SparseSequence can hold discontinuous sequence. Use this class for storing the sequence items with their known position from a long continuous sequence. This class uses SortedDictionary to store the sequence items with their position. Position is zero based indexes at which a sequence items are present in the original continues sequence. For example: To store sequence items at position 10, 101, 200, 1501 this class can be used as shown in the below code. // Create a SparseSequence by specifying the Alphabet. SparseSequence mySparseSequence= new SparseSequence(Alphabets.DNA); // By default count will be set to zero. To insert a sequence item at a position greater than zero, // Count has to be set to a value greater than the maximum position value. // If try to insert a sequence item at a position greater than the count an exception will occur. // You can limit the SparseSequence length by setting the count to desired value. In this example it will be 1502 as the maximum index is 1501. mySparseSequence.Count = 1502; // To access the value in a SparseSequence use Indexer or an Enumerator like below. // Accessing SparsesSequence using Indexer. byte seqItem1 = mySparseSequence [10] ; // this will return sequence item A. byte seqItem2 = mySparseSequence [1501] ; // this will return sequence item G. byte seqItem3 = mySparseSequence [102] ; // this will return null as there is no sequence item at this position. // Accessing SparsesSequence using Enumerator. foreach(byte seqItem in mySparseSequence) {…}

public class SparseSequence : ISequence, 
	IEnumerable<byte>, IEnumerable

Public Class SparseSequence
	Implements ISequence, IEnumerable(Of Byte), 
	IEnumerable

public ref class SparseSequence : ISequence, 
	IEnumerable<unsigned char>, IEnumerable

type SparseSequence =  
    class
        interface ISequence
        interface IEnumerable<byte>
        interface IEnumerable
    end