title: Convert from a "vector<vector<float>>" to a "Mat" type openCV C++
body: <p>I have to evaluate the FFT of a vector vector float (named 'raggio') and I wolud save the result in DFT_raggio. </p>
  
  <pre><code>vector&lt;vector&lt;float&gt;&gt; raggio,DFT_raggio;
  
  
  DFT_raggio.resize(raggio.size());
  for (int i = 0; i &lt; raggio.size(); i++)
  {
      DFT_raggio[i].resize(raggio[i].size());
      cvFFT(&amp;raggio[i], &amp;DFT_raggio[i], DFT_COMPLEX_OUTPUT, 0);
  }
  </code></pre>
  
  <p>I tried using cvFFT but in the execution the code stops with errors.</p>
  
  <p><strong>UPDATE:</strong> Is there a way to copy the content of a single vector of a vector vector float in a Mat type?</p>