strsplit 并不总是在 '?' 上拆分

Question

我想（对于 LSAfun::genericSummary）将一些字符串拆分为 c(".", "!", "?")。我使用选项 fixed = TRUE 但它仍然是 return 的错误结果。我想明白为什么它不起作用，因为我无法修改调用。

实际上，它不是直接调用的，而是通过LSAfun::genericSummary调用的。结果不是预期的，因为 strsplit 意外的结果。

strsplit("Faut-il reconnaitre le vote blanc ? Faut-il rendre le vote obligatoire ?",
         split = c(".", "!", "?"), fixed = TRUE)[[1]]

returns :

[1] "Faut-il reconnaitre le vote blanc ? Faut-il rendre le vote obligatoire ?"

预计：

[1] "Faut-il reconnaitre le vote blanc " " Faut-il rendre le vote obligatoire " ""

我迷路了...有人需要解释吗？

> sessionInfo()
R version 3.3.0 (2016-05-03)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 7 x64 (build 7601) Service Pack 1

locale:
[1] LC_COLLATE=French_France.1252  LC_CTYPE=French_France.1252    LC_MONETARY=French_France.1252 LC_NUMERIC=C                   LC_TIME=French_France.1252    

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

loaded via a namespace (and not attached):
[1] tools_3.3.0 yaml_2.1.18

函数：

function (text, k, split = c(".", "!", "?"), min = 5, breakdown = FALSE, 
    ...) 
{
    sentences <- unlist(strsplit(text, split = split, fixed = T))
    if (breakdown == TRUE) {
        sentences <- breakdown(sentences)
    }
    sentences <- sentences[nchar(sentences) > min]
    td = tempfile()
    dir.create(td)
    for (i in 1:length(sentences)) {
        docname <- paste("sentence", i, ".txt", sep = "")
        write(sentences[i], file = paste(td, docname, sep = "/"))
    }
    A <- textmatrix(td, ...)
    rownames <- rownames(A)
    colnames <- colnames(A)
    A <- matrix(A, nrow = nrow(A), ncol = ncol(A))
    rownames(A) <- rownames
    colnames(A) <- colnames
    unlink(td, T, T)
    Vt <- lsa(A, dims = length(sentences))$dk
    snum <- vector(length = k)
    for (i in 1:k) {
        snum[i] <- names(Vt[, i][abs(Vt[, i]) == max(abs(Vt[, 
            i]))])
    }
    snum <- gsub(snum, pattern = "[[:alpha:]]", replacement = "")
    snum <- gsub(snum, pattern = "[[:punct:]]", replacement = "")
    snum <- as.integer(snum)
    summary.sentences <- sentences[snum]
    return(summary.sentences)
}
<environment: namespace:LSAfun>

Answer 1

对于多个 split 元素，将其放在 [] 内并删除 fixed = TRUE 或 paste 带有 | 的模式以拆分其中之一

strsplit("Faut-il reconnaitre le vote blanc ? Faut-il rendre le vote obligatoire ?",
            split = "[.!?]")[[1]]

根据?strsplit

split - If empty matches occur, in particular if split has length 0, x is split into single characters. If split has length greater than 1, it is re-cycled along x.

Answer 2

您也可以省略 fixed = TRUE 部分并转义字符，即

strsplit("Faut-il reconnaitre le vote blanc ? Faut-il rendre le vote obligatoire ?", c("\.|!|\?"))

当然它不会那么有效，因为我们正在通过正则表达式引擎。

strsplit 并不总是在 '?' 上拆分

strsplit doesn't always split on '?'

r

strsplit