我为使用 S3 类的函数创建了一个 roxygen 文件。我 roxygenize 然后构建并检查并收到警告：
* checking S3 generic/method consistency ... WARNING
common:
function(word.list, ...)
common.list:
function(word.list, overlap, equal.or)
See section 'Generic functions and methods' of the 'Writing R
Extensions' manual.
所以我花时间研究：
http://cran.r-project.org/doc/manuals/R-exts.html#Generic-functions-and-methods & https://github.com/hadley/devtools/wiki/S3
但我无法弄清楚我在下面的文件中做错了什么。该功能按预期工作。
1）为什么会出现警告？2）我怎样才能让它消失？
#' Find Common Words Between Groups
#'
#' Find common words between grouping variables (e.g. people).
#'
#' @param word.list A list of names chacter vectors.
#' @param overlap Minimum/exact amount of overlap.
#' @param equal.or A character vector of c(\code{"equal"}, \code{"greater"},
#' \code{"more"}, \code{"less"}).
#' @param \dots In liu of word.list the user may input n number of character
#' vectors.
#' @rdname common
#' @return Returns a dataframe of all words that match the criteria set by
#' \code{overlap} and \code{equal.or}.
#' @export
#' @examples
#' a <- c("a", "cat", "dog", "the", "the")
#' b <- c("corn", "a", "chicken", "the")
#' d <- c("house", "feed", "a", "the", "chicken")
#' common(a, b, d, overlap=2)
#' common(a, b, d, overlap=3)
#'
#' r <- list(a, b, d)
#' common(r)
#' common(r, overlap=2)
common <-
function(word.list, ...){
UseMethod("common")
}
#' @return \code{NULL}
#'
#' @rdname common
#' @method common list
#' @S3method common list
common.list <-
function(word.list, overlap = "all", equal.or = "more"){
if(overlap=="all") {
OL <- length(word.list)
} else {
OL <- overlap
}
LIS <- sapply(word.list, unique)
DF <- as.data.frame(table(unlist(LIS)), stringsAsFactors = FALSE)
names(DF) <- c("word", "freq")
DF <- DF[order(-DF$freq, DF$word), ]
DF <- switch(equal.or,
equal = DF[DF$freq == OL, ],
greater = DF[DF$freq > (OL - 1), ],
more = DF[DF$freq > (OL - 1), ],
less = DF[DF$freq < (OL + 1), ])
rownames(DF) <- 1:nrow(DF)
return(DF)
}
#' @return \code{NULL}
#'
#' @rdname common
#' @method common default
#' @S3method common default
common.default <-
function(..., overlap = "all", equal.or = "equal"){
LIS <- list(...)
return(common.list(LIS, overlap, equal.or))
}