<div class="gmail_quote">On Wed, May 4, 2011 at 15:29,  <span dir="ltr"><<a href="mailto:domenico.borzacchiello@univ-st-etienne.fr">domenico.borzacchiello@univ-st-etienne.fr</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div id=":aq">               -fieldsplit_pressure_pc_type lsc \<br>
                -fieldsplit_pressure_lsc_ksp_type fgmres \<br>
                -fieldsplit_pressure_lsc_ksp_max_it 100 \<br>
                -fieldsplit_pressure_lsc_ksp_constant_null_space \<br>
                -fieldsplit_pressure_lsc_pc_type lu \<br>
                -fieldsplit_pressure_lsc_pc_factor_mat_solver_package mumps</div></blockquote></div><br><div>Perhaps this direct solve is the problem? That operator is expected to be singular due to the constant null space so a direct solve is expected to produce nonsense.</div>