我有一个数据框列表，我在下面展示了一些数据框：
> str(ls.df.val.keep)
List of 87
$ AT_VALUES_IMV_EU28_EXTRA :'data.frame': 1554 obs. of 4 variables:
..$ PARTNER : Factor w/ 3 levels "EU28_EXTRA","EU28_INTRA",..: 1 1 1 1 1 1 1 1 1 1 ...
..$ PRODUCT : int [1:1554] 2207 2207 2207 2207 2207 2207 2207 2207 2207 2207 ...
..$ PERIOD : Date[1:1554], format: "2010-01-01" "2010-02-01" "2010-03-01" "2010-04-01" ...
..$ INDICATOR_VALUE: num [1:1554] 1033828 291810 227820 104650 254214 ...
$ AT_VALUES_IMV_EU28_INTRA :'data.frame': 4380 obs. of 4 variables:
..$ PARTNER : Factor w/ 3 levels "EU28_EXTRA","EU28_INTRA",..: 2 2 2 2 2 2 2 2 2 2 ...
..$ PRODUCT : int [1:4380] 2207 2207 2207 2207 2207 2207 2207 2207 2207 2207 ...
..$ PERIOD : Date[1:4380], format: "2010-01-01" "2010-02-01" "2010-03-01" "2010-04-01" ...
..$ INDICATOR_VALUE: num [1:4380] 1894626 2177029 1271173 994368 1746904 ...
$ AT_VALUES_IMV_IN :'data.frame': 6 obs. of 4 variables:
..$ PARTNER : Factor w/ 3 levels "EU28_EXTRA","EU28_INTRA",..: 3 3 3 3 3 3
..$ PRODUCT : int [1:6] 2208 2208 220890 220890 22089069 22089069
..$ PERIOD : Date[1:6], format: "2010-09-01" "2012-07-01" "2010-09-01" "2012-07-01" ...
..$ INDICATOR_VALUE: num [1:6] 58 37 58 37 58 37
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我想将自定义函数dcast（）用于此列表的元素，这些元素是我的87个数据帧。对于每个数据帧，所需的结果应如下所示，具体取决于它具有的列数：
22082027 22082029 22082040 22082062 22082086 22082089 22083011 22083019 22083030 22083041 22083061 22083069 22083071 22083082 22084011
1 NA NA NA NA NA NA 400675 NA 3103 NA 186 NA NA NA 22297
2 NA 2594 NA NA NA NA 667309 3011 NA NA NA NA NA 1916 NA
3 NA NA NA NA NA NA NA NA NA NA NA NA NA 263 93482
4 NA NA NA NA NA NA 503155 4516 NA NA NA NA NA 5359 NA
5 NA 175 NA NA NA NA 226936 4514 NA NA NA NA 39389 NA NA
我尝试了各种解决方案和代码片段，而非正在运行：
## First solution
all.cast <- list()
for (i in 1:length(ls.df.val.keep)) {
all.cast[[i]] <- dcast(ls.df.val.keep[[i]], PERIOD ~ PRODUCT, value.var = "INDICATOR_VALUE")
}
ls.df.val.dcas <- list()
ls.df.val.dcas <- lapply(names(ls.df.val.keep), myfunc)
它产生错误：
Error: value.var (INDICATOR_VALUE) not found in input
Called from: cast(data, formula, fun.aggregate, ..., subset = subset, fill = fill,
drop = drop, value.var = value.var)
ls.df.val.dcas < - lapply(ls.df.val.keep, function(x) dcast(x, PERIOD ~ PRODUCT, value.var="INDICATOR_VALUE"))
错误是：
Error in dim(ordered) <- ns :
dims [product 1] do not match the length of object [0]
llply(ls.df.val.keep, .fun=function(x) dcast(x, PERIOD ~ PRODUCT, value.var="INDICATOR_VALUE"))
错误是：
Error in do.ply(i) :
task 9 failed - "dims [product 1] do not match the length of object [0]"
In addition: Warning message:
In setup_parallel() : No parallel backend registered
all.cast <- list()
for (i in 1:length(ls.df.val.keep)) {
all.cast[[i]] <- dcast(ls.df.val.keep[[i]], PERIOD ~ PRODUCT, value.var = "INDICATOR_VALUE")
}
再次出现错误：
Error in dim(ordered) <- ns :
dims [product 1] do not match the length of object [0]
奇怪的是，如果我把每个数据帧的名称或只是列表的元素，例如ls.df.val.keep [[3]]，他们工作！我还有许多其他事情要用lapply来做这个列表，但是我在第一步就被困住了！ 有没有我没看到的东西？
我正在添加@jake请求的数据帧数据样本：
> head(ls.df.val.keep[[1]])
PARTNER PRODUCT PERIOD INDICATOR_VALUE
58136 EU28_EXTRA 2207 2010-01-01 1033828
58138 EU28_EXTRA 2207 2010-02-01 291810
58140 EU28_EXTRA 220710 2010-03-01 227820
58142 EU28_EXTRA 220710 2010-04-01 104650
58144 EU28_EXTRA 22071000 2010-09-01 254214
58146 EU28_EXTRA 22071000 2010-10-01 572446
.. .. ..
答案 0 :(得分：0)
拉入Pierre发现的空数据框丢失错误，您可以使用purrr来实现目标。
library(purrr)
library(dplyr)
library(reshape2)
dcast_list <- map_if(ls.df.val.keep, negate(is_empty), ~dcast(.x, PERIOD ~ PRODUCT, value.var = "INDICATOR_VALUE"))
这将返回数据帧列表，并保持空数据帧不变。如果要删除它们，请在地图之前将其过滤掉。