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<div>It works! Thank you again Matt.</div>
<div><br>
</div>
<div>Miguel</div>
<br id="lineBreakAtBeginningOfMessage">
<div><br>
<blockquote type="cite">
<div>On 24 Jan 2025, at 17:07, MIGUEL MOLINOS PEREZ <mmolinos@us.es> wrote:</div>
<br class="Apple-interchange-newline">
<div>
<div style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;">
Ohh, I wasn't aware of this function. Thank you Matt, I’ll see if that solves the problem.
<div><br>
</div>
<div>Miguel<br id="lineBreakAtBeginningOfMessage">
<div><br>
<blockquote type="cite">
<div>On 24 Jan 2025, at 17:00, Matthew Knepley <knepley@gmail.com> wrote:</div>
<br class="Apple-interchange-newline">
<div>
<div dir="ltr">
<div dir="ltr">On Fri, Jan 24, 2025 at 10:56 AM MIGUEL MOLINOS PEREZ <<a href="mailto:mmolinos@us.es">mmolinos@us.es</a>> wrote:<br>
</div>
<div class="gmail_quote gmail_quote_container">
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div>Sorry I wasn’t clear enough. By “the box is updated” I mean: I run DMGetBoundingBox and the resulting coordinates are updated according to the deformation gradient “F". </div>
</blockquote>
<div><br>
</div>
<div>Oh, if you change the periodic extent, which you are, you have to recall DMSetPeriodicity(), which is what DMGetBoundaingBox() consults for the periodic extent (because the coordinates cannot be trusted).</div>
<div><br>
</div>
<div> Thanks,</div>
<div><br>
</div>
<div> Matt</div>
<div> </div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div>
<div>Thanks,</div>
<div>Miguel<br id="m_2177750787986839080lineBreakAtBeginningOfMessage">
<div><br>
<blockquote type="cite">
<div>On 24 Jan 2025, at 16:50, Matthew Knepley <<a href="mailto:knepley@gmail.com" target="_blank">knepley@gmail.com</a>> wrote:</div>
<br>
<div>
<div dir="ltr" style="font-family:Helvetica;font-size:12px;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;text-decoration:none">
<div dir="ltr">On Fri, Jan 24, 2025 at 10:36 AM MIGUEL MOLINOS PEREZ <<a href="mailto:mmolinos@us.es" target="_blank">mmolinos@us.es</a>> wrote:<br>
</div>
<div class="gmail_quote">
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div>
<div>Thanks Matt, I tried that too, and the problem remains. The box is updated only if I set no periodic bcc.</div>
</div>
</blockquote>
<div><br>
</div>
<div>What do you mean by "The box is updated"? I am trying to understand how you test things. Clearly the coordinates are updated,</div>
<div>even in the periodic case. Thus, I need to understand the test. Once we do that, we can work backwards to the first broken thing.</div>
<div><br>
</div>
<div> Thanks,</div>
<div><br>
</div>
<div> Matt</div>
<div> </div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div>
<div>Miguel</div>
<div><br>
<blockquote type="cite">
<div>On 24 Jan 2025, at 14:20, Matthew Knepley <<a href="mailto:knepley@gmail.com" target="_blank">knepley@gmail.com</a>> wrote:</div>
<br>
<div>
<div dir="ltr" style="font-family:Helvetica;font-size:12px;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;text-decoration:none">
<div dir="ltr">On Fri, Jan 24, 2025 at 4:41 AM MIGUEL MOLINOS PEREZ <<a href="mailto:mmolinos@us.es" target="_blank">mmolinos@us.es</a>> wrote:</div>
<div class="gmail_quote">
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div>Dear Matt, the error was in the implementation of the volume expansion function. I updated it, and it works finte under finite domains. However, if I include periodic boundary conditions the volume of the cell does not accommodate the volume expansion
of the particles. The deformation gradient is not the identity… I guess I am missing the fine detail on how periodic bcc are implemented in DMDA mesh, I’m right?</div>
</blockquote>
<div><br>
</div>
<div>DMDA identifies vertices using a VecScatter to implement periodic BC. This should be insensitive to coordinates. However, I don't think the algorithm below is correct for local coordinates. You use GlobalToLocal(), which means that some global coordinate
"wins" for each local cell, so cells on the periodic boundary can be wrong. I would set the local coordinates by hand as well.</div>
<div><br>
</div>
<div> Thanks,</div>
<div><br>
</div>
<div> Matt</div>
<div> </div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div>
<div>Thanks,</div>
<div>Miguel</div>
<div><br>
</div>
<div>
<div style="color:rgb(212,212,212);background-color:rgb(30,30,30);font-family:Menlo,Monaco,"Courier New",monospace;line-height:18px;white-space:pre-wrap">
<div><span style="color:rgb(86,156,214)">static</span> <span style="color:rgb(78,201,176)">
PetscErrorCode</span> <span style="color:rgb(220,220,170)">Volumetric_Expansion_DMDA</span>(<span style="color:rgb(78,201,176)">DM</span>
<span style="color:rgb(86,156,214)">*</span> <span style="color:rgb(156,220,254)">
da</span>,</div>
