Calculate sequence distance / similarity for aligned sequences.
Install devtools if you haven't, by install.packages("devtools").
Then, install this package by devtools::install_github("Yue-Jiang/alndist").
Optionally, install the package, also install dependencies and build vignettes devtools::install_github("Yue-Jiang/alndist", dependencies = TRUE, build_vignettes = TRUE).