如何將字符串而非實時數字指定爲給定特定數據框的值？

Question

（再現的示例中所示）的功能如下causfinder::causalitycombinations：

causalitycombinations <- function (nvars, ncausers, ndependents) 
{ 
    independents <- combn(nvars, ncausers) 
    swingnumber <- dim(combn(nvars - ncausers, ndependents))[[2]] 
    numberofallcombinations <- dim(combn(nvars, ncausers))[[2]] * swingnumber 
    dependents <- matrix(, nrow = dim(combn(nvars, ncausers))[[2]] * swingnumber, ncol = ndependents) 
    for (i in as.integer(1:dim(combn(nvars, ncausers))[[2]])) { 
     dependents[(swingnumber * (i - 1) + 1):(swingnumber * i), ] <- t(combn(setdiff(seq(1:nvars), independents[, i]), ndependents)) 
    } 
    swingedindependents <- matrix(, nrow = dim(combn(nvars, ncausers))[[2]] * swingnumber, ncol = ncausers) 
    for (i in as.integer(1:dim(combn(nvars, ncausers))[[2]])) { 
     for (j in as.integer(1:swingnumber)) { 
      swingedindependents[(i - 1) * swingnumber + j, ] <- independents[, i] 
     } 
    } 
    independentsdependents <- cbind(swingedindependents, dependents) 
    others <- matrix(, nrow = dim(combn(nvars, ncausers))[[2]] * swingnumber, ncol = nvars - ncausers - ndependents) 
    for (i in as.integer(1:((dim(combn(nvars, ncausers))[[2]]) * 
     swingnumber))) { 
     others[i, ] <- setdiff(seq(1:nvars), independentsdependents[i, ]) 
    } 
    causalitiestemplate <- cbind(independentsdependents, others) 
    causalitiestemplate 
} 

列出了所有的多元因果關係的組合。例如，在一個4變量系統中，以系統的其他兩個變量爲條件，它們是（當變量被分配到數字1,2,3,4並且該分配在整個分析過程中保持）：

causalitycombinations(4,1,1) 

     [,1] [,2] [,3] [,4] 
[1,] 1 2 3 4 
[2,] 1 3 2 4 
[3,] 1 4 2 3 
[4,] 2 1 3 4 
[5,] 2 3 1 4 
[6,] 2 4 1 3 # to check whether 2nd var Grangercauses 4th var condioned on 1 and 3 
[7,] 3 1 2 4 
[8,] 3 2 1 4 
[9,] 3 4 1 2 
[10,] 4 1 2 3 
[11,] 4 2 1 3 
[12,] 4 3 1 2 

現在，

data.frame(from = causalitycombinations(4,1,1)[,1], to= causalitycombinations(4,1,1)[,2], 
       pval = c(0.5,0.6,0.1, #I just typed random p-vals here 
          0.4,0.8,0.2, 
          0.1,0.5,0.9, 
          0.0,0.0,0.1) 
       ) 

生產：

from to pval 
1  1 2 0.5 
2  1 3 0.6 
3  1 4 0.1 
4  2 1 0.4 
5  2 3 0.8 
6  2 4 0.2 
7  3 1 0.1 
8  3 2 0.5 
9  3 4 0.9 
10 4 1 0.0 
11 4 2 0.0 
12 4 3 0.1 

1. 在上述 「從」 和 「到」 列的條目，我想打印變量的名字（比如：「inf」，「gdp」，「exc」，「stock」）而不是他們的代表號碼（即1,2,3,4）。如何實現這一目標？

2. 同樣地，如何列出組合與字符串而非數字

Answer 1

我們可以更新與串矢量通過位置相匹配的名字列：

# update columns with matching name 
df1$from <- c("inf", "gdp", "exc", "stock")[df1$from] 
df1$to <- c("inf", "gdp", "exc", "stock")[df1$to] 

# result 
df1 
#  from to pval 
# 1 inf gdp 0.5 
# 2 inf exc 0.6 
# 3 inf stock 0.1 
# 4 gdp inf 0.4 
# 5 gdp exc 0.8 
# 6 gdp stock 0.2 
# 7 exc inf 0.1 
# 8 exc gdp 0.5 
# 9 exc stock 0.9 
# 10 stock inf 0.0 
# 11 stock gdp 0.0 
# 12 stock exc 0.1 

# input data 
df1 <- read.table(text=" from to pval 
1  1 2 0.5 
2  1 3 0.6 
3  1 4 0.1 
4  2 1 0.4 
5  2 3 0.8 
6  2 4 0.2 
7  3 1 0.1 
8  3 2 0.5 
9  3 4 0.9 
10 4 1 0.0 
11 4 2 0.0 
12 4 3 0.1", header = TRUE)