我有一个表单的数据框:
LociDT4Length
[[1]]
Cohort V1
1: CEU 237
2: Lupus 203
3: RA 298
4: YRI 278
[[2]]
Cohort V1
1: CEU 625
2: Lupus 569
3: RA 1022
4: YRI 762
[[3]]
Cohort V1
1: CEU 161
2: Lupus 203
3: RA 268
4: YRI 285
[[4]]
Cohort V1
1: CEU 1631
2: Lupus 1363
3: RA 1705
4: YRI 1887
前几天,我学会了命令:
with(LociDT4Length[[1]], ifelse(Cohort=="RA", V1/62,
ifelse(Cohort=="Lupus", V1/62,
ifelse(Cohort=="CEU", V1/96,
ifelse(Cohort=="YRI", V1/80,NA)))))
适本地返回结果:
[1] 2.468750 3.274194 4.806452 3.475000
但是,我尝试将此语句放入循环中,对每个嵌套的 DF 都返回了一个警告,并返回了不正确的结果。错误信息是:
1: In `[<-.data.table`(x, j = name, value = value) :
Coerced 'double' RHS to 'integer' to match the column's type; may have
truncated precision. Either change the target column to 'double' first
(by creating a new 'double' vector length 4 (nrows of entire table) and
assign that; i.e. 'replace' column), or coerce RHS to 'integer' (e.g. 1L,
NA_[real|integer]_, as.*, etc) to make your intent clear and for speed.
Or, set the column type correctly up front when you create the table and
stick to it, please.
所以,我想弄清楚如何使用如下语句来诱使 R 重复应用此语句:
for (i in 1:length(LociDT4Length)){
with(LociDT4Length[[i]], ifelse(Cohort=="RA", V1/62,
ifelse(Cohort=="Lupus", V1/62,
ifelse(Cohort=="CEU", V1/96,
ifelse(Cohort=="YRI", V1/80,NA)))))
}
或者我想使用 lapply 将此语句应用于此嵌套数组中的 46 个嵌套 DF。
有什么建议吗?如果 ifelse 语法又差又笨重,我也愿意改变它。
非常感谢。
最佳答案
这应该可行:
lapply(LociDT4Length, function(x)
with(x,ifelse(Cohort %in% c("RA","Lupus"), V1/62,
ifelse(Cohort=="CEU", V1/96,
ifelse(Cohort=="YRI", V1/80,NA)))))
要避免嵌套 ifelse
试试这个:
#define cohort and matching divisor
origin=c("RA","Lupus","CEU","YRI")
divisor=c(62,62,96,80)
#avoid ifelse
lapply(LociDT4Length, function(x)
with(x,V1/divisor[match(Cohort,origin)]))
关于r - 在 R 中的嵌套数据框中多次调用 ifelse,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/24115714/