title: Trying to divide rownames by the character '_'
body: <p>Morning everyone,
  I'm new in this community,
  I'm working in RStudio and my question is this:
  I have a data frame (with the name of some genes) where the columns are joined by this character '_':</p>
  <pre><code>               Sample_01
  BGN_BGN        1.0000000  
  RPS4Y1_BGN    -0.2367307  
  COMP_BGN       0.2664066 
  COL2A1_BGN     0.2746505  
  LOC653219_BGN -0.2651348 
  XAGE1_BGN     -0.2604609 
  </code></pre>
  <p>I want to divide the names of the genes, and these genes should be in a different column where corresponds, for example: column 1(gen1) - column 2(gen2) - column 3(Sample_01).</p>
  <p>Thanks in advance</p>