title: Realistic simulated elevation data in R / Perlin noise
body: <p>Does anyone know how to create a simulation raster elevation dataset - i.e. a 2d matrix of realistic elevation values - in R?  R's <code>jitter</code> doesn't seem appropriate.  In Java/Processing the <code>noise()</code> function achieves this with a <a href="http://en.wikipedia.org/wiki/Perlin_noise" rel="noreferrer">Perlin noise</a> algorithm e.g.:</p>
  
  <pre><code>size(200, 200);
  float ns = 0.03; // for scaling
  for (float i=0; i&lt;200; i++) {
    for (float j=0; j&lt;200; j++) {
      stroke(noise(i*ns, j*ns) * 255);
      point(i, j);
    }
  }
  </code></pre>
  
  <p><img src="https://i.stack.imgur.com/cG5ok.png" alt="enter image description here"></p>
  
  <p>But I've found no references to Perlin noise in R literature.  Thanks in advance.</p>