R 中的子集和拆分数据框的问题（使用 cbind.fill 和 rbind.fill 制作）

Question

##### Code to generate the sample DF

cbind.fill <- function(...){
                            nm <- list(...) 
                            nm <- lapply(nm, as.matrix)
                            n <- max(sapply(nm, nrow)) 
                            do.call(cbind, lapply(nm, function (x) 
                            rbind(x, matrix(, n-nrow(x), ncol(x))))) 
                        }

a <- data.frame(c("Pen","Pen","Pen","Ryu","Ryu","Ken"))
b <- data.frame(c("banana", "apple", 23, "Carrot", "grape"))
c <- data.frame(c("ryu",45,"ynwa"))
final <- data.frame(cbind.fill(a,b,c))
colnames(final) <- c("A","B","C")

    A      B    C           #This is my sample data set
1 Pen banana  ryu
2 Pen  apple   45
3 Pen     23 ynwa
4 Ryu Carrot <NA>
5 Ryu  grape <NA>
6 Ken   <NA> <NA>

################## 预期输出

输出请求：我需要将上面的输出拆分为 3 个数据帧，如下所示：

    A      B    C           #This is my 1st data frame
1 Pen banana  ryu
2 Pen  apple   45
3 Pen     23 ynwa

    A      B    C           #This is my 2nd data frame

4 Ryu Carrot <NA>
5 Ryu  grape <NA>

    A      B    C           #This is my 3rd data frame
6 Ken   <NA> <NA>

#######到目前为止我已经试过了

> final[final=="Pen",]

        #when I subset "Pen", Now i have to remove the NA

        A      B    C
1     Pen banana  ryu
2     Pen  apple   45
3     Pen     23 ynwa
NA   <NA>   <NA> <NA>
NA.1 <NA>   <NA> <NA>
NA.2 <NA>   <NA> <NA>
NA.3 <NA>   <NA> <NA>

> final_pen <- final[complete.cases(final=="Pen"),]

    #I use complete.cases to remove NA, and this looks exactly how i want, I move onto RYU

    A      B    C
1 Pen banana  ryu
2 Pen  apple   45
3 Pen     23 ynwa



> final_ryu <- final[final=="Ryu",] 

    #I subset Ryu

        A      B    C
4     Ryu Carrot <NA>
5     Ryu  grape <NA>
NA   <NA>   <NA> <NA>
NA.1 <NA>   <NA> <NA>
NA.2 <NA>   <NA> <NA>
NA.3 <NA>   <NA> <NA>

现在，当我在这里做一个完整的案例时，整个数据框都消失了，因为这里的每一行和每一列都有一个 NA。我期望的输出如下：

        A      B
4     Ryu Carrot 
5     Ryu  grape

我不想硬编码和子集化，因为我会对大量数据执行此操作并使用循环将大数据帧拆分为多个数据帧。请帮忙。这是我的第二个 post，我仍在学习掌握它的窍门。所以如果你认为这是一个愚蠢的问题，请不要投票。

Answer 1

从示例来看，您似乎想要将数据帧拆分为多个，然后从子帧中删除所有为空的列。尝试这样的事情。

您将不得不使用列表来维护创建的新数据框。

# Sample Data Frame
> df = data.frame( Column1 = paste0('a',c(rep(1,5),rep(2,5),rep(3,5))), Column2 = c(rep(1:2, 5), rep(NA,5)), Column3 = c(rep(NA,5),rep(1:2,5))  )
> df
   Column1 Column2 Column3
1       a1       1      NA
2       a1       2      NA
3       a1       1      NA
4       a1       2      NA
5       a1       1      NA
6       a2       2       1
7       a2       1       2
8       a2       2       1
9       a2       1       2
10      a2       2       1
11      a3      NA       2
12      a3      NA       1
13      a3      NA       2
14      a3      NA       1
15      a3      NA       2

#First. Lets Split on 1st Column.
> dflist = list()
> uniquevals = unique(df$Column1) 
> for (i in 1:length(uniquevals)) {
+     dflist[[i]] = df[df$Column1 == uniquevals[i],]
+ }
> dflist
[[1]]
  Column1 Column2 Column3
1      a1       1      NA
2      a1       2      NA
3      a1       1      NA
4      a1       2      NA
5      a1       1      NA

[[2]]
   Column1 Column2 Column3
6       a2       2       1
7       a2       1       2
8       a2       2       1
9       a2       1       2
10      a2       2       1

[[3]]
   Column1 Column2 Column3
11      a3      NA       2
12      a3      NA       1
13      a3      NA       2
14      a3      NA       1
15      a3      NA       2

#Next - Let's remove all columns where all values are NA
> newlist = lapply(X = dflist, FUN = function(df) { return(  df[,apply(X = df, MARGIN = 2, FUN = function(x) { !all(is.na(x)) } )] ) }  )
> newlist
[[1]]
  Column1 Column2
1      a1       1
2      a1       2
3      a1       1
4      a1       2
5      a1       1

[[2]]
   Column1 Column2 Column3
6       a2       2       1
7       a2       1       2
8       a2       2       1
9       a2       1       2
10      a2       2       1

[[3]]
   Column1 Column3
11      a3       2
12      a3       1
13      a3       2
14      a3       1
15      a3       2

完成！！

R 中的子集和拆分数据框的问题（使用 cbind.fill 和 rbind.fill 制作）

Problems to subset and split data frame in R (made using cbind.fill and rbind.fill)

r

subset

dataframe

dplyr