<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">On Fri, Mar 21, 2014 at 3:33 PM, Luc Berger-Vergiat <span dir="ltr"><<a href="mailto:lb2653@columbia.edu" target="_blank">lb2653@columbia.edu</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
  
    
  
  <div bgcolor="#FFFFFF" text="#000000">
    <div>I hear you though that is not what
      petsc does.<br>
      When I name the fields as you suggest:<br>
      <blockquote>
        <div>-fieldsplit_0_fieldsplit_Field_0_fields 1<br>
        </div>
        <div>-fieldsplit_0_fieldsplit_Field_1_fields 0</div></blockquote></div></div></blockquote><div><br></div><div>I could be wrong. Is it possible to reproduce this bad behavior with SNES ex19, which has four fields?</div>
<div><br></div><div>  Thanks,</div><div><br></div><div>     Matt</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div bgcolor="#FFFFFF" text="#000000">
<div><blockquote><div>petsc ignores it and still call the fields</div></blockquote><div>
        <blockquote>-fieldsplit_0_fieldsplit_Field_2<br>
          -fieldsplit_0_fieldsplit_Field_3<br>
        </blockquote>
        But the automatic naming scheme is not really the issue. It
        would just be nice to be able to switch the two fields.<br>
        I will try to change the order in which I pass the IS to the DM
        and see if I can go around the problem that way.<br>
      </div>
      <pre cols="72">Best,
Luc</pre>
      On 03/21/2014 12:13 PM, Matthew Knepley wrote:<br>
    </div>
    <blockquote type="cite">
      <div dir="ltr">
        <div class="gmail_extra">
          <div class="gmail_quote">On Fri, Mar 21, 2014 at 9:37 AM, Luc
            Berger-Vergiat <span dir="ltr"><<a href="mailto:lb2653@columbia.edu" target="_blank">lb2653@columbia.edu</a>></span>
            wrote:<br>
            <blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
              <div bgcolor="#FFFFFF" text="#000000">
                <div>Is there a way to now what the new numbering is?<br>
                  I am assuming that in y example since there are two
                  fields only the numbers associated with them are 0 and
                  1 hence I tried:<br>
                  <blockquote>-fieldsplit_0_fieldsplit_Field_2_fields 1<br>
                    -fieldsplit_0_fieldsplit_Field_3_fields 0<br>
                  </blockquote>
                </div>
              </div>
            </blockquote>
            <div><br>
            </div>
            <div>If its an inner fieldsplit, the numbering for options
              starts over again</div>
            <div><br>
            </div>
            <div>  -fieldsplit_0_fieldsplit_Field_0_fields 1<br>
            </div>
            <div>  -fieldsplit_0_fieldsplit_Field_1_fields 0<br>
            </div>
            <div><br>
            </div>
            <div>  Thanks,</div>
            <div><br>
            </div>
            <div>     Matt</div>
            <blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
              <div bgcolor="#FFFFFF" text="#000000">
                <div>
                  <blockquote> </blockquote>
                  which did not work. As mentioned earlier, the
                  following does not work either:<br>
                  <blockquote>-fieldsplit_0_fieldsplit_Field_2_fields 3<br>
                    -fieldsplit_0_fieldsplit_Field_3_fields 2<br>
                  </blockquote>
                  and without too much expectation I also passed the
                  following<br>
                  <blockquote>-fieldsplit_0_fieldsplit_Field_2_fields
                    Field_3<br>
                    -fieldsplit_0_fieldsplit_Field_3_fields Field_2</blockquote>
                  to no avail.<br>
                  <br>
                  By the way I attached the output from -ksp_view in
                  case I might be doing something wrong?<br>
                  <br>
                  <pre cols="72">Best,
Luc</pre>
                  On 03/20/2014 09:01 PM, Matthew Knepley wrote:<br>
                </div>
                <blockquote type="cite">
                  <div dir="ltr">
                    <div class="gmail_extra">
                      <div class="gmail_quote">On Thu, Mar 20, 2014 at
                        6:20 PM, Luc Berger-Vergiat <span dir="ltr"><<a href="mailto:lb2653@columbia.edu" target="_blank">lb2653@columbia.edu</a>></span>
                        wrote:<br>
                        <blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
                          <div bgcolor="#FFFFFF" text="#000000"> Hi all,<br>
                            I am solving a four field problem using two
                            Schur complements. Here are the arguments
                            that I usually pass to PETSc to do it:<br>
                            <blockquote>-ksp_type gmres -pc_type
                              fieldsplit -pc_fieldsplit_type schur
                              -pc_fieldsplit_schur_factorization_type
                              full -pc_fieldsplit_schur_precondition
