feat(matplotlib): implement column-stratigraphic

Author: github-actions[bot]

plots/column-stratigraphic/implementations/matplotlib.py

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+"""pyplots.ai
+column-stratigraphic: Stratigraphic Column with Lithology Patterns
+Library: matplotlib | Python 3.13
+Quality: pending | Created: 2026-03-15
+"""
+
+import matplotlib.patches as mpatches
+import matplotlib.pyplot as plt
+
+
+# Data - synthetic sedimentary borehole section (depth increasing downward, younger at top)
+layers = [
+    {"top": 0, "bottom": 12, "lithology": "conglomerate", "formation": "Ogallala Fm", "age": "Miocene"},
+    {"top": 12, "bottom": 30, "lithology": "sandstone", "formation": "Arikaree Fm", "age": "Miocene"},
+    {"top": 30, "bottom": 50, "lithology": "siltstone", "formation": "White River Fm", "age": "Oligocene"},
+    {"top": 50, "bottom": 72, "lithology": "shale", "formation": "Chadron Fm", "age": "Eocene"},
+    {"top": 72, "bottom": 95, "lithology": "limestone", "formation": "Niobrara Fm", "age": "Cretaceous"},
+    {"top": 95, "bottom": 118, "lithology": "shale", "formation": "Carlile Shale", "age": "Cretaceous"},
+    {"top": 118, "bottom": 140, "lithology": "limestone", "formation": "Greenhorn Fm", "age": "Cretaceous"},
+    {"top": 140, "bottom": 158, "lithology": "sandstone", "formation": "Dakota Fm", "age": "Cretaceous"},
+    {"top": 158, "bottom": 175, "lithology": "siltstone", "formation": "Morrison Fm", "age": "Jurassic"},
+    {"top": 175, "bottom": 200, "lithology": "sandstone", "formation": "Entrada Fm", "age": "Jurassic"},
+]
+
+# Lithology styles: color, hatch pattern
+lithology_styles = {
+    "sandstone": {"color": "#F5DEB3", "hatch": "...", "edgecolor": "#8B7355"},
+    "shale": {"color": "#A9A9A9", "hatch": "---", "edgecolor": "#555555"},
+    "limestone": {"color": "#87CEEB", "hatch": "++", "edgecolor": "#4682B4"},
+    "siltstone": {"color": "#C4B69C", "hatch": "//", "edgecolor": "#8B7D6B"},
+    "conglomerate": {"color": "#DEB887", "hatch": "ooo", "edgecolor": "#8B6914"},
+}
+
+# Plot
+fig, ax = plt.subplots(figsize=(10, 16))
+
+column_left = 0.0
+column_width = 3.0
+max_depth = 200
+
+for layer in layers:
+    top = layer["top"]
+    bottom = layer["bottom"]
+    thickness = bottom - top
+    style = lithology_styles[layer["lithology"]]
+
+    rect = mpatches.FancyBboxPatch(
+        (column_left, top),
+        column_width,
+        thickness,
+        boxstyle="square,pad=0",
+        facecolor=style["color"],
+        edgecolor=style["edgecolor"],
+        linewidth=1.5,
+        hatch=style["hatch"],
+    )
+    ax.add_patch(rect)
+
+    mid_depth = (top + bottom) / 2
+    ax.text(
+        column_left + column_width + 0.3,
+        mid_depth,
+        layer["formation"],
+        fontsize=14,
+        va="center",
+        ha="left",
+        fontweight="medium",
+    )
+
+# Age labels on the left with bracket lines
+age_spans = {}
+for layer in layers:
+    age = layer["age"]
+    if age not in age_spans:
+        age_spans[age] = {"top": layer["top"], "bottom": layer["bottom"]}
+    else:
+        age_spans[age]["top"] = min(age_spans[age]["top"], layer["top"])
+        age_spans[age]["bottom"] = max(age_spans[age]["bottom"], layer["bottom"])
+
+for age, span in age_spans.items():
+    mid = (span["top"] + span["bottom"]) / 2
+    ax.annotate(age, xy=(-0.3, mid), fontsize=13, va="center", ha="right", fontstyle="italic", color="#333333")
+    ax.plot([-0.15, -0.05], [span["top"], span["top"]], color="#333333", linewidth=1.0, clip_on=False)
+    ax.plot([-0.15, -0.05], [span["bottom"], span["bottom"]], color="#333333", linewidth=1.0, clip_on=False)
+    ax.plot([-0.1, -0.1], [span["top"], span["bottom"]], color="#333333", linewidth=1.0, clip_on=False)
+
+# Legend
+legend_handles = []
+for lith, style in lithology_styles.items():
+    patch = mpatches.Patch(
+        facecolor=style["color"],
+        edgecolor=style["edgecolor"],
+        hatch=style["hatch"],
+        label=lith.capitalize(),
+        linewidth=1.0,
+    )
+    legend_handles.append(patch)
+
+ax.legend(
+    handles=legend_handles,
+    loc="lower right",
+    fontsize=13,
+    framealpha=0.9,
+    edgecolor="#cccccc",
+    title="Lithology",
+    title_fontsize=14,
+)
+
+# Style
+ax.set_xlim(-2.5, column_left + column_width + 4.5)
+ax.set_ylim(max_depth, 0)
+ax.set_ylabel("Depth (m)", fontsize=20)
+ax.set_title("column-stratigraphic · matplotlib · pyplots.ai", fontsize=24, fontweight="medium", pad=20)
+ax.tick_params(axis="y", labelsize=16)
+ax.set_xticks([])
+ax.spines["top"].set_visible(False)
+ax.spines["right"].set_visible(False)
+ax.spines["bottom"].set_visible(False)
+ax.yaxis.grid(True, alpha=0.15, linewidth=0.8)
+
+plt.tight_layout()
+plt.savefig("plot.png", dpi=300, bbox_inches="tight")