title: R memory limit warning vs "unable to allocate..."
body: <p>Does a memory warning affect my R analysis?</p>
  
  <p>When running a large data analysis script in R I get a warning something like:</p>
  
  <blockquote>
    <p>In '... '
    reached total allocation of <em>_</em>__Mb: see help...</p>
  </blockquote>
  
  <p>But my script continues without error, just the warning. With other data sets I get an error something like:</p>
  
  <blockquote>
    <p>Error: cannot allocate vector of size ___Mb:</p>
  </blockquote>
  
  <p>I know the error breaks my data analysis, but is there anything wrong with just getting the warning? I have not noticed anything missing in my data set but it is very large and I have no good means to check everything. I am at 18000Mb allocated to memory and cannot reasonably allocate more.</p>