bool ScaffoldDistanceRefinementVisitor::visit(ScaffoldGraph* /*pGraph*/, ScaffoldVertex* pVertex)
{
for(size_t idx = 0; idx < ED_COUNT; idx++)
{
EdgeDir dir = EDGE_DIRECTIONS[idx];
ScaffoldEdgePtrVector edgeVec = pVertex->getEdges(dir);
for(size_t i = 0; i < edgeVec.size(); ++i)
{
Vertex* pX = m_pStringGraph->getVertex(edgeVec[i]->getStartID());
Vertex* pY = m_pStringGraph->getVertex(edgeVec[i]->getEndID());
assert(pX != NULL && pY != NULL);
SGWalkVector walks;
SGSearch::findWalks(pX, pY, edgeVec[i]->getDir(), edgeVec[i]->getDistance() + pY->getSeqLen() + 1000, true, 100000, walks);
// Select the walk closest to the distance estimate
if(walks.size() > 0)
{
int closest = std::numeric_limits<int>::max();
int est = edgeVec[i]->getDistance();
size_t idx = -1;
for(size_t j = 0; j < walks.size(); ++j)
{
int diff = abs(walks[j].getEndToStartDistance() - est);
if(diff < closest)
{
closest = diff;
idx = j;
}
}
printf("%s -> %s\t%d\t%d\t%s\n", pX->getID().c_str(),
pY->getID().c_str(),
edgeVec[i]->getDistance(),
walks[idx].getEndToStartDistance(),
walks[idx].pathSignature().c_str());
}
else
{
printf("%s -> %s\t%d\tN/A\n", pX->getID().c_str(), pY->getID().c_str(), edgeVec[i]->getDistance());
}
}
}
return false;
}
// Attempt to resolve a scaffold link by finding a walk through the graph linking the two vertices
bool ScaffoldRecord::graphResolve(const ResolveParams& params, const std::string& startID,
const ScaffoldLink& link, std::string& outExtensionString) const
{
assert(params.pGraph != NULL);
// Get the vertex to start the search from
Vertex* pStartVertex = params.pGraph->getVertex(startID);
Vertex* pEndVertex = params.pGraph->getVertex(link.endpointID);
assert(pStartVertex != NULL && pEndVertex != NULL);
int threshold = static_cast<int>(params.distanceFactor * link.stdDev);
int maxDistance = link.distance + threshold;
int maxExtensionDistance = maxDistance + pEndVertex->getSeqLen();
SGWalkVector walks;
SGSearch::findWalks(pStartVertex, pEndVertex, link.getDir(), maxExtensionDistance, 10000, true, walks);
int numWalksValid = 0;
int numWalksClosest = 0;
int selectedIdx = -1;
int closestDist = std::numeric_limits<int>::max();
#ifdef DEBUGRESOLVE
std::cout << "Attempting graph resolve of link " << startID << " -- " << link.endpointID << " expected distance: " << link.distance << " orientation: " << link.edgeData.getComp() << "\n";
#endif
// Select the closest walk to the distance estimate
for(size_t i = 0; i < walks.size(); ++i)
{
// Check that the orientation of the walk is the same as the expected link
std::vector<EdgeComp> vertexOrientations = walks[i].getOrientationsToStart();
assert(walks[i].getLastEdge()->getEndID() == link.endpointID);
if(vertexOrientations.back() != link.edgeData.getComp())
{
#ifdef DEBUGRESOLVE
std::cout << "SKIPPING WALK OF THE WRONG ORIENTATION\n";
#endif
continue;
}
int walkDistance = walks[i].getEndToStartDistance();
int diff = abs(abs(link.distance - walkDistance));
if(diff <= threshold)
{
#ifdef DEBUGRESOLVE
std::cout << " Walk distance: " << walkDistance << " diff: " << diff << " threshold: " << threshold << " close: " << closestDist << "\n";
#endif
++numWalksValid;
if(diff < closestDist)
{
selectedIdx = i;
closestDist = diff;
numWalksClosest = 1;
}
else if(diff == closestDist)
{
numWalksClosest += 1;
}
}
}
// Choose the best path, if any, depending on the algorithm to use
bool useWalk = false;
if(numWalksValid > 0)
{
if(params.resolveMask & RESOLVE_GRAPH_BEST)
{
// If the unique flag is not set, or we only have 1 closest walk, select it
if(!(params.resolveMask & RESOLVE_GRAPH_UNIQUE) || numWalksClosest == 1)
useWalk = true;
else if((params.resolveMask & RESOLVE_GRAPH_UNIQUE) && numWalksClosest > 1)
params.pStats->graphWalkTooMany += 1;
}
else
{
if(numWalksValid == 1)
useWalk = true;
else if(numWalksValid > 1)
params.pStats->graphWalkTooMany += 1;
}
}
#ifdef DEBUGRESOLVE
std::cout << " Num walks: " << walks.size() << " Num valid: " << numWalksValid << " Num closest: " << numWalksClosest << " using: " << useWalk << "\n";
#endif
// Was an acceptable walk found?