<div><span style="color:rgb(86,156,214)">const</span> <span style="color:rgb(78,201,176)">
Eigen</span>::<span style="color:rgb(78,201,176)">Matrix3d</span><span style="color:rgb(86,156,214)">&</span>
<span style="color:rgb(156,220,254)">F</span>) {</div>
<br>
<div><span style="color:rgb(78,201,176)">PetscInt</span> <span style="color:rgb(156,220,254)">
i</span>, <span style="color:rgb(156,220,254)">j</span>, <span style="color:rgb(156,220,254)">
mstart</span>, <span style="color:rgb(156,220,254)">m</span>, <span style="color:rgb(156,220,254)">
nstart</span>, <span style="color:rgb(156,220,254)">n</span>, <span style="color:rgb(156,220,254)">
pstart</span>, <span style="color:rgb(156,220,254)">p</span>, <span style="color:rgb(156,220,254)">
k</span>;</div>
<div><span style="color:rgb(78,201,176)">Vec</span> <span style="color:rgb(156,220,254)">
local</span>, <span style="color:rgb(156,220,254)">global</span>;</div>
<div><span style="color:rgb(78,201,176)">DMDACoor3d</span> <span style="color:rgb(86,156,214)">
***</span><span style="color:rgb(156,220,254)">coors</span>, ***<span style="color:rgb(156,220,254)">coorslocal</span>;</div>
<div><span style="color:rgb(78,201,176)">DM</span> <span style="color:rgb(156,220,254)">
cda</span>;</div>
<br>
<div><span style="color:rgb(86,156,214)">PetscFunctionBeginUser</span>;</div>
<div><span style="color:rgb(86,156,214)">PetscCall</span>(<span style="color:rgb(220,220,170)">DMGetCoordinateDM</span>(*<span style="color:rgb(156,220,254)">da</span>, &<span style="color:rgb(156,220,254)">cda</span>));</div>
<div><span style="color:rgb(86,156,214)">PetscCall</span>(<span style="color:rgb(220,220,170)">DMGetCoordinates</span>(*<span style="color:rgb(156,220,254)">da</span>, &<span style="color:rgb(156,220,254)">global</span>));</div>
<div><span style="color:rgb(86,156,214)">PetscCall</span>(<span style="color:rgb(220,220,170)">DMGetCoordinatesLocal</span>(*<span style="color:rgb(156,220,254)">da</span>, &<span style="color:rgb(156,220,254)">local</span>));</div>
<div><span style="color:rgb(86,156,214)">PetscCall</span>(<span style="color:rgb(220,220,170)">DMDAVecGetArray</span>(<span style="color:rgb(156,220,254)">cda</span>,
<span style="color:rgb(156,220,254)">global</span>, &<span style="color:rgb(156,220,254)">coors</span>));</div>
<div><span style="color:rgb(86,156,214)">PetscCall</span>(<span style="color:rgb(220,220,170)">DMDAVecGetArrayRead</span>(<span style="color:rgb(156,220,254)">cda</span>,
<span style="color:rgb(156,220,254)">local</span>, &<span style="color:rgb(156,220,254)">coorslocal</span>));</div>
<div><span style="color:rgb(86,156,214)">PetscCall</span>(<span style="color:rgb(220,220,170)">DMDAGetCorners</span>(<span style="color:rgb(156,220,254)">cda</span>, &<span style="color:rgb(156,220,254)">mstart</span>, &<span style="color:rgb(156,220,254)">nstart</span>,
&<span style="color:rgb(156,220,254)">pstart</span>, &<span style="color:rgb(156,220,254)">m</span>, &<span style="color:rgb(156,220,254)">n</span>, &<span style="color:rgb(156,220,254)">p</span>));</div>
<div><span style="color:rgb(197,134,192)">for</span> (<span style="color:rgb(156,220,254)">i</span> =
<span style="color:rgb(156,220,254)">mstart</span>; <span style="color:rgb(156,220,254)">
i</span> < <span style="color:rgb(156,220,254)">mstart</span> + <span style="color:rgb(156,220,254)">
m</span>; <span style="color:rgb(156,220,254)">i</span>++) {</div>
<div><span style="color:rgb(197,134,192)">for</span> (<span style="color:rgb(156,220,254)">j</span> =
<span style="color:rgb(156,220,254)">nstart</span>; <span style="color:rgb(156,220,254)">
j</span> < <span style="color:rgb(156,220,254)">nstart</span> + <span style="color:rgb(156,220,254)">
n</span>; <span style="color:rgb(156,220,254)">j</span>++) {</div>
<div><span style="color:rgb(197,134,192)">for</span> (<span style="color:rgb(156,220,254)">k</span> =
<span style="color:rgb(156,220,254)">pstart</span>; <span style="color:rgb(156,220,254)">
k</span> < <span style="color:rgb(156,220,254)">pstart</span> + <span style="color:rgb(156,220,254)">
p</span>; <span style="color:rgb(156,220,254)">k</span>++) {</div>
<div><span style="color:rgb(156,220,254)">coors</span>[<span style="color:rgb(156,220,254)">k</span>][<span style="color:rgb(156,220,254)">j</span>][<span style="color:rgb(156,220,254)">i</span>].<span style="color:rgb(156,220,254)">x</span> =
<span style="color:rgb(156,220,254)">coorslocal</span>[<span style="color:rgb(156,220,254)">k</span>][<span style="color:rgb(156,220,254)">j</span>][<span style="color:rgb(156,220,254)">i</span>].<span style="color:rgb(156,220,254)">x</span> *
<span style="color:rgb(156,220,254)">F</span>(<span style="color:rgb(181,206,168)">0</span>,
<span style="color:rgb(181,206,168)">0</span>);</div>
<div><span style="color:rgb(156,220,254)">coors</span>[<span style="color:rgb(156,220,254)">k</span>][<span style="color:rgb(156,220,254)">j</span>][<span style="color:rgb(156,220,254)">i</span>].<span style="color:rgb(156,220,254)">y</span> =
