title: zoo merge() and merged column names
body: <p>I am relatively new to R. I am merging data contained in multiple csv files into a single zoo object.</p>
  
  <p>Here is a snippet of the code in my <strong>for loop</strong>:</p>
  
  <pre><code>temp &lt;- read.csv(filename, stringsAsFactors=F)
  temp_dates &lt;- as.Date(temp[,2])
  temp &lt;- zoo(temp[,17], temp_dates)
  dataset &lt;- temp[seq_specified_dates]
  
  # merge data into output
  if (length(output) == 0)
      output &lt;- dataset
  else
      output &lt;- merge(output, dataset, all=FALSE)
  </code></pre>
  
  <p>When I run head() on the output zoo object, I notice bizarrely named column names like: 'dataset.output.output.output' etc. How can I assign more meaningful names to the merged columns. ?</p>
  
  <p>Also, how do I reference a particular column in a zoo object?. For example if output was a dataframe, I could reference the 'Patient_A' column as output$Patient_A. How do I reference a specific column in a merged zoo object?</p>