Search code examples
rmatchdigits

Match vectors on subset of digits in each element

I am trying to see whether the elements in vector match with the first four digits of elements within a second vector (they are nested identifiers) and I'm not quite sure how to run the match. For example:

X     Y 
1111  111120
1111  890933
2222  780777
2222  222247

I would like to create code to tell me whether the first four digits of element i in vector y match the digits in element i in vector x. Extending the example, I hope to see:

True
False
False
True

Thanks for any thoughts.

Solution

  • Using apply to loop over the rows and use grepl will work...

    apply( df , 1 , function(x) grepl( x[1] , x[2] ) )
#[1]  TRUE FALSE FALSE  TRUE