<span style="color:rgb(156,220,254)">coorslocal</span>[<span style="color:rgb(156,220,254)">k</span>][<span style="color:rgb(156,220,254)">j</span>][<span style="color:rgb(156,220,254)">i</span>].<span style="color:rgb(156,220,254)">y</span> *
<span style="color:rgb(156,220,254)">F</span>(<span style="color:rgb(181,206,168)">1</span>,
<span style="color:rgb(181,206,168)">1</span>);</div>
<div><span style="color:rgb(156,220,254)">coors</span>[<span style="color:rgb(156,220,254)">k</span>][<span style="color:rgb(156,220,254)">j</span>][<span style="color:rgb(156,220,254)">i</span>].<span style="color:rgb(156,220,254)">z</span> =
<span style="color:rgb(156,220,254)">coorslocal</span>[<span style="color:rgb(156,220,254)">k</span>][<span style="color:rgb(156,220,254)">j</span>][<span style="color:rgb(156,220,254)">i</span>].<span style="color:rgb(156,220,254)">z</span> *
<span style="color:rgb(156,220,254)">F</span>(<span style="color:rgb(181,206,168)">2</span>,
<span style="color:rgb(181,206,168)">2</span>);</div>
<div>}</div>
<div>}</div>
<div>}</div>
<div><span style="color:rgb(86,156,214)">PetscCall</span>(<span style="color:rgb(220,220,170)">DMDAVecRestoreArray</span>(<span style="color:rgb(156,220,254)">cda</span>,
<span style="color:rgb(156,220,254)">global</span>, &<span style="color:rgb(156,220,254)">coors</span>));</div>
<div><span style="color:rgb(86,156,214)">PetscCall</span>(<span style="color:rgb(220,220,170)">DMDAVecRestoreArrayRead</span>(<span style="color:rgb(156,220,254)">cda</span>,
<span style="color:rgb(156,220,254)">local</span>, &<span style="color:rgb(156,220,254)">coorslocal</span>));</div>
<br>
<div><span style="color:rgb(86,156,214)">PetscCall</span>(<span style="color:rgb(220,220,170)">DMGlobalToLocalBegin</span>(<span style="color:rgb(156,220,254)">cda</span>,
<span style="color:rgb(156,220,254)">global</span>, <span style="color:rgb(79,193,255)">
INSERT_VALUES</span>, <span style="color:rgb(156,220,254)">local</span>));</div>
<div><span style="color:rgb(86,156,214)">PetscCall</span>(<span style="color:rgb(220,220,170)">DMGlobalToLocalEnd</span>(<span style="color:rgb(156,220,254)">cda</span>,
<span style="color:rgb(156,220,254)">global</span>, <span style="color:rgb(79,193,255)">
INSERT_VALUES</span>, <span style="color:rgb(156,220,254)">local</span>));</div>
<br>
<div><span style="color:rgb(86,156,214)">PetscFunctionReturn</span>(<span style="color:rgb(86,156,214)">PETSC_SUCCESS</span>);</div>
<div>}</div>
</div>
<div><br>
<blockquote type="cite">
<div>On 17 Jan 2025, at 18:01, MIGUEL MOLINOS PEREZ <<a href="mailto:mmolinos@us.es" target="_blank">mmolinos@us.es</a>> wrote:</div>
<br>
<div>
<div>You are right!! Thank you again!
<div><br>
</div>
<div>Miguel<br id="m_2177750787986839080m_-200429214972155754m_-7672759965074514727lineBreakAtBeginningOfMessage">
<div><br>
<blockquote type="cite">
<div>On Jan 17, 2025, at 5:18 PM, Matthew Knepley <<a href="mailto:knepley@gmail.com" target="_blank">knepley@gmail.com</a>> wrote:</div>
<br>
<div>
<div dir="ltr" style="font-family:Helvetica;font-size:12px;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;text-decoration:none">
<div dir="ltr">On Fri, Jan 17, 2025 at 10:49 AM MIGUEL MOLINOS PEREZ <<a href="mailto:mmolinos@us.es" target="_blank">mmolinos@us.es</a>> wrote:<br>
</div>
<div class="gmail_quote">
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div>
<div>Now the error is in the call to <span>DMSwarmMigrate</span><font><span> </span></font></div>
</div>
</blockquote>
<div><br>
</div>
<div>You have almost certainly overwritten memory somewhere. Can you use vlagrind or Address Sanitizer?</div>
<div><br>
</div>
<div> Thanks,</div>
<div><br>
</div>
<div> Matt</div>
<div> </div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div>
<div><font><span>Miguel</span></font></div>
<div><br>
</div>
<div>[0]PETSC ERROR: ------------------------------------------------------------------------</div>
<div>[0]PETSC ERROR: Caught signal number 11 SEGV: Segmentation Violation, probably memory access out of range</div>
<div>[0]PETSC ERROR: Try option -start_in_debugger or -on_error_attach_debugger</div>
<div>[0]PETSC ERROR: or see<span> </span><a href="https://urldefense.us/v3/__https://petsc.org/release/faq/*valgrind__;Iw!!G_uCfscf7eWS!cHcYc8E8heB7GrC_nkwCyiyqQGCyKWk3TmgCNKUaObDuWYXcQBRBcpn6FIP89413lopJQu1866DnIcTmBxXFRg$" target="_blank">https://petsc.org/release/faq/#valgrind</a><span> </span>and<span> </span><a href="https://urldefense.us/v3/__https://petsc.org/release/faq/__;!!G_uCfscf7eWS!cHcYc8E8heB7GrC_nkwCyiyqQGCyKWk3TmgCNKUaObDuWYXcQBRBcpn6FIP89413lopJQu1866DnIcSJj_8xog$" target="_blank">https://petsc.org/release/faq/</a></div>
<div>[0]PETSC ERROR: --------------------- Stack Frames ------------------------------------</div>
