我有一个逻辑矩阵如下：
none ants beeswasps grasshoppers flies maggots beetles other
[1,] T F F F F F F F
[2,] T F F F F F F F
[3,] T F F F F F F F
[4,] T F F F F F F F
[5,] T F F F F F F F
[6,] T F F F F F F F
[7,] F F T F F F T T
我想在元素为true时更改具有相应列名称的元素，而不是其他文本。因此，结果矩阵将是：
none ants beeswasps grasshoppers flies maggots beetles other
[1,] none
[2,] none
[3,] none
[4,] none
[5,] none
[6,] none
[7,] beeswasps beetles other
这是一个包含许多T/F值的大矩阵，因此需要一个强大的方法，而不仅仅是创建另一个看起来像我想要的矩阵。
这是一个代码段
C = matrix(
c(T,T,T,T,T,T,F,F,F,F,F,F,F,F,F,F,F,F,F,F,T,F,F,F,F,F,F,F,F,F,F,F,F,F,F,F,F,F,F,F,F,F,F,F,F,F,F,F,T,F,F,F,F,F,F,T),
nrow=7, ncol=8)
colnames(C) <- c("none", "ants", "beeswasps", "grasshoppers", "flies", "maggots", "beetles", "other")
答案 0 :(得分：2)
我认为这可以胜任：
for (i in colnames(m)){
m[, i] <- ifelse(m[, i], i, "")
}
更改""以上（例如，使用NA），如果您想要其他内容填写＆＃34; no entry＆＃34;例。
以下是模仿矩阵的reproducible示例：
m <- structure(c(FALSE, FALSE, TRUE, TRUE, FALSE, FALSE, FALSE, FALSE,
TRUE, FALSE, FALSE, FALSE, FALSE, FALSE, TRUE, FALSE, FALSE,
FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE,
FALSE, FALSE, FALSE, FALSE, FALSE, TRUE, FALSE, FALSE, FALSE,
TRUE, TRUE, FALSE, FALSE, TRUE, FALSE, FALSE, TRUE, FALSE, FALSE,
TRUE, FALSE, FALSE, FALSE, FALSE, TRUE, TRUE, FALSE, FALSE, TRUE,
FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, TRUE,
FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE,
FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE), .Dim = c(10L,
8L), .Dimnames = list(NULL, c("none", "ants", "beeswasps", "grasshoppers",
"flies", "maggots", "beetles", "other")))
m之前：
> m
none ants beeswasps grasshoppers flies maggots beetles other
[1,] FALSE FALSE FALSE FALSE FALSE TRUE FALSE FALSE
[2,] FALSE FALSE FALSE TRUE FALSE TRUE FALSE FALSE
[3,] TRUE FALSE FALSE FALSE TRUE FALSE FALSE FALSE
[4,] TRUE FALSE FALSE FALSE FALSE FALSE TRUE FALSE
[5,] FALSE TRUE FALSE FALSE FALSE TRUE FALSE FALSE
[6,] FALSE FALSE FALSE TRUE TRUE FALSE FALSE FALSE
[7,] FALSE FALSE FALSE TRUE FALSE FALSE FALSE FALSE
[8,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
[9,] TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
[10,] FALSE FALSE FALSE TRUE FALSE FALSE FALSE FALSE
m之后：
> m
none ants beeswasps grasshoppers flies maggots beetles other
[1,] "" "" "" "" "" "maggots" "" ""
[2,] "" "" "" "grasshoppers" "" "maggots" "" ""
[3,] "none" "" "" "" "flies" "" "" ""
[4,] "none" "" "" "" "" "" "beetles" ""
[5,] "" "ants" "" "" "" "maggots" "" ""
[6,] "" "" "" "grasshoppers" "flies" "" "" ""
[7,] "" "" "" "grasshoppers" "" "" "" ""
[8,] "" "" "" "" "" "" "" ""
[9,] "none" "" "" "" "" "" "" ""
[10,] "" "" "" "grasshoppers" "" "" "" ""
答案 1 :(得分：1)
对于每一行x，您需要结果行ifelse(x, colnames(C), NA)。在apply中对此进行编码会给出：
> t(apply(C, 1, function(x) ifelse(x, colnames(C), NA)))
none ants beeswasps grasshoppers flies maggots beetles other
[1,] "none" NA NA NA NA NA NA NA
[2,] "none" NA NA NA NA NA NA NA
[3,] "none" NA NA NA NA NA NA NA
[4,] "none" NA NA NA NA NA NA NA
[5,] "none" NA NA NA NA NA NA NA
[6,] "none" NA NA NA NA NA NA NA
[7,] NA NA "beeswasps" NA NA NA "beetles" "other"
答案 2 :(得分：0)
或者你可以做什么完全矢量化（没有任何loop或apply家庭功能）：
> m
# none ants beeswasps grasshoppers flies maggots beetles other
# [1,] FALSE FALSE FALSE FALSE FALSE TRUE FALSE FALSE
# [2,] FALSE FALSE FALSE TRUE FALSE TRUE FALSE FALSE
# [3,] TRUE FALSE FALSE FALSE TRUE FALSE FALSE FALSE
# [4,] TRUE FALSE FALSE FALSE FALSE FALSE TRUE FALSE
# [5,] FALSE TRUE FALSE FALSE FALSE TRUE FALSE FALSE
# [6,] FALSE FALSE FALSE TRUE TRUE FALSE FALSE FALSE
# [7,] FALSE FALSE FALSE TRUE FALSE FALSE FALSE FALSE
# [8,] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
# [9,] TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
# [10,] FALSE FALSE FALSE TRUE FALSE FALSE FALSE FALSE
w=which(m==T, arr.ind = TRUE)[,2]
m[m==T]=colnames(m[,w])
m[m==F]=""
> m
# none ants beeswasps grasshoppers flies maggots beetles other
# [1,] "" "" "" "" "" "maggots" "" ""
# [2,] "" "" "" "grasshoppers" "" "maggots" "" ""
# [3,] "none" "" "" "" "flies" "" "" ""
# [4,] "none" "" "" "" "" "" "beetles" ""
# [5,] "" "ants" "" "" "" "maggots" "" ""
# [6,] "" "" "" "grasshoppers" "flies" "" "" ""
# [7,] "" "" "" "grasshoppers" "" "" "" ""
# [8,] "" "" "" "" "" "" "" ""
# [9,] "none" "" "" "" "" "" "" ""
# [10,] "" "" "" "grasshoppers" "" "" "" ""