title: Java object analogue to R data.frame
body: <p>I really like data.frames in R because you can store different types of data in one data structure and you have a lot of different methods to modify the data (add column, combine data.frames,...), it is really easy to extract a <em>subset</em> from the data,...</p>
  
  <p>Is there any Java library available which have the same functionality? I'm mostly interested in storing different types of data in a matrix-like fashion and be able to extract a subset of the data. </p>
  
  <p>Using a two-dimensional array in Java can provide a similar structure, but it is much more difficult to add a column and afterwards extract the top k records.</p>