Update demo_tnt-elements.py

Author: jmv2009

python/demo/demo_tnt-elements.py

@@ -168,7 +168,7 @@
 
 
 def create_tnt_quad(degree):
-    assert degree > 1
+    assert degree > 0
     # Polyset
     ndofs = (degree + 1) ** 2 + 4
     npoly = (degree + 2) ** 2
@@ -309,7 +309,7 @@ def poisson_error(V: fem.FunctionSpace):
 tnt_ndofs.append(V.dofmap.index_map.size_global)
 tnt_errors.append(poisson_error(V))
 print(f"TNT degree 1 error: {tnt_errors[-1]}")
-for degree in range(2, 9):
+for degree in range(1, 9):
     V = fem.functionspace(msh, create_tnt_quad(degree))
     tnt_degrees.append(degree + 1)
     tnt_ndofs.append(V.dofmap.index_map.size_global)