<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 style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
Hi Mark,</div>
<div style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
<br>
</div>
<div style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
Thanks for your reply! <br>
</div>
<div style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
<br>
</div>
<div style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
Maybe I have a misunderstanding of the documentation of KSPComputeRitz (<a href="https://petsc.org/main/docs/manualpages/KSP/KSPComputeRitz/" id="LPlnk308872">https://petsc.org/main/docs/manualpages/KSP/KSPComputeRitz/</a>). It says "-this is currently not
implemented when PETSc is built with complex numbers". <br>
</div>
<div style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
<br>
</div>
<div style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
But if it works, I will give it a try.</div>
<div style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
<br>
</div>
<div style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
Thanks,</div>
<div style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
Feng<br>
<pre><span class="n"><br></span></pre>
<pre><span class="n"><a href="https://petsc.org/main/docs/manualpages/KSP/KSPComputeRitz/"></a></span></pre>
<br>
</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> Mark Adams <mfadams@lbl.gov><br>
<b>Sent:</b> 14 July 2022 12:23<br>
<b>To:</b> feng wang <snailsoar@hotmail.com><br>
<b>Cc:</b> petsc-users@mcs.anl.gov <petsc-users@mcs.anl.gov><br>
<b>Subject:</b> Re: [petsc-users] KSPComputeRitz, GMRES, matrix with complex number</font>
<div> </div>
</div>
<div>
<div dir="ltr">Why do you say it only works with Real? You need to configure PETSc to use complex numbers and it should work.
<div>This is an advanced method and it does not have any tests, which basically says it is very experimental.</div>
<div>Don't expect it to be very robust.</div>
<div><br>
<div>Mark</div>
</div>
</div>
<br>
<div class="x_gmail_quote">
<div dir="ltr" class="x_gmail_attr">On Thu, Jul 14, 2022 at 7:19 AM feng wang <<a href="mailto:snailsoar@hotmail.com">snailsoar@hotmail.com</a>> wrote:<br>
</div>
<blockquote class="x_gmail_quote" style="margin:0px 0px 0px 0.8ex; border-left:1px solid rgb(204,204,204); padding-left:1ex">
<div dir="ltr">
<div style="font-family:Calibri,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
Dear All,</div>
<div style="font-family:Calibri,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div style="font-family:Calibri,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
I am using GMRES with complex numbers and would like to compute the Ritz values.<span> I am looking at
<a href="https://petsc.org/main/docs/manualpages/KSP/KSPComputeRitz/" target="_blank">
KSPComputeRitz</a> and it seems to me that it only works with Petsc compiled with real numbers. Is there an easy alternative way to compute Ritz values for matrices with complex numbers?</span></div>
<div style="font-family:Calibri,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
<br>
</div>
<div style="font-family:Calibri,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
Thanks,</div>
<div style="font-family:Calibri,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)">
Feng<br>
</div>
</div>
</blockquote>
</div>
</div>
</body>
</html>