title: Hodogram using ggplot2
body: <p>I would like to create a facetted plot using ggplot2, representing monthly wind hodograms.</p>
  
  <p>I recently read the following post : <a href="https://stackoverflow.com/questions/19050481/how-to-map-wind-direction-and-speed-velocity-plot-with-r">How to map wind direction and speed (velocity plot) with R</a>. I think this is probably a good start for me. The following dataset represents windvalues as u and v components, with a timestep of 3 hours. I would like to represent it as an hodogram, meaning that each vector is following the previous one.</p>
  
  <pre><code>                u             v
   [1,]  -4.0000000 -6.928203e+00
   [2,]  -6.1283555 -5.142301e+00
   [3,]  -5.0000000  1.224647e-15
   [4,]  -3.7587705  1.368081e+00
   [5,]   4.0000000 -4.898587e-16
   [6,]   4.6984631 -1.710101e+00
   [7,]   5.6381557  2.052121e+00
   [8,]   6.1283555  5.142301e+00
   [9,]  -9.1925333 -7.713451e+00
  [10,]  -6.5778483  2.394141e+00
  [11,]  -5.3623111  4.499513e+00
  [12,]  -4.5962667  3.856726e+00
  [13,]  -7.0000000  1.714506e-15
  [14,]  -6.5778483 -2.394141e+00
  [15,]   6.0000000 -7.347881e-16
  [16,]  -6.5778483 -2.394141e+00
  [17,]  -6.0000000  1.469576e-15
  [18,]  -8.0000000  1.959435e-15
  [19,]  -5.6381557  2.052121e+00
  [20,]  -6.0000000  1.469576e-15
  [21,]  -4.5962667  3.856726e+00
  [22,]   2.0000000 -3.464102e+00
  [23,]   5.6381557 -2.052121e+00
  [24,]   6.0000000 -7.347881e-16
  [25,]   5.6381557 -2.052121e+00
  [26,]  -5.3623111 -4.499513e+00
  [27,]  -4.5962667 -3.856726e+00
  [28,]  -6.1283555 -5.142301e+00
  [29,]  -4.6984631 -1.710101e+00
  [30,]   0.8682409 -4.924039e+00
  [31,]   2.5000000 -4.330127e+00
  [32,]  -0.8682409 -4.924039e+00
  [33,]  -6.0000000  1.469576e-15
  [34,]  -5.3623111 -4.499513e+00
  [35,]  -3.8302222 -3.213938e+00
  [36,]  -4.5962667 -3.856726e+00
  [37,]  -3.5000000 -6.062178e+00
  [38,]   1.0418891 -5.908847e+00
  [39,]   5.3623111 -4.499513e+00
  [40,]   4.5962667 -3.856726e+00
  [41,]   3.8302222 -3.213938e+00
  [42,]   3.0000000 -5.196152e+00
  [43,]   5.3623111 -4.499513e+00
  [44,]   5.3623111 -4.499513e+00
  [45,]   4.5962667 -3.856726e+00
  [46,]   3.0000000 -5.196152e+00
  [47,]   4.5962667 -3.856726e+00
  [48,]   3.8302222 -3.213938e+00
  [49,]   1.0418891 -5.908847e+00
  [50,]   3.8302222 -3.213938e+00
  </code></pre>
  
  <p>You can find a hodogram example here : <img src="https://i.stack.imgur.com/j3iQ2.png" alt="enter image description here"> (like the one on the bottom left corner).</p>
  
  <p>With these hodograms (1 per month), I would like to plot a facetted graph with ggplot2 but I think (I hope) that I can manage this part.</p>
  
  <p>Any help would be appreciated.</p>
  
  <p>Thank you very much by advance !</p>