R/words.pos.R

In seqinr: Biological Sequences Retrieval and Analysis

words.pos <- function(pattern, text, ignore.case = FALSE,
                      perl = TRUE, fixed = FALSE, useBytes = TRUE, ...)
{
    position <- regexpr(pattern, text, ignore.case, perl, fixed, useBytes, ...)[1]
    result <- numeric(0)
    while(position != -1 )
    {
        result <- c(result, position )
        text <- substr(text, position + 1, nchar(text))
        position <- regexpr(pattern, text, ignore.case, perl, fixed, useBytes, ...)[1]
    }
    return(cumsum(result))
}