title: What is the best way to combine multiple csv files data input using d3.csv in d3.json ?
body: <p>I am still new to javascript and d3 . I am trying to find the best way to combine multiple csv external files into d3 then do something with it.  Currently I am using script like this below for one file.</p>
  
  <pre><code>d3.csv("file1.csv",funciton(error,data) {
  
  // do something 
  
  } 
  </code></pre>
  
  <p>Is there a way that I can concatenate <strong>file1.csv + file2.csv + .. file9.csv</strong> 
  into one file something similar to this .. in d3 ? </p>
  
  <pre><code>d3.csv( concat("file1.csv","file2,csv",..file9.csv") ,function(error,data) {
  
  // do something 
  
  } 
  </code></pre>