follow dev39, finish r_vec and p_vec in ./test/test-dev40.ipynb(refer to https://github.com/Gustavroot/MGMLMC_for_mat_with_displ/blob/main/src/build_2lvl_method_g5_comp.m). :)
follow dev39, finish r_vec and p_vec in ./test/test-dev40.ipynb(refer to https://github.com/Gustavroot/MGMLMC_for_mat_with_displ/blob/main/src/build_2lvl_method_g5_comp.m). :)