mod level max/min dB for nicer plot with new clipped cmap handling

Author: fs446

doc/examples/wfs-referencing.ipynb

@@ -58,7 +58,7 @@
     "    fig, [ax_amp, ax_lvl] = plt.subplots(2, 1, sharex=True)\n",
     "    fig.set_figheight(fig.get_figwidth() * 3/2)\n",
     "    sfs.plot2d.amplitude(p, grid, vmax=2, vmin=-2, ax=ax_amp)\n",
-    "    sfs.plot2d.level(p, grid, vmax=6, vmin=-6, ax=ax_lvl)\n",
+    "    sfs.plot2d.level(p, grid, vmax=12, vmin=-12, ax=ax_lvl)\n",
     "    sfs.plot2d.level_contour(p, grid, levels=[0], colors='w', ax=ax_lvl)\n",
     "    xref = np.broadcast_to(xref, array.x.shape)\n",
     "    for ax in ax_amp, ax_lvl:\n",