if(useWalk)
{
assert(selectedIdx != -1);
outExtensionString = walks[selectedIdx].getString(SGWT_EXTENSION);
params.pStats->graphWalkFound += 1;
// Mark all vertices in the walk as visited
VertexPtrVec vertexPtrVector = walks[selectedIdx].getVertices();
for(size_t i = 0; i < vertexPtrVector.size(); ++i)
params.pSequenceCollection->setPlaced(vertexPtrVector[i]->getID());
return true;
}
else
{
if(numWalksValid == 0)
params.pStats->graphWalkNoPath += 1;
assert(outExtensionString.empty());
return false;
}
}
bool SGSmoothingVisitor::visit(StringGraph* pGraph, Vertex* pVertex)
{
(void)pGraph;
if(pVertex->getColor() == GC_RED)
return false;
bool found = false;
for(size_t idx = 0; idx < ED_COUNT; idx++)
{
EdgeDir dir = EDGE_DIRECTIONS[idx];
EdgePtrVec edges = pVertex->getEdges(dir);
if(edges.size() <= 1)
continue;
for(size_t i = 0; i < edges.size(); ++i)
{
if(edges[i]->getEnd()->getColor() == GC_RED)
return false;
}
//std::cout << "Smoothing " << pVertex->getID() << "\n";
const int MAX_WALKS = 10;
const int MAX_DISTANCE = 5000;
bool bIsDegenerate = false;
bool bFailGapCheck = false;
bool bFailDivergenceCheck = false;
bool bFailIndelSizeCheck = false;
SGWalkVector variantWalks;
SGSearch::findVariantWalks(pVertex, dir, MAX_DISTANCE, MAX_WALKS, variantWalks);
if(variantWalks.size() > 0)
{
found = true;
size_t selectedIdx = -1;
size_t selectedCoverage = 0;
// Calculate the minimum amount overlapped on the start/end vertex.
// This is used to properly extract the sequences from walks that represent the variation.
int minOverlapX = std::numeric_limits<int>::max();
int minOverlapY = std::numeric_limits<int>::max();
for(size_t i = 0; i < variantWalks.size(); ++i)
{
if(variantWalks[i].getNumEdges() <= 1)
bIsDegenerate = true;
// Calculate the walk coverage using the internal vertices of the walk.
