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        <div><span>I was wrong with the decomposed case structure:<br><br>In case of a multicore simulation, I get a decomposed case with local data (matrix+rhs+x, neighbour processors (==rank) numbers) on each process/rank. There are no halo regions (instead the original application works with data streams to exchange processor border data). There's no global addressing available at this point. The underlying mesh is decomposed using scotch.<br><br>Is this data useable/sufficient to solve a linear system with petsc?<br><br>If so, what data structure would be required by petsc?<br><br>Klaus</span><br></div><div><br></div>
        
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                    Am Montag, 3. Dezember 2018, 15:12:58 MEZ hat Dave May <dave.mayhem23@gmail.com> Folgendes geschrieben:
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                <div><div id="yiv0349591767"><div><div><br clear="none"></div><div><br clear="none"><div class="yiv0349591767gmail_quote"><div dir="ltr">On Mon, 3 Dec 2018 at 13:52, Klaus Burkart via petsc-users <<a rel="nofollow" shape="rect" ymailto="mailto:petsc-users@mcs.anl.gov" target="_blank" href="mailto:petsc-users@mcs.anl.gov">petsc-users@mcs.anl.gov</a>> wrote:<br clear="none"></div><blockquote class="yiv0349591767gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><div><span>Hello,<br clear="none"><br clear="none">I want to solve a cfd case, after decomposition, I get a sub matrix allocated to each process. The example below shows how the data is allocated to the processes (the sample data includes only the lower parts of the matrices). Row and column addresses are local.<br clear="none"><br clear="none">What petsc program setup/concept can be used to solve multiple linear systems in parallel, one on each process? </span></div></blockquote><div><br clear="none"></div><div>Create your KSP, Mat and Vec objects  using PETSC_COMM_SELF. </div><div class="yiv0349591767yqt1323112812" id="yiv0349591767yqtfd61390"><div><br clear="none"></div><div><br clear="none"></div><blockquote class="yiv0349591767gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><div><span><br clear="none"><br clear="none">Klaus<br clear="none"><br clear="none">Sample raw data:<br clear="none"><br clear="none">process    matrix section    value                row           column<br clear="none">0        lower        1,80E-05        1        0<br clear="none">0        lower        1,80E-05        5        0<br clear="none">0        lower        1,96E-05        2        1<br clear="none">0        lower        2,20E-05        6        1<br clear="none">0        lower        1,96E-05        3        2<br clear="none">0        lower        2,20E-05        7        2<br clear="none">0        lower        1,96E-05        4        3<br clear="none">0        lower        2,20E-05        8        3<br clear="none">0        lower        2,20E-05        9        4<br clear="none">0        lower        2,20E-05        6        5<br clear="none">0        lower        1,96E-05        10        5<br clear="none">0        lower        2,44E-05        7        6<br clear="none">0        lower        2,44E-05        11        6<br clear="none">0        lower        2,44E-05        8        7<br clear="none">0        lower        2,44E-05        12        7<br clear="none">0        lower        2,44E-05        9        8<br clear="none">0        lower        2,44E-05        13        8<br clear="none">0        lower        2,44E-05        14        9<br clear="none">0        lower        2,20E-05        11        10<br clear="none">0        lower        1,96E-05        15        10<br clear="none">0        lower        2,44E-05        12        11<br clear="none">0        lower        2,44E-05        16        11<br clear="none">0        lower        2,44E-05        13        12<br clear="none">0        lower        2,44E-05        17        12<br clear="none">0        lower        2,44E-05        14        13<br clear="none">0        lower        2,44E-05        18        13<br clear="none">0        lower        2,44E-05        19        14<br clear="none">0        lower        2,20E-05        16        15<br clear="none">0        lower        1,96E-05        20        15<br clear="none">0        lower        2,44E-05        17        16<br clear="none">0        lower        2,44E-05        21        16<br clear="none">0        lower        2,44E-05        18        17<br clear="none">0        lower        2,44E-05        22        17<br clear="none">0        lower        2,44E-05        19        18<br clear="none">0        lower        2,44E-05        23        18<br clear="none">0        lower        2,44E-05        24        19<br clear="none">0        lower        2,20E-05        21        20<br clear="none">0        lower        2,44E-05        22        21<br clear="none">0        lower        2,44E-05        23        22<br clear="none">0        lower        2,44E-05        24        23<br clear="none">1        lower        2,20E-05        1        0<br clear="none">1        lower        1,96E-05        5        0<br clear="none">1        lower        2,44E-05        2        1<br clear="none">1        lower        2,44E-05        6        1<br clear="none">1        lower        2,44E-05        3        2<br clear="none">1        lower        2,44E-05        7        2<br clear="none">1        lower        2,44E-05        4        3<br clear="none">1        lower        2,44E-05        8        3<br clear="none">1        lower        2,44E-05        9        4<br clear="none">1        lower        2,20E-05        6        5<br clear="none">1        lower        1,96E-05        10        5<br clear="none">1        lower        2,44E-05        7        6<br clear="none">1        lower        2,44E-05        11        6<br clear="none">1        lower        2,44E-05        8        7<br clear="none">1        lower        2,44E-05        12        7<br clear="none">1        lower        2,44E-05        9        8<br clear="none">1        lower        2,44E-05        13        8<br clear="none">1        lower        2,44E-05        14        9<br clear="none">1        lower        2,20E-05        11        10<br clear="none">1        lower        1,96E-05        15        10<br clear="none">1        lower        2,44E-05        12        11<br clear="none">1        lower        2,44E-05        16        11<br clear="none">1        lower        2,44E-05        13        12<br clear="none">1        lower        2,44E-05        17        12<br clear="none">1        lower        2,44E-05        