Hi PETSc devs, I'm writing some C++ code that calls PETSc, and I'd like to be able to place the result of VecGetArray into an std::vector and then later call VecRestoreArray on that data, or get the same effects. It seems like the correct way to do this would be something like:
Vec x; std::vector<PetscScalar> vals, idx; int num_vals, global_offset; PetscErrorCode ierr; ... /* do some stuff to x and compute num_vals and global_offset*/ ... vals.resize(num_vals); idx.resize(num_vals); std::iota(idx.begin(), idx.end(), global_offset); ierr = VecGetValues(x, num_vals, idx.data(), vals.data());CHKERRQ(ierr); /* do stuff to vals */ ... ierr = VecSetValues(x, num_vals, idx.data(), vals.data(), [whatever insert mode]);CHKERRQ(ierr); idx.clear(); vals.clear(); Is that correct (in the sense that it does what you'd expect if you replaced the vectors with pointers to indices/data and used VecGet/RestoreArray() instead of VecGet/SetValues, and it doesn't violate any of std::vector's invariants, e.g. by reallocating its memory)? If not, is there a "normal" way to do this? Thanks! -Zane Jakobs