<div dir="ltr"><div dir="ltr"><div dir="ltr"><br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Tue, 26 Mar 2019 at 10:36, Myriam Peyrounette <<a href="mailto:myriam.peyrounette@idris.fr">myriam.peyrounette@idris.fr</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div bgcolor="#FFFFFF">
<p>Oh you were right, the three options are unsused (-matptap_via
scalable, -inner_offdiag_matmatmult_via scalable and
-inner_diag_matmatmult_via scalable). Does this mean I am not
using the associated PtAP functions?</p></div></blockquote><div><br></div><div>No - not necessarily. All it means is the options were not parsed. </div><div><br></div><div>If your matrices have an option prefix associated with them (e.g. abc) , then you need to provide the option as</div><div> -abc_matptap_via scalable</div><div><br></div><div>If you are not sure if you matrices have a prefix, look at the result of -ksp_view (see below for an example)</div><div><br></div><div>
<p class="gmail-p1" style="margin:0px;font:10px Monaco;color:rgb(245,245,245);background-color:rgb(0,0,0)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures"><span class="gmail-Apple-converted-space"> </span>Mat Object: 2 MPI processes</span></p>
<p class="gmail-p1" style="margin:0px;font:10px Monaco;color:rgb(245,245,245);background-color:rgb(0,0,0)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures"><span class="gmail-Apple-converted-space"> </span>type: mpiaij</span></p>
<p class="gmail-p1" style="margin:0px;font:10px Monaco;color:rgb(245,245,245);background-color:rgb(0,0,0)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures"><span class="gmail-Apple-converted-space"> </span>rows=363, cols=363, bs=3</span></p>
<p class="gmail-p1" style="margin:0px;font:10px Monaco;color:rgb(245,245,245);background-color:rgb(0,0,0)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures"><span class="gmail-Apple-converted-space"> </span>total: nonzeros=8649, allocated nonzeros=8649</span></p>
<p class="gmail-p1" style="margin:0px;font:10px Monaco;color:rgb(245,245,245);background-color:rgb(0,0,0)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures"><span class="gmail-Apple-converted-space"> </span>total number of mallocs used during MatSetValues calls =0</span></p>
<p class="gmail-p1" style="margin:0px;font:10px Monaco;color:rgb(245,245,245);background-color:rgb(0,0,0)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures"><span class="gmail-Apple-converted-space"> </span>Mat Object: (B_) 2 MPI processes</span></p>
<p class="gmail-p1" style="margin:0px;font:10px Monaco;color:rgb(245,245,245);background-color:rgb(0,0,0)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures"><span class="gmail-Apple-converted-space"> </span>type: mpiaij</span></p>
<p class="gmail-p1" style="margin:0px;font:10px Monaco;color:rgb(245,245,245);background-color:rgb(0,0,0)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures"><span class="gmail-Apple-converted-space"> </span>rows=363, cols=363, bs=3</span></p>
<p class="gmail-p1" style="margin:0px;font:10px Monaco;color:rgb(245,245,245);background-color:rgb(0,0,0)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures"><span class="gmail-Apple-converted-space"> </span>total: nonzeros=8649, allocated nonzeros=8649</span></p>
<p class="gmail-p1" style="margin:0px;font:10px Monaco;color:rgb(245,245,245);background-color:rgb(0,0,0)"><span class="gmail-s1" style="font-variant-ligatures:no-common-ligatures"><span class="gmail-Apple-converted-space"> </span>total number of mallocs used during MatSetValues calls =0</span></p></div><div><br></div><div>The first matrix has no options prefix, but the second does and it's called "B_".</div><div><br></div><div><br></div><div><br></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 bgcolor="#FFFFFF">
