Question

嗨我有一个字符表，我试图将其转换为数字：

vec1 <- c("B","D","E","NA")
vec2 <- c("B","D","E","NA")
vec3 <- c("B","C","E","NA")
vec4 <- c("B","D","E","NA")
vec5 <- c("B","NA","E","E")
vec6 <- c("B","NA","NA","NA")
mat1 <- (cbind(vec1,vec2,vec3,vec4,vec5,vec6))

mat1
#     vec1 vec2 vec3 vec4 vec5 vec6
#[1,] "B"  "B"  "B"  "B"  "B"  "B" 
#[2,] "D"  "D"  "C"  "D"  "NA" "NA"
#[3,] "E"  "E"  "E"  "E"  "E"  "NA"
#[4,] "NA" "NA" "NA" "NA" "E"  "NA"

mat1[mat1 == "NA"] <- 0
mat1[mat1 != 0] <- 1

mat1
#     vec1 vec2 vec3 vec4 vec5 vec6
#[1,] "1"  "1"  "1"  "1"  "1"  "1" 
#[2,] "1"  "1"  "1"  "1"  "0"  "0" 
#[3,] "1"  "1"  "1"  "1"  "1"  "0" 
#[4,] "0"  "0"  "0"  "0"  "1"  "0" 

mat2
#     vec1 vec2 vec3 vec4 vec5 vec6
#[1,]    2    2    2    2    2    2
#[2,]    2    2    2    2    1    1
#[3,]    2    2    2    2    2    1
#[4,]    1    1    1    1    2    1

mat2 <- sapply(as.data.frame(mat1), as.numeric)

这可以使用，即我可以从所有值中减去1以得到原始的引用值，但是如何将引用的值更改为数值？

谢谢，

马特

Answer 1

尽管@ Vlo不满（并且赋值箭头的方向不正确），但是从字符到数字的向量类的更改是相当安全的。他的代码不必要地复杂，因为矩阵属于character类，而不是factor，因此转换为data.frame然后需要使用as.character是不必要的。 R矩阵不能是因子，因为矩阵不应该具有除dim向量和dimname-lists（以及携带其自己的类的“核心”原子向量）之外的任何属性。有一个class<-函数：

 class(mat1) <- "numeric"   # See the help page:  ?`class<-`

它也适用于符合逻辑的角色：

> m <- matrix( c('TRUE','FALSE'), 4,4)
> class(m) <- 'logical'     # assignment of `as.logical` to `m[]` fails.
> m
      [,1]  [,2]  [,3]  [,4]
[1,]  TRUE  TRUE  TRUE  TRUE
[2,] FALSE FALSE FALSE FALSE
[3,]  TRUE  TRUE  TRUE  TRUE
[4,] FALSE FALSE FALSE FALSE

如果您想使用apply函数，这将成功：

> mat2 <- apply(mat1,2, function(x) as.numeric(x) )
> mat2
     vec1 vec2 vec3 vec4 vec5 vec6
[1,]    1    1    1    1    1    1
[2,]    1    1    1    1    0    0
[3,]    1    1    1    1    1    0
[4,]    0    0    0    0    1    0

R将引用的数字转换为数字

1 个答案: