api: add _latex print for function for notebooks

Author: mloubout

devito/types/basic.py

@@ -858,6 +858,8 @@ def __str__(self):
     def _sympystr(self, printer):
         return str(self)
 
+    _latex = _sympystr
+
     def __eq__(self, other):
         try:
             return (self.function is other.function and

examples/seismic/tutorials/07_DRP_schemes.ipynb

@@ -99,7 +99,7 @@
      "name": "stdout",
      "output_type": "stream",
      "text": [
-      "W(x, 1, u(t, x, y), x)*u(t, x, y) + W(x - h_x, 1, u(t, x, y), x)*u(t, x - h_x, y) + W(x + h_x, 1, u(t, x, y), x)*u(t, x + h_x, y)\n"
+      "u(t, x, y)*W(x, 1, u(t, x, y), x) + u(t, x - h_x, y)*W(x - h_x, 1, u(t, x, y), x) + u(t, x + h_x, y)*W(x + h_x, 1, u(t, x, y), x)\n"
      ]
     }
    ],