<div>[0]PETSC ERROR: The line numbers in the error traceback are not always exact.</div>
<div>[0]PETSC ERROR: #1 DMSwarmDataBucketGetSizes() at /Users/migmolper/petsc/src/dm/impls/swarm/data_bucket.c:297</div>
<div>[0]PETSC ERROR: #2 DMSwarmMigrate_CellDMScatter() at /Users/migmolper/petsc/src/dm/impls/swarm/swarm_migrate.c:201</div>
<div>[0]PETSC ERROR: #3 DMSwarmMigrate() at /Users/migmolper/petsc/src/dm/impls/swarm/swarm.c:1349</div>
<div>[0]PETSC ERROR: #4 main() at /Users/migmolper/DMD/driver-tasting-SOLERA.cpp:41</div>
<div>application called MPI_Abort(MPI_COMM_WORLD, 59) - process 0</div>
<div><br>
<blockquote type="cite">
<div>On Jan 17, 2025, at 4:22 PM, Matthew Knepley <<a href="mailto:knepley@gmail.com" target="_blank">knepley@gmail.com</a>> wrote:</div>
<br>
<div>
<div dir="ltr" style="font-family:Helvetica;font-size:12px;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;text-decoration:none">
<div dir="ltr">On Fri, Jan 17, 2025 at 10:08 AM MIGUEL MOLINOS PEREZ <<a href="mailto:mmolinos@us.es" target="_blank">mmolinos@us.es</a>> wrote:<br>
</div>
<div class="gmail_quote">
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div>
<div>Thank you Matt, this the piece of code I use to change the coordinates of the DM obtained using:</div>
</div>
</blockquote>
<div><br>
</div>
<div>You do not need the call to DMSetCoordinates(). What happens when you remove it?</div>
<div><br>
</div>
<div> Thanks,</div>
<div><br>
</div>
<div> Matt</div>
<div> </div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div>
<div><br>
</div>
<div>
<div style="color:rgb(212,212,212);background-color:rgb(30,30,30);font-family:Menlo,Monaco,"Courier New",monospace;line-height:18px;white-space:pre-wrap">
<div><span style="color:rgb(220,220,170)">DMSwarmGetCellDM</span>(<span style="color:rgb(156,220,254)">Simulation</span>.<span style="color:rgb(156,220,254)">atomistic_data</span>, &<span style="color:rgb(156,220,254)">bounding_cell</span>);</div>
<div><span style="color:rgb(220,220,170)">DMGetApplicationContext</span>(<span style="color:rgb(156,220,254)">bounding_cell</span>, &<span style="color:rgb(156,220,254)">background_mesh</span>);</div>
</div>
</div>
<div><br>
</div>
<div>Thanks,</div>
<div>Miguel</div>
<div><br>
</div>
<div style="background-color:rgb(30,30,30);font-family:Menlo,Monaco,"Courier New",monospace;line-height:18px;white-space:pre-wrap">
<div style="color:rgb(212,212,212)"><span style="color:rgb(106,153,85)">/************************************************************************/</span></div>
<font color="#d4d4d4"><br>
</font>
<div style="color:rgb(212,212,212)"><span style="color:rgb(78,201,176)">PetscErrorCode</span>
<span style="color:rgb(220,220,170)">Volumetric_Expansion</span>(<span style="color:rgb(78,201,176)">DM</span>
<span style="color:rgb(156,220,254)">dm</span>, <span style="color:rgb(86,156,214)">
const</span> <span style="color:rgb(78,201,176)">Eigen</span>::<span style="color:rgb(78,201,176)">Matrix3d</span><span style="color:rgb(86,156,214)">&</span>
<span style="color:rgb(156,220,254)">F</span>) {</div>
<div style="color:rgb(212,212,212)"><span style="color:rgb(78,201,176)">PetscErrorCode</span>
<span style="color:rgb(156,220,254)">ierr</span>;</div>
<div style="color:rgb(212,212,212)"><span style="color:rgb(78,201,176)">Vec</span>
<span style="color:rgb(156,220,254)">coordinates</span>;</div>
<div style="color:rgb(212,212,212)"><span style="color:rgb(78,201,176)">PetscScalar</span><span style="color:rgb(86,156,214)">*</span>
<span style="color:rgb(156,220,254)">coordArray</span>;</div>
<div style="color:rgb(212,212,212)"><span style="color:rgb(78,201,176)">PetscInt</span>
<span style="color:rgb(156,220,254)">xs</span>, <span style="color:rgb(156,220,254)">
ys</span>, <span style="color:rgb(156,220,254)">zs</span>, <span style="color:rgb(156,220,254)">
xm</span>, <span style="color:rgb(156,220,254)">ym</span>, <span style="color:rgb(156,220,254)">
zm</span>, <span style="color:rgb(156,220,254)">i</span>, <span style="color:rgb(156,220,254)">
j</span>, <span style="color:rgb(156,220,254)">k</span>;</div>
<div style="color:rgb(212,212,212)"><span style="color:rgb(78,201,176)">PetscInt</span>
<span style="color:rgb(156,220,254)">dim</span>, <span style="color:rgb(156,220,254)">
M</span>, <span style="color:rgb(156,220,254)">N</span>, <span style="color:rgb(156,220,254)">
P</span>;</div>
<font color="#d4d4d4"><br>
</font>
<div style="color:rgb(212,212,212)"><span style="color:rgb(156,220,254)">PetscFunctionBegin</span>;</div>
<div style="color:rgb(212,212,212)"><span style="color:rgb(106,153,85)">// Get DMDA information</span></div>
<div style="color:rgb(212,212,212)"><span style="color:rgb(156,220,254)">ierr</span> =
<span style="color:rgb(220,220,170)">DMDAGetInfo</span>(<span style="color:rgb(156,220,254)">dm</span>, &<span style="color:rgb(156,220,254)">dim</span>, &<span style="color:rgb(156,220,254)">M</span>, &<span style="color:rgb(156,220,254)">N</span>, &<span style="color:rgb(156,220,254)">P</span>,
