四分位數按組數據幀

Question

我有一個看起來像這樣的數據保存爲新的變量：

id <- c(1,1,1,2,2,2,3,3,3,4,4,4,5,5,5,6,6,6,7,7,7,8,8,8,9,9,9) 
yr <- c(1,2,3,1,2,3,1,2,3,1,2,3,1,2,3,1,2,3,1,2,3,1,2,3,1,2,3) 
gr <- c(3,4,5,3,4,5,3,4,5,4,5,6,4,5,6,4,5,6,5,6,7,5,6,7,5,6,7) 
x <- c(33,48,31,41,31,36,25,38,28,17,39,53,60,60,19,39,34,47,20,28,38,15,17,49,48,45,39) 
df <- data.frame(id,yr,gr,x) 

    id yr gr x 
1 1 1 3 33 
2 1 2 4 48 
3 1 3 5 31 
4 2 1 3 41 
5 2 2 4 31 
6 2 3 5 36 
7 3 1 3 25 
8 3 2 4 38 
9 3 3 5 28 
10 4 1 4 17 
11 4 2 5 39 
12 4 3 6 53 
13 5 1 4 60 
14 5 2 5 60 
15 5 3 6 19 
16 6 1 4 39 
17 6 2 5 34 
18 6 3 6 47 
19 7 1 5 20 
20 7 2 6 28 
21 7 3 7 38 
22 8 1 5 15 
23 8 2 6 17 
24 8 3 7 49 
25 9 1 5 48 
26 9 2 6 45 
27 9 3 7 39 

我想創建一個包含計算的「X」的位數的數據幀的新變量在「年」和「gr」的每個獨特組合中。也就是說，我不想根據示例中的所有27行數據找到「x」的分位數，我想通過兩個分組變量計算分位數：yr和gr。例如，當yr = 1和gr = 3，yr = 1和gr = 4等時，「x」的分位數等。

一旦計算出這些值，我希望它們被附加到數據框中一列，說「x_quant」。

我能夠將數據拆分成我需要的單獨組，並且我知道如何計算分位數，但是我無法以適合於在現有中創建新列的方式組合這兩個步驟數據幀。

你們都可以提供的任何幫助將會非常令人滿意！非常感謝！

〜KJ

Answer 1

# turn "yr" and "gr" into sortable column 
df$y <- paste(df$yr,"",df$gr) 
df.ordered <- df[order(df$y),] #sort df based on group 
grp <- split(df.ordered,df.ordered$y);grp 

# get quantiles and turn results into string 
q <- vector('list') 
for (i in 1:length(grp)) { 
    a <- quantile(grp[[i]]$x) 
    q[i] <- paste(a[1],"",a[2],"",a[3],"",a[4],"",a[5]) 
} 
x_quant <- unlist(sapply(q, `[`, 1)) 
x_quant <- rep(x_quant,each=3) 

# append quantile back to data frame. Gave new column a more descriptive name 
df.ordered$xq_0_25_50_75_100 <- x_quant 
df.ordered$y <- NULL 
df <- df.ordered;df </pre> 

輸出：

> # turn "yr" and "gr" into sortable column 
> df$y <- paste(df$yr,"",df$gr) 
> df.ordered <- df[order(df$y),] #sort df based on group 
> grp <- split(df.ordered,df.ordered$y);grp 
$`1 3` 
    id yr gr x y 
1 1 1 3 33 1 3 
4 2 1 3 41 1 3 
7 3 1 3 25 1 3 

$`1 4` 
    id yr gr x y 
10 4 1 4 17 1 4 
13 5 1 4 60 1 4 
16 6 1 4 39 1 4 

$`1 5` 
    id yr gr x y 
19 7 1 5 20 1 5 
22 8 1 5 15 1 5 
25 9 1 5 48 1 5 

$`2 4` 
    id yr gr x y 
2 1 2 4 48 2 4 
5 2 2 4 31 2 4 
8 3 2 4 38 2 4 

$`2 5` 
    id yr gr x y 
11 4 2 5 39 2 5 
14 5 2 5 60 2 5 
17 6 2 5 34 2 5 

$`2 6` 
    id yr gr x y 
20 7 2 6 28 2 6 
23 8 2 6 17 2 6 
26 9 2 6 45 2 6 

$`3 5` 
    id yr gr x y 
3 1 3 5 31 3 5 
6 2 3 5 36 3 5 
9 3 3 5 28 3 5 

$`3 6` 
    id yr gr x y 
12 4 3 6 53 3 6 
15 5 3 6 19 3 6 
18 6 3 6 47 3 6 

$`3 7` 
    id yr gr x y 
21 7 3 7 38 3 7 
24 8 3 7 49 3 7 
27 9 3 7 39 3 7 

> # get quantiles and turn results into string 
> q <- vector('list') 
> for (i in 1:length(grp)) { 
+ a <- quantile(grp[[i]]$x) 
+ q[i] <- paste(a[1],"",a[2],"",a[3],"",a[4],"",a[5]) 
+ } 
> x_quant <- unlist(sapply(q, `[`, 1)) 
> x_quant <- rep(x_quant,each=3) 
> # append quantile back to data frame 
> df.ordered$xq_0_25_50_75_100 <- x_quant 
> df.ordered$y <- NULL 
> df <- df.ordered 
> df 
    id yr gr x  xq_0_25_50_75_100 
1 1 1 3 33  25 29 33 37 41 
4 2 1 3 41  25 29 33 37 41 
7 3 1 3 25  25 29 33 37 41 
10 4 1 4 17 17 28 39 49.5 60 
13 5 1 4 60 17 28 39 49.5 60 
16 6 1 4 39 17 28 39 49.5 60 
19 7 1 5 20 15 17.5 20 34 48 
22 8 1 5 15 15 17.5 20 34 48 
25 9 1 5 48 15 17.5 20 34 48 
2 1 2 4 48 31 34.5 38 43 48 
5 2 2 4 31 31 34.5 38 43 48 
8 3 2 4 38 31 34.5 38 43 48 
11 4 2 5 39 34 36.5 39 49.5 60 
14 5 2 5 60 34 36.5 39 49.5 60 
17 6 2 5 34 34 36.5 39 49.5 60 
20 7 2 6 28 17 22.5 28 36.5 45 
23 8 2 6 17 17 22.5 28 36.5 45 
26 9 2 6 45 17 22.5 28 36.5 45 
3 1 3 5 31 28 29.5 31 33.5 36 
6 2 3 5 36 28 29.5 31 33.5 36 
9 3 3 5 28 28 29.5 31 33.5 36 
12 4 3 6 53  19 33 47 50 53 
15 5 3 6 19  19 33 47 50 53 
18 6 3 6 47  19 33 47 50 53 
21 7 3 7 38 38 38.5 39 44 49 
24 8 3 7 49 38 38.5 39 44 49 
27 9 3 7 39 38 38.5 39 44 49 
>