scripts/figure_pdr_gaps.py

#!/usr/bin/env python
"""Figure: per-PDR mean relative-to-best makespan gap (Claim 3 heuristic side).

Bar chart of the 24 composite PDRs sorted by mean gap, LIFO+LIT highlighted as
the best single fixed rule. Reproduces the ordering behind Table 5's heuristic
block.
"""
from __future__ import annotations

import json
from pathlib import Path

import matplotlib

matplotlib.use("Agg")
import matplotlib.pyplot as plt  # noqa: E402

ROOT = Path("/home/ubuntu/samuel/dynasched-repro")
GAPS = ROOT / "outputs" / "pdr_gaps.json"
OUT = ROOT / "figs" / "pdr_gaps_bar.png"


def main():
    g = json.loads(GAPS.read_text())
    ranked = g["ranked_rules"]
    mean_gap = g["mean_gap_pct"]
    vals = [mean_gap[r] for r in ranked]

    colors = []
    for r in ranked:
        if r == "LIFO:LIT":
            colors.append("#0f766e")  # highlight best
        elif r == "SPT:SPT":
            colors.append("#b91c1c")  # highlight weak reference
        else:
            colors.append("#94a3b8")

    fig, ax = plt.subplots(figsize=(11, 6))
    bars = ax.bar(range(len(ranked)), vals, color=colors)
    ax.set_xticks(range(len(ranked)))
    ax.set_xticklabels(
        [r.replace(":", "+") for r in ranked], rotation=60, ha="right", fontsize=8
    )
    ax.set_ylabel("Mean relative-to-best makespan gap (%)")
    ax.set_title(
        "DynaSched-Subset (70 instances): per-PDR mean gap vs best-observed\n"
        "24 composite priority dispatch rules — LIFO+LIT is the best single fixed rule"
    )

    # annotate LIFO+LIT and SPT+SPT
    for i, r in enumerate(ranked):
        if r in ("LIFO:LIT", "SPT:SPT"):
            ax.text(
                i,
                vals[i] + max(vals) * 0.01,
                f"{vals[i]:.2f}%",
                ha="center",
                va="bottom",
                fontsize=8,
                fontweight="bold",
            )

    best = g["best_rule"].replace(":", "+")
    ax.axhline(mean_gap[g["best_rule"]], color="#0f766e", ls="--", lw=0.8, alpha=0.6)
    ax.text(
        len(ranked) - 1,
        mean_gap[g["best_rule"]],
        f" best={best} {g['best_mean_gap']:.2f}% (paper 1.11%)",
        va="bottom",
        ha="right",
        color="#0f766e",
        fontsize=9,
    )

    from matplotlib.patches import Patch

    ax.legend(
        handles=[
            Patch(color="#0f766e", label="LIFO+LIT (best fixed rule)"),
            Patch(color="#b91c1c", label="SPT+SPT (weak reference)"),
            Patch(color="#94a3b8", label="other PDRs"),
        ],
        fontsize=8,
    )
    plt.tight_layout()
    OUT.parent.mkdir(parents=True, exist_ok=True)
    fig.savefig(OUT, dpi=130)
    print(f"Wrote {OUT}")


if __name__ == "__main__":
    main()