Commit

rebuild_eye.py

@@ -0,0 +1,91 @@
+#!/usr/bin/env python3
+"""
+Rebuild the folded CLK+ eye diagram for the v2 report.
+
+The original plot_eye() in make_flicker_report.py looks for an LP-11 → HS
+transition (CLK+ > 0.5 V then falling). In session 20260515_135656 the
+captures landed entirely in HS state (CLK+ stays in ~0.07–0.36 V), so the
+edge detector returned None for every segment and the plot rendered with
+zero overlays.
+
+This script auto-detects the common mode per segment and folds around
+every crossing of common mode — which is what the eye really wants.
+"""
+
+from __future__ import annotations
+
+from pathlib import Path
+import numpy as np
+import matplotlib
+matplotlib.use("Agg")
+import matplotlib.pyplot as plt
+
+ARRIVE_PURPLE      = "#5f016f"
+ARRIVE_PURPLE_DARK = "#3e0049"
+
+SESSION = Path("data/flicker_bursts/20260515_135656")
+BURST = 15
+N_SEGS = 20
+UI_NS = 2.315
+OUT = Path("flicker_investigation_report_v2_plots/mipi_typical_eye.png")
+
+
+def fold_segment(t_ns: np.ndarray, v_mv: np.ndarray, ui_ns: float,
+                 ax: plt.Axes) -> int:
+    """Overlay every common-mode crossing in this segment as a ±1 UI slice."""
+    cm = float(np.median(v_mv))
+    above = (v_mv > cm).astype(int)
+    edges = np.where(np.diff(above) != 0)[0]
+    n = 0
+    for e in edges:
+        t_cross = t_ns[e]
+        mask = (t_ns >= t_cross - ui_ns) & (t_ns <= t_ns[e] + ui_ns)
+        if mask.sum() < 3:
+            continue
+        ax.plot(t_ns[mask] - t_cross, v_mv[mask] - cm,
+                color=ARRIVE_PURPLE, linewidth=0.4, alpha=0.18)
+        n += 1
+    return n
+
+
+def main() -> None:
+    clk_files = sorted(SESSION.glob(f"burst_{BURST:04d}_*_mipi_seg*_clk.csv"))
+    if not clk_files:
+        raise SystemExit(f"no CLK files for burst {BURST} in {SESSION}")
+
+    fig, ax = plt.subplots(figsize=(8.5, 3.0))
+    total_segs = 0
+    total_xings = 0
+    for f in clk_files[:N_SEGS]:
+        arr = np.genfromtxt(f, delimiter=",")
+        t_ns = arr[:, 0] * 1e9
+        v_mv = arr[:, 1] * 1000
+        n = fold_segment(t_ns, v_mv, UI_NS, ax)
+        if n:
+            total_segs += 1
+            total_xings += n
+
+    ax.axhline(0, color="grey", linewidth=0.4, alpha=0.5)
+    ax.axvline(-UI_NS / 2, color="grey", linestyle=":", linewidth=0.4, alpha=0.5)
+    ax.axvline(+UI_NS / 2, color="grey", linestyle=":", linewidth=0.4, alpha=0.5)
+    ax.set_xlabel(f"time (ns, folded on UI = {UI_NS} ns)")
+    ax.set_ylabel("CLK+ − common-mode (mV)")
+    ax.set_xlim(-UI_NS, UI_NS)
+    ax.set_title(
+        f"CLK+ folded eye ({total_segs} segments × ~{total_xings // max(total_segs,1)} "
+        f"crossings overlaid on a 2-UI window, burst {BURST})",
+        color=ARRIVE_PURPLE, fontsize=11)
+    ax.grid(True, alpha=0.25)
+    ax.text(0.01, 0.95,
+            f"{total_segs} segments × ~{total_xings // max(total_segs,1)} cycles overlaid",
+            transform=ax.transAxes, fontsize=9, color=ARRIVE_PURPLE_DARK,
+            bbox=dict(facecolor="white", edgecolor="none", alpha=0.85), va="top")
+
+    OUT.parent.mkdir(parents=True, exist_ok=True)
+    fig.tight_layout()
+    fig.savefig(OUT, dpi=140)
+    print(f"wrote {OUT}  ({total_segs} segments, {total_xings} crossings)")
+
+
+if __name__ == "__main__":
+    main()