<p>Myriam<br>
</p>
<br>
<div class="gmail-m_-8509232780790875615moz-cite-prefix">Le 03/26/19 à 11:10, Dave May a écrit :<br>
</div>
<blockquote type="cite">
<div dir="ltr">
<div dir="ltr"><br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Tue, 26 Mar 2019 at
09:52, Myriam Peyrounette via petsc-users <<a href="mailto:petsc-users@mcs.anl.gov" target="_blank">petsc-users@mcs.anl.gov</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div bgcolor="#FFFFFF">
<p>How can I be sure they are indeed used? Can I print
this information in some log file? <br>
</p>
</div>
</blockquote>
<div>Yes. Re-run the job with the command line option</div>
<div><br>
</div>
<div>-options_left true<br>
</div>
<div><br>
</div>
<div>This will report all options parsed, and importantly,
will also indicate if any options were unused.</div>
<div> </div>
<div><br>
</div>
<div>Thanks</div>
<div>Dave</div>
<div><br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div bgcolor="#FFFFFF">
<p> </p>
<p>Thanks in advance<br>
</p>
<p>Myriam<br>
</p>
<br>
<div class="gmail-m_-8509232780790875615gmail-m_-6197033154084460570moz-cite-prefix">Le
03/25/19 à 18:24, Matthew Knepley a écrit :<br>
</div>
<blockquote type="cite">
<div dir="ltr">
<div dir="ltr">On Mon, Mar 25, 2019 at 10:54 AM
Myriam Peyrounette via petsc-users <<a href="mailto:petsc-users@mcs.anl.gov" target="_blank">petsc-users@mcs.anl.gov</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 bgcolor="#FFFFFF">
<p>Hi,</p>
<p>thanks for the explanations. I tried the
last PETSc version (commit
fbc5705bc518d02a4999f188aad4ccff5f754cbf),
which includes the patch you talked about.
But the memory scaling shows no improvement
(see scaling attached), even when using the
"scalable" options :(</p>
<p>I had a look at the PETSc functions
MatPtAPNumeric_MPIAIJ_MPIAIJ and
MatPtAPSymbolic_MPIAIJ_MPIAIJ (especially at
the differences before and after the first
"bad" commit), but I can't find what induced
this memory issue.</p>
</div>
</blockquote>
<div>Are you sure that the option was used? It
just looks suspicious to me that they use
exactly the same amount of memory. It should be
different, even if it does not solve the
problem.</div>
<div><br>
</div>
<div> Thanks,</div>
<div><br>
</div>
<div> Matt </div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div bgcolor="#FFFFFF">
<p>Myriam<br>
</p>
<p><br>
</p>
<p><br>
</p>
<br>
<div class="gmail-m_-8509232780790875615gmail-m_-6197033154084460570gmail-m_7299408251829905453moz-cite-prefix">Le
03/20/19 à 17:38, Fande Kong a écrit :<br>
</div>
<blockquote type="cite">
<div dir="ltr">
<div dir="ltr">
<div dir="ltr">
<div dir="ltr">
<div dir="ltr">
<div dir="ltr">
<div>Hi Myriam,</div>
<div><br>
</div>
<div>There are three algorithms
in PETSc to do PtAP ( const
char *algTypes[3] =
{"scalable","nonscalable","hypre"};),
and can be specified using the
petsc options: -matptap_via
xxxx.</div>
<div><br>
</div>
<div>(1) -matptap_via hypre:
This call the hypre package to
do the PtAP trough an
all-at-once triple product. In
our experiences, it is the
most memory efficient, but
could be slow.</div>
<div><br>
</div>
<div>(2) -matptap_via scalable:
This involves a row-wise
algorithm plus an outer
product. This will use more
memory than hypre, but way
faster. This used to have a
bug that could take all your
memory, and I have a fix at <a href="https://bitbucket.org/petsc/petsc/pull-requests/1452/mpiptap-enable-large-scale-simulations/diff" target="_blank">https://bitbucket.org/petsc/petsc/pull-requests/1452/mpiptap-enable-large-scale-simulations/diff</a>.
