我需要檢查一列中的字符串是否包含來自另一列的同一行(對於所有行)的相應(數值)值。Vectorize data.table like,grepl或類似的大數據字符串比較
如果我只是檢查一個模式的字符串,這將是簡單的使用data.table的like
或grepl
。但是,我的模式值對於每一行都不相同。
有一個有點相關的問題here,但不像那個問題,我需要創建一個邏輯標誌,指示模式是否存在。
假設這是我的數據集;
DT <- structure(list(category = c("administration", "nurse practitioner",
"trucking", "administration", "warehousing", "warehousing", "trucking",
"nurse practitioner", "nurse practitioner"), industry = c("admin",
"truck", "truck", "admin", "nurse", "admin", "truck", "nurse",
"truck")), .Names = c("category", "industry"), class = "data.frame", row.names = c(NA,
-9L))
setDT(DT)
> DT
category industry
1: administration admin
2: nurse practitioner truck
3: trucking truck
4: administration admin
5: warehousing nurse
6: warehousing admin
7: trucking truck
8: nurse practitioner nurse
9: nurse practitioner truck
我期望的結果會是這樣一個向量:
> DT
matches
1: TRUE
2: FALSE
3: TRUE
4: TRUE
5: FALSE
6: FALSE
7: TRUE
8: TRUE
9: FALSE
當然,1和0是一樣TRUE和FALSE一樣好。
這裏有一些事情我想,沒有工作:
apply(DT,1,grepl, pattern = DT[,2], x = DT[,1])
[1] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
> apply(DT,1,grepl, pattern = DT[,1], x = DT[,2])
[1] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
> grepl(DT[,2], DT[,1])
[1] FALSE
> DT[Vectorize(grepl)(industry, category, fixed = TRUE)]
category industry
1: administration admin
2: trucking truck
3: administration admin
4: trucking truck
5: nurse practitioner nurse
> DT[stringi::stri_detect_fixed(category, industry)]
category industry
1: administration admin
2: trucking truck
3: administration admin
4: trucking truck
5: nurse practitioner nurse
> for(i in 1:nrow(DT)){print(grepl(DT[i,2], DT[i,1]))}
[1] FALSE
[1] FALSE
[1] FALSE
[1] FALSE
[1] FALSE
[1] FALSE
[1] FALSE
[1] FALSE
[1] FALSE
> for(i in 1:nrow(DT)){print(grepl(DT[i,2], DT[i,1], fixed = T))}
[1] FALSE
[1] FALSE
[1] FALSE
[1] FALSE
[1] FALSE
[1] FALSE
[1] FALSE
[1] FALSE
[1] FALSE
> DT[category %like% industry]
category industry
1: administration admin
2: administration admin
Warning message:
In grepl(pattern, vector) :
argument 'pattern' has length > 1 and only the first element will be used
@akrun對解決方案是正確的,Frank對錯誤是正確的。非常感謝! –
@Frank謝謝,我更新瞭解決方案。如果缺少任何東西,請隨時添加。 – akrun