예제 #1
0
파일: Align.java 프로젝트: nh13/SRMA
  private static void updateSAM(
      SAMRecord rec,
      ReferenceSequence sequence,
      SAMProgramRecord programRecord,
      AlignHeapNode bestAlignHeapNode,
      SRMAUtil.Space space,
      String read,
      String qualities,
      String softClipStartBases,
      String softClipStartQualities,
      String softClipEndBases,
      String softClipEndQualities,
      boolean strand,
      boolean correctBases)
      throws Exception {
    AlignHeapNode curAlignHeapNode = null;
    AlignHeapNode prevAlignHeapNode = null;

    int alignmentStart = 0;
    int readIndex = -1;
    byte readBases[] = null;
    byte baseQualities[] = null;
    byte colorErrors[] = null;
    int i;
    int numEdits = 0;
    List<String> optFieldTags = new LinkedList<String>();
    List<Object> optFieldValues = new LinkedList<Object>();
    Object attr;

    // Debugging stuff
    String readName = rec.getReadName();

    if (null == bestAlignHeapNode) {
      // Do not modify the alignment
      return;
    }

    // To generate a new CIGAR
    List<CigarElement> cigarElements = null;
    CigarOperator prevCigarOperator = null, curCigarOperator = null;
    int prevCigarOperatorLength = 0;

    // TODO
    // setInferredInsertSize (invalidates paired end reads)
    // setMappingQuality (?)
    // setFlag
    // update base qualities for color space reads

    // clear attributes, but save some
    Align.clearAttributes(rec, optFieldTags, optFieldValues);

    readBases = new byte[read.length()];
    baseQualities = new byte[qualities.length()];
    for (i = 0; i < qualities.length(); i++) {
      // Must subtract 33 for PHRED scaling
      baseQualities[i] = (byte) (qualities.charAt(i) - 33);
    }

    if (strand) {
      readIndex = 0;
    } else {
      readIndex = read.length() - 1;
    }
    cigarElements = new LinkedList<CigarElement>();
    if (strand) { // reverse strand is the current position
      alignmentStart = bestAlignHeapNode.node.position;
    } else {
      alignmentStart = bestAlignHeapNode.startPosition;
    }

    assert null != bestAlignHeapNode;
    curAlignHeapNode = bestAlignHeapNode;

    while (null != curAlignHeapNode) {
      // Get the current cigar operator
      if (null != prevAlignHeapNode
          && CigarOperator.DELETION != prevCigarOperator
          && 1 < Math.abs(curAlignHeapNode.node.position - prevAlignHeapNode.node.position)) {
        curCigarOperator = CigarOperator.DELETION;
      } else {
        switch (curAlignHeapNode.node.type) {
          case Node.MISMATCH: // Fall through
          case Node.MATCH:
            curCigarOperator = CigarOperator.MATCH_OR_MISMATCH;
            break;
          case Node.INSERTION:
            // System.out.println("INS");
            curCigarOperator = CigarOperator.INSERTION;
            break;
          default:
            throw new Exception("Unknown node type");
        }
        if (space == SRMAUtil.Space.COLORSPACE || correctBases) {
          readBases[readIndex] = (byte) curAlignHeapNode.node.base;
          if (strand) {
            readIndex++;
          } else {
            readIndex--;
          }
          // count the number of mismatches
          switch (curAlignHeapNode.node.type) {
            case Node.MISMATCH:
            case Node.INSERTION:
              numEdits++;
              break;
            default:
              break;
          }
        } else {
          // count the number of mismatches
          switch (curAlignHeapNode.node.type) {
            case Node.MATCH:
              if (read.charAt(curAlignHeapNode.readOffset) != curAlignHeapNode.node.base) {
                numEdits++;
              }
              break;
            case Node.MISMATCH: // Fall through
              if (read.charAt(curAlignHeapNode.readOffset)
                  != sequence.getBases()[curAlignHeapNode.node.position - 1]) {
                numEdits++;
              }
              break;
            case Node.INSERTION:
              numEdits++;
              break;
            default:
              break;
          }
        }
      }
      if (prevCigarOperator != curCigarOperator) {
        // different cigar operator

