title: how to subset a file - select a numbers of rows or columns
body: <p>I would like to have your advice/help on how to subset a big file (millions of rows or lines).</p>
  
  <p>For example, </p>
  
  <p>(1)
  I have big file (millions of rows, tab-delimited). I want to a subset of this file with only rows from 10000 to 100000.</p>
  
  <p>(2)
  I have big file (millions of columns, tab-delimited). I want to a subset of this file with only columns from 10000 to 100000.</p>
  
  <p>I know there are tools like head, tail, cut, split, and awk or sed. I can use them to do simple subsetting. But, I do not know how to do this job.</p>
  
  <p>Could you please give any advice? Thanks in advance.</p>