Neelcrew

Before understanding the Needleman-Wunsch algorithm, which is for Dynamic Programming for Global Alignment. Let us look at what is Dynamic programming and why it is better than the Dot-Matrix method. Dynamic programming method is fundamentally similar to the Dot-Matrix method but additionally, it gives the quantitative value by converting the dots matrix into a scoring matrix to account for matches and mismatches between sequences.  Dynamic programming works by first constructing a two-dimensional matrix whose axis are the two sequences to be compared. The residue matching is according to a particular scoring matrix. These scores are calculated one row at a time. This starts with the first row of one sequence, which is used to scan through the entire length of the other sequence, followed by scanning the rest of the row. The matching score is calculated. The best score is kept in the box. This process is iterative. Once the matrix is completed. Let the matrix f