I'm not aware of package for amino acid sequence analysis, but it'd
better to search yourself using, e.g., RSiteSearch() and help.search().
Regarding your question consider the following:
strg1 <- c("AAA", "AA", "AAAA")
strg2 <- c("BBB", "BBBB", "BBB")
strg <- paste(strg1, strg2, sep = "")
nA <- nchar(gsub("B", "", strg, fixed = TRUE))
nB <- nchar(gsub("A", "", strg, fixed = TRUE))
strg
nA # freq of A's
nB # freq of B's
I hope it helps.
Best,
Dimitris
----
Dimitris Rizopoulos
Ph.D. Student
Biostatistical Centre
School of Public Health
Catholic University of Leuven
Address: Kapucijnenvoer 35, Leuven, Belgium
Tel: +32/(0)16/336899
Fax: +32/(0)16/337015
Web: http://med.kuleuven.be/biostat/
http://www.student.kuleuven.be/~m0390867/dimitris.htm
Quoting ucecgxu at ucl.ac.uk:
> Dear R-helpers:
>
> thank your for your attention.
>
> i am a newer to R and i am doing some protein category classification
> based on
> the amino acid sequence.while i have some question urgent.
>
> 1. any packages for analysis amino acid sequence
> 2. given two sequences "AAA" and "BBB",how can i
combine them into
> "AAABBB"
>
> 3. based on "AAABBB",how can i get some statistics of this string
> such as how
> many letters,how many "A"s in the string.
>
>
> Thank you very much and i am looking forward to hearing from you
> soon
>
> have a nice day!
>
> Best Regards
>
> Marshall
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide!
> http://www.R-project.org/posting-guide.html
>
>
Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm