我有一个 4 列和 20000 多行的数据矩阵，其中包含带有数字、大写字母、破折号和点的条目。我想将它们表示为它们的 ASCII 码、数字。我尝试了 strtoi、chartoraw 和 utf8toint 函数，但不断收到错误，主要是“要替换的项目数不是替换长度的倍数”。
如何在没有任何 NA 强制的情况下将整个矩阵转换为数值矩阵？
【问题讨论】：
dput(head(your_matrix)，因为我不知道如何在一个矩阵中有不同的类。
标签： r matrix character ascii type-conversion
> (tmp <- matrix(c(LETTERS[1:20],"3","?","a","-"),6) )
[,1] [,2] [,3] [,4]
[1,] "A" "G" "M" "S"
[2,] "B" "H" "N" "T"
[3,] "C" "I" "O" "3"
[4,] "D" "J" "P" "?"
[5,] "E" "K" "Q" "a"
[6,] "F" "L" "R" "-"
> (tmp <-apply(tmp,c(1,2), utf8ToInt) )
[,1] [,2] [,3] [,4]
[1,] 65 71 77 83
[2,] 66 72 78 84
[3,] 67 73 79 51
[4,] 68 74 80 63
[5,] 69 75 81 97
[6,] 70 76 82 45
> intToUtf8(tmp)
[1] "ABCDEFGHIJKLMNOPQRST3?a-"
根据评论编辑：
#Altered paste function which we will call twice
pasteC <- function(x){paste(x,collapse="")}
#Replicate your example of a cell elements being a list
values <-c(LETTERS[1:20],"3","?","a","-")
#place in a data.frame
tmp <- data.frame(id = 1:20)
tmp$var <- list(values)
tmp$var.int <- sapply(tmp$var, function(x) pasteC(utf8ToInt(pasteC(x)) ) )
tmp
【讨论】：
不确定您的问题，但如果您想将字符矩阵转换为数字，请考虑使用加密摘要。
x <- matrix(letters[1:9],3,3)
x
[,1] [,2] [,3]
[1,] "a" "d" "g"
[2,] "b" "e" "h"
[3,] "c" "f" "i"
digest(x)
[1] "b94e24be564d1af6dfedba8c3616b56d"
【讨论】：