R-分组依据,然后遍历分组并提取原始列值

时间:2020-10-08 20:01:38

标签: r dplyr

我的数据框(df):

ID1 | ID2 |  V1  |  V2 |  V3
A   | B   | var1 | foo |  1   
C   | D   | var2 | bar |  2
E   | F   | var3 | foo |  3
G   | F   | var3 | foo |  3
H   | I   | var4 | zap |  2
...

ID1和ID2包含重叠的值,因为它是上矩阵三角形的长格式版本,其中删除了相同的比较符号(例如A,A),并添加了一些其他元数据(V1,V2,V3)。

以上内容必须按V1,V2和V3分组,最终输出将是组成每个组的ID列表(ID1和ID2包含重叠的变量)(每个列表是一个单独的文件)。 / p>

到目前为止,我已经对变量进行了分组,但停留在如何遍历dplyr的每个组并为每个组获取值的工作上。

我想到的伪代码如下:

# Group
cluster <- df %>% group_by(V1,V2,V3) 

[?] # loop through each group in cluster
    
    [?] # get group values as x, y and z
    
    # Get IDs into lists and merge
    ID1 <- df %>% filter(V1 == x, V2 ==y, V3 == z) %>%
           pull(ID1)

    ID2 <- df %>% filter(V1 == x, V2 ==y, V3 == z) %>%
           pull(ID2)

    merged <- c(ID1,ID2) 
   
    merged_unique <- unique(unlist(merged))

    # Print out to file
    fileConn <- file(paste(X ,Y, Z,"txt", sep="."))
    writeLines(merged_unique, fileConn)
    close(fileConn)

我希望我的最终输出是:

  • 文件var1.foo.1.txt:
A
B
  • 文件var2.bar.2.txt:
C
D
  • 文件var3.foo.3.txt:
E
F
G
  • 文件var4.zap.2.txt:
H
I

感谢您的帮助。

2 个答案:

答案 0 :(得分:1)

我不确定预期的输出。希望下面的代码能有所帮助

lapply(
  split(
    df[c("ID1", "ID2")],
    with(df, do.call(paste, list(V1, V2, V3)))
  ),
  function(v) unique(unlist(v))
)

给出

$`var1 foo 1`
[1] "A" "B"

$`var2 bar 2`
[1] "C" "D"

$`var3 foo 3`
[1] "E" "G" "F"

$`var4 zap 2`
[1] "H" "I"

如果要将所有组保存到不同的*.txt文件中,可以尝试以下代码

lst <- lapply(
  split(
    df[c("ID1", "ID2")],
    with(df, do.call(paste, list(V1, V2, V3,sep = "_")))
  ),
  function(v) unique(unlist(v))
)

sapply(seq_along(lst),function(k) writeLines(lst[[k]],paste0(names(lst[k]),".txt")))

答案 1 :(得分:1)

生成“数据”:

val <- df$B[match('b', df$A)]

集群数据并获得唯一集群:

df <- data.frame("ID1" = c("A","B","C","E","G","H"), "ID2" = c("B","B","D","Fe","Fe","I"), "V1" = c("var1","var1","var2","var3","var3","var4"),"V2" = c("foo","foo","bar","foo","foo","zed"), "V3" = c(1,1,2,3,3,2))

循环浏览,假设仅两个ID列和3个要素列,然后将每个结果打印到一个新文件中:

library(dplyr)
df_clust <- df %>% group_by(V1,V2,V3) 
df_tally <- df_clust %>% tally()