suffixdb.cpp

   1 /*
   2  *  suffixdb.cpp
   3  *
   4  *
   5  *  Created by Pat Schloss on 12/16/08.
   6  *  Copyright 2008 Patrick D. Schloss. All rights reserved.
   7  *
   8  *      This is a child class of the Database abstract datatype.  The class is basically a database of suffix trees and an
   9  *      encapsulation of the method for finding the most similar tree to an inputted sequence.  the suffixForest objecct
  10  *      is a vector of SuffixTrees, with each template sequence being represented by a different SuffixTree.  The class also
  11  *      provides a method to take an unaligned sequence and find the closest sequence in the suffixForest.  The search
  12  *      method is inspired by the article and Perl source code provided at http://www.ddj.com/web-development/184416093.  I
  13  *      would estimate that the time complexity is O(LN) for each search, which is slower than the kmer searching, but
  14  *      faster than blast
  15  *
  16  */
  17
  18 #include "database.hpp"
  19 #include "sequence.hpp"
  20 #include "suffixtree.hpp"
  21 #include "suffixdb.hpp"
  22
  23 /**************************************************************************************************/
  24
  25 SuffixDB::SuffixDB(int numSeqs) : Database() {
  26         suffixForest.resize(numSeqs);
  27         count = 0;
  28 }
  29 /**************************************************************************************************/
  30 //assumes sequences have been added using addSequence
  31 vector<int> SuffixDB::findClosestSequences(Sequence* candidateSeq, int num){
  32         try {
  33                 vector<int> topMatches;
  34                 string processedSeq = candidateSeq->convert2ints();             //      the candidate sequence needs to be a string of ints
  35
  36                 vector<seqMatch> seqMatches;
  37                 for(int i=0;i<suffixForest.size();i++){                                 //      scan through the forest and see what the minimum
  38                         int count = suffixForest[i].countSuffixes(processedSeq);        //      return score is and keep track of the
  39                         seqMatch temp(i, count);
  40                         seqMatches.push_back(temp);
  41                 }
  42
  43                 //sorts putting smallest matches first
  44                 sort(seqMatches.begin(), seqMatches.end(), compareSeqMatchesReverse);
  45
  46                 searchScore = seqMatches[0].match;
  47                 searchScore = 100 * (1. - searchScore / (float)processedSeq.length());
  48
  49                 //save top matches
  50                 for (int i = 0; i < num; i++) {
  51                         topMatches.push_back(seqMatches[i].seq);
  52                 }
  53
  54                 //      return the Sequence object that has the minimum score
  55                 return topMatches;
  56         }
  57         catch(exception& e) {
  58                 errorOut(e, "SuffixDB", "findClosestSequences");
  59                 exit(1);
  60         }
  61 }
  62 /**************************************************************************************************/
  63 //adding the sequences generates the db
  64 void SuffixDB::addSequence(Sequence seq) {
  65         try {
  66                 suffixForest[count].loadSequence(seq);
  67                 count++;
  68         }
  69         catch(exception& e) {
  70                 errorOut(e, "SuffixDB", "addSequence");
  71                 exit(1);
  72         }
  73 }
  74 /**************************************************************************************************/
  75
  76 SuffixDB::~SuffixDB(){
  77         for (int i = (suffixForest.size()-1); i >= 0; i--) {  suffixForest.pop_back();  }
  78 }
  79 /**************************************************************************************************/