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<DIV><SPAN class=825482612-22042010><FONT face=Arial
size=2>Hi,</FONT></SPAN></DIV>
<DIV><SPAN class=825482612-22042010><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=825482612-22042010><FONT face=Arial size=2>I'm new to these
postings. On very large cases, regardless of where I stop the debugger it
is always copying data. I've put it into a debugger because on smaller
cases it runs fine, on larger it takes a while (very long time) to get
going. The stack trace always gives something like:</FONT></SPAN></DIV>
<DIV><SPAN class=825482612-22042010><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=825482612-22042010><FONT face=Arial
size=2>memcpy</FONT></SPAN></DIV>
<DIV><SPAN class=825482612-22042010><FONT face=Arial
size=2>PetscMemCpy</FONT></SPAN></DIV>
<DIV><SPAN class=825482612-22042010><FONT face=Arial
size=2>MatSetValues_SeqAIJ</FONT></SPAN></DIV>
<DIV><SPAN class=825482612-22042010><FONT face=Arial
size=2>MatSetValues</FONT></SPAN></DIV>
<DIV><SPAN class=825482612-22042010><FONT face=Arial size=2>my own wrapper to
add values to a location within the matrix.</FONT></SPAN></DIV>
<DIV><SPAN class=825482612-22042010><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=825482612-22042010><FONT face=Arial size=2>I'm using
Seq_BAIJ. My bets are that I've got the sparsity wrong, or the
preallocation wrong, but I'm not sure why. I know this could be anything,
but has anybody got any thoughts, remember stopping the debugger at random,
regardless of the frequency always gives the above....</FONT></SPAN></DIV>
<DIV><SPAN class=825482612-22042010><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=825482612-22042010><FONT face=Arial size=2>I set up the matrix
like this</FONT></SPAN></DIV>
<DIV><SPAN class=825482612-22042010><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=825482612-22042010><FONT face=Arial size=2>
MatCreate(PETSC_COMM_SELF,&_storage);<BR>
MatSetSizes(_storage,PETSC_DECIDE,PETSC_DECIDE,numVars*numLocs,numVars*numLocs);<BR>
MatSetFromOptions(_storage);<BR>
MatSeqBAIJSetPreallocation(_storage,numVars,PETSC_NULL,sparsityStart);</FONT></SPAN></DIV>
<DIV><SPAN class=825482612-22042010><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=825482612-22042010><FONT face=Arial size=2>However, using this
makes zero difference to the speed</FONT></SPAN></DIV>
<DIV><SPAN class=825482612-22042010><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=825482612-22042010><FONT face=Arial size=2>
MatCreateSeqBAIJ(PETSC_COMM_SELF,<BR>
numVars,<BR>
numVars*numLocs,<BR>
numVars*numLocs,<BR>
0, </FONT></SPAN></DIV>
<DIV><SPAN class=825482612-22042010><FONT face=Arial
size=2> sparsityStart,</FONT></SPAN></DIV>
<DIV><SPAN class=825482612-22042010><FONT face=Arial
size=2> &_storage);</FONT></SPAN></DIV>
<DIV><SPAN class=825482612-22042010><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=825482612-22042010><FONT face=Arial size=2>It is so slow that
it has not even completed one cycle of the solver....</FONT></SPAN></DIV>
<DIV><SPAN class=825482612-22042010><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=825482612-22042010><FONT face=Arial size=2>Cheers
again,<BR>Andy</FONT></SPAN></DIV> <br>
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