[英]r - How to combine multiple lists of lists into a dataframe
I am trying to combine 2 lists of lists that are of unequal length into a data frame. 我正在尝试将长度不等的2个列表列表合并到一个数据帧中。
I am starting with a list containing 2 matrices. 我从一个包含2个矩阵的列表开始。
mtx_a <- matrix(data = c(1:24), nrow = 4)
mtx_b <- matrix(data = c(25:36), nrow = 3)
row.names(mtx_a) <- c("A", "B", "C", "D")
row.names(mtx_b) <- c("A", "B", "C")
colnames(mtx_a) <- c("V1", "V2", "W1", "W2", "X1", "X2")
colnames(mtx_b) <- c("Y1", "Y2", "Z1", "Z2")
mtx_list <- list(mtx_a, mtx_b)
names(mtx_list) <- c("mtx_a", "mtx_b")
mtx_list
I have extracted a specific row based on rowname to examine. 我已经提取了基于行名的特定行进行检查。
mtx_list <- lapply(mtx_list, function(mtx_list){
mtx_list[row.names(mtx_list) %in% c("A"),]})
Next I extracted specific columns based on their index. 接下来,我根据它们的索引提取了特定的列。 (Alternating columns are equivalent to condition 1 and 2). (备用列等效于条件1和2)。
cond_1 <- lapply(lapply(mtx_list, function(mtx_list) {
mtx_list[c(T,F)]}), unname)
cond_2 <- lapply(lapply(mtx_list, function(mtx_list) {
mtx_list[c(F,T)]}), unname)
I am trying to generate a data frame that looks like this: 我正在尝试生成一个看起来像这样的数据框:
cond_1 cond_2
mtx_a 1 5
mtx_a 9 13
mtx_a 17 21
mtx_b 25 28
mtx_b 31 34
I have tried the following but have not have any success: 我尝试了以下方法,但没有成功:
list(cond_1, cond_2)
library(plyr)
ldply(c(cond_1, cond_2))
Extract all the "A"
rows first, then just feed into a 2-column matrix: 首先提取所有"A"
行,然后将其输入2列矩阵:
matrix(unlist(lapply(mtx_list, `[`, "A", )), ncol=2, byrow=TRUE)
# [,1] [,2]
#[1,] 1 5
#[2,] 9 13
#[3,] 17 21
#[4,] 25 28
#[5,] 31 34
That can be wrapped in data.frame()
if need be. 如果需要,可以将其包装在data.frame()
中。
You can use Map
to cbind
respective list elements. 您可以使用Map
cbind
各个列表元素。
do.call(rbind, Map(cbind, cond_1, cond_2))
# [,1] [,2]
#[1,] 1 5
#[2,] 9 13
#[3,] 17 21
#[4,] 25 28
#[5,] 31 34
A little more work can give you slightly better result 多做一些工作可以为您带来更好的结果
data.frame(mtx = unlist(lapply(1:length(cond_1),
function(i)
rep(names(cond_1)[i], length(cond_1[[i]])))),
do.call(rbind, Map(cbind, cond_1, cond_2)))
# mtx X1 X2
#1 mtx_a 1 5
#2 mtx_a 9 13
#3 mtx_a 17 21
#4 mtx_b 25 28
#5 mtx_b 31 34
Here is an alternative using sapply
. 这是使用sapply
的替代方法。 I wrapped it in a function for easier repeated use. 我将其包装在一个函数中,以方便重复使用。
getter <- function(rowName) {
# loop through matrices in list, pull out rows that match name
temp <- unlist(sapply(mtx_list, function(x) x[rowName,]), use.names=FALSE)
# return data.frame with alternating values
data.frame(var1=temp[c(TRUE, FALSE)], var2=temp[c(FALSE, TRUE)])
}
getter("A")
var1 var2
1 1 5
2 9 13
3 17 21
4 25 28
5 31 34
Note that it is necessary that all matrices in the list contain the row name for this function to work. 请注意,列表中的所有矩阵都必须包含行名称,此功能才能起作用。
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