Abbreivate a binomial scientific name

abbreviate.species.names <- function(x)
{ 
    ## Purpose: Abbreivate a binomial scientific name. 
    ## Arguments:
    ##   x: a vector of strings for the names of the species. 
    ## Return: a vector of strings with the abbreviated names
    ## Author: Feiming Chen, Date: 20 Apr 2017, 14:01
    ## ________________________________________________

    x1 <- gsub(" +", " ", x)
    x2 <- sub("^ +", "", x1)
    x3 <- sub(" +$", "", x2)
    x4 <- strsplit(x3, " ")

    sapply(x4, function(y) {
        if (length(y) == 2) {
            ans <- paste0(toupper(substr(y[1], 1, 1)), ".", tolower(y[2]))
        } else ans <- y
        ans
    })
}
if (F) {                                # Unit Test
    x = c("Escherichia coli", "Tyrannosaurus rex", "N/A", " Canis   lupus  ")
    abbreviate.species.names(x)         # "E.coli"  "T.rex"   "N/A"     "C.lupus"
}