R/count_taxa.R

In ropensci/taxlist: Handling Taxonomic Lists

#' @name count_taxa
#'
#' @title Count taxa within a taxlist object.
#'
#' @description
#' Counting number of taxa within [taxlist-class] objects or
#' character vectors containing taxon names.
#'
#' @param object An object containing a taxonomic list or a formula.
#' @param data An object of class [taxlist-class] in the `formula` method.
#' @param na.rm Logical value, whether NAs have to be removed from the input
#'     vector or not.
#' @param level Character value indicating the taxonomic rank of counted taxa.
#' @param ... further arguments passed among methods.
#'
#' @details
#' This function is written by convenience in order to reduce code for counting
#' taxa within [taxlist-class] objects and it is just a wrapper of [length()].
#'
#' @return An integer with the number of taxa.
#'
#' @author Miguel Alvarez \email{kamapu78@@gmail.com}
#'
#' @example examples/count_taxa.R
#'
#' @rdname count_taxa
#'
#' @exportMethod count_taxa
setGeneric(
  "count_taxa",
  function(object, data, ...) {
    standardGeneric("count_taxa")
  }
)

#' @rdname count_taxa
#' @aliases count_taxa,character,missing-method
setMethod(
  "count_taxa", signature(object = "character", data = "missing"),
  function(object, na.rm = TRUE, ...) {
    if (na.rm) object <- object[!is.na(object)]
    return(length(unique(object)))
  }
)

#' @rdname count_taxa
#' @aliases count_taxa,factor,missing-method
setMethod(
  "count_taxa", signature(object = "factor", data = "missing"),
  function(object, na.rm = TRUE, ...) {
    if (na.rm) object <- object[!is.na(object)]
    return(count_taxa(paste(object)))
  }
)

#' @rdname count_taxa
#' @aliases count_taxa,taxlist,missing-method
setMethod(
  "count_taxa", signature(object = "taxlist", data = "missing"),
  function(object, level, ...) {
    if (missing(level)) {
      n_taxa <- nrow(object@taxonRelations)
    } else {
      if (!level %in% levels(object)) {
        stop(paste(
          "Value of argument 'level' is not a level in",
          "'object'."
        ))
      }
      n_taxa <- nrow(object@taxonRelations[
        paste(object@taxonRelations$Level) == level,
      ])
    }
    return(n_taxa)
  }
)

#' @rdname count_taxa
#'
#' @param include_na Logical value indicating whether `NA` values in a taxon
#'     trait should be considered for counting taxa or just ignored (only
#'     used in `formula` method).
#' @param suffix Character value used as suffix for the counted rank in the
#'     output data frame (only used in `formula` method).
#'
#' @aliases count_taxa,formula,taxlist-method
setMethod(
  "count_taxa", signature(object = "formula", data = "taxlist"),
  function(object, data, include_na = FALSE, suffix = "_count", ...) {
    # Some checks
    nr_response <- attr(terms(object), "response")
    if (nr_response > 1) {
      stop("More than one response in formula are not allowed.")
    }
    if (nr_response > 0 & !as.character(object)[2] %in%
      taxlist::levels(data)) {
      stop(paste(
        "Response in 'object' have to be a taxonomic rank",
        "in 'data'."
      ))
    }
    if (any(!attr(terms(object), "term.labels") %in%
      colnames(data@taxonTraits))) {
      stop(paste(
        "Some terms in 'object' are not included as traits",
        "in 'data'."
      ))
    }
    # Counting NAs
    if (include_na) {
      traits_df <- data.frame(
        TaxonConceptID =
          data@taxonRelations$TaxonConceptID
      )
      for (i in attr(terms(object), "term.labels")) {
        ## traits_df[ ,i] <- with(data@taxonTraits,
        ##         get(i)[match(traits_df$TaxonConceptID,
        ##                         TaxonConceptID)])
        traits_df[, i] <- data@taxonTraits[
          match(
            traits_df$TaxonConceptID,
            data@taxonTraits$TaxonConceptID
          ), i
        ]
        traits_df[, i] <- replace_x(
          paste(traits_df[, i]),
          c("", "NA"), rep("NAs", 2)
        )
      }
      data@taxonTraits <- traits_df
    }
    # Counting all taxa
    if (nr_response == 0) {
      object <- as.formula(paste(
        "TaxonConceptID", "~",
        paste(attr(terms(object), "term.labels"),
          collapse = " + "
        )
      ))
    }
    data <- aggregate(object, data@taxonTraits, length, ...)
    if (nr_response == 0) {
      colnames(data)[colnames(data) == "TaxonConceptID"] <-
        paste0("taxa", suffix)
    } else {
      colnames(data)[colnames(data) == as.character(object)[2]] <-
        paste0(as.character(object)[2], suffix)
    }
    return(data)
  }
)