workshop: single Show2D for 3 CoM panels

notebooks/berk_workshop_v1.ipynb

@@ -312,7 +312,7 @@
     "com_row = (data_f * qx).sum(dim=(-2, -1)) / total_per_dp\n",
     "com_col = (data_f * qy).sum(dim=(-2, -1)) / total_per_dp\n",
     "\n",
-    "# Detrend so the colormap is zero-centered on the signed deflection.\n",
+    "# Detrend so RdBu_r is zero-centered on the signed deflection.\n",
     "com_row -= com_row.mean()\n",
     "com_col -= com_col.mean()\n",
     "\n",
@@ -323,43 +323,11 @@
     "print(f\"|CoM| max     {com_mag.max().item():.4f} px\")\n",
     "\n",
     "quantem.widget.Show2D(\n",
-    "    com_row.cpu().numpy(),\n",
-    "    title=\"CoM row (qx) — DPC\",\n",
+    "    [com_row.cpu().numpy(), com_col.cpu().numpy(), com_mag.cpu().numpy()],\n",
+    "    labels=[\"CoM row (qx)\", \"CoM col (qy)\", \"|CoM| total\"],\n",
     "    sampling=meta[\"sampling\"][:2],\n",
     "    units=meta[\"units\"][:2],\n",
-    "    cmap=\"RdBu_r\",\n",
-    ")"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "id": "5d80052b",
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "quantem.widget.Show2D(\n",
-    "    com_col.cpu().numpy(),\n",
-    "    title=\"CoM col (qy) — DPC\",\n",
-    "    sampling=meta[\"sampling\"][:2],\n",
-    "    units=meta[\"units\"][:2],\n",
-    "    cmap=\"RdBu_r\",\n",
-    ")"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "id": "24a5fdee",
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "quantem.widget.Show2D(\n",
-    "    com_mag.cpu().numpy(),\n",
-    "    title=\"|CoM| (total deflection)\",\n",
-    "    sampling=meta[\"sampling\"][:2],\n",
-    "    units=meta[\"units\"][:2],\n",
-    "    cmap=\"magma\",\n",
+    "    cmap=[\"RdBu_r\", \"RdBu_r\", \"magma\"],\n",
     ")"
    ]
   },
@@ -371,13 +339,12 @@
     "## What you just did\n",
     "\n",
     "1. Loaded real 4D-STEM gold from Hugging Face → torch tensor on the Colab T4.\n",
-    "2. Browsed it with `Show4DSTEM` and found the probe center via CoM of the mean DP.\n",
-    "3. Bright field via aperture mask × per-scan sum, rendered with `Show2D`.\n",
-    "4. Dark field via the complementary mask.\n",
-    "5. DPC / CoM maps: row, column, and total magnitude — three interactive `Show2D` widgets.\n",
+    "2. Browsed it with `Show4DSTEM`; hardcoded the aperture at the detector center.\n",
+    "3. Bright field via aperture mask × per-scan sum (`Show2D`).\n",
+    "4. Dark field via the complementary mask (`Show2D`).\n",
+    "5. DPC / CoM: a single `Show2D` with three panels — CoM row, CoM col, and `|CoM|` magnitude.\n",
     "\n",
-    "Every reduction ran on the GPU in milliseconds; every visualization is an\n",
-    "interactive WebGPU widget (zoom, contrast, scale bar).\n",
+    "Every reduction on the GPU in milliseconds; every viz is an interactive WebGPU widget.\n",
     "\n",
     "## Try next\n",
     "\n",