I am trying to use grep to test whether a vector of strings are present in another vector or not, and to output the values that are present (the matching patterns).
I have a data frame like this:
I have a vector of strings patterns to be found in the "Letter" columns, for example: c("A1", "A9", "A6").
I would like to check whether any of the strings in the pattern vector is present in the "Letter" column. If they are, I would like the output of unique values.
The problem is, I don't know how to use grep with multiple patterns. I tried:
matches <- unique (
grep("A1| A9 | A6", myfile$Letter, value=TRUE, fixed=TRUE)
But it gives me 0 matches which are not true, any suggestions?