在data.frame中为引用到data.frame的不同列的列名设置值

Question

很难描述我的需求，所以我将用一个直观的例子来说明。

我有一个data.frame，它类似于:

foo <- data.frame(
id=c("blah", "foo", "bar"), 
minplayers=c(2,3,1), 
maxplayers=c(4,4,3), 
players1.cash=c(10,20,10), 
players2.cash=c(0,10,10),
players3.cash=c(1,0,0),
players4.cash=c(8,8,9)
)

给出如下内容:

+-----+-----+-----+---------------+---------------+---------------+---------------+
|id   | min | max | players1.cash | players2.cash | players3.cash | players4.cash |
+-----+-----+-----+---------------+---------------+---------------+---------------+
|blah |  2  |  4  |     10        |      0        |       1       |       8       |
+-----+-----+-----+---------------+---------------+---------------+---------------+
|foo  |  3  |  4  |     20        |      10       |       0       |       8       |
+-----+-----+-----+---------------+---------------+---------------+---------------+
|bar  |  1  |  3  |     10        |      10       |       0       |       9       |
+-----+-----+-----+---------------+---------------+---------------+---------------+

我需要的是将所有玩家n设置为NA。如果n在 {min,max}间隔之外(对于该行)，则为每行提供现金值。在图片:

+-----+-----+-----+---------------+---------------+---------------+---------------+
|id   | min | max | players1.cash | players2.cash | players3.cash | players4.cash |
+-----+-----+-----+---------------+---------------+---------------+---------------+
|blah |  2  |  4  |     NA        |      0        |       1       |       8       |
+-----+-----+-----+---------------+---------------+---------------+---------------+
|foo  |  3  |  4  |     NA        |      NA       |       0       |       8       |
+-----+-----+-----+---------------+---------------+---------------+---------------+
|bar  |  1  |  3  |     10        |      10       |       0       |       NA      |
+-----+-----+-----+---------------+---------------+---------------+---------------+

换句话说:我只是想让玩家的数字(1到4)在每一行的最小/最大的各自边界。如果是，我想保留球员的价值，如果不是，那就写上NA。

Answer 1

您可以使用vectorized方法:

ix = grep("^players(\d+)\.cash", names(foo))
numbers = as.numeric(gsub("^players(\d+)\.cash", "\1", names(foo)[ix]))
m = matrix(numbers, ncol=length(ix), nrow=nrow(foo), byrow=T)
foo[ix][!(m>=foo$minplayers & m<=foo$maxplayers)] <-NA
#> foo
#    id minplayers maxplayers players1.cash players2.cash players3.cash players4.cash
#1 blah          2          4            NA             0             1             8
#2  foo          3          4            NA            NA             0             8
#3  bar          1          3            10            10             0            NA