将“字符”矩阵转换为“逻辑”

时间:2013-10-24 14:56:00

标签: r matrix

我有一个矩阵(值class character就像这样:

mat <- matrix(c("0", "TRUE", "1", "2",
                "FALSE", "TRUE", "TRUE", "2"), nrow = 4, ncol = 2)
#> mat
#     [,1]   [,2]   
#[1,] "0"    "FALSE"
#[2,] "TRUE" "TRUE" 
#[3,] "1"    "TRUE" 
#[4,] "2"    "2"  

我需要将它转换为这样的矩阵:

      [,1]  [,2]
[1,] FALSE FALSE
[2,]  TRUE  TRUE
[3,]  TRUE  TRUE
[4,]  TRUE  TRUE

as.logicalNA输出为“字符数字”值,而as.numericNA输出为“字符逻辑”值。

我找到了一个解决方案,但我认为我错过了一些明显可以立即转换的内容:

new_mat2 <- array(as.numeric(mat), dim(mat))
new_mat <- array(as.logical(mat), dim(mat))

new_mat[is.na(new_mat)] <- new_mat2[is.na(new_mat)]
mat2 <- array(as.logical(new_mat), dim(new_mat))

#> mat2
#      [,1]  [,2]
#[1,] FALSE FALSE
#[2,]  TRUE  TRUE
#[3,]  TRUE  TRUE
#[4,]  TRUE  TRUE

有什么建议吗?

4 个答案:

答案 0 :(得分:14)

试试这个:

> mat[,] <- ifelse(mat %in% c("0", "FALSE"), FALSE, TRUE) # pay attention to @Señor O comment to shorten this step.
> mat
     [,1]    [,2]   
[1,] "FALSE" "FALSE"
[2,] "TRUE"  "TRUE" 
[3,] "TRUE"  "TRUE" 
[4,] "TRUE"  "TRUE" 

如果您希望mat成为由逻辑值组成的data.frame,则:

> mat <- sapply(as.data.frame(mat), as.logical)
> mat
        V1    V2
[1,] FALSE FALSE
[2,]  TRUE  TRUE
[3,]  TRUE  TRUE
[4,]  TRUE  TRUE
> sapply(mat, class)  # checking class
[1] "logical" "logical" "logical" "logical" "logical" "logical" "logical" "logical"

答案 1 :(得分:3)

NA是一个逻辑常数,因此它必须遵守真值表定律。我们可以利用这些来做......

mat2 <- as.logical(mat) & ( as.integer(mat) > 0 )
mat2[is.na(mat2)] <- TRUE
dim(mat2) <- dim(mat)
#      [,1]  [,2]
#[1,] FALSE FALSE
#[2,]  TRUE  TRUE
#[3,]  TRUE  TRUE
#[4,]  TRUE  TRUE

如果您的原始矩阵中没有NA,那么这只会 ,因为我们依赖于NA本身就是一个逻辑常量。如果给定的值为FALSE,则as.logical将评估为TRUE,但不能(&)为as.integer,因此会FALSE 。如果"0" as.logical将评估为NA,而as.integer > 0将评估为FALSENA&amp; FALSE评估为FALSE。满足两个FALSE条件,因此剩余的NA 必须TRUE

答案 2 :(得分:3)

mat!=&#34; 0&#34; &安培; mat!=&#34; FALSE&#34;

> mat
     [,1]   [,2]   
[1,] "0"    "FALSE"
[2,] "TRUE" "TRUE" 
[3,] "1"    "TRUE" 
[4,] "2"    "2"    

> mat != "0" & mat != "FALSE"
      [,1]  [,2]
[1,] FALSE FALSE
[2,]  TRUE  TRUE
[3,]  TRUE  TRUE
[4,]  TRUE  TRUE

答案 3 :(得分:0)

我所知道的最直接的是:

as.numeric(factor(matrix))

其中'matrix'是我们想要更改为数字

的矩阵的名称