title: How to subset data using multiple characters in a column
body: <p>This is a very simple question. </p>
  
  <p>I have a lengthy dataset and want to create a subset based on certain entries in a particular column. In this case, I am setting it up like this:</p>
  
  <p>Example data:</p>
  
  <pre><code>&gt; NL
  
  SNP alleles
  
  rs1234 A_T
  
  rs1235 A_G
  
  rs2343 A_T
  
  rs2342 G_C
  
  rs1134 C_G
  
  rs1675 T_A
  
  rs8543 A_T
  
  rs2842 G_A
  
  P &lt;- subset(NL, alleles = "A_T", alleles = "T_A", alleles = "G_C", alleles = "C_G")
  </code></pre>
  
  <p>This runs without error, but the resulting P is not subset in any way (tail of P still shows same number of entries as original NL). </p>
  
  <p>What am I doing wrong? </p>