        // add the previous cigar operator
        if (null != prevCigarOperator) {
          if (strand) { // reverse
            // append
            cigarElements.add(new CigarElement(prevCigarOperatorLength, prevCigarOperator));
          } else {
            // prepend
            cigarElements.add(0, new CigarElement(prevCigarOperatorLength, prevCigarOperator));
          }
        }

        // update prevCigarOperator
        prevCigarOperator = curCigarOperator;
        if (curCigarOperator == CigarOperator.DELETION) {
          // length of deletion
          prevCigarOperatorLength =
              Math.abs(curAlignHeapNode.node.position - prevAlignHeapNode.node.position) - 1;
          numEdits += prevCigarOperatorLength; // deletions
        } else {
          prevCigarOperatorLength = 1;
        }
      } else {
        // same cigar operator
        prevCigarOperatorLength++;
      }

      // Update
      if (CigarOperator.DELETION != curCigarOperator) {
        prevAlignHeapNode = curAlignHeapNode;
        curAlignHeapNode = curAlignHeapNode.prev;
      }
    }
    if (0 < prevCigarOperatorLength) {
      if (null == prevCigarOperator || CigarOperator.DELETION == prevCigarOperator) {
        throw new Exception("Ended with a null cigar operator or a deletion cigar operator");
      }
      if (strand) { // reverse
        // append
        cigarElements.add(new CigarElement(prevCigarOperatorLength, prevCigarOperator));
      } else {
        // prepend
        cigarElements.add(0, new CigarElement(prevCigarOperatorLength, prevCigarOperator));
      }
    }

    if (space == SRMAUtil.Space.COLORSPACE) { // color space, read bases already inferred
      // Get color error string
      colorErrors = new byte[read.length()];
      char prevBase = SRMAUtil.COLORSPACE_ADAPTOR;
      if (strand) { // reverse
        for (i = 0; i < read.length(); i++) {
          char nextBase = SRMAUtil.colorSpaceNextBase(prevBase, read.charAt(i));
          if (nextBase == SRMAUtil.getCompliment((char) readBases[read.length() - i - 1])) {
            colorErrors[i] = (byte) Alignment.GAP;
          } else {
            colorErrors[i] = (byte) read.charAt(i);
          }
          if (0 < i) {
            // qualities are assumed to be always in the same direction as the color errors
            baseQualities[read.length() - i] =
                getColorQuality(
                    colorErrors[i - 1],
                    colorErrors[i],
                    (byte) (qualities.charAt(i - 1) - 33),
                    (byte) (qualities.charAt(i) - 33));
          }
          prevBase = SRMAUtil.getCompliment((char) readBases[read.length() - i - 1]);
        }
        // last color
        baseQualities[0] = (byte) (qualities.charAt(read.length() - 1) - 33);
      } else {
        for (i = 0; i < read.length(); i++) {
          char nextBase = SRMAUtil.colorSpaceNextBase(prevBase, read.charAt(i));
          if (nextBase == readBases[i]) {
            colorErrors[i] = (byte) Alignment.GAP;
          } else {
            colorErrors[i] = (byte) read.charAt(i);
          }
          if (0 < i) {
            baseQualities[i - 1] =
                getColorQuality(
                    colorErrors[i - 1],
                    colorErrors[i],
                    (byte) (qualities.charAt(i - 1) - 33),
                    (byte) (qualities.charAt(i) - 33));
          }
          prevBase = (char) readBases[i];
        }
        // last color
        baseQualities[read.length() - 1] = (byte) (qualities.charAt(read.length() - 1) - 33);
      }
    } else if (correctBases) { // bases were corrected
      if (strand) {
        for (i = 0; i < read.length(); i++) {
          if (readBases[i] == (byte) read.charAt(read.length() - i - 1)) {
            baseQualities[i] = (byte) (qualities.charAt(read.length() - i - 1) - 33);
          } else {
            // TODO: how much to down-weight ?
            baseQualities[i] =
                (byte)
                    (SRMAUtil.QUAL2CHAR(
                            SRMAUtil.CHAR2QUAL(qualities.charAt(read.length() - i - 1))
                                - CORRECT_BASE_QUALITY_PENALTY)
                        - 33);
            if (baseQualities[i] <= 0) {
              baseQualities[i] = 1;
            }
          }
        }
      } else {
        for (i = 0; i < read.length(); i++) {
          if (readBases[i] == (byte) read.charAt(i)) {
            baseQualities[i] = (byte) (qualities.charAt(i) - 33);
          } else {
            // TODO: how much to down-weight ?
            baseQualities[i] =
                (byte)
                    (SRMAUtil.QUAL2CHAR(
                            SRMAUtil.CHAR2QUAL(qualities.charAt(i)) - CORRECT_BASE_QUALITY_PENALTY)
                        - 33);
            if (baseQualities[i] <= 0) {
              baseQualities[i] = 1;
            }
          }
        }
      }
      rec.setAttribute("XO", read);
      rec.setAttribute("XQ", qualities);
    } else { // bases not corrected
      readBases = new byte[read.length()];
      baseQualities = new byte[qualities.length()]; // qualities.length() == read.length()
      if (strand) { // reverse
        for (i = 0; i < read.length(); i++) {
          readBases[i] = (byte) read.charAt(read.length() - i - 1);
          baseQualities[i] = (byte) (qualities.charAt(read.length() - i - 1) - 33);
        }
      } else {
        for (i = 0; i < read.length(); i++) {
          readBases[i] = (byte) read.charAt(i);
          baseQualities[i] = (byte) (qualities.charAt(i) - 33);
        }
      }
    }

