title: How to change the number of axis ticks in seaborn plots
body: <p>I would like to be able to control the number of axis ticks on a seaborn plot in Python 3.5. I'm very accustomed to using R's ggplot, so I'm having some trouble with analogous functionality in Python. </p>
  
  <p>As a example, here is the kind of data I'm currently working with:</p>
  
  <pre><code>test = pd.DataFrame()
  test["X"] = [1,2,3,1,2,3]
  test["Y"] = [1,5,3,7,2,4]
  test["Category"] = ["A", "A", "A", "B", "B", "B"]
  </code></pre>
  
  <p>And I would like to do something like ggplot's facet_wrap() by doing:</p>
  
  <pre><code>sns.set(style = "ticks", color_codes = True)
  test_plot = sns.FacetGrid(test, col = "Category")
  test_plot = (test_plot.map(sns.plt.plot, "X", "Y").add_legend())
  test_plot.set_xticks(np.arange(1,4,1))
  sns.plt.show(test_plot)
  </code></pre>
  
  <p>However, I get the following errors. The problem seems to be something about setting axis labels in FacetGrid, but I don't know how to resolve it. Is this