title: split a character from a number with multiple digits
body: <p>I have a column in a dataframe where the values are letter-number combinations like G1, K8, A132, etc. I want to split the letter from the number but retain the number as a single number. I have been using strsplit but this gives a list of values as seen below where I would liek to have the output of <code>G</code> and <code>10</code>:</p>
  
  <pre><code>x &lt;- "G10"
  strsplit(x, "")[[1]][1]
  "G"
  strsplit(x, "")[[1]][-1]
  "1" "0"
  </code></pre>
  
  <p>this leads to the predictable downstream problems when I try to use the numbers as numbers. Here is a  <code>paste</code> example where I would like to get "somethingelse_10":</p>
  
  <pre><code>z &lt;-strsplit(x, "")[[1]][-1]
  paste("somethingelse",z, sep="_")
  "somethingelse_1" "somethingelse_0"
  </code></pre>
  
  <p>Is there an easy way to split numbers from letters?</p>