title: Wireframe isosurface with Mayavi
body: <p>The <a href="http://docs.enthought.com/mayavi/mayavi/auto/mlab_helper_functions.html#mesh" rel="nofollow noreferrer"><code>mesh</code></a> function in Mayavi accepts a <code>representation</code> keyword that allows the surface to be viewed as the triangulated wireframe mesh. How can achieve a similar result for an iso surface using <code>mlab.pipeline.iso_surface</code> or <code>mlab.contour3d</code>?</p>
  
  <p>For example, I'd like to achieve something to the effect:</p>
  
  <pre><code>import numpy as np
  from mayavi import mlab
  
  # Create image volume with sphere as zero level surface.
  x,y,z = np.mgrid[-20:21, -20:21, -20:21].astype(np.float)
  vol = np.sqrt(x**2 + y**2 + z**2) - 7
  
  # Visualize the level surface.
  sf = mlab.pipeline.scalar_field(vol)
  mlab.pipeline.iso_surface(sf, contours=[0.0],
                            representation='wireframe')
  mlab.show()
  </code></pre>
  
  <p>Of course, this code doesn't run because the <code>representation</code> keyword argument doesn't exist for the <code>iso_surface</code> function.</p>