    // Add in soft-clipping
    if (null != softClipStartBases) { // prepend
      cigarElements.add(0, new CigarElement(softClipStartBases.length(), CigarOperator.S));

      byte tmpBases[] = new byte[readBases.length + softClipStartBases.length()];
      System.arraycopy(readBases, 0, tmpBases, softClipStartBases.length(), readBases.length);
      readBases = tmpBases;
      for (i = 0; i < softClipStartBases.length(); i++) {
        readBases[i] = (byte) softClipStartBases.charAt(i);
      }

      byte tmpQualities[] = new byte[baseQualities.length + softClipStartQualities.length()];
      System.arraycopy(
          baseQualities, 0, tmpQualities, softClipStartQualities.length(), baseQualities.length);
      baseQualities = tmpQualities;
      for (i = 0; i < softClipStartQualities.length(); i++) {
        baseQualities[i] = (byte) softClipStartQualities.charAt(i);
      }
    }
    if (null != softClipEndBases) { // append
      cigarElements.add(new CigarElement(softClipEndBases.length(), CigarOperator.S));

      byte tmpBases[] = new byte[readBases.length + softClipEndBases.length()];
      System.arraycopy(readBases, 0, tmpBases, 0, readBases.length);
      for (i = 0; i < softClipEndBases.length(); i++) {
        tmpBases[i + readBases.length] = (byte) softClipEndBases.charAt(i);
      }
      readBases = tmpBases;

      byte tmpQualities[] = new byte[baseQualities.length + softClipEndQualities.length()];
      System.arraycopy(baseQualities, 0, tmpQualities, 0, baseQualities.length);
      for (i = 0; i < softClipEndQualities.length(); i++) {
        tmpQualities[i + baseQualities.length] = (byte) softClipEndQualities.charAt(i);
      }
      baseQualities = tmpQualities;
    }

    // Update SAM record
    rec.setCigar(new Cigar(cigarElements));
    rec.setAlignmentStart(alignmentStart);
    rec.setReadBases(readBases);
    rec.setBaseQualities(baseQualities);
    // Reset saved attributes
    Align.resetAttributes(rec, optFieldTags, optFieldValues);
    // Set new attributes
    if (space == SRMAUtil.Space.COLORSPACE) {
      // set the XE attribute for colorError string
      rec.setAttribute("XE", new String(colorErrors));
    }
    rec.setAttribute("AS", bestAlignHeapNode.score);
    rec.setAttribute("XC", bestAlignHeapNode.alleleCoverageSum);
    rec.setAttribute("PG", programRecord.getId());
    rec.setAttribute("NM", numEdits);
  }
예제 #2
0
파일: Align.java 프로젝트: nh13/SRMA
  public static void align(
      Graph graph,
      SAMRecord rec,
      Node recNode,
      ReferenceSequence sequence,
      SAMProgramRecord programRecord,
      int offset,
      AlleleCoverageCutoffs alleleCoverageCutoffs,
      boolean correctBases,
      boolean useSequenceQualities,
      int MAXIMUM_TOTAL_COVERAGE,
      int MAX_HEAP_SIZE)
      throws Exception {

