Fig. 3

Examples of creating an occurrence bit vector from the strided BWT bit vectors. a An example of the bit vectors in a BWT window. Each bit vector is 256 bits wide representing 256 symbols, but only the first 8 positions are shown for brevity. By performing bitwise operations on these bit vectors an occurrence vector can be generated where a set bit indicates the presence of the queried symbol at the bit’s position in the window. b Creating an occurrence bit vector for Group 1 amino acid ‘A’ in 2 SIMD operations. c Creating an occurrence bit vector for Group 2 amino acid ‘H’ in 3 SIMD operations