When using this option, we may
want to have extra options
such as
-inner_offdiag_matmatmult_via
scalable
-inner_diag_matmatmult_via
scalable to select inner
scalable algorithms.</div>
<div><br>
</div>
<div>(3) -matptap_via
nonscalable: Suppose to be
even faster, but use more
memory. It does dense matrix
operations.</div>
<div><br>
</div>
<div><br>
</div>
<div>Thanks,</div>
<div><br>
</div>
<div>Fande Kong</div>
<div><br>
</div>
<div><br>
</div>
<div><br>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Wed,
Mar 20, 2019 at 10:06 AM
Myriam Peyrounette via
petsc-users <<a href="mailto:petsc-users@mcs.anl.gov" target="_blank">petsc-users@mcs.anl.gov</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div bgcolor="#FFFFFF">
<p>More precisely:
something happens when
upgrading the functions
MatPtAPNumeric_MPIAIJ_MPIAIJ and/or MatPtAPSymbolic_MPIAIJ_MPIAIJ. <br>
</p>
<p>Unfortunately, there
are a lot of differences
between the old and new
versions of these
functions. I keep
investigating but if you
have any idea, please
let me know.</p>
<p>Best,<br>
</p>
<p>Myriam<br>
</p>
<br>
<div class="gmail-m_-8509232780790875615gmail-m_-6197033154084460570gmail-m_7299408251829905453gmail-m_7961152398334556293moz-cite-prefix">Le
03/20/19 à 13:48, Myriam
Peyrounette a écrit :<br>
</div>
<blockquote type="cite">
<p>Hi all,</p>
<p>I used git bisect to
determine when the
memory need increased.
I found that the first
"bad" commit is
aa690a28a7284adb519c28cb44eae20a2c131c85.</p>
<p>Barry was right, this
commit seems to be
about an evolution of
<span class="gmail-m_-8509232780790875615gmail-m_-6197033154084460570gmail-m_7299408251829905453gmail-m_7961152398334556293blob-code-inner"><span class="gmail-m_-8509232780790875615gmail-m_-6197033154084460570gmail-m_7299408251829905453gmail-m_7961152398334556293pl-en gmail-m_-6197033154084460570gmail-m_7299408251829905453gmail-m_7961152398334556293x gmail-m_7299408251829905453gmail-m_7961152398334556293x-first gmail-m_-6197033154084460570gmail-m_7299408251829905453gmail-m_7961152398334556293x-last">MatPtAPSymbolic_MPIAIJ_MPIAIJ.
You mentioned the
option
"-matptap_via
scalable" but I
can't find any
information about
it. Can you tell
me more?</span></span></p>
<p><span class="gmail-m_-8509232780790875615gmail-m_-6197033154084460570gmail-m_7299408251829905453gmail-m_7961152398334556293blob-code-inner"><span class="gmail-m_-8509232780790875615gmail-m_-6197033154084460570gmail-m_7299408251829905453gmail-m_7961152398334556293pl-en gmail-m_-6197033154084460570gmail-m_7299408251829905453gmail-m_7961152398334556293x gmail-m_7299408251829905453gmail-m_7961152398334556293x-first gmail-m_-6197033154084460570gmail-m_7299408251829905453gmail-m_7961152398334556293x-last">Thanks</span></span></p>
<p><span class="gmail-m_-8509232780790875615gmail-m_-6197033154084460570gmail-m_7299408251829905453gmail-m_7961152398334556293blob-code-inner"><span class="gmail-m_-8509232780790875615gmail-m_-6197033154084460570gmail-m_7299408251829905453gmail-m_7961152398334556293pl-en gmail-m_-6197033154084460570gmail-m_7299408251829905453gmail-m_7961152398334556293x gmail-m_7299408251829905453gmail-m_7961152398334556293x-first gmail-m_-6197033154084460570gmail-m_7299408251829905453gmail-m_7961152398334556293x-last">Myriam</span></span></p>
<p><span class="gmail-m_-8509232780790875615gmail-m_-6197033154084460570gmail-m_7299408251829905453gmail-m_7961152398334556293blob-code-inner"><span class="gmail-m_-8509232780790875615gmail-m_-6197033154084460570gmail-m_7299408251829905453gmail-m_7961152398334556293pl-en gmail-m_-6197033154084460570gmail-m_7299408251829905453gmail-m_7961152398334556293x gmail-m_7299408251829905453gmail-m_7961152398334556293x-first gmail-m_-6197033154084460570gmail-m_7299408251829905453gmail-m_7961152398334556293x-last"></span></span></p>
<br>
<div class="gmail-m_-8509232780790875615gmail-m_-6197033154084460570gmail-m_7299408251829905453gmail-m_7961152398334556293moz-cite-prefix">Le
03/11/19 à 14:40, Mark
Adams a écrit :<br>
</div>
<blockquote type="cite">
<div dir="ltr">Is
there a difference
in memory usage on
your tiny problem? I
assume no.
