title: UseMethod("type") error; no applicable method for 'type" applied to an object of class "c('double', 'numeric')"
body: <p>In a dataframe, I have a column that has numeric values and some mixed in character data for some rows. I want to remove all rows with the character data and keep those rows with a number value. The df I have is 6 million rows, so I simply made a small object to try to solve my issue and then implement at a larger scale. </p>
  
  <p>Here is what I did:</p>
  
  <pre><code>a &lt;- c("fruit", "love", 53)
  
  b &lt;- str_replace_all("^[:alpha:]", 0)
  </code></pre>
  
  <p>Reading answers to other UseMethod errors on here (about factors), I tried to change "a" to as.character(a) and attempt "b" again. But, I get the same error. I'm trying to simply make any alphabetic value into the number zero and I'm fairly new at all this. </p>