<span style="color:rgb(86,156,214)">NULL</span>, <span style="color:rgb(86,156,214)">
NULL</span>, <span style="color:rgb(86,156,214)">NULL</span>, <span style="color:rgb(86,156,214)">
NULL</span>, <span style="color:rgb(86,156,214)">NULL</span>, <span style="color:rgb(86,156,214)">
NULL</span>,</div>
<div style="color:rgb(212,212,212)"><span style="color:rgb(86,156,214)">NULL</span>,
<span style="color:rgb(86,156,214)">NULL</span>, <span style="color:rgb(86,156,214)">
NULL</span>);</div>
<div style="color:rgb(212,212,212)"><span style="color:rgb(220,220,170)">CHKERRQ</span>(<span style="color:rgb(156,220,254)">ierr</span>);</div>
<div style="color:rgb(212,212,212)"><span style="color:rgb(156,220,254)">ierr</span> =
<span style="color:rgb(220,220,170)">DMDAGetCorners</span>(<span style="color:rgb(156,220,254)">dm</span>, &<span style="color:rgb(156,220,254)">xs</span>, &<span style="color:rgb(156,220,254)">ys</span>, &<span style="color:rgb(156,220,254)">zs</span>, &<span style="color:rgb(156,220,254)">xm</span>,
&<span style="color:rgb(156,220,254)">ym</span>, &<span style="color:rgb(156,220,254)">zm</span>);</div>
<div style="color:rgb(212,212,212)"><span style="color:rgb(220,220,170)">CHKERRQ</span>(<span style="color:rgb(156,220,254)">ierr</span>);</div>
<font color="#d4d4d4"><br>
</font>
<div style="color:rgb(212,212,212)"><span style="color:rgb(106,153,85)">// Get the coordinates vector</span></div>
<div style="color:rgb(212,212,212)"><span style="color:rgb(156,220,254)">ierr</span> =
<span style="color:rgb(220,220,170)">DMGetCoordinates</span>(<span style="color:rgb(156,220,254)">dm</span>, &<span style="color:rgb(156,220,254)">coordinates</span>);</div>
<div style="color:rgb(212,212,212)"><span style="color:rgb(220,220,170)">CHKERRQ</span>(<span style="color:rgb(156,220,254)">ierr</span>);</div>
<div style="color:rgb(212,212,212)"><span style="color:rgb(156,220,254)">ierr</span> =
<span style="color:rgb(220,220,170)">VecGetArray</span>(<span style="color:rgb(156,220,254)">coordinates</span>, &<span style="color:rgb(156,220,254)">coordArray</span>);</div>
<div style="color:rgb(212,212,212)"><span style="color:rgb(220,220,170)">CHKERRQ</span>(<span style="color:rgb(156,220,254)">ierr</span>);</div>
<font color="#d4d4d4"><br>
</font>
<div style="color:rgb(212,212,212)"><span style="color:rgb(106,153,85)">// Update the coordinates based on the desired transformation</span></div>
<div style="color:rgb(212,212,212)"><span style="color:rgb(197,134,192)">for</span> (<span style="color:rgb(156,220,254)">k</span> =
<span style="color:rgb(156,220,254)">zs</span>; <span style="color:rgb(156,220,254)">
k</span> < <span style="color:rgb(156,220,254)">zs</span> + <span style="color:rgb(156,220,254)">
zm</span>; <span style="color:rgb(156,220,254)">k</span>++) {</div>
<div style="color:rgb(212,212,212)"><span style="color:rgb(197,134,192)">for</span> (<span style="color:rgb(156,220,254)">j</span> =
<span style="color:rgb(156,220,254)">ys</span>; <span style="color:rgb(156,220,254)">
j</span> < <span style="color:rgb(156,220,254)">ys</span> + <span style="color:rgb(156,220,254)">
ym</span>; <span style="color:rgb(156,220,254)">j</span>++) {</div>
<div style="color:rgb(212,212,212)"><span style="color:rgb(197,134,192)">for</span> (<span style="color:rgb(156,220,254)">i</span> =
<span style="color:rgb(156,220,254)">xs</span>; <span style="color:rgb(156,220,254)">
i</span> < <span style="color:rgb(156,220,254)">xs</span> + <span style="color:rgb(156,220,254)">
xm</span>; <span style="color:rgb(156,220,254)">i</span>++) {</div>
<div style="color:rgb(212,212,212)"><span style="color:rgb(78,201,176)">PetscInt</span>
<span style="color:rgb(156,220,254)">idx</span> =</div>
<div style="color:rgb(212,212,212)">((<span style="color:rgb(156,220,254)">k</span> *
<span style="color:rgb(156,220,254)">N</span> + <span style="color:rgb(156,220,254)">
j</span>) * <span style="color:rgb(156,220,254)">M</span> + <span style="color:rgb(156,220,254)">
i</span>) * <span style="color:rgb(156,220,254)">dim</span>;<span style="color:rgb(106,153,85)"> // Index for the i, j, k point</span></div>
<div><font color="#d4d4d4"></font><span style="color:rgb(156,220,254)">coordArray</span><font color="#d4d4d4">[</font><span style="color:rgb(156,220,254)">idx</span><font color="#d4d4d4">] =
</font><span style="color:rgb(156,220,254)">coordArray</span><font color="#d4d4d4">[</font><span style="color:rgb(156,220,254)">idx</span><font color="#d4d4d4">] *
</font><font color="#b5cea8"><span>F(0,0)</span></font><font color="#d4d4d4">;</font><span style="color:rgb(106,153,85)"> // Update x-coordinate</span></div>
<div><span style="color:rgb(212,212,212)"><span style="color:rgb(156,220,254)">coordArray</span>[<span style="color:rgb(156,220,254)">idx</span> +
