18

使用 R 中的命令paste,我想同时使用参数sepcollapse,但你不能缩写collapsecoll甚至collaps. 然而,对于其他功能,部分缩写有效。

例如:

paste(letters, colla=", ")
# [1] "a , " "b , " "c , " "d , " "e , " "f , " "g , " "h , " "i , " "j , " "k , " "l , " "m , " "n , " "o , " "p , " "q , " "r , "
[19] "s , " "t , " "u , " "v , " "w , " "x , " "y , " "z , "
paste(letters, collapse=", ")
# [1] "a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z"

没有其他以 开头的参数可以折叠coll,这会干扰部分参数匹配。

为什么我在调用时必须输入整个参数名称paste,而我不必为其他函数输入?

4

2 回答 2

23

我相信这...是导致您必须使用精确参数匹配的粘贴。具体来说,在参数列表中的事实,collapse之后。...

示范:

f1 <- function(x, collapse) cat("collapse",collapse)
f2 <- function(..., collapse) cat("collapse",collapse)
f3 <- function(collapse, ...) cat("collapse",collapse)

> f1(c="test",1)
collapse test
> f2(1,c="test")
Error in base::cat(...) : argument "collapse" is missing, with no default
> f2(1,collapse="test")
collapse test
> f3(c="test",1)
collapse test
于 2012-12-05T13:46:21.573 回答
2

包装器功能可能会有所帮助,就像paste0

p <- function(..., s=" ", clap=NULL) {   # or whichever abbreviation you prefer. I originally had `col`, but that was dumb. 
   paste(..., sep=s, collapse=clap)
}

p0 <- function(...,  clap=NULL) {
   paste(..., sep="", collapse=clap)
}

例如:

p(c("hello", "world"), c("abc", "123"), clap="$")
# [1] "hello abc$world 123"


p0(c("hello", "world"), c("abc", "123"), clap="$")
# [1] "helloabc$world123"
于 2012-12-05T18:47:10.457 回答