S3方法帮助(roxygen2)

Question

我试图在一个包中使用S3方法,并认为我在这里问一个问题之后理解了如何设置它:使用Roxygen构建R包时的S3方法一致性警告

但现在我得到的结果我没想到.如果我直接在R中运行下面的代码,它会给我预期的结果,但是如果我把它编译成一个包,我就得不到正确的结果(请注意,当它应该只采用唯一的单词时,它会被计算两次vector a).我不确定我的设置是不正确的.

.R文件:

#' 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
#' \dontrun{
#' 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(word_list(DATA$state, DATA$person)$cwl, overlap = 2) 
#' } 
common <-
function(word.list, ...){
    UseMethod("common")
}

#' @return \code{NULL}
#'
#' @rdname common
#' @method 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 = "more", word.list){
        LIS <- list(...)
        return(common.list(LIS, overlap, equal.or))
}


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)  


r <- list(a, b, d)                                                                                   
common(r, overlap=2)                                                                                            

从命令行运行代码(预期行为):

> common(a, b, d, overlap=2)  
     word freq
1       a    3
2     the    3
3 chicken    2
>                                                                           
>                                                                                                      
> r <- list(a, b, d)                                                                                   
> common(r, overlap=2)                                                                                            
     word freq
1       a    3
2     the    3
3 chicken    2

包编译后的输出:

> 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)  
     word freq
1       a    3
2     the    3
3 chicken    2
>                                                                           
>                                                                                                      
> r <- list(a, b, d)                                                                                   
> common(r, overlap=2)                                                                                            
     word freq
1     the    4
2       a    3
3 chicken    2

Answer 1

您看到的错误很可能是因为没有导出公共通用的列表方法,因此common.default会被调用.您可以使用以下方法来解决此问题devtools::missing_s3- 该函数有点启发式,因此您可能会得到一些误报(例如,它目前无法判断这is.list不是一种方法).这是一个非常常见的问题(它已经抓住了我很多次),并且下一次roxygen迭代会做更多的事情来防止它.

目前,要使用roxygen正确导出S3方法,您需要执行以下任一操作:

• @S3method generic class (如果您不想记录该方法,则别无其他)
• @method generic class而 @export如果你要导出并记录.

你永远不应该@S3method和@method相同的文档块.

更新roxygen2> 3.0.0

现在,roxygen会自动判断函数是否为S3方法,因此:

• 永远不要使用@S3method或@method
• 使用@export,如果你想导出的方法(你通常做,即使通用不)