<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
<style type="text/css" style="display:none;"> P {margin-top:0;margin-bottom:0;} </style>
</head>
<body dir="ltr">
<div class="elementToProof" style="font-family: "Segoe UI", "Segoe UI Web (West European)", "Segoe UI", -apple-system, "system-ui", Roboto, "Helvetica Neue", sans-serif; font-size: 15px; color: rgb(36, 36, 36);">
<span style="background-color: rgb(255, 255, 255);">Carl-Johan</span><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">,</span></div>
<div class="elementToProof"><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">You can use MatSolveTranspose() to solve
</span><span style="font-family: "Segoe UI", "Segoe UI Web (West European)", "Segoe UI", -apple-system, "system-ui", Roboto, "Helvetica Neue", sans-serif; font-size: 15px; color: rgb(36, 36, 36); background-color: rgb(255, 255, 255);">A'*x = b</span><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">.
See petsc/src/ksp/ksp/tutorials/ex79.c</span></div>
<div class="elementToProof" style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<br>
</div>
<div class="elementToProof"><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">`MatCreateTranspose()` is used if you only need a matrix that behaves like the transpose,
but don't need the storage to be changed, i.e., A and A' share same matrix storage, thus
</span><span style="font-family: "Segoe UI", "Segoe UI Web (West European)", "Segoe UI", -apple-system, "system-ui", Roboto, "Helvetica Neue", sans-serif; font-size: 15px; color: rgb(36, 36, 36); background-color: rgb(255, 255, 255);">MatGetRow()
</span><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">needs to get columns of A, which is not supported.</span></div>
<div class="elementToProof" style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<br>
</div>
<div class="elementToProof" style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Hong</div>
<div id="appendonsend"></div>
<hr style="display:inline-block;width:98%" tabindex="-1">
<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> petsc-users <petsc-users-bounces@mcs.anl.gov> on behalf of Carl-Johan Thore <carljohanthore@gmail.com><br>
<b>Sent:</b> Tuesday, April 9, 2024 6:38 AM<br>
<b>To:</b> petsc-users <petsc-users@mcs.anl.gov><br>
<b>Subject:</b> [petsc-users] MatCreateTranspose</font>
<div> </div>
</div>
<style>
<!--
#x_pfptBannerwyat4vs
{display:block!important;
visibility:visible!important;
opacity:1!important;
background-color:#D0D8DC!important;
max-width:none!important;
max-height:none!important}
-->
</style>
<div>
<div style="display:none!important; display:none; visibility:hidden; font-size:1px; color:#ffffff; line-height:1px; height:0px; max-height:0px; opacity:0; overflow:hidden">
Hi, I have a matrix A with transpose A' and would like to solve the linear system A'*x = b using the pcredistribute preconditioner. It seemed like a good idea to use MatCreateTranspose, but this leads to [0]PETSC ERROR: ---------------------
</div>
<div style="display:none!important; display:none; visibility:hidden; font-size:1px; color:#ffffff; line-height:1px; height:0px; max-height:0px; opacity:0; overflow:hidden">
ZjQcmQRYFpfptBannerStart</div>
<div dir="ltr" id="x_pfptBannerwyat4vs" style="display:block!important; text-align:left!important; margin:16px 0px 16px 0px!important; padding:8px 16px 8px 16px!important; border-radius:4px!important; min-width:200px!important; background-color:#D0D8DC!important; background-color:#D0D8DC; border-top:4px solid #90a4ae!important; border-top:4px solid #90a4ae">
<div id="x_pfptBannerwyat4vs" style="float:left!important; display:block!important; margin:0px 0px 1px 0px!important; max-width:600px!important">
<div id="x_pfptBannerwyat4vs" style="display:block!important; visibility:visible!important; background-color:#D0D8DC!important; color:#000000!important; color:#000000; font-family:'Arial',sans-serif!important; font-family:'Arial',sans-serif; font-weight:bold!important; font-weight:bold; font-size:14px!important; line-height:18px!important; line-height:18px">
This Message Is From an External Sender </div>
<div id="x_pfptBannerwyat4vs" style="display:block!important; visibility:visible!important; background-color:#D0D8DC!important; color:#000000!important; color:#000000; font-weight:normal; font-family:'Arial',sans-serif!important; font-family:'Arial',sans-serif; font-size:12px!important; line-height:18px!important; line-height:18px; margin-top:2px!important">
This message came from outside your organization. </div>
</div>
<div style="clear:both!important; display:block!important; visibility:hidden!important; line-height:0!important; font-size:0.01px!important; height:0px">
</div>
</div>
<div style="display:none!important; display:none; visibility:hidden; font-size:1px; color:#ffffff; line-height:1px; height:0px; max-height:0px; opacity:0; overflow:hidden">
ZjQcmQRYFpfptBannerEnd</div>
<div dir="ltr">Hi,<br>
<br>
I have a matrix A with transpose A' and would like to solve the linear system A'*x = b using the pcredistribute preconditioner. It seemed like a good idea to use MatCreateTranspose, but this leads to<br>
<br>
[0]PETSC ERROR: --------------------- Error Message --------------------------------------------------------------<br>
[0]PETSC ERROR: No support for this operation for this object type<br>
[0]PETSC ERROR: No method getrow for Mat of type transpose<br>
[0]PETSC ERROR: See <a href="https://urldefense.us/v3/__https://petsc.org/release/faq/__;!!G_uCfscf7eWS!bVYrcPfbXSXCcthSH37OClTgnf7RxkizULEW1ZZJ5yYG3-50366x_OFSPmOgGWEcOeFyOmAMSFewAyCnxIUg7K8W_neRPw$">
https://petsc.org/release/faq/</a> for trouble shooting.<br>
[0]PETSC ERROR: Petsc Release Version 3.21.0, unknown<br>
[0]PETSC ERROR: Configure options COPTFLAGS="-O3 -march=native" CXXOPTFLAGS="-O3 -march=native" --with-fortran-bindings=0 FOPTFLAGS="-O3 -march=native" CUDAOPTFLAGS=-O3 --with-cuda --with-cusp --with-debugging=0 --download-scalapack --download-hdf5 --download-zlib
--download-mumps --download-parmetis --download-metis --download-ptscotch --download-hypre --download-spai<br>
[0]PETSC ERROR: #1 MatGetRow() at /mnt/c/mathware/petsc/petsc-v3-21-0/src/mat/interface/matrix.c:573<br>
[0]PETSC ERROR: #2 PCSetUp_Redistribute() at /mnt/c/mathware/petsc/petsc-v3-21-0/src/ksp/pc/impls/redistribute/redistribute.c:111<br>
[0]PETSC ERROR: #3 PCSetUp() at /mnt/c/mathware/petsc/petsc-v3-21-0/src/ksp/pc/interface/precon.c:1079<br>
[0]PETSC ERROR: #4 KSPSetUp() at /mnt/c/mathware/petsc/petsc-v3-21-0/src/ksp/ksp/interface/itfunc.c:415<br>
<br>
MatTranspose is a working alternative, but MatCreateTranspose would be preferable. In principle the solution seems straightforward -- just add a getrow method -- but is it, and is it a good idea (performancewise etc)?<br>
<br>
Kind regards,<br>
Carl-Johan </div>
</div>
</body>
</html>