Multiple Pattern Search - Pick the most hit Line from document - r

Question

I am trying to search a list of terms or keywords in list of sentences. Here, I wanted to pick that line from the list of lines (which are review comments from customers) which matches to most of my terms or keywords that appear in.
At present i am doing this,
mydata<-c("i like this product, awesome",
"i could not go with this produt, since s/w is problem",
"Very good s/w. keep up the good work. i really like it")
terms<-c("really, "good", "like", "product")
termco(mydata, 1:3, terms)
and i get
3 word.count really good like product
1 1 5 0 0 1(20.00%) 1(20.00%)
2 2 11 0 0 0 0
3 3 12 1(8.33%) 2(16.67%) 1(8.33%) 0
I also tried few other suggestions HERE. But i could not get the result i wanted. But solution is very nice.
My expectation is that, a particular line or lines should only be displayed which has maximum number of terms or keywords that i am searching.
In this case i expected below line, since i have maximum number of terms or keywords present i.e., "really, "good", and "like"
"Very good s/w. keep up the good work. i really like it"
Thank in Advance!!

Answer 1

Here is a base R solution using apply and grep. The basic idea is to call grep(term, sentence), for every term in a given sentence. Then, we sum the number of hit terms for each sentence. Note carefully that we add word boundary markers around each term. This is to prevent false matches where a term happens to be a substring of another word in a sentence.
sapply(mydata, function(x) {
Reduce("+", sapply(terms, function(y) {
sum(grep(paste0("\\b", y, "\\b"), x))
}))
})
i like this product, awesome
2
i could not go with this product, since s/w is problem
1
Very good s/w. keep up the good work. i really like it
3
Demo

Answer 2

Using stringr's str_count can help as well:
Using str_count to get the counts(4 in total for last record) of the all matches and then use which.max to get the index of the vector(In this case it will return 3, which means third element the vector mydata)
mydata[which.max(stringr::str_count(mydata, paste0(terms, collapse="|")))]
Incase you want an absolute match with boundary conditions, you may use:
mydata[which.max(stringr::str_count(mydata,paste0("\\b",paste0(terms, collapse="\\b|\\b"),"\\b")))]
In your case both will give you same answer, however second will give less number of matches. E.g. when you have words like "keeping" instead of "keep" in a sentence. In this case the later regex will not match as its not absolute however, prior regex will match as there are no boundary conditions set.
Output:
> mydata[which.max(stringr::str_count(mydata, paste0(terms, collapse="|")))]
[1] "Very good s/w. keep up the good work. i really like it"