<span style="color:rgb(181,206,168)">1</span>] = <span style="color:rgb(156,220,254)">
coordArray</span>[<span style="color:rgb(156,220,254)">idx</span> + <span style="color:rgb(181,206,168)">
1</span>] * </span><font color="#b5cea8"><span>F(1,1)</span></font><font color="#d4d4d4">;</font><span style="color:rgb(106,153,85)"> // Update y-coordinate</span></div>
<div><span style="color:rgb(212,212,212)"><span style="color:rgb(156,220,254)">coordArray</span>[<span style="color:rgb(156,220,254)">idx</span> +
<span style="color:rgb(181,206,168)">2</span>] = <span style="color:rgb(156,220,254)">
coordArray</span>[<span style="color:rgb(156,220,254)">idx</span> + <span style="color:rgb(181,206,168)">
2</span>] * </span><font color="#b5cea8"><span>F(2,2)</span></font><font color="#d4d4d4">;</font><span style="color:rgb(106,153,85)"> // Update z-coordinate</span></div>
<div style="color:rgb(212,212,212)">}</div>
<div style="color:rgb(212,212,212)">}</div>
<div style="color:rgb(212,212,212)">}</div>
<font color="#d4d4d4"><br>
</font>
<div style="color:rgb(212,212,212)"><span style="color:rgb(106,153,85)">// Restore the coordinates vector</span></div>
<div style="color:rgb(212,212,212)"><span style="color:rgb(156,220,254)">ierr</span> =
<span style="color:rgb(220,220,170)">VecRestoreArray</span>(<span style="color:rgb(156,220,254)">coordinates</span>, &<span style="color:rgb(156,220,254)">coordArray</span>);</div>
<div style="color:rgb(212,212,212)"><span style="color:rgb(220,220,170)">CHKERRQ</span>(<span style="color:rgb(156,220,254)">ierr</span>);</div>
<font color="#d4d4d4"><br>
</font>
<div style="color:rgb(212,212,212)"><span style="color:rgb(106,153,85)">// Set the updated coordinates back to the DMDA</span></div>
<div style="color:rgb(212,212,212)"><span style="color:rgb(156,220,254)">ierr</span> =
<span style="color:rgb(220,220,170)">DMSetCoordinates</span>(<span style="color:rgb(156,220,254)">dm</span>,
<span style="color:rgb(156,220,254)">coordinates</span>);</div>
<div style="color:rgb(212,212,212)"><span style="color:rgb(220,220,170)">CHKERRQ</span>(<span style="color:rgb(156,220,254)">ierr</span>);</div>
<font color="#d4d4d4"><br>
</font>
<div style="color:rgb(212,212,212)"><span style="color:rgb(220,220,170)">PetscFunctionReturn</span>(<span style="color:rgb(181,206,168)">0</span>);</div>
<div style="color:rgb(212,212,212)">}</div>
<font color="#d4d4d4"><br>
</font>
<div style="color:rgb(212,212,212)"><span style="color:rgb(106,153,85)">/************************************************************************/</span></div>
</div>
<div><br>
<blockquote type="cite">
<div>On 17 Jan 2025, at 16:00, Matthew Knepley <<a href="mailto:knepley@gmail.com" target="_blank">knepley@gmail.com</a>> wrote:</div>
<br>
<div>
<div dir="ltr">
<div dir="ltr">On Fri, Jan 17, 2025 at 9:45 AM MIGUEL MOLINOS PEREZ <<a href="mailto:mmolinos@us.es" target="_blank">mmolinos@us.es</a>> wrote:<br>
</div>
<div class="gmail_quote">
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div>
<div dir="auto">
<div>I tried what you suggested, but still I got this error message. Maybe I should use main release?</div>
</div>
</div>
</blockquote>
<div><br>
</div>
<div>No. I suspect something is wrong with the way you are setting coordinates. Can you share the code?</div>
<div><br>
</div>
<div> Thanks,</div>
<div><br>
</div>
<div> Matt</div>
<div> </div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div>
<div dir="auto">
<div>Miguel</div>
<div>
<div style="font-family:Helvetica;font-size:12px;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;text-decoration:none">
<br>
</div>
<div style="font-family:Helvetica;font-size:12px;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;text-decoration:none">
<div>[4]PETSC ERROR: ------------------------------------------------------------------------</div>
<div>[4]PETSC ERROR: Caught signal number 11 SEGV: Segmentation Violation, probably memory access out of range</div>
<div>[4]PETSC ERROR: Try option -start_in_debugger or -on_error_attach_debugger</div>
<div>[4]PETSC ERROR: or see<span> </span><a href="https://urldefense.us/v3/__https://petsc.org/release/faq/*valgrind__;Iw!!G_uCfscf7eWS!cHcYc8E8heB7GrC_nkwCyiyqQGCyKWk3TmgCNKUaObDuWYXcQBRBcpn6FIP89413lopJQu1866DnIcTmBxXFRg$" target="_blank">https://petsc.org/release/faq/#valgrind</a><span> </span>and<span> </span><a href="https://urldefense.us/v3/__https://petsc.org/release/faq/__;!!G_uCfscf7eWS!cHcYc8E8heB7GrC_nkwCyiyqQGCyKWk3TmgCNKUaObDuWYXcQBRBcpn6FIP89413lopJQu1866DnIcSJj_8xog$" target="_blank">https://petsc.org/release/faq/</a></div>
<div>[4]PETSC ERROR: --------------------- Stack Frames ------------------------------------</div>
<div>[4]PETSC ERROR: The line numbers in the error traceback are not always exact.</div>
<div>[4]PETSC ERROR: #1 Pack_PetscReal_1_0() at /Users/migmolper/petsc/src/vec/is/sf/impls/basic/sfpack.c:373</div>
