R/retrieveCoding.r

In AndreasFischer1985/quantqual: Software package for analyzing quantitative and qualitative data.

#' Function retrieveCoding
#' 
#' Retrieves certain codings.
#' @param corpus Character vector containing one document per element.
#' @details Retrieves certain codings.
#' @keywords text mining
#' @export
#' @examples
#' retrieveCoding("<h1>hello</h1> world","h1")

retrieveCoding <- function (corpus, coding) 
{
    coding = paste0("<", coding, ">(.*?)</", coding, ">")
    l = stringr::str_locate_all(corpus, coding)
    m = stringr::str_match_all(corpus, coding)
    m1 = character(0)
    l1 = numeric(0)
    l2 = numeric(0)
    i1 = numeric(0)
    for (i in 1:length(corpus)) {
        m1 = c(m1, m[[i]][, 1])
        l1 = c(l1, l[[i]][, 1])
        l2 = c(l2, l[[i]][, 2])
        i1 = c(i1, rep(i, length(m[[i]][, 1])))
    }
    d = data.frame(text = m1, document = i1, from = l1, to = l2)
    if (dim(d)[1] > 0) 
        rownames(d) = 1:length(m1)
    return(d)
}