                              selfp -pc_fieldsplit_0_fields 2,3
                              -pc_fieldsplit_1_fields 0,1
                              -fieldsplit_0_ksp_type preonly
                              -fieldsplit_0_pc_type fieldsplit
                              -fieldsplit_0_pc_fieldsplit_type schur
                              -fieldsplit_0_pc_fieldsplit_schur_factorization_type
                              full
                              -fieldsplit_0_pc_fieldsplit_schur_precondition
                              selfp
                              -fieldsplit_0_fieldsplit_Field_2_fields 2
                              -fieldsplit_0_fieldsplit_Field_3_fields 3
                              -fieldsplit_0_fieldsplit_Field_2_ksp_type
                              preonly
                              -fieldsplit_0_fieldsplit_Field_2_pc_type
                              ilu
                              -fieldsplit_0_fieldsplit_Field_3_ksp_type
                              preonly
                              -fieldsplit_0_fieldsplit_Field_3_pc_type
                              jacobi -fieldsplit_1_ksp_type preonly
                              -fieldsplit_1_pc_type lu -malloc_log mlog
                              -log_summary time.log<br>
                            </blockquote>
                            One issue with this is that when I change
                            -fieldsplit_0_fieldsplit_Field_2_fields 2 to
                            -fieldsplit_0_fieldsplit_Field_2_fields 3 it
                            is ineffective, as if PETSc automatically
                            assign IS 2 to Field 2 even though it is not
                            what I want.<br>
                            Is there a way to pass the arguments
                            correctly so that PETSc goes about switching
                            the IS set of
                            -fieldsplit_0_fieldsplit_Field_2 and
                            -fieldsplit_0_fieldsplit_Field_3?<br>
                            This is crucial to me since I am using the
                            selfp option and the matrix associated to IS
                            3 is diagonal. By assigning the fields
                            correctly I can get an exact Schur
                            preconditioner and hence very fast
                            convergence. Right now my convergence is not
                            optimal because of this.<br>
                          </div>
                        </blockquote>
                        <div><br>
                        </div>
                        <div>I believe the inner Schur field statements
                          should not be using the original numbering,
                          but the inner numbering, after they have been
                          reordered.</div>
                        <div><br>
                        </div>
                        <div>   Matt</div>
                        <div> </div>
                        <blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
                          <div bgcolor="#FFFFFF" text="#000000">Thanks!<br>
                            <br>
                            Best,<br>
                            Luc<br>
                          </div>
                        </blockquote>
                      </div>
                      <br>
                      <br clear="all"><span class="HOEnZb"><font color="#888888">
                      <span><font color="#888888">
                          <div><br>
                          </div>
                          -- <br>
                          What most experimenters take for granted
                          before they begin their experiments is
                          infinitely more interesting than any results
                          to which their experiments lead.<br>
                          -- Norbert Wiener </font></span></font></span></div><span class="HOEnZb"><font color="#888888">
                  </font></span></div><span class="HOEnZb"><font color="#888888">
                </font></span></blockquote><span class="HOEnZb"><font color="#888888">
                <br>
              </font></span></div><span class="HOEnZb"><font color="#888888">
            </font></span></blockquote><span class="HOEnZb"><font color="#888888">
          </font></span></div><span class="HOEnZb"><font color="#888888">
          <br>
          <br clear="all">
          <div><br>
          </div>
          -- <br>
          What most experimenters take for granted before they begin
          their experiments is infinitely more interesting than any
          results to which their experiments lead.<br>
          -- Norbert Wiener
        </font></span></div>
      </div>
    </blockquote>
    <br>
  </div>

</blockquote></div><br><br clear="all"><div><br></div>-- <br>What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br>
-- Norbert Wiener
</div></div>