我想遍历一个子列表,其中"sub sub"列表保持不变。我提到的所有代码都只是可重现的示例(请注意,实际数据非常大(,应该可以毫无问题地工作。
我有一个列表列表,每个列表有 2 个子列表,如下所示:
library(data.table)
library(mice)
df <- fread(
"A B C D E F iso year
0 A NA 1 NA NA NLD 2009
1 Y NA 2 NA NA NLD 2009
0 Q NA 3 NA NA AUS 2011
1 NA NA 4 NA NA AUS 2011
0 0 NA 7 NA NA NLD 2008
1 1 NA 1 NA NA NLD 2008
0 1 NA 3 NA NA AUS 2012
0 NA 1 NA 1 NA ECU 2009
1 NA 0 NA 2 0 ECU 2009
0 NA 0 NA 3 0 BRA 2011
1 NA 0 NA 4 0 BRA 2011
0 NA 1 NA 7 NA ECU 2008
1 NA 0 NA 1 0 ECU 2008
0 NA 0 NA 3 2 BRA 2012
1 NA 0 NA 4 NA BRA 2012",
header = TRUE
)
# Creates a list
df_iso <- split(df, df$iso) # Creates a list of dataframes
# Creates a list of lists
mylist.names <- names(df_iso)
df_iso_list <- vector("list", length(mylist.names))
names(df_iso_list) <- mylist.names
f <- function(x) return(list(a = list(), b = list()))
new_nested <- lapply(df_iso, f)
现在new_nested$AUS$a
访问子列表AUS
的列表a
。目前为止,一切都好。
我想将下面的两个列表(df_iso_1, df_iso_2
(重新分发到我刚刚创建的列表结构中。
df_iso_1 = list()
for (i in 1:length(df_iso)) {
tryCatch({
df_iso_1 [[i]] <- mice(df_iso[[i]], m=1, maxit = 5, seed=1)
if (i==1000) stop("stop")
}, error=function(e){cat("ERROR :",conditionMessage(e), "n")})
}
df_iso_2 = list()
for (i in 1:length(df_iso)) {
tryCatch({
df_iso_2 [[i]] <- mice(df_iso[[i]], m=1, maxit = 5, seed=2)
if (i==1000) stop("stop")
}, error=function(e){cat("ERROR :",conditionMessage(e), "n")})
}
names(df_iso_1) <- names(df_iso)
names(df_iso_2) <- names(df_iso)
尽管new_nested$AUS$a
访问该列表,但我想使用索引循环浏览iso
代码,而不是按名称引用它们:
for (n in length(df_iso)) {
new_nested$[i]$a <- df_iso_1[n]
}
但是,这不起作用。循环浏览这些列表的正确语法是什么?
期望输出:
从df_iso_1
到df_iso_2
,mids
对象是按iso
代码池化的。换句话说,所有iso
代码都放在新结构中:
因此,new_nested
的列表NLD
填充了来自df_iso_1
和df_iso_2
的 NLDmids
对象,其列表列表AUS
填充了来自df_iso_1
和df_iso_2
的 AUSmids
对象。
这里有两种方法。第一种是用seq_len(length(df_iso))
修复循环并匹配输出,将df_iso_1[n]
更改为df_iso1[[n]]
:
for (n in seq_len(length(df_iso))) {
new_nested[[names(df_iso)[n]]]$a <- df_iso_1[[n]]
new_nested[[names(df_iso)[n]]]$b <- df_iso_2[[n]]
}
new_nested$AUS$a
Class: mids
Number of multiple imputations: 1
Imputation methods:
A B C D E F iso year
"" "" "" "" "" "" "" ""
PredictorMatrix:
A B C D E F iso year
A 0 0 0 0 0 0 0 1
B 0 0 0 0 0 0 0 0
C 0 0 0 0 0 0 0 0
D 1 0 0 0 0 0 0 1
E 0 0 0 0 0 0 0 0
F 0 0 0 0 0 0 0 0
Number of logged events: 6
it im dep meth out
1 0 0 constant B
2 0 0 constant C
3 0 0 constant E
4 0 0 constant F
5 0 0 constant iso
6 0 0 collinear D
第二种方法是使用mapply
遍历df_iso_n
列表的每个元素,以将它们组合成一个新的列表矩阵:
mapply(list, df_iso_1, df_iso_2)
# AUS BRA ECU NLD
#[1,] List,21 List,21 List,21 List,21
#[2,] List,21 List,21 List,21 List,21
mapply(list, df_iso_1, df_iso_2)[, 'AUS']
[[1]]
Class: mids
Number of multiple imputations: 1
Imputation methods:
A B C D E F iso year
"" "" "" "" "" "" "" ""
PredictorMatrix:
A B C D E F iso year
A 0 0 0 0 0 0 0 1
B 0 0 0 0 0 0 0 0
C 0 0 0 0 0 0 0 0
D 1 0 0 0 0 0 0 1
E 0 0 0 0 0 0 0 0
F 0 0 0 0 0 0 0 0
Number of logged events: 6
it im dep meth out
1 0 0 constant B
2 0 0 constant C
3 0 0 constant E
4 0 0 constant F
5 0 0 constant iso
6 0 0 collinear D
[[2]]
Class: mids
Number of multiple imputations: 1
Imputation methods:
A B C D E F iso year
"" "" "" "" "" "" "" ""
PredictorMatrix:
A B C D E F iso year
A 0 0 0 0 0 0 0 1
B 0 0 0 0 0 0 0 0
C 0 0 0 0 0 0 0 0
D 1 0 0 0 0 0 0 1
E 0 0 0 0 0 0 0 0
F 0 0 0 0 0 0 0 0
Number of logged events: 6
it im dep meth out
1 0 0 constant B
2 0 0 constant C
3 0 0 constant E
4 0 0 constant F
5 0 0 constant iso
6 0 0 collinear D
此外,考虑重构代码仍然是一个好主意。这在很大程度上在 3 行中完成所有操作:
seeds = c(1,2)
by(data = df, INDICES = df$iso,
FUN = function(ISO) lapply(seeds, function(seed) mice(ISO, m = 1, maxit = 5, seed = seed)))
df$iso: AUS
[[1]]
Class: mids
Number of multiple imputations: 1
Imputation methods:
A B C D E F iso year
"" "" "" "" "" "" "" ""
PredictorMatrix:
A B C D E F iso year
A 0 0 0 0 0 0 0 1
B 0 0 0 0 0 0 0 0
C 0 0 0 0 0 0 0 0
D 1 0 0 0 0 0 0 1
E 0 0 0 0 0 0 0 0
F 0 0 0 0 0 0 0 0
Number of logged events: 6
it im dep meth out
1 0 0 constant B
2 0 0 constant C
3 0 0 constant E
4 0 0 constant F
5 0 0 constant iso
6 0 0 collinear D
[[2]]
Class: mids
Number of multiple imputations: 1
Imputation methods:
A B C D E F iso year
"" "" "" "" "" "" "" ""
PredictorMatrix:
A B C D E F iso year
A 0 0 0 0 0 0 0 1
B 0 0 0 0 0 0 0 0
C 0 0 0 0 0 0 0 0
D 1 0 0 0 0 0 0 1
E 0 0 0 0 0 0 0 0
F 0 0 0 0 0 0 0 0
Number of logged events: 6
it im dep meth out
1 0 0 constant B
2 0 0 constant C
3 0 0 constant E
4 0 0 constant F
5 0 0 constant iso
6 0 0 collinear D
----------------------------------------------------
df$iso: BRA
[[1]]
...