<html><head><meta http-equiv="content-type" content="text/html; charset=us-ascii"></head><body style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div><br></div> The error indicates not enough nonzero blocks are preallocated for. Try something really simple, preallocate for one block and put in one block then call MatAssemblyBegin/End(), MatView(), if that works then work up to your full problem.<div><br></div><div> Barry</div><div><br><div><br><blockquote type="cite"><div>On Nov 3, 2022, at 3:11 PM, Edoardo alinovi <edoardo.alinovi@gmail.com> wrote:</div><br class="Apple-interchange-newline"><div><div dir="ltr">Just to give a bit more of context I am doing like this:<div><br></div><div> call MatCreate(PETSC_COMM_WORLD, this%A, ierr)<br><br> call MatSetSizes(this%A, lm, lm, M, M, ierr) ! lm is the local size of the matrix , M the global one<br><br> call MatSetType(this%A, myType, ierr) ! myType is MATMPIBAIJ<br> <br> call MatSetBlockSize(this%A, 4-bdim, ierr) ! 4-bdim is equal to 3 in this case<br><br> call MatMPIBAIJSetPreallocation(this%A, 4-bdim, flubioSolvers%d_nz, mesh%d_nnz, flubioSolvers%o_nz, mesh%o_nnz, ierr) ! d_nnz and o_nnz is the number of diagonal and off diagonal non zero blocks<br><br> call MatSetUp(this%A, ierr)<br></div><div> </div><div> ... some non relevant code .....</div><div><br></div><div> call MatSetValuesBlocked(this%A, 4-bdim, mesh%cellGlobalAddr(iElement)-1, 4-bdim, mesh%cellGlobalAddr(iElement)-1, blockValues, INSERT_VALUES, ierr) mesh%cellGlobalAddr(iElement)-1 is an integer equal (not an array) to the block element number the block matrix <i>blockValues (3x3) </i>belongs to.<br></div><div><br></div><div>Any evident errors? </div><div><br></div><div><br></div><div><br></div><div><br></div></div>
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