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列表中的一個元素,我想檢查我的data_frame_1的至少一個元素是data_frame_2並添加它像一個新列檢查如果字符串包含有R
我的代碼:
library(data.table)
object_to_check <- data.table(c('aaax', 'bbbx', 'cccy', 'dddk', 'mmmt'))
colnames(object_to_check) <- 'x'
list_of_element <- data.table(c('ax', 'kh', 'dk'))
colnames(list_of_element) <- 'y'
Fun2 <- function(element_to_find, string_to_check) {
element_to_find <- '0'
if (element_to_find == '0') {
for (i in 1:length(list_of_element)) {
m <- lista[i]
element_to_find <- ifelse(grepl(m, string_to_check, ignore.case = T) == T,string_to_check,'')
}
}
}
object_to_check <- object_to_check[, check := Fun2(check, x)]
我的代碼給我這個錯誤:
Warning message:
In `[.data.table`(object_to_check, , `:=`(check, Fun2(check, x))) :
Adding new column 'check' then assigning NULL (deleting it).
我卡在這個錯誤,我無法找到我的問題的解決方案。同一個人能幫助我嗎?
所需的輸出:
x check
aaax ax
bbbx NA
cccx NA
dddk dk
mmmt NA
感謝
https://stackoverflow.com/questions/3171426/compare-two-data-frames-to-find-the-rows-in-data-frame-1-that-are -not-present-in – Freak
請根據示例 – akrun