英文:
Vectorising stringr::str_count
问题
I'm trying to vectorize the 'pattern' argument of stringr::str_count in R as follows:
library(stringr)# Define the patterns you want to countpatterns <- c("apple", "banana", "orange")# Create a vectorized version of str_countvectorized_str_count <- Vectorize(str_count, vectorize.args = "pattern")# Input stringstring <- "I like apples, bananas, and oranges. Apples are my favorite."# Count the occurrences of patterns in the stringcounts <- vectorized_str_count(string, pattern = patterns)# Print the countsprint(counts)
I am expecting to get 2, 1, 1 as outputs since there are two occurrences of 'apple' in the original string. However, it returns 1, 1, 1.
How can I amend the code to get what I'm after? I know I could do this by constructing a regex search term but there are various reasons I don't want to do this due to other problems. Many thanks.
英文:
I'm trying to vectorise the 'pattern' argument of stringr::str_count in R as follows:
# Define the patterns you want to countpatterns <- c("apple", "banana", "orange")# Create a vectorized version of str_countvectorized_str_count <- Vectorize(str_count, vectorize.args = "pattern")# Input stringstring <- "I like apples, bananas, and oranges. Apples are my favorite."# Count the occurrences of patterns in the stringcounts <- vectorized_str_count(string, pattern = patterns)# Print the countsprint(counts)
I am expecting to get 2, 1, 1 as outputs since there are two occurences of 'apple' in the original string. However it returns 1, 1, 1
How can I amend the code to get what I'm after? I know I could do this by constructing a regex search term but there are various reasons I don't want to do this due to other problems. Many thanks
答案1
得分: 1
str_count() 函数已对 pattern 参数进行了向量化处理。
对于第一个模式，您只会得到一个匹配，因为模式是区分大小写的：apple 不匹配 Apple。添加 (?i) 或使用 regex() 使模式大小写不敏感：
library(stringr)x <- "我喜欢苹果，香蕉和橙子。苹果是我最喜欢的。"str_count(x, c("(?i)苹果", "香蕉", "橙子"))#> [1] 1 1 1str_count(x, regex(c("苹果", "香蕉", "橙子"), ignore_case = TRUE))#> [1] 1 1 1
英文:
str_count() is already vectorised over the pattern argument.
You get only
one match for the first pattern because the pattern is case-sensitive: apple
does not match Apple. Add (?i) or use regex() to make a pattern case-insensitive:
library(stringr)x <- "I like apples, bananas, and oranges. Apples are my favorite."str_count(x, c("(?i)apple", "banana", "orange"))#> [1] 2 1 1str_count(x, regex(c("apple", "banana", "orange"), ignore_case = TRUE))#> [1] 2 1 1
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