Poisson
Poisson solver added in toy models. In Implicit Diffusion propagator a new parameter 'A_mat' is created so that one can select mass matrix. M1_perp is added in mass matrices in mass.py. Inverse Jacobian is also added in mass.py as DFinv.
Poisson solver added in toy models. In Implicit Diffusion propagator a new parameter 'A_mat' is created so that one can select mass matrix. M1_perp is added in mass matrices in mass.py. Inverse Jacobian is also added in mass.py as DFinv.