Hi,

I’m confused about the basis used for the DG elements of order 1 on triangular elements:

The following code, which assembles the mass matrix of the pressure space `Ph`

, gives a diagonal matrix, which surprises me. Can you tell me exactly how the basis for the space `L2(mesh, order=1)`

looks? Because in another code, it corresponds to {x, y, 1-x-y} on each element, which leads to a block tridiagonal mass matrix.

```
Vh = VectorH1(mesh, order=2)
Ph = L2(mesh, order=1)
Wh = FESpace([Vh, Ph])
a = BilinearForm(Wh)
a += p * q * dx
a.Assemble()
```

Thank you in advance.