// The walk with the highest coverage will be retained
size_t walkCoverage = 0;
for(size_t j = 1; j < variantWalks[i].getNumVertices() - 1; ++j)
walkCoverage += variantWalks[i].getVertex(j)->getCoverage();
if(walkCoverage > selectedCoverage || selectedCoverage == 0)
{
selectedIdx = i;
selectedCoverage = walkCoverage;
}
Edge* pFirstEdge = variantWalks[i].getFirstEdge();
Edge* pLastEdge = variantWalks[i].getLastEdge();
if((int)pFirstEdge->getMatchLength() < minOverlapX)
minOverlapX = pFirstEdge->getMatchLength();
if((int)pLastEdge->getTwin()->getMatchLength() < minOverlapY)
minOverlapY = pLastEdge->getTwin()->getMatchLength();
}
// Calculate the strings for each walk that represent the region of variation
StringVector walkStrings;
for(size_t i = 0; i < variantWalks.size(); ++i)
{
Vertex* pStartVertex = variantWalks[i].getStartVertex();
Vertex* pLastVertex = variantWalks[i].getLastVertex();
assert(pStartVertex != NULL && pLastVertex != NULL);
std::string full = variantWalks[i].getString(SGWT_START_TO_END);
int posStart = 0;
int posEnd = 0;
if(dir == ED_ANTISENSE)
{
// pLast -----------
// pStart ------------
// full --------------------
// out ----
posStart = pLastVertex->getSeqLen() - minOverlapY;
posEnd = full.size() - (pStartVertex->getSeqLen() - minOverlapX);
}
else
{
// pStart --------------
// pLast -----------
// full ---------------------
// out ----
posStart = pStartVertex->getSeqLen() - minOverlapX; // match start position
posEnd = full.size() - (pLastVertex->getSeqLen() - minOverlapY); // match end position
}
std::string out;
if(posEnd > posStart)
out = full.substr(posStart, posEnd - posStart);
walkStrings.push_back(out);
}
assert(selectedIdx != (size_t)-1);
SGWalk& selectedWalk = variantWalks[selectedIdx];
assert(selectedWalk.isIndexed());
// Check the divergence of the other walks to this walk
StringVector cigarStrings;
std::vector<int> maxIndel;
std::vector<double> gapPercent; // percentage of matching that is gaps
std::vector<double> totalPercent; // percent of total alignment that is mismatch or gap
cigarStrings.resize(variantWalks.size());
gapPercent.resize(variantWalks.size());
totalPercent.resize(variantWalks.size());
maxIndel.resize(variantWalks.size());
for(size_t i = 0; i < variantWalks.size(); ++i)
{
if(i == selectedIdx)
continue;
// We want to compute the total gap length, total mismatches and percent
// divergence between the two paths.
int matchLen = 0;
int totalDiff = 0;
int gapLength = 0;
int maxGapLength = 0;
// We have to handle the degenerate case where one internal string has zero length
// this can happen when there is an isolated insertion/deletion and the walks are like:
// x -> y -> z
// x -> z
if(walkStrings[selectedIdx].empty() || walkStrings[i].empty())
{
matchLen = std::max(walkStrings[selectedIdx].size(), walkStrings[i].size());
totalDiff = matchLen;
gapLength = matchLen;
}
else
{
AlnAln *aln_global;
aln_global = aln_stdaln(walkStrings[selectedIdx].c_str(), walkStrings[i].c_str(), &aln_param_blast, 1, 1);
// Calculate the alignment parameters
while(aln_global->outm[matchLen] != '\0')
{
if(aln_global->outm[matchLen] == ' ')
totalDiff += 1;
matchLen += 1;
}
std::stringstream cigarSS;
for (int j = 0; j != aln_global->n_cigar; ++j)
{
char cigarOp = "MID"[aln_global->cigar32[j]&0xf];
int cigarLen = aln_global->cigar32[j]>>4;
if(cigarOp == 'I' || cigarOp == 'D')
{
gapLength += cigarLen;
if(gapLength > maxGapLength)
maxGapLength = gapLength;
}
cigarSS << cigarLen;
cigarSS << cigarOp;
}
cigarStrings[i] = cigarSS.str();
aln_free_AlnAln(aln_global);
}
double percentDiff = (double)totalDiff / matchLen;
double percentGap = (double)gapLength / matchLen;
if(percentDiff > m_maxTotalDivergence)
bFailDivergenceCheck = true;
if(percentGap > m_maxGapDivergence)
