title: Turning off Tick Marks in Bokeh
body: <p>I am working on the Bokeh (0.6.1) tutorial and trying to turn off the tick marks and labels in one of the exercise plots, <a href="http://bokeh.pydata.org/tutorial/solutions/gallery/scatter.html">the scatter plot</a>:</p>
  
  <pre><code>from __future__ import division
  
  import numpy as np
  from six.moves import zip
  from bokeh.plotting import *
  from bokeh.objects import Range1d
  
  output_file("scatter.html")
  
  figure()
  
  N = 4000
  
  x = np.random.random(size=N) * 100
  y = np.random.random(size=N) * 100
  radii = np.random.random(size=N) * 1.5
  colors = [
      "#%02x%02x%02x" % (r, g, 150) 
      for r, g in zip(np.floor(50+2*x), np.floor(30+2*y))
  ]
  
  circle(x, y, radius=radii,
         fill_color=colors, fill_alpha=0.6,
         line_color=None, Title="Colorful Scatter")
  
  grid().grid_line_color = None
  axis().axis_line_color = None
  
  # QUESTION PART 1: Is this the right way to turn off tick labels?
  axis().major_label_text_font_size = '0pt'  
  # QUESTION PART 2: ...and how to turn off tick marks also?
  
  show()  # open a browser
  </code></pre>
  
  <p>I have managed to turn off the tick labels but no amount of searching the documentation and googling has revealed the incantation needed to turn off the tick marks. </p>
  
  <p>Also I am not sure that setting <code>axis().major_label_text_font_size</code> to <code>0pt</code> is the right way to turn off tick labels or if it is a kludge. Nothing else seemed to work.</p>
  
  <p>Am I missing something obvious?</p>