title: Edit several dataframes in loop with column names and adding columns
body: <p>I have 10 datasets in a folder, with 4 columns, which I wish to read in as seperate dataframes in r, for which I use the following to do:</p>
  
  <pre><code>temp = list.files(pattern="*.csv")
  for(i in 1:length(temp)){
    assign(paste("name",i,sep = ""), as.data.frame(read.table(temp[i])))
  }
  </code></pre>
  
  <p>Then if i want to change the column names as well as adding a new column V5 &lt;- V3**2 in either the same loop or a different loop, how could this be done.</p>
  
  <p>The other suggestions for changing column names i've seen here in stackoverflow suggest creating a list of columns and then changing them. But they dont change the data in the global environment.</p>
  
  <p>Could any of you help with this?</p>
  
  <p>Many thanks.</p>