Page Maximal Unique Matches
Example for using the Mums Iterator.
Given a set of sequences, a unique match is a match that occurs exactly once in each sequence. A maximal unique match (MUM) is a unique match that is not part of any longer unique match. The following example demonstrates how to iterate over all MUMs and output them.
///A tutorial about finding Mums.
#include <iostream>
#include <seqan/index.h>
using namespace seqan;
int main()
{
// We begin with a StringSet that stores multiple strings.
StringSet<String<char> > mySet;
resize(mySet, 3);
mySet[0] = "SeqAn is a library for sequence analysis.";
mySet[1] = "The String class is the fundamental sequence type in SeqAn.";
mySet[2] = "Subsequences can be handled with SeqAn's Segment class.";
// Then we create an Index of this StringSet.
typedef Index<StringSet<String<char> > > TMyIndex;
TMyIndex myIndex(mySet);
// To find maximal unique matches (Mums), we use the Mums Iterator and set the minimum MUM length to 3.
Iterator<TMyIndex, Mums>::Type myMUMiterator(myIndex, 3);
String<SAValue<TMyIndex>::Type> occs;
while (!atEnd(myMUMiterator))
{
// A multiple match can be represented by the positions it occurs at in every sequence and its length.
// getOccurrences@ returns an unordered sequence of pairs (seqNo,seqOfs) the match occurs at.
occs = getOccurrences(myMUMiterator);
//To order them ascending according seqNo we use orderOccurrences.
orderOccurrences(occs);
for (unsigned i = 0; i < length(occs); ++i)
std::cout << getValueI2(occs[i]) << ", ";
// repLength returns the length of the match.
std::cout << repLength(myMUMiterator) << " ";
// The match string itself can be determined with representative.
std::cout << "\t\"" << representative(myMUMiterator) << '\"' << std::endl;
++myMUMiterator;
}
return 0;
}
Demo: demos/dox/index/mums.cpp
The only maximal matches that occur in all 3 sequences are "SeqAn" and "sequence". They occur exactly once and thus are maximal unique matches.
weese@tanne:~/seqan$ cd demos weese@tanne:~/seqan/demos$ make index_mums weese@tanne:~/seqan/demos$ ./index_mums 0, 53, 33, 5 "SeqAn" 23, 36, 3, 8 "sequence" weese@tanne:~/seqan/demos$ *