As discussed in some previous posts, fieldsplit is a powerful tool through which you can specify each field with a certain solver. You can refer to https://community.freefem.org/t/adapting-the-mal-preconditioner-to-stokes-fieldsplit-2d/4041/3
As discussed in some previous posts, fieldsplit is a powerful tool through which you can specify each field with a certain solver. You can refer to https://community.freefem.org/t/adapting-the-mal-preconditioner-to-stokes-fieldsplit-2d/4041/3