    int i;
    AlignHeapNode curAlignHeapNode = null;
    AlignHeapNode nextAlignHeapNode = null;
    AlignHeapNode bestAlignHeapNode = null;
    AlignHeap heap = null;
    String read = null; // could be cs
    String readBases = null; // always nt
    String qualities = null; // could be cq
    SRMAUtil.Space space = SRMAUtil.Space.NTSPACE;
    ListIterator<NodeRecord> iter = null;
    AlignHeapNodeComparator comp = null;
    int alignmentStart = -1;
    int numStartNodesAdded = 0;
    boolean strand = rec.getReadNegativeStrandFlag(); // false -> forward, true -> reverse
    String softClipStartBases = null;
    String softClipStartQualities = null;
    String softClipEndBases = null;
    String softClipEndQualities = null;

    // Debugging stuff
    String readName = rec.getReadName();

    assert SRMAUtil.Space.COLORSPACE != space;

    // Get space
    read = (String) rec.getAttribute("CS");
    if (null == read) {
      // Use base space
      space = SRMAUtil.Space.NTSPACE;
    } else {
      // assumes CS and CQ are always in sequencing order
      space = SRMAUtil.Space.COLORSPACE;
    }

    // Get read and qualities
    if (space == SRMAUtil.Space.NTSPACE) {
      byte tmpRead[] = rec.getReadString().getBytes();
      byte tmpQualities[] = rec.getBaseQualityString().getBytes();
      // Reverse once
      if (strand) { // reverse
        SAMRecordUtil.reverseArray(tmpRead);
        SAMRecordUtil.reverseArray(tmpQualities);
      }
      read = new String(tmpRead);
      readBases = new String(tmpRead);
      qualities = new String(tmpQualities);
      // Reverse again
      if (strand) { // reverse
        SAMRecordUtil.reverseArray(tmpRead);
        SAMRecordUtil.reverseArray(tmpQualities);
      }
    } else {
      byte tmpRead[] = rec.getReadString().getBytes();
      // Reverse once
      if (strand) { // reverse
        SAMRecordUtil.reverseArray(tmpRead);
      }
      readBases = new String(tmpRead);
      // Reverse again
      if (strand) { // reverse
        SAMRecordUtil.reverseArray(tmpRead);
      }
      read = SRMAUtil.normalizeColorSpaceRead(read);
      qualities = (String) rec.getAttribute("CQ");
      // Some aligners include a quality value for the adapter.  A quality value
      // IMHO should not be given for an unobserved (assumed) peice of data.  Trim
      // the first quality in this case
      if (qualities.length() == 1 + read.length()) { // trim the first quality
        qualities = qualities.substring(1);
      }
    }
    // Reverse back
    if (readBases.length() <= 0) {
      throw new Exception("Error.  The current alignment has no bases.");
    }
    if (read.length() <= 0) {
      throw new Exception("Error.  The current alignment has no bases.");
    }
    if (qualities.length() <= 0) {
      throw new Exception("Error.  The current alignment has no qualities.");
    }
    if (readBases.length() != read.length()) {
      if (space == SRMAUtil.Space.COLORSPACE) {
        throw new Exception(
            "Error.  The current alignment's read bases length does not match the length of the colors in the CS tag ["
                + rec.getReadName()
                + "].");
      } else {
        throw new Exception("Error.  Internal error: readBases.length() != read.length()");
      }
    }

    // Deal with soft-clipping
    // - save the soft clipped sequence for latter
    {
      List<CigarElement> cigarElements = null;

      cigarElements = rec.getCigar().getCigarElements();
      CigarElement e1 = cigarElements.get(0); // first
      CigarElement e2 = cigarElements.get(cigarElements.size() - 1); // last

