Dear Wolfgang Bangerth, Thank you for your clarification.
it is still not very clear to me why I am not getting the same mass matrix when doing this two different approaches when, as far as I understand should be the same. In order to get a 2x2 block matrix containing the mass matrix for the top left and bottom right I do the following: *Mass_matrix_tmp(i,j)+=((fe_values[real_component].value(i, q_point) * fe_values[real_component].value(j, q_point)) * fe_values.JxW(q_point));* *Mass_matrix_tmp(i,j)+=((fe_values[imag_component].value(i, q_point) * fe_values[imag_component].value(j, q_point)) * fe_values.JxW(q_point));* which gives different results compared to: * if (fe.system_to_component_index(i).first == fe.system_to_component_index(j).first)* * Mass_matrix_tmp(i,j)+= ((fe_values.shape_value(i, q_point) * fe_values.shape_value(j, q_point)) * fe_values.JxW(q_point));* Could you please clarify why this two approaches do not give the same results? Thank you again Regards, El martes, 9 de noviembre de 2021 a las 17:21:49 UTC+1, Wolfgang Bangerth escribió: > On 11/9/21 8:24 AM, Joss G. wrote: > > *Is it correct the following approach to get the global mass matrix of > > one component? *I get a big 2x2 block matrix with non-zero values on the > > left top block. Is this corresponding to the global mass matrix of one > > of the components? > > /Mass_matrix_tmp(i,j)+=((fe_values[real_component].value(i, q_point) * > > fe_values[real_component].value(j, q_point)) * fe_values.JxW(q_point));/ > > Yes, this will work. > > Best > W. > > -- > ------------------------------------------------------------------------ > Wolfgang Bangerth email: [email protected] > www: http://www.math.colostate.edu/~bangerth/ > -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/dealii/2eb79ad3-2d03-4863-a437-b371ee3d41ean%40googlegroups.com.
