如何从TDM矩阵中分离出二元数的数值向量

Question

我在R中有一个大数字（46201个元素，3.3 Mb）。

 tdm_pairs.matrix <- as.matrix(tdm_pairs)
 top_pairs <- colSums(tdm_pairs.matrix)
 head(sort(top_pairs, decreasing = T),2)

  i know  i dont i think   i can  i just  i want 
 46      42      41      31      30      28 

我试着把每个分开：

 unlist(strsplit(as.character(top_pairs)," ")) 
 "46" "42" "41" "31" "30" "28"

我正在寻找拆分每个，所以输出将类似于此：

 "i" "know" "46"
 "i" "dont" "42"

Answer 1

由于文件很大，因此您可能要使用stringi

library(stringi)
data.frame(stri_split_fixed(names(top_pairs), " ", simplify=T),
    count=top_pairs, row.names=seq_along(top_pairs))

#   X1   X2 count
# 1  i know    46
# 2  i dont    42

Answer 2

像这样吗

> top_pairs <- structure(c(46, 42), .Names = c("i know", "i dont"))
> do.call(rbind, strsplit(paste(names(top_pairs), top_pairs), " "))
     [,1] [,2]   [,3]
[1,] "i"  "know" "46"
[2,] "i"  "dont" "42"

或者，如果您想保留数值，则可以使用tidyr转换为数据框：

> library(magrittr)
> library(tidyr)
> data.frame(names=names(top_pairs), count=top_pairs) %>%
    separate(names, into=c("name1", "name2"), sep=" ") %>%
    set_rownames(NULL)

  name1 name2 count
1     i  know    46
2     i  dont    42