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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Thanks Jacob. In my problem the rows/columns are not contiguous. Your suggestions are also very good. I will think about how to make use it somewhere else in
my code.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Best<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Bin<o:p></o:p></span></p>
<p class="MsoNormal"><a name="_MailEndCompose"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></a></p>
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<p class="MsoNormal"><b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif"> Jacob Faibussowitsch [mailto:jacob.fai@gmail.com]
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<b>Sent:</b> Monday, 13 April 2020 11:47 PM<br>
<b>To:</b> Junchao Zhang <junchao.zhang@gmail.com><br>
<b>Cc:</b> Bin Liu <lbllm2018@hotmail.com>; petsc-users@mcs.anl.gov<br>
<b>Subject:</b> Re: [petsc-users] inserting multiple rows together into a matrix<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Also if you know that the rows/cols are contiguous <span style="color:black">(next to each other) </span>in your sparse matrix then it is recommended to use MatSetValuesBlocked as it is more efficient.<o:p></o:p></p>
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<p class="MsoNormal"><span style="color:black">Best regards,<br>
<br>
Jacob Faibussowitsch<br>
(Jacob Fai - booss - oh - vitch)<br>
Cell: (312) 694-3391<o:p></o:p></span></p>
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<p class="MsoNormal">On Apr 13, 2020, at 10:32 AM, Junchao Zhang <<a href="mailto:junchao.zhang@gmail.com">junchao.zhang@gmail.com</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal">Add two rows 2 ,4, and each row has three nonzeros at column 3, 7, 9<o:p></o:p></p>
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<p class="MsoNormal"><span style="font-family:"Courier New"">m=2;</span><o:p></o:p></p>
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<p class="MsoNormal"><span style="font-family:"Courier New"">n=3;</span><o:p></o:p></p>
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<p class="MsoNormal"><span style="font-family:"Courier New"">idxm[] = {2, 4};</span><o:p></o:p></p>
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<p class="MsoNormal"><span style="font-family:"Courier New"">idxn[] = {3, 7, 9};</span><o:p></o:p></p>
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<p class="MsoNormal"><span style="font-family:"Courier New"">v[6] = {0.1, 0.2, ....};</span><o:p></o:p></p>
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<p class="MsoNormal"><span style="font-family:"Courier New"">MatSetValues(mat, m, idxm, n, idxn,v, INSERT_VALUES);</span><o:p></o:p></p>
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<p class="MsoNormal">--Junchao Zhang<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">On Mon, Apr 13, 2020 at 9:59 AM Bin Liu <<a href="mailto:lbllm2018@hotmail.com">lbllm2018@hotmail.com</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span lang="EN-US">Hi all,</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span lang="EN-US"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span lang="EN-US">I know how to insert values in one row into the matrix via routine “MatSetValues”. I understand I logically should be able to insert multiple rows into the matrix
with one call of “MatSetValues”. However, I am not sure how to do it. I searched in the PETSc mail list and did not find a relevant question answered before. Could anyone help me and give me a simple example code?</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span lang="EN-US"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span lang="EN-US">Regards</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span lang="EN-US">B.
</span><o:p></o:p></p>
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