// Call scotch with options from dictionary.
Foam::label Foam::ptscotchDecomp::decompose
(
const fileName& meshPath,
const List<int>& adjncy,
const List<int>& xadj,
const scalarField& cWeights,
List<int>& finalDecomp
) const
{
if (debug)
{
Pout<< "ptscotchDecomp : entering with xadj:" << xadj.size() << endl;
}
// Dump graph
if (decompositionDict_.found("ptscotchCoeffs"))
{
const dictionary& scotchCoeffs =
decompositionDict_.subDict("ptscotchCoeffs");
if (scotchCoeffs.lookupOrDefault("writeGraph", false))
{
OFstream str
(
meshPath + "_" + Foam::name(Pstream::myProcNo()) + ".dgr"
);
Pout<< "Dumping Scotch graph file to " << str.name() << endl
<< "Use this in combination with dgpart." << endl;
globalIndex globalCells(xadj.size()-1);
// Distributed graph file (.grf)
label version = 2;
str << version << nl;
// Number of files (procglbnbr)
str << Pstream::nProcs();
// My file number (procloc)
str << ' ' << Pstream::myProcNo() << nl;
// Total number of vertices (vertglbnbr)
str << globalCells.size();
// Total number of connections (edgeglbnbr)
str << ' ' << returnReduce(xadj[xadj.size()-1], sumOp<label>())
<< nl;
// Local number of vertices (vertlocnbr)
str << xadj.size()-1;
// Local number of connections (edgelocnbr)
str << ' ' << xadj[xadj.size()-1] << nl;
// Numbering starts from 0
label baseval = 0;
// 100*hasVertlabels+10*hasEdgeWeights+1*hasVertWeighs
str << baseval << ' ' << "000" << nl;
for (label cellI = 0; cellI < xadj.size()-1; cellI++)
{
label start = xadj[cellI];
label end = xadj[cellI+1];
str << end-start;
for (label i = start; i < end; i++)
{
str << ' ' << adjncy[i];
}
str << nl;
}
}
}
// Strategy
// ~~~~~~~~
// Default.
SCOTCH_Strat stradat;
check(SCOTCH_stratInit(&stradat), "SCOTCH_stratInit");
if (decompositionDict_.found("scotchCoeffs"))
{
const dictionary& scotchCoeffs =
decompositionDict_.subDict("scotchCoeffs");
string strategy;
if (scotchCoeffs.readIfPresent("strategy", strategy))
{
if (debug)
{
Info<< "ptscotchDecomp : Using strategy " << strategy << endl;
}
SCOTCH_stratDgraphMap(&stradat, strategy.c_str());
//fprintf(stdout, "S\tStrat=");
//SCOTCH_stratSave(&stradat, stdout);
//fprintf(stdout, "\n");
}
}
// Graph
// ~~~~~
List<int> velotab;
// Check for externally provided cellweights and if so initialise weights
scalar minWeights = gMin(cWeights);
if (!cWeights.empty())
{
if (minWeights <= 0)
{
WarningIn
(
"ptscotchDecomp::decompose(..)"
) << "Illegal minimum weight " << minWeights
<< endl;
}
if (cWeights.size() != xadj.size()-1)
{
FatalErrorIn
(
"ptscotchDecomp::decompose(..)"
) << "Number of cell weights " << cWeights.size()
<< " does not equal number of cells " << xadj.size()-1
<< exit(FatalError);
}
}
scalar velotabSum = gSum(cWeights)/minWeights;
scalar rangeScale(1.0);
if (Pstream::master())
{
if (velotabSum > scalar(INT_MAX - 1))
{
// 0.9 factor of safety to avoid floating point round-off in
// rangeScale tipping the subsequent sum over the integer limit.
rangeScale = 0.9*scalar(INT_MAX - 1)/velotabSum;
WarningIn
(
"ptscotchDecomp::decompose(...)"
) << "Sum of weights has overflowed integer: " << velotabSum
<< ", compressing weight scale by a factor of " << rangeScale
<< endl;
}
}
Pstream::scatter(rangeScale);
if (!cWeights.empty())
{
// Convert to integers.
velotab.setSize(cWeights.size());
forAll(velotab, i)
{
velotab[i] = int((cWeights[i]/minWeights - 1)*rangeScale) + 1;
}
