examples: Add safemath

Author: EdCaunt

examples/userapi/07_functions_on_subdomains.ipynb

@@ -2887,34 +2887,22 @@
      "name": "stderr",
      "output_type": "stream",
      "text": [
-      "Operator `Kernel` ran in 0.68 s\n"
+      "Operator `Kernel` ran in 0.74 s\n"
      ]
-    },
-    {
-     "data": {
-      "text/plain": [
-       "PerformanceSummary([(PerfKey(name='section0', rank=None),\n",
-       "                     PerfEntry(time=0.198681000000007, gflopss=0.0, gpointss=0.0, oi=0.0, ops=0, itershapes=[])),\n",
-       "                    (PerfKey(name='section1', rank=None),\n",
-       "                     PerfEntry(time=0.19470700000000477, gflopss=0.0, gpointss=0.0, oi=0.0, ops=0, itershapes=[])),\n",
-       "                    (PerfKey(name='section2', rank=None),\n",
-       "                     PerfEntry(time=0.14005600000000007, gflopss=0.0, gpointss=0.0, oi=0.0, ops=0, itershapes=[])),\n",
-       "                    (PerfKey(name='section3', rank=None),\n",
-       "                     PerfEntry(time=0.1434430000000003, gflopss=0.0, gpointss=0.0, oi=0.0, ops=0, itershapes=[]))])"
-      ]
-     },
-     "execution_count": 45,
-     "metadata": {},
-     "output_type": "execute_result"
     }
    ],
    "source": [
     "#NBVAL_IGNORE_OUTPUT\n",
-    "op1 = Operator([eq_v,\n",
+    "from devito import switchconfig\n",
+    "\n",
+    "# Note: switchconfig(safe_math=True) is only required here to get consistent norms for testing purposes\n",
+    "# This is not required more widely and can be omitted in practical applications\n",
+    "with switchconfig(safe_math=True):\n",
+    "    op1 = Operator([eq_v,\n",
     "                eq_p, eq_t,\n",
     "                eq_p_tr, eq_txx_tr, eq_tyy_tr]\n",
     "               + src_term + rec_term)\n",
-    "op1(dt=dt)"
+    "    op1(dt=dt)"
    ]
   },
   {
@@ -3013,18 +3001,9 @@
    "execution_count": 48,
    "id": "692979ac-8bbf-4349-8b3f-ab98f11667bc",
    "metadata": {},
-   "outputs": [
-    {
-     "name": "stdout",
-     "output_type": "stream",
-     "text": [
-      "4263.511\n"
-     ]
-    }
-   ],
+   "outputs": [],
    "source": [
-    "print(np.linalg.norm(rec.data))\n",
-    "# assert np.isclose(np.linalg.norm(rec.data), 4263.511, atol=0, rtol=1e-4)"
+    "assert np.isclose(np.linalg.norm(rec.data), 4263.511, atol=0, rtol=1e-4)"
    ]
   }
  ],