<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<style type="text/css" style="display:none;"> P {margin-top:0;margin-bottom:0;} </style>
</head>
<body dir="ltr">
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<span style="color: rgb(50, 49, 48); font-family: "Segoe UI", "Segoe UI Web (West European)", "Segoe UI", -apple-system, system-ui, Roboto, "Helvetica Neue", sans-serif; background-color: rgb(255, 255, 255); display: inline !important">Marius,</span><br>
</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<span style="color: rgb(50, 49, 48); font-family: "Segoe UI", "Segoe UI Web (West European)", "Segoe UI", -apple-system, system-ui, Roboto, "Helvetica Neue", sans-serif; background-color: rgb(255, 255, 255); display: inline !important">C1 = Ampidense*Bmpiaij <span style="font-family: "Segoe UI", "Segoe UI Web (West European)", "Segoe UI", -apple-system, system-ui, Roboto, "Helvetica Neue", sans-serif; background-color: rgb(255, 255, 255); display: inline !important">inherits
the number of local rows from A and the number of local columns from B.</span></span></div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<span style="color: rgb(50, 49, 48); font-family: "Segoe UI", "Segoe UI Web (West European)", "Segoe UI", -apple-system, system-ui, Roboto, "Helvetica Neue", sans-serif; background-color: rgb(255, 255, 255); display: inline !important"><span style="font-family: "Segoe UI", "Segoe UI Web (West European)", "Segoe UI", -apple-system, system-ui, Roboto, "Helvetica Neue", sans-serif; background-color: rgb(255, 255, 255); display: inline !important">C2
= Ampidense*Bmpidense is computed via external package Elemental, which petsc does not dictate the parallel layout of C2 in current petsc/elemental interface. I am not sure if we can do it. Do you want C2 maintains local number of A?</span></span></div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<span style="color: rgb(50, 49, 48); font-family: "Segoe UI", "Segoe UI Web (West European)", "Segoe UI", -apple-system, system-ui, Roboto, "Helvetica Neue", sans-serif; background-color: rgb(255, 255, 255); display: inline !important"><span style="font-family: "Segoe UI", "Segoe UI Web (West European)", "Segoe UI", -apple-system, system-ui, Roboto, "Helvetica Neue", sans-serif; background-color: rgb(255, 255, 255); display: inline !important">Hong</span></span></div>
<div id="appendonsend"></div>
<div style="font-family:Calibri,Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<hr tabindex="-1" style="display:inline-block; width:98%">
<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>From:</b> petsc-users <petsc-users-bounces@mcs.anl.gov> on behalf of Stefano Zampini <stefano.zampini@gmail.com><br>
<b>Sent:</b> Sunday, April 19, 2020 11:26 AM<br>
<b>To:</b> Marius Buerkle <mbuerkle@web.de><br>
<b>Cc:</b> PETSc users list <petsc-users@mcs.anl.gov><br>
<b>Subject:</b> Re: [petsc-users] MatMatMult with MAT_INITIAL_MATRIX</font>
<div> </div>
</div>
<div>
<div dir="auto">
<div>Matrix C should always inherit the number of local rows from A and the number of local columns from B. Is it not the case for your code? If so, please provide a MWE to reproduce<br>
Also, which version of PETSc are you using?</div>
<div dir="auto"><br>
<div class="x_gmail_quote" dir="auto">
<div dir="ltr" class="x_gmail_attr">Il Dom 19 Apr 2020, 19:21 Marius Buerkle <<a href="mailto:mbuerkle@web.de">mbuerkle@web.de</a>> ha scritto:<br>
</div>
<blockquote class="x_gmail_quote" style="margin:0 0 0 .8ex; border-left:1px #ccc solid; padding-left:1ex">
<br>
Hi,<br>
<br>
I have a question about the behavior of MAT_INITIAL_MATRIX for MatMatMult. I a have a set of MPIDENSE and MPIAIJ matrices for which I have defined the number of local rows (and local columns) manually, i.e. not used PETSC_DECIDE for MatSetSizes. The number
of local rows is different from what PETSC_DECIDE would choose. If I do a MatMatMult with A=MPIDENSE and B=MPIAIJ with MAT_INITIAL_MATRIX then matrix C will have the number of local rows corresponding to A and B, namely what I have defined with MatSetSizes
when creating the matrices A and B. But when both matrices are dense, A=MPIDENSE and B=MPIDENSE, then the resulting matrix C will have different number of local rows, namely what I would get with if I would create the matrix with PETSC_DECIDE. Is this behavior
normal? The problem is that I have to multiply both resulting matrices which will then throw a "Nonconforming object sizes error" as they have different number of local rows. Any ideas what goes wrong here?<br>
<br>
<br>
Marius<br>
</blockquote>
</div>
</div>
</div>
</div>
</body>
</html>