bFailGapCheck = true;
if(maxGapLength > m_maxIndelLength)
bFailIndelSizeCheck = true;
gapPercent[i] = percentGap;
totalPercent[i] = percentDiff;
maxIndel[i] = maxGapLength;
}
if(bIsDegenerate || bFailGapCheck || bFailDivergenceCheck || bFailIndelSizeCheck)
continue;
// Write the selected path to the variants file as variant 0
int variantIdx = 0;
std::string selectedSequence = selectedWalk.getString(SGWT_START_TO_END);
std::stringstream ss;
ss << "variant-" << m_numRemovedTotal << "/" << variantIdx++;
writeFastaRecord(&m_outFile, ss.str(), selectedSequence);
// The vertex set for each walk is not necessarily disjoint,
// the selected walk may contain vertices that are part
// of other paths. We handle this be initially marking all
// vertices of the
for(size_t i = 0; i < variantWalks.size(); ++i)
{
if(i == selectedIdx)
continue;
SGWalk& currWalk = variantWalks[i];
for(size_t j = 0; j < currWalk.getNumEdges() - 1; ++j)
{
Edge* currEdge = currWalk.getEdge(j);
// If the vertex is also on the selected path, do not mark it
Vertex* currVertex = currEdge->getEnd();
if(!selectedWalk.containsVertex(currVertex->getID()))
{
currEdge->getEnd()->setColor(GC_RED);
}
}
// Write the variant to a file
std::string variantSequence = currWalk.getString(SGWT_START_TO_END);
std::stringstream variantID;
std::stringstream ss;
ss << "variant-" << m_numRemovedTotal << "/" << variantIdx++;
ss << " IGD:" << (double)gapPercent[i] << " ITD:" << totalPercent[i] << " MID: " << maxIndel[i] << " InternalCigar:" << cigarStrings[i];
writeFastaRecord(&m_outFile, ss.str(), variantSequence);
}
if(variantWalks.size() == 2)
m_simpleBubblesRemoved += 1;
else
m_complexBubblesRemoved += 1;
++m_numRemovedTotal;
}
}
// Returns true if the paired reads are a short-insert pair
bool filterByGraph(StringGraph* pGraph,
const BamTools::RefVector& referenceVector,
BamTools::BamAlignment& record1,
BamTools::BamAlignment& record2)
{
std::string vertexID1 = referenceVector[record1.RefID].RefName;
std::string vertexID2 = referenceVector[record2.RefID].RefName;
// Get the vertices for this pair using the mapped IDs
Vertex* pX = pGraph->getVertex(vertexID1);
Vertex* pY = pGraph->getVertex(vertexID2);
// Ensure that the vertices are found
assert(pX != NULL && pY != NULL);
#ifdef DEBUG_CONNECT
std::cout << "Finding path from " << vertexID1 << " to " << vertexID2 << "\n";
#endif
EdgeDir walkDirectionXOut = ED_SENSE;
EdgeDir walkDirectionYIn = ED_SENSE;
// Flip walk directions if the alignment is to the reverse strand
if(record1.IsReverseStrand())
walkDirectionXOut = !walkDirectionXOut;
if(record2.IsReverseStrand())
walkDirectionYIn = !walkDirectionYIn;
int fromX = walkDirectionXOut == ED_SENSE ? record1.Position : record1.GetEndPosition();
int toY = walkDirectionYIn == ED_SENSE ? record2.Position : record2.GetEndPosition();
// Calculate the amount of contig X that already covers the fragment
// Using this number, we calculate how far we should search
int coveredX = walkDirectionXOut == ED_SENSE ? pX->getSeqLen() - fromX : fromX;
int maxWalkDistance = opt::maxDistance - coveredX;
bool bShortInsertPair = false;
if(pX == pY)
{
if(abs(record1.InsertSize) < opt::maxDistance)
bShortInsertPair = true;
}
else
{
SGWalkVector walks;
SGSearch::findWalks(pX, pY, walkDirectionXOut, maxWalkDistance, 10000, true, walks);
if(!walks.empty())
{
for(size_t i = 0; i < walks.size(); ++i)
{
std::string fragment = walks[i].getFragmentString(pX,
pY,
fromX,
toY,
walkDirectionXOut,
walkDirectionYIn);
if((int)fragment.size() < opt::maxDistance)
{
bShortInsertPair = true;
//std::cout << "Found completing fragment (" << pX->getID() << " -> " << pY->getID() << ": " << fragment.size() << "\n";
break;
}
}
}
}
return bShortInsertPair;
}
// Run the bubble construction process