      // Soft-clipped
      if (CigarOperator.S == e1.getOperator()) {
        if (space == SRMAUtil.Space.COLORSPACE) {
          throw new Exception(
              "Error.  Soft clipping with color-space data not currently supported.");
        }
        int l = e1.getLength();
        if (strand) { // reverse
          softClipStartBases = readBases.substring(readBases.length() - l);
          softClipStartQualities = qualities.substring(qualities.length() - l);
          readBases = readBases.substring(0, readBases.length() - l);
          read = read.substring(0, read.length() - l);
          qualities = qualities.substring(0, qualities.length() - l);
        } else {
          softClipStartBases = readBases.substring(0, l - 1);
          softClipStartQualities = qualities.substring(0, l - 1);
          readBases = readBases.substring(l);
          read = read.substring(l);
          qualities = qualities.substring(l);
        }
      }
      if (CigarOperator.S == e2.getOperator()) {
        if (space == SRMAUtil.Space.COLORSPACE) {
          throw new Exception(
              "Error.  Soft clipping with color-space data not currently supported.");
        }
        int l = e2.getLength();
        if (strand) { // reverse
          softClipEndBases = readBases.substring(0, l - 1);
          softClipEndQualities = qualities.substring(0, l - 1);
          readBases = readBases.substring(l);
          read = read.substring(l);
          qualities = qualities.substring(l);
        } else {
          softClipEndBases = readBases.substring(readBases.length() - l);
          softClipEndQualities = qualities.substring(qualities.length() - l);
          readBases = readBases.substring(0, readBases.length() - l);
          read = read.substring(0, read.length() - l);
          qualities = qualities.substring(0, qualities.length() - l);
        }
      }
    }

    // Remove mate pair information
    Align.removeMateInfo(rec);

    comp =
        new AlignHeapNodeComparator(
            (strand) ? AlignHeap.HeapType.MAXHEAP : AlignHeap.HeapType.MINHEAP);

    // Bound by original alignment if possible
    bestAlignHeapNode =
        Align.boundWithOriginalAlignment(
            rec,
            graph,
            recNode,
            comp,
            strand,
            read,
            qualities,
            readBases,
            space,
            sequence,
            alleleCoverageCutoffs,
            useSequenceQualities,
            MAXIMUM_TOTAL_COVERAGE,
            MAX_HEAP_SIZE);

    /*
    System.err.println("readName="+rec.getReadName());
    if(null != bestAlignHeapNode) {
    System.err.println("\nFOUND BEST:" + rec.toString());
    }
    else {
    System.err.println("\nNOT FOUND (BEST): " + rec.toString());
    }
    Align.updateSAM(rec, programRecord, bestAlignHeapNode, space, read, qualities, softClipStartBases, softClipStartQualities, softClipEndBases, softClipEndQualities, strand, correctBases);
    return;
    */

    heap = new AlignHeap((strand) ? AlignHeap.HeapType.MAXHEAP : AlignHeap.HeapType.MINHEAP);

    // Add start nodes
    if (strand) { // reverse
      alignmentStart = rec.getAlignmentEnd();
      for (i = alignmentStart + offset; alignmentStart - offset <= i; i--) {
        int position = graph.getPriorityQueueIndexAtPositionOrBefore(i);
        PriorityQueue<Node> startNodeQueue = graph.getPriorityQueue(position);
        if (0 != position && null != startNodeQueue) {
          Iterator<Node> startNodeQueueIter = startNodeQueue.iterator();
          while (startNodeQueueIter.hasNext()) {
            Node startNode = startNodeQueueIter.next();
            int f = passFilters(graph, startNode, alleleCoverageCutoffs, MAXIMUM_TOTAL_COVERAGE);
            if (0 == f) {
              heap.add(
                  new AlignHeapNode(
                      null,
                      startNode,
                      startNode.coverage,
                      read.charAt(0),
                      qualities.charAt(0),
                      useSequenceQualities,
                      space));
            } else if (f < 0) {
              return;
            }
            if (startNode.position < i) {
              i = startNode.position;
            }
            numStartNodesAdded++;
          }
        }
      }
    } else {
      alignmentStart = rec.getAlignmentStart();
      for (i = alignmentStart - offset; i <= alignmentStart + offset; i++) {
        int position = graph.getPriorityQueueIndexAtPositionOrGreater(i);
        PriorityQueue<Node> startNodeQueue = graph.getPriorityQueue(position);
        if (0 != position && null != startNodeQueue) {
          Iterator<Node> startNodeQueueIter = startNodeQueue.iterator();
          while (startNodeQueueIter.hasNext()) {
            Node startNode = startNodeQueueIter.next();
            int f = passFilters(graph, startNode, alleleCoverageCutoffs, MAXIMUM_TOTAL_COVERAGE);
            if (0 == f) {
              heap.add(
                  new AlignHeapNode(
                      null,
                      startNode,
                      startNode.coverage,
                      read.charAt(0),
                      qualities.charAt(0),
                      useSequenceQualities,
                      space));
            } else if (f < 0) {
              return;
            }
            if (i < startNode.position) {
              i = startNode.position;
            }
            numStartNodesAdded++;
          }
        }
      }
    }
    if (numStartNodesAdded == 0) {
      throw new Exception("Did not add any start nodes!");
    }

