无法从 R 中的句子中提取确切的短语

Question

我正在尝试从 R 中的句子中提取精确短语。它也在提取部分匹配的句子。示例：

  phrase <- c("r is not working","roster is not working")
  sentence <- c("ABC is not working and roster is not working","CDE is working but printer is not working")

  extract <- sapply(phrase, grepl, x = sentence)
  extract

输出为：

              r is not working      roster is not working
  [1,]             TRUE                  TRUE
  [2,]             TRUE                 FALSE

我想要的输出是：

              r is not working      roster is not working
  [1,]               FALSE                  TRUE
  [2,]               FALSE                  FALSE

短语"r is not working"不应与两个句子都匹配。有什么办法可以解决这个问题。有什么想法吗？谢谢！！

Answer 1

grepl 计算正则表达式。

如果您想坚持使用这些，将您的搜索模式锚定到字符串的开头和结尾：

phrase <- c("^r is not working$", "^roster is not working$")

如果您想检查完全匹配，只需使用

extract <- sapply(sentence, `%in%`, phrase)

无法从 R 中的句子中提取确切的短语

Not able to extract exact phrase from the sentence in R

r

grepl