get_pos_based_seq_weights: Get position based weights of sequences in alignment
Description
This function calculates position based weights of sequences based on Heinkoff & Heinkoff (1994) for given MSA. The score is calculated as sum of scores for each sequence position c. Score for position c is equal 1/r if there is r different residues at column c in MSA but 1/rs if r symbol is repeated in s sequences.
(optional) a logical parameter, if TRUE(default) the gaps in MSA are included
normalized
(optional) logical parameter, if TRUE (default) weights for all sequences are divided by number of columns in alignment (when gap = TRUE weights sum up to 1)
Value
weights
a vector of position based weights for each sequence in given alignment
Details
The weights might be calculated only for amino acids symbols or for all symbols (including gaps). Also weights can be normalized by number of columns in MSA, then the sum of weights for all sequences is 1.
References
Henikoff, S. & Henikoff, J. G. Position-based sequence weights. Journal of Molecular Biology 243, 574<U+2013>578 (1994).