14        13<br clear="none">1        lower        2,44E-05        18        13<br clear="none">1        lower        2,44E-05        19        14<br clear="none">1        lower        2,20E-05        16        15<br clear="none">1        lower        1,80E-05        20        15<br clear="none">1        lower        2,44E-05        17        16<br clear="none">1        lower        2,20E-05        21        16<br clear="none">1        lower        2,44E-05        18        17<br clear="none">1        lower        2,20E-05        22        17<br clear="none">1        lower        2,44E-05        19        18<br clear="none">1        lower        2,20E-05        23        18<br clear="none">1        lower        2,20E-05        24        19<br clear="none">1        lower        1,80E-05        21        20<br clear="none">1        lower        1,96E-05        22        21<br clear="none">1        lower        1,96E-05        23        22<br clear="none">1        lower        1,96E-05        24        23<br clear="none">2        lower        1,96E-05        1        0<br clear="none">2        lower        2,20E-05        5        0<br clear="none">2        lower        1,96E-05        2        1<br clear="none">2        lower        2,20E-05        6        1<br clear="none">2        lower        1,96E-05        3        2<br clear="none">2        lower        2,20E-05        7        2<br clear="none">2        lower        1,80E-05        4        3<br clear="none">2        lower        2,20E-05        8        3<br clear="none">2        lower        1,80E-05        9        4<br clear="none">2        lower        2,44E-05        6        5<br clear="none">2        lower        2,44E-05        10        5<br clear="none">2        lower        2,44E-05        7        6<br clear="none">2        lower        2,44E-05        11        6<br clear="none">2        lower        2,44E-05        8        7<br clear="none">2        lower        2,44E-05        12        7<br clear="none">2        lower        2,20E-05        9        8<br clear="none">2        lower        2,44E-05        13        8<br clear="none">2        lower        1,96E-05        14        9<br clear="none">2        lower        2,44E-05        11        10<br clear="none">2        lower        2,44E-05        15        10<br clear="none">2        lower        2,44E-05        12        11<br clear="none">2        lower        2,44E-05        16        11<br clear="none">2        lower        2,44E-05        13        12<br clear="none">2        lower        2,44E-05        17        12<br clear="none">2        lower        2,20E-05        14        13<br clear="none">2        lower        2,44E-05        18        13<br clear="none">2        lower        1,96E-05        19        14<br clear="none">2        lower        2,44E-05        16        15<br clear="none">2        lower        2,44E-05        20        15<br clear="none">2        lower        2,44E-05        17        16<br clear="none">2        lower        2,44E-05        21        16<br clear="none">2        lower        2,44E-05        18        17<br clear="none">2        lower        2,44E-05        22        17<br clear="none">2        lower        2,20E-05        19        18<br clear="none">2        lower        2,44E-05        23        18<br clear="none">2        lower        1,96E-05        24        19<br clear="none">2        lower        2,44E-05        21        20<br clear="none">2        lower        2,44E-05        22        21<br clear="none">2        lower        2,44E-05        23        22<br clear="none">2        lower        2,20E-05        24        23<br clear="none">3        lower        2,44E-05        1        0<br clear="none">3        lower        2,44E-05        5        0<br clear="none">3        lower        2,44E-05        2        1<br clear="none">3        lower        2,44E-05        6        1<br clear="none">3        lower        2,44E-05        3        2<br clear="none">3        lower        2,44E-05        7        2<br clear="none">3        lower        2,20E-05        4        3<br clear="none">3        lower        2,44E-05        8        3<br clear="none">3        lower        1,96E-05        9        4<br clear="none">3        lower        2,44E-05        6        5<br clear="none">3        lower        2,44E-05        10        5<br clear="none">3        lower        2,44E-05        7        6<br clear="none">3        lower        2,44E-05        11        6<br clear="none">3        lower        2,44E-05        8        7<br clear="none">3        lower        2,44E-05        12        7<br clear="none">3        lower        2,20E-05        9        8<br clear="none">3        lower        2,44E-05        13        8<br clear="none">3        lower        1,96E-05        14        9<br clear="none">3        lower        2,44E-05        11        10<br clear="none">3        lower        2,44E-05        15        10<br clear="none">3        lower        2,44E-05        12        11<br clear="none">3        lower        2,44E-05        16        11<br clear="none">3        lower        2,44E-05        13        12<br clear="none">3        lower        2,44E-05        17        12<br clear="none">3        lower        2,20E-05        14        13<br clear="none">3        lower        2,44E-05        18        13<br clear="none">3        lower        1,96E-05        19        14<br clear="none">3        lower        2,44E-05        16        15<br clear="none">3        lower        2,20E-05        20        15<br clear="none">3        lower        2,44E-05        17        16<br clear="none">3        lower        2,20E-05        21        16<br clear="none">3        lower        2,44E-05        18        17<br clear="none">3        lower        2,20E-05        22        17<br clear="none">3        lower        2,20E-05        19        18<br clear="none">3        lower        2,20E-05        23        18<br clear="none">3        lower        1,80E-05        24        19<br clear="none">3        lower        1,96E-05        21        20<br clear="none">3        lower        1,96E-05        22        21<br clear="none">3        lower        1,96E-05        23        22<br clear="none">3        lower        1,80E-05        24        23<br clear="none"></span><div><br clear="none"></div><div class="yiv0349591767m_-1942437483139585720ydpd19d12bcyahoo-style-wrap" style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:10px;"></div></div></blockquote></div></div></div><div class="yiv0349591767yqt1323112812" id="yiv0349591767yqtfd92481">
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