Re: [petsc-users] Composing different Field Components into single Vector (or data array)

[Blaise Bourdin]

Hi, If you have created your vectors using sections, all you need is to call DMCreateSuperDM. See src/dm/impls/plex/tests/ex26.c:300 for an example. Blaise On Apr 17, 2023, at 1:30 PM, James Wright <jrwrigh....@gmail.com> wrote: Hello, I currently have two DMPlex objects, both `DMClone`ed from the same "original" DMPlex object. They have different fields with different numbers of components on each of them. I would like to compose certain components from each into a single contiguous array. I'd also like to do this from a DMGlobal vector. What is the best/most robust way to do that? Obviously I can just `VecGetArrayRead` each of the vectors and loop through them manually, but that relies on knowledge of the array data layout. There's `DMPlexGetLocalOffsets`, but since I want to use the global Vec, there isn't a corresponding `DMPlexGetGlobalOffsets` (that I can see anyways). This manually looping would also require that the underlying arrangement of the DOFs is the same between the two DMPlex objects, but I assume this is true from the `DMClone` operation. Thanks, James Wright Graduate Research Assistant, PhD University of Colorado Boulder Cell: (864) 498 8869  Email: ja...@jameswright.xyz Website: jameswright.xyz —  Canada Research Chair in Mathematical and Computational Aspects of Solid Mechanics (Tier 1) Professor, Department of Mathematics & Statistics Hamilton Hall room 409A, McMaster University 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada  https://www.math.mcmaster.ca/bourdin | +1 (905) 525 9140 ext. 27243