<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div><br></div> Do you need the explicit sparse representation of the Kronecker product? Or do you want to apply it as an operator or solve systems with it? If the latter you can use <a href="https://petsc.org/release/docs/manualpages/Mat/MatCreateKAIJ/#matcreatekaij">https://petsc.org/release/docs/manualpages/Mat/MatCreateKAIJ/#matcreatekaij</a><div><br></div><div> Barry</div><div><br><div><font color="#b42419" face="Menlo"><span style="caret-color: rgb(180, 36, 25); font-size: 14px;"><b><br></b></span></font><div><br><blockquote type="cite"><div>On Jan 30, 2023, at 12:53 PM, Guglielmo, Tyler Hardy via petsc-users <petsc-users@mcs.anl.gov> wrote:</div><br class="Apple-interchange-newline"><div><meta charset="UTF-8"><div class="WordSection1" style="page: WordSection1; caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 18px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><div style="margin: 0in; font-size: 11pt; font-family: Calibri, sans-serif;">Hi all,<o:p></o:p></div><div style="margin: 0in; font-size: 11pt; font-family: Calibri, sans-serif;"><o:p> </o:p></div><div style="margin: 0in; font-size: 11pt; font-family: Calibri, sans-serif;">I am wondering if there is any functionality for taking Kronecker products of large sparse matrices that are parallel? MatSeqAIJKron is as close as I have found, but it seems like this does not work for parallel matrices. Any ideas here? <o:p></o:p></div><div style="margin: 0in; font-size: 11pt; font-family: Calibri, sans-serif;"><o:p> </o:p></div><div style="margin: 0in; font-size: 11pt; font-family: Calibri, sans-serif;">An option could be to make A and B sequential, compute the Kronecker product, C, then scatter C into a parallel matrix? This seems like a horribly inefficient procedure. I’m still fairly new to petsc, so thanks for patience :)!<o:p></o:p></div><div style="margin: 0in; font-size: 11pt; font-family: Calibri, sans-serif;"><o:p> </o:p></div><div style="margin: 0in; font-size: 11pt; font-family: Calibri, sans-serif;">Best,<o:p></o:p></div><div style="margin: 0in; font-size: 11pt; font-family: Calibri, sans-serif;">Tyler<span class="Apple-converted-space"> </span><o:p></o:p></div><div style="margin: 0in; font-size: 11pt; font-family: Calibri, sans-serif;"><o:p> </o:p></div><div><div><div style="margin: 0in; font-size: 11pt; font-family: Calibri, sans-serif;">+++++++++++++++++++++++++++++<o:p></o:p></div><div style="margin: 0in; font-size: 11pt; font-family: Calibri, sans-serif;">Tyler Guglielmo<o:p></o:p></div><div style="margin: 0in; font-size: 11pt; font-family: Calibri, sans-serif;">Postdoctoral Researcher<o:p></o:p></div><div style="margin: 0in; font-size: 11pt; font-family: Calibri, sans-serif;">Lawrence Livermore National Lab<o:p></o:p></div><div style="margin: 0in; font-size: 11pt; font-family: Calibri, sans-serif;">Office: 925-423-6186<o:p></o:p></div><div style="margin: 0in; font-size: 11pt; font-family: Calibri, sans-serif;">Cell: 210-480-8000<o:p></o:p></div><div style="margin: 0in; font-size: 11pt; font-family: Calibri, sans-serif;">+++++++++++++++++++++++++++++</div></div></div></div></div></blockquote></div><br></div></div></body></html>