<div>[4]PETSC ERROR: #2 PetscSFLinkPackRootData_Private() at /Users/migmolper/petsc/src/vec/is/sf/impls/basic/sfpack.c:932</div>
<div>[4]PETSC ERROR: #3 PetscSFLinkPackRootData() at /Users/migmolper/petsc/src/vec/is/sf/impls/basic/sfpack.c:966</div>
<div>[4]PETSC ERROR: #4 PetscSFBcastBegin_Basic() at /Users/migmolper/petsc/src/vec/is/sf/impls/basic/sfbasic.c:357</div>
<div>[4]PETSC ERROR: #5 PetscSFBcastWithMemTypeBegin() at /Users/migmolper/petsc/src/vec/is/sf/interface/sf.c:1513</div>
<div>[4]PETSC ERROR: #6 VecScatterBegin_Internal() at /Users/migmolper/petsc/src/vec/is/sf/interface/vscat.c:70</div>
<div>[4]PETSC ERROR: #7 VecScatterBegin() at /Users/migmolper/petsc/src/vec/is/sf/interface/vscat.c:1316</div>
<div>[4]PETSC ERROR: #8 DMGlobalToLocalBegin_DA() at /Users/migmolper/petsc/src/dm/impls/da/dagtol.c:15</div>
<div>[4]PETSC ERROR: #9 DMGlobalToLocalBegin() at /Users/migmolper/petsc/src/dm/interface/dm.c:2844</div>
<div>[4]PETSC ERROR: #10 DMGetCoordinatesLocalSetUp() at /Users/migmolper/petsc/src/dm/interface/dmcoordinates.c:565</div>
<div>[4]PETSC ERROR: #11 DMGetCoordinatesLocal() at /Users/migmolper/petsc/src/dm/interface/dmcoordinates.c:599</div>
<div>[4]PETSC ERROR: #12 _DMLocatePoints_DMDARegular_IS() at /Users/migmolper/DMD/SOLERA/Atoms/Atom.cpp:531</div>
<div>[4]PETSC ERROR: #13 DMLocatePoints_DMDARegular() at /Users/migmolper/DMD/SOLERA/Atoms/Atom.cpp:586</div>
<div>[4]PETSC ERROR: #14 DMLocatePoints() at /Users/migmolper/petsc/src/dm/interface/dmcoordinates.c:1194</div>
<div>[4]PETSC ERROR: #15 DMSwarmMigrate_CellDMScatter() at /Users/migmolper/petsc/src/dm/impls/swarm/swarm_migrate.c:219</div>
<div>[4]PETSC ERROR: #16 DMSwarmMigrate() at /Users/migmolper/petsc/src/dm/impls/swarm/swarm.c:1349</div>
<div>[4]PETSC ERROR: #17 main() at /Users/migmolper/DMD/driver-tasting-SOLERA.cpp:41</div>
<br>
<br>
<br>
</div>
</div>
<div>
<blockquote type="cite">
<div>On Jan 15, 2025, at 4:56 PM, MIGUEL MOLINOS PEREZ <<a href="mailto:mmolinos@us.es" target="_blank">mmolinos@us.es</a>> wrote:</div>
<br>
<div>
<div>Thank you Matt for the useful info. I’ll try your idea.
<div><br>
</div>
<div>Miguel</div>
<div>
<div><br>
<blockquote type="cite">
<div>On 15 Jan 2025, at 16:48, Matthew Knepley <<a href="mailto:knepley@gmail.com" target="_blank">knepley@gmail.com</a>> wrote:</div>
<br>
<div>
<div dir="ltr" style="font-family:Helvetica;font-size:12px;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;text-decoration:none">
<div dir="ltr">On Wed, Jan 15, 2025 at 10:41 AM MIGUEL MOLINOS PEREZ <<a href="mailto:mmolinos@us.es" target="_blank">mmolinos@us.es</a>> wrote:</div>
<div class="gmail_quote">
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div>
<div>Thank you Matt.</div>
<div><br>
</div>
<div>Yes, I am getting the "CellDM" from the DMSwarm.</div>
<br>
<div>
<blockquote type="cite">
<div>
<div dir="ltr">
<div class="gmail_quote">
<div>1. I have recently overhauled this functionality because it was not flexible enough for the plasma simulation we do. Thus main and release work differently.</div>
</div>
</div>
</div>
</blockquote>
<div><br>
</div>
<div>Nice to hear that. Should I move to main?</div>
</div>
</div>
</blockquote>
<div><br>
</div>
<div>The changes allow you to have several cell DMs. I want to bin particles in space, but also in velocity, and then in the tensor product of space and velocity. Moreover, sometimes I want to use different Swarm fields as the DM field for the solver. You can
do all that with main now. If you just need a single DM with the same DM fields, release is fine.</div>
<div> </div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div>
<div>
<blockquote type="cite">
<div>
<div dir="ltr">
<div class="gmail_quote">
<div>2. I assume you are using release</div>
</div>
</div>
</div>
</blockquote>
<div><br>
</div>
<div>You are correct. </div>
<br>
<blockquote type="cite">
<div>
<div dir="ltr">
<div class="gmail_quote">
<div>3. In both main and release, if you change the coordinates of your CellDM mesh, you need to rebin the particles. The easiest way to do this is to call DMSwarmMigrate(sw, PETSC_FALSE).</div>
</div>
</div>
</div>
</blockquote>
<div><br>
</div>
<div>What do you mean by rebin?</div>
</div>
</div>
</blockquote>
<div><br>
</div>
<div>When you provide the cell DM, Swrm makes a "sort context" that bins the particles into DM cells. If you change the coordinates, this binning will change, so you need it to "rebin" or recreate the sort context.</div>
<div><br>
</div>
<div> Thanks,</div>
<div><br>
</div>
<div> Matt</div>
<div> </div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div>
<div>
<div>Miguel</div>
<div><br>
</div>
<br>
<blockquote type="cite">
<div>
<div dir="ltr">
<div class="gmail_quote">
<div> Thanks,</div>
<div><br>
</div>
<div> Matt</div>
<div> </div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
Best,<br>
Miguel<br>
</blockquote>
