax1.set_ylabel("Value", fontsize=dm.fs(0))
ax1.set_title("Basic Stem Plot", fontsize=dm.fs(1))
ax1.legend(loc="best", fontsize=dm.fs(-1), ncol=1)
ax1.set_xticks([0, 2, 4, 6, 8])
ax1.set_yticks([-1, -0.5, 0, 0.5, 1])

# Panel B: Stem with markers
ax2 = fig.add_subplot(gs[0, 1])
# Explicit parameters: different marker style
markerline2, stemlines2, baseline2 = ax2.stem(
    x, y2, linefmt="-", markerfmt="s", basefmt="-", label="Data"
)
plt.setp(stemlines2, linewidth=0.7, color=mcolors.to_rgb("oc.red5"))
plt.setp(baseline2, linewidth=0.5, color=mcolors.to_rgb("oc.gray5"))
plt.setp(
    markerline2,
    markersize=4,
    markeredgewidth=0.3,
    markerfacecolor=mcolors.to_rgb("oc.red7"),
    markeredgecolor=mcolors.to_rgb("oc.red7"),
)
ax2.set_xlabel("Index", fontsize=dm.fs(0))
ax2.set_ylabel("Value", fontsize=dm.fs(0))
ax2.set_title("Stem with Markers", fontsize=dm.fs(1))
ax2.legend(loc="best", fontsize=dm.fs(-1), ncol=1)
ax2.set_xticks([0, 2, 4, 6, 8])
ax2.set_yticks([-1, -0.5, 0, 0.5, 1])

# Panel C: Multiple stem series
ax3 = fig.add_subplot(gs[1, 0])
# First stem: lw=0.7
markerline3a, stemlines3a, baseline3a = ax3.stem(
    x, y1, linefmt="-", markerfmt="o", basefmt="-", label="Series A"
)
plt.setp(stemlines3a, linewidth=0.7, color=mcolors.to_rgb("oc.blue5"))
plt.setp(
    markerline3a,
    markersize=3,
    markeredgewidth=0.3,
    markerfacecolor=mcolors.to_rgb("oc.blue7"),
    markeredgecolor=mcolors.to_rgb("oc.blue7"),
)
# Second stem: lw=0.7
markerline3b, stemlines3b, baseline3b = ax3.stem(
    x, y2, linefmt="-", markerfmt="s", basefmt="-", label="Series B"
)
plt.setp(stemlines3b, linewidth=0.7, color=mcolors.to_rgb("oc.red5"))
plt.setp(
    markerline3b,
    markersize=3,
    markeredgewidth=0.3,
    markerfacecolor=mcolors.to_rgb("oc.red7"),
    markeredgecolor=mcolors.to_rgb("oc.red7"),
)
plt.setp(baseline3a, linewidth=0.5, color=mcolors.to_rgb("oc.gray5"))
ax3.set_xlabel("Index", fontsize=dm.fs(0))
ax3.set_ylabel("Value", fontsize=dm.fs(0))
ax3.set_title("Multiple Stem Series", fontsize=dm.fs(1))
ax3.legend(loc="best", fontsize=dm.fs(-1), ncol=1)
ax3.set_xticks([0, 2, 4, 6, 8])
ax3.set_yticks([-1, -0.5, 0, 0.5, 1])

# Panel D: Categorical stems with jitter
ax4 = fig.add_subplot(gs[1, 1])
cats = np.array(["A", "B", "C", "D"])
cat_values = np.array([2.5, 3.8, 1.9, 3.1])
jitter_x = np.arange(len(cats))
markerline4, stemlines4, baseline4 = ax4.stem(
    jitter_x,
    cat_values,
    linefmt="-",
    markerfmt="o",
    basefmt="-",
    label="Category stems",
)
plt.setp(stemlines4, linewidth=0.7, color=mcolors.to_rgb("oc.purple5"))
plt.setp(
    markerline4,
    markersize=5,
    markeredgewidth=0.3,
    markerfacecolor=mcolors.to_rgb("oc.purple7"),
    markeredgecolor=mcolors.to_rgb("oc.purple7"),
)
plt.setp(baseline4, linewidth=0.5, color=mcolors.to_rgb("oc.gray5"))
ax4.set_xticks(jitter_x)
ax4.set_xticklabels(cats, fontsize=dm.fs(0))
ax4.set_ylabel("Value", fontsize=dm.fs(0))
ax4.set_title("Categorical Stem Plot", fontsize=dm.fs(1))
ax4.set_ylim(0, 4.5)
ax4.legend(loc="best", fontsize=dm.fs(-1), ncol=1)
ax4.grid(True, linestyle="--", linewidth=0.3, alpha=0.3)

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

# Show plot
plt.show()