-pc_fieldsplit_block_size 3 (you may not need this if the code sets the
block size to 3).
-pc_fieldsplit_0_fields 0,1
-pc_fieldsplit_1_fields 2
> On Jul 31, 2020, at 7:05 PM, Raju Mandhapati via petsc-users
> <petsc-users@mcs.anl.gov> wrote:
>
> Hello,
>
> I have a matrix assembled in interlaced format. I am not able to follow how
> to use fieldsplit. Is there a good example to show how to do this. My
> variable are in this format [ {u1,v1,p1}, {u2,v2,p2}, ....,{un,vn,pn}], where
> n is the number of grid points and u,v,p are the velocity and pressure
> components. The matrix is assembled as
>
> [ uu11 uv11 up11 uu12 uv12 up12 ......
> vu11 vv11 vp11 vu12 vv12 vp12 .......
> pu11 pv11 pp11 pu12 pv12 pp12 ......
>
> uu21 uv21 up21 uu22 uv22 up22 ......
> vu21 vv21 vp21 vu22 vv22 vp22 .......
> pu21 pv21 pp21 pu22 pv22 pp22 ......
>
> .
> .
>
> ]
>
> I want to split u and v fields as one block and p field as another block.
>
> Any help would be appreciated.
>
> Raju.
>
>
>