</div>
<span class="gmail_signature_prefix">--<span> </span></span><br>
<div dir="ltr" class="gmail_signature">
<div dir="ltr">
<div>
<div dir="ltr">
<div>
<div dir="ltr">
<div>What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br>
-- Norbert Wiener</div>
<div><br>
</div>
<div><a href="https://urldefense.us/v3/__http://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!cHcYc8E8heB7GrC_nkwCyiyqQGCyKWk3TmgCNKUaObDuWYXcQBRBcpn6FIP89413lopJQu1866DnIcTjNgNiRQ$" target="_blank">https://www.cse.buffalo.edu/~knepley/</a><br>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</blockquote>
</div>
<br>
</div>
</blockquote>
</div>
<div><br clear="all">
</div>
<div><br>
</div>
<span class="gmail_signature_prefix">--<span> </span></span><br>
<div dir="ltr" class="gmail_signature">
<div dir="ltr">
<div>
<div dir="ltr">
<div>
<div dir="ltr">
<div>What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br>
-- Norbert Wiener</div>
<div><br>
</div>
<div><a href="https://urldefense.us/v3/__http://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!cHcYc8E8heB7GrC_nkwCyiyqQGCyKWk3TmgCNKUaObDuWYXcQBRBcpn6FIP89413lopJQu1866DnIcTjNgNiRQ$" target="_blank">https://www.cse.buffalo.edu/~knepley/</a></div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</blockquote>
</div>
<br>
</div>
</div>
</div>
</blockquote>
</div>
<br>
</div>
</div>
</blockquote>
</div>
<div><br clear="all">
</div>
<div><br>
</div>
<span class="gmail_signature_prefix">--<span> </span></span><br>
<div dir="ltr" class="gmail_signature">
<div dir="ltr">
<div>
<div dir="ltr">
<div>
<div dir="ltr">
<div>What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br>
-- Norbert Wiener</div>
<div><br>
</div>
<div><a href="https://urldefense.us/v3/__http://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!cHcYc8E8heB7GrC_nkwCyiyqQGCyKWk3TmgCNKUaObDuWYXcQBRBcpn6FIP89413lopJQu1866DnIcTjNgNiRQ$" target="_blank">https://www.cse.buffalo.edu/~knepley/</a><br>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</blockquote>
</div>
<br>
</div>
</blockquote>
</div>
<div><br clear="all">
</div>
<div><br>
</div>
<span class="gmail_signature_prefix">--<span> </span></span><br>
<div dir="ltr" class="gmail_signature">
<div dir="ltr">
<div>
<div dir="ltr">
<div>
<div dir="ltr">
<div>What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br>
-- Norbert Wiener</div>
<div><br>
</div>
<div><a href="https://urldefense.us/v3/__http://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!cHcYc8E8heB7GrC_nkwCyiyqQGCyKWk3TmgCNKUaObDuWYXcQBRBcpn6FIP89413lopJQu1866DnIcTjNgNiRQ$" target="_blank">https://www.cse.buffalo.edu/~knepley/</a></div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</blockquote>
</div>
<br>
</div>
</blockquote>
</div>
<div><br clear="all">
</div>
<div><br>
</div>
<span class="gmail_signature_prefix">--<span> </span></span><br>
<div dir="ltr" class="gmail_signature">
<div dir="ltr">
<div>
<div dir="ltr">
<div>
<div dir="ltr">
<div>What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br>
-- Norbert Wiener</div>
<div><br>
</div>
<div><a href="https://urldefense.us/v3/__http://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!cHcYc8E8heB7GrC_nkwCyiyqQGCyKWk3TmgCNKUaObDuWYXcQBRBcpn6FIP89413lopJQu1866DnIcTjNgNiRQ$" target="_blank">https://www.cse.buffalo.edu/~knepley/</a></div>
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<span class="gmail_signature_prefix">--<span> </span></span><br>
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<div>What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br>
-- Norbert Wiener</div>
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<div><a href="https://urldefense.us/v3/__http://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!cHcYc8E8heB7GrC_nkwCyiyqQGCyKWk3TmgCNKUaObDuWYXcQBRBcpn6FIP89413lopJQu1866DnIcTjNgNiRQ$" target="_blank">https://www.cse.buffalo.edu/~knepley/</a></div>
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<div>What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br>
-- Norbert Wiener</div>
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</div>
<div><a href="https://urldefense.us/v3/__http://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!cHcYc8E8heB7GrC_nkwCyiyqQGCyKWk3TmgCNKUaObDuWYXcQBRBcpn6FIP89413lopJQu1866DnIcTjNgNiRQ$" target="_blank">https://www.cse.buffalo.edu/~knepley/</a></div>
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<span class="gmail_signature_prefix">-- </span><br>
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<div>What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br>
-- Norbert Wiener</div>
<div><br>
</div>
<div><a href="https://urldefense.us/v3/__http://www.cse.buffalo.edu/*knepley/__;fg!!G_uCfscf7eWS!cHcYc8E8heB7GrC_nkwCyiyqQGCyKWk3TmgCNKUaObDuWYXcQBRBcpn6FIP89413lopJQu1866DnIcTjNgNiRQ$" target="_blank">https://www.cse.buffalo.edu/~knepley/</a><br>
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