title: how to adjust # of ticks on Bokeh axis (labels are overlapping on small figures)
body: <p>I have a multi-figure Bokeh plot of vertically stacked &amp; aligned figures.  Because I want to align the plots vertically, the y-axis labels are rotated to be vertical rather than horizontal. </p>
  
  <p>In certain scenarios, Bokeh produces too many ticks, such that the tick labels overlap completely, making illegible.  Here is an example:</p>
  
  <pre><code>import bokeh.plotting as bp
  import numpy as np
  
  y = np.random.uniform(0, 300, 50)
  x = np.arange(len(y))
  
  bp.output_file("/tmp/test.html", "test")
  plot = bp.figure(plot_width=800, plot_height=200)
  plot.yaxis.axis_label_text_font_size = "12pt"
  plot.yaxis.major_label_orientation = 'vertical'
  
  plot.line (x,y)
  bp.show(plot)
  </code></pre>
  
  <p>Short of making the renderer clever enough to produce fewer labels automatically, is there a way to indicate the # of labels to be placed on an axis?   </p>
  
  <p>It seems that the # of labels generated has to do with the range of the data, in terms of its affinity to a power of 10.</p>