dajuno

"""
Solve a simple Poisson system with a low rank update using PETSc MatCreateLRC.
The low rank update is defined at 3 boundaries with different weights, Dirichlet
BC is applied to the other boundary.

https://www.mcs.anl.gov/petsc/petsc-3.13/docs/manualpages/Mat/MatCreateLRC.html

some hints:
https://fenicsproject.discourse.group/t/add-matrix-to-assembled-matrix/122/2
https://lists.mcs.anl.gov/pipermail/petsc-users/2020-February/040228.html

dajuno

if &compatible
  set nocompatible
endif

filetype plugin indent on

" should be set before loading polyglot
let g:polyglot_disabled = ['yaml', 'latex']  " disable vim-polyglot

call plug#begin('~/.config/nvim/plugged')

dajuno

/* compile with:
 g++ -O3 -std=c++11 vec_dot.cpp -I/usr/include/openblas -fopenmp -lcblas
 
 (or clang++)
 
NOTE: 
  - in main, comment either the OpenMP or the BLAS block! using both leads to degraded performance.
  - on my TP X13 G3 with Intel i7-1260P, adding -march=native will lead to lower performance!!
  - other flags like -funroll-loops -flto -finline-functions did not seem to lead to significant performance increases
*/