    // Get first node off the heap
    curAlignHeapNode = heap.poll();

    while (null != curAlignHeapNode) {

      if (MAX_HEAP_SIZE <= heap.size()) {
        // too many to consider
        return;
      }

      // System.err.println("strand:" + strand + "\tsize:" + heap.size() + "\talignmentStart:" +
      // alignmentStart + "\toffset:" + offset + "\treadOffset:" + curAlignHeapNode.readOffset);
      // System.err.print("size:" + heap.size() + ":" + curAlignHeapNode.readOffset + ":" +
      // curAlignHeapNode.score + ":" + curAlignHeapNode.alleleCoverageSum + ":" +
      // curAlignHeapNode.startPosition + "\t");
      // curAlignHeapNode.node.print(System.err);
      // System.err.print("\rposition:" + curAlignHeapNode.node.position + "\treadOffset:" +
      // curAlignHeapNode.readOffset);

      // Remove all non-insertions with the same contig/pos/read-offset/type/base and lower score
      nextAlignHeapNode = heap.peek();
      while (Node.INSERTION != curAlignHeapNode.node.type
          && null != nextAlignHeapNode
          && 0 == comp.compare(curAlignHeapNode, nextAlignHeapNode)) {
        if (curAlignHeapNode.score < nextAlignHeapNode.score
            || (curAlignHeapNode.score == nextAlignHeapNode.score
                && curAlignHeapNode.alleleCoverageSum < nextAlignHeapNode.alleleCoverageSum)) {
          // Update current node
          curAlignHeapNode = heap.poll();
        } else {
          // Ignore next node
          heap.poll();
        }
        nextAlignHeapNode = heap.peek();
      }
      nextAlignHeapNode = null;

      // Check if the alignment is complete
      if (curAlignHeapNode.readOffset == read.length() - 1) {
        // All read bases examined, store if has the best alignment.

        // System.err.print(curAlignHeapNode.alleleCoverageSum + ":" + curAlignHeapNode.score +
        // ":");
        // System.err.print(curAlignHeapNode.startPosition + ":");
        // curAlignHeapNode.node.print(System.err);

        if (null == bestAlignHeapNode
            || bestAlignHeapNode.score < curAlignHeapNode.score
            || (bestAlignHeapNode.score == curAlignHeapNode.score
                && bestAlignHeapNode.alleleCoverageSum < curAlignHeapNode.alleleCoverageSum)) {
          bestAlignHeapNode = curAlignHeapNode;
        }
      } else if (null != bestAlignHeapNode && curAlignHeapNode.score < bestAlignHeapNode.score) {
        // ignore, under the assumption that scores can only become more negative.
      } else {
        if (strand) { // reverse
          // Go to all the "prev" nodes
          iter = curAlignHeapNode.node.prev.listIterator();
        } else { // forward
          // Go to all "next" nodes
          iter = curAlignHeapNode.node.next.listIterator();
        }
        while (iter.hasNext()) {
          NodeRecord next = iter.next();
          int f =
              passFilters(
                  graph, next.node, next.coverage, alleleCoverageCutoffs, MAXIMUM_TOTAL_COVERAGE);
          if (0 == f) {
            heap.add(
                new AlignHeapNode(
                    curAlignHeapNode,
                    next.node,
                    next.coverage,
                    read.charAt(curAlignHeapNode.readOffset + 1),
                    qualities.charAt(curAlignHeapNode.readOffset + 1),
                    useSequenceQualities,
                    space));
          } else if (f < 0) {
            return;
          }
        }
        iter = null;
      }
      // Get next node
      curAlignHeapNode = heap.poll();
    }

    // Recover alignment
    Align.updateSAM(
        rec,
        sequence,
        programRecord,
        bestAlignHeapNode,
        space,
        read,
        qualities,
        softClipStartBases,
        softClipStartQualities,
        softClipEndBases,
        softClipEndQualities,
        strand,
        correctBases);
  }