R - Filter strings containing a string from a vector

Question

I am looking for a function that takes a dataframe column, checks to see if it contains text from a row vector, and filters it after matching (including partial text matching).

For example, take the following data frame:

animal |count aardvark |8 cat |2 catfish |6 dog |12 dolphin |3 penguin |38 prairie dog|59 zebra |17 

and the next vector

 c("cat", "dog") 

I would like to run through the “animal” column, checking whether this value fully or partially matches one of the lines in the vector, and filter out those that are not. Resulting data frame:

 animal |count cat |2 catfish |6 dog |12 prairie dog|59 

Thanks!

Sean

Answer 1

We can use grep

 df1[grep(paste(v1, collapse="|"), df1$animal),] 

---

Or using dplyr

 df1 %>% filter(grepl(paste(v1, collapse="|"), animal)) 

Answer 2

Using dplyr , you can try the following if your table is df :

 library(dplyr) library(stringr) animalList <- c("cat", "dog") filter(df, str_detect(animal, paste(animalList, collapse="|"))) 

I personally find that using dplyr and stringr easier to read after a few months while viewing the code.