<div><br>
</div>
<div>I don't see
anything that
could come from
GAMG other than
the RAP stuff that
you have discussed
already.</div>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On
Mon, Mar 11, 2019
at 9:32 AM Myriam
Peyrounette <<a href="mailto:myriam.peyrounette@idris.fr" target="_blank">myriam.peyrounette@idris.fr</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div bgcolor="#FFFFFF">
<p>The code I am
using here is
the example 42
of PETSc (<a class="gmail-m_-8509232780790875615gmail-m_-6197033154084460570gmail-m_7299408251829905453gmail-m_7961152398334556293gmail-m_4941328961016005032moz-txt-link-freetext" href="https://www.mcs.anl.gov/petsc/petsc-3.9/src/ksp/ksp/examples/tutorials/ex42.c.html" target="_blank">https://www.mcs.anl.gov/petsc/petsc-3.9/src/ksp/ksp/examples/tutorials/ex42.c.html</a>).
Indeed it
solves the
Stokes
equation. I
thought it was
a good idea to
use an example
you might know
(and didn't
find any that
uses GAMG
functions). I
just changed
the PCMG setup
so that the
memory problem
appears. And
it appears
when adding
PCGAMG.</p>
<p>I don't care
about the
performance or
even the
result
rightness
here, but only
about the
difference in
memory use
between 3.6
and 3.10. Do
you think
finding a more
adapted script
would help?<br>
</p>
<p>I used the
threshold of
0.1 only once,
at the
beginning, to
test its
influence. I
used the
default
threshold (of
0, I guess)
for all the
other runs.</p>
<p>Myriam<br>
</p>
<br>
<div class="gmail-m_-8509232780790875615gmail-m_-6197033154084460570gmail-m_7299408251829905453gmail-m_7961152398334556293gmail-m_4941328961016005032moz-cite-prefix">Le
03/11/19 à
13:52, Mark
Adams a
écrit :<br>
</div>
<blockquote type="cite">
<div dir="ltr">
<div dir="ltr">In
looking at
this larger
scale run ...
<div><br>
</div>
<div>* Your
eigen
estimates are
much lower
than your tiny
test problem.
But this is
Stokes
apparently and
it should not
work anyway.
Maybe you have
a small time
step that adds
a lot of mass
that brings
the eigen
estimates
down. And your
min eigenvalue
(not used) is
positive. I
would expect
negative for
Stokes ...</div>
<div><br>
</div>
<div>* You
seem to be
setting a
threshold
value of 0.1
-- that is
very high</div>
<div><br>
</div>
<div>* v3.6
says "using
nonzero
initial guess"
but this is
not in v3.10.
Maybe we just
stopped
printing that.</div>
<div><br>
</div>
<div>* There
were some
changes to
coasening
parameters in
going from
v3.6 but it
does not look
like your
problem was
effected. (The
coarsening
algo is
non-deterministic
by default and
you can see
small
difference on
different
runs)</div>
<div><br>
</div>
<div>* We may
have also
added a
"noisy" RHS
for eigen
estimates by
default from
v3.6.</div>
<div><br>
</div>
<div>* And for
non-symetric
problems you
can try
-pc_gamg_agg_nsmooths 0, but again GAMG is not built for Stokes anyway.</div>
<div><br>
</div>
</div>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Tue, Mar 5, 2019 at 11:53 AM Myriam Peyrounette
<<a href="mailto:myriam.peyrounette@idris.fr" target="_blank">myriam.peyrounette@idris.fr</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div bgcolor="#FFFFFF">
<p>I used
PCView to
display the
size of the
linear system
in each level
of the MG.
You'll find
the outputs
attached to
this mail (zip
file) for both
the default
threshold
value and a
value of 0.1,
and for both
3.6 and 3.10
PETSc
versions. <br>
</p>
<p>For
convenience, I
summarized the
information in
a graph, also
attached (png
file).</p>
<p>As you can
see, there are
slight
differences
between the
two versions
but none is
critical, in
my opinion. Do
you see
anything
suspicious in
the outputs?</p>
<p>+ I can't
find the
default
threshold
value. Do you
know where I
can find it?<br>
</p>
<p>Thanks for
the follow-up</p>
<p>Myriam<br>
</p>
<br>
<div class="gmail-m_-8509232780790875615gmail-m_-6197033154084460570gmail-m_7299408251829905453gmail-m_7961152398334556293gmail-m_4941328961016005032gmail-m_4553173887686987135moz-cite-prefix">Le
03/05/19 à
14:06, Matthew
Knepley a
écrit :<br>
</div>
<blockquote type="cite">
<div dir="ltr">
<div dir="ltr">On
Tue, Mar 5,
2019 at 7:14
AM Myriam
Peyrounette
<<a href="mailto:myriam.peyrounette@idris.fr" target="_blank">myriam.peyrounette@idris.fr</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 bgcolor="#FFFFFF">
<p>Hi Matt,</p>
<p>I plotted
the memory
scalings using
different
threshold
values. The
two scalings
are slightly
translated
(from -22 to
-88 mB) but
this gain is
neglectable.
The
3.6-scaling
keeps being
robust while
the
3.10-scaling
deteriorates.</p>
<p>Do you have
any other
suggestion?</p>
</div>
</blockquote>
<div>Mark,
what is the
option she can
give to output
all the GAMG
data?</div>
<div><br>
</div>
<div>Also, run
using
-ksp_view.
GAMG will
report all the
sizes of its
grids, so it
should be easy
to see</div>
<div>if the
coarse grid
sizes are
increasing,
and also what
the effect of
the threshold
value is.</div>
<div><br>
</div>
<div> Thanks,</div>
<div><br>
</div>
<div>
Matt <br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div bgcolor="#FFFFFF">
<p>Thanks<br>
</p>
Myriam <br>
<br>
<div class="gmail-m_-8509232780790875615gmail-m_-6197033154084460570gmail-m_7299408251829905453gmail-m_7961152398334556293gmail-m_4941328961016005032gmail-m_4553173887686987135gmail-m_-3242500023102749998moz-cite-prefix">Le
03/02/19 à
02:27, Matthew
Knepley a
écrit :<br>
</div>
<blockquote type="cite">
<div dir="ltr">
<div dir="ltr">
<div dir="ltr">On
Fri, Mar 1,
2019 at 10:53
AM Myriam
Peyrounette
via
petsc-users
<<a href="mailto:petsc-users@mcs.anl.gov" target="_blank">petsc-users@mcs.anl.gov</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">Hi,<br>
<br>
I used to run
my code with
PETSc 3.6.
Since I
upgraded the
PETSc version<br>
to 3.10, this
code has a bad
memory
scaling.<br>
<br>
To report this
issue, I took
the PETSc
script ex42.c
and slightly<br>
modified it so
that the KSP
and PC
configurations
are the same
as in my<br>
code. In
particular, I
use a
"personnalised"
multi-grid
method. The<br>
modifications
are indicated
by the keyword
"TopBridge" in
the attached<br>
scripts.<br>
<br>
To plot the
memory (weak)
scaling, I ran
four
calculations
for each<br>
script with
increasing
problem sizes
and
computations
cores:<br>
<br>
1. 100,000
elts on 4
cores<br>
2. 1 million
elts on 40
cores<br>
3. 10 millions
elts on 400
cores<br>
4. 100
millions elts
on 4,000 cores<br>
<br>
The resulting
graph is also
attached. The
scaling using
PETSc 3.10<br>
clearly
deteriorates
for large
cases, while
the one using
PETSc 3.6 is<br>
robust.<br>
<br>
After a few
tests, I found
that the
scaling is
mostly
sensitive to
the<br>
use of the AMG
method for the
coarse grid
(line 1780 in<br>
main_ex42_petsc36.cc). In particular, the performance strongly<br>
deteriorates
when
commenting
lines 1777 to
1790 (in
main_ex42_petsc36.cc).<br>
<br>
Do you have
any idea of
what changed
between
version 3.6
and version<br>
3.10 that may
imply such
degradation?<br>
</blockquote>
<div><br>
</div>
<div>I believe
the default
values for
PCGAMG changed
between
versions. It
sounds like
the coarsening
rate</div>
<div>is not
great enough,