HaplotypeBuilderReturnCode DeBruijnHaplotypeBuilder::run(StringVector& out_haplotypes)
{
PROFILE_FUNC("GraphCompare::buildVariantStringGraph")
assert(!m_startingKmer.empty());
std::map<std::string, int> kmerCountMap;
// We search until we find the first common vertex in each direction
size_t MIN_TARGET_COUNT = m_parameters.bReferenceMode ? 1 : 2;
size_t MAX_ITERATIONS = 2000;
size_t MAX_SIMULTANEOUS_BRANCHES = 40;
size_t MAX_TOTAL_BRANCHES = 50;
// Tracking stats
size_t max_simul_branches_used = 0;
size_t total_branches = 0;
size_t iterations = 0;
// Initialize the graph
StringGraph* pGraph = new StringGraph;
BuilderExtensionQueue queue;
Vertex* pVertex = new(pGraph->getVertexAllocator()) Vertex(m_startingKmer, m_startingKmer);
pVertex->setColor(GC_BLACK);
pGraph->addVertex(pVertex);
// Add the vertex to the extension queue
queue.push(BuilderExtensionNode(pVertex, ED_SENSE));
queue.push(BuilderExtensionNode(pVertex, ED_ANTISENSE));
std::vector<Vertex*> sense_join_vector;
std::vector<Vertex*> antisense_join_vector;
// Perform the extension. The while conditions are heuristics to avoid searching
// the graph too much
while(!queue.empty() && iterations++ < MAX_ITERATIONS && queue.size() < MAX_SIMULTANEOUS_BRANCHES && total_branches < MAX_TOTAL_BRANCHES)
{
if(queue.size() > max_simul_branches_used)
max_simul_branches_used = queue.size();
BuilderExtensionNode curr = queue.front();
queue.pop();
// Calculate de Bruijn extensions for this node
std::string vertStr = curr.pVertex->getSeq().toString();
AlphaCount64 extensionCounts = BWTAlgorithms::calculateDeBruijnExtensionsSingleIndex(vertStr, m_parameters.variantIndex.pBWT, curr.direction);
std::string extensionsUsed;
for(size_t i = 0; i < DNA_ALPHABET::size; ++i)
{
char b = DNA_ALPHABET::getBase(i);
size_t count = extensionCounts.get(b);
bool acceptExt = count >= m_parameters.minDBGCount;
if(!acceptExt)
continue;
extensionsUsed.push_back(b);
std::string newStr = VariationBuilderCommon::makeDeBruijnVertex(vertStr, b, curr.direction);
kmerCountMap[newStr] = count;
// Create the new vertex and edge in the graph
// Skip if the vertex already exists
if(pGraph->getVertex(newStr) != NULL)
continue;
// Allocate the new vertex and add it to the graph
Vertex* pVertex = new(pGraph->getVertexAllocator()) Vertex(newStr, newStr);
pVertex->setColor(GC_BLACK);
pGraph->addVertex(pVertex);
// Add edges
VariationBuilderCommon::addSameStrandDeBruijnEdges(pGraph, curr.pVertex, pVertex, curr.direction);
// Check if this sequence is present in the FM-index of the target
// If so, it is the join point of the de Bruijn graph and we extend no further.
size_t targetCount = BWTAlgorithms::countSequenceOccurrences(newStr, m_parameters.baseIndex);
if(targetCount >= MIN_TARGET_COUNT)
{
if(curr.direction == ED_SENSE)
sense_join_vector.push_back(pVertex);
else
antisense_join_vector.push_back(pVertex);
}
else
{
// Add the vertex to the extension queue
queue.push(BuilderExtensionNode(pVertex, curr.direction));
}
}
// Update the total number of times we branches the search
if(!extensionsUsed.empty())
total_branches += extensionsUsed.size() - 1;
}
// If the graph construction was successful, walk the graph
// between the endpoints to make a string
// Generate haplotypes between every pair of antisense/sense join vertices
for(size_t i = 0; i < antisense_join_vector.size(); ++i) {
for(size_t j = 0; j < sense_join_vector.size(); ++j) {
SGWalkVector outWalks;
SGSearch::findWalks(antisense_join_vector[i],
sense_join_vector[j],
ED_SENSE,
100000, // max distance to search
10000, // max nodes to search
true, // exhaustive search
outWalks);
for(size_t k = 0; k < outWalks.size(); ++k)
out_haplotypes.push_back(outWalks[k].getString(SGWT_START_TO_END));
}
}
delete pGraph;
return HBRC_OK;
}