so that these
grids are too
large. This
can be set
using:</div>
<div><br>
</div>
<div> <a href="https://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/PC/PCGAMGSetThreshold.html" target="_blank">https://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/PC/PCGAMGSetThreshold.html</a></div>
<div><br>
</div>
<div>There is
some
explanation of
this effect on
that page. Let
us know if
setting this
does not
correct the
situation.</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">
Let me know if
you need
further
information.<br>
<br>
Best,<br>
<br>
Myriam
Peyrounette<br>
<br>
<br>
-- <br>
Myriam
Peyrounette<br>
CNRS/IDRIS -
HLST<br>
--<br>
<br>
</blockquote>
</div>
<br clear="all">
<div><br>
</div>
-- <br>
<div dir="ltr" class="gmail-m_-8509232780790875615gmail-m_-6197033154084460570gmail-m_7299408251829905453gmail-m_7961152398334556293gmail-m_4941328961016005032gmail-m_4553173887686987135gmail-m_-3242500023102749998gmail_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="http://www.cse.buffalo.edu/%7Eknepley/" target="_blank">https://www.cse.buffalo.edu/~knepley/</a><br>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</blockquote>
<br>
<pre class="gmail-m_-8509232780790875615gmail-m_-6197033154084460570gmail-m_7299408251829905453gmail-m_7961152398334556293gmail-m_4941328961016005032gmail-m_4553173887686987135gmail-m_-3242500023102749998moz-signature" cols="72">--
Myriam Peyrounette
CNRS/IDRIS - HLST
--
</pre>
</div>
</blockquote>
</div>
<br clear="all">
<div><br>
</div>
-- <br>
<div dir="ltr" class="gmail-m_-8509232780790875615gmail-m_-6197033154084460570gmail-m_7299408251829905453gmail-m_7961152398334556293gmail-m_4941328961016005032gmail-m_4553173887686987135gmail_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="http://www.cse.buffalo.edu/%7Eknepley/" target="_blank">https://www.cse.buffalo.edu/~knepley/</a><br>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</blockquote>
<br>
<pre class="gmail-m_-8509232780790875615gmail-m_-6197033154084460570gmail-m_7299408251829905453gmail-m_7961152398334556293gmail-m_4941328961016005032gmail-m_4553173887686987135moz-signature" cols="72">--
Myriam Peyrounette
CNRS/IDRIS - HLST
--
</pre>
</div>
</blockquote>
</div>
</blockquote>
<br>
<pre class="gmail-m_-8509232780790875615gmail-m_-6197033154084460570gmail-m_7299408251829905453gmail-m_7961152398334556293gmail-m_4941328961016005032moz-signature" cols="72">--
Myriam Peyrounette
CNRS/IDRIS - HLST
--
</pre>
</div>
</blockquote>
</div>
</blockquote>
<br>
<pre class="gmail-m_-8509232780790875615gmail-m_-6197033154084460570gmail-m_7299408251829905453gmail-m_7961152398334556293moz-signature" cols="72">--
Myriam Peyrounette
CNRS/IDRIS - HLST
--
</pre>
</blockquote>
<br>
<pre class="gmail-m_-8509232780790875615gmail-m_-6197033154084460570gmail-m_7299408251829905453gmail-m_7961152398334556293moz-signature" cols="72">--
Myriam Peyrounette
CNRS/IDRIS - HLST
--
</pre>
</div>
</blockquote>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</blockquote>
<br>
<pre class="gmail-m_-8509232780790875615gmail-m_-6197033154084460570gmail-m_7299408251829905453moz-signature" cols="72">--
Myriam Peyrounette
CNRS/IDRIS - HLST
--
</pre>
</div>
</blockquote>
</div>
<br clear="all">
<div><br>
</div>
-- <br>
<div dir="ltr" class="gmail-m_-8509232780790875615gmail-m_-6197033154084460570gmail_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="http://www.cse.buffalo.edu/%7Eknepley/" target="_blank">https://www.cse.buffalo.edu/~knepley/</a><br>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</blockquote>
<br>
<pre class="gmail-m_-8509232780790875615gmail-m_-6197033154084460570moz-signature" cols="72">--
Myriam Peyrounette
CNRS/IDRIS - HLST
--
</pre>
</div>
</blockquote>
</div>
</div>
</div>
</blockquote>
<br>
<pre class="gmail-m_-8509232780790875615moz-signature" cols="72">--
Myriam Peyrounette
CNRS/IDRIS - HLST
--
</pre>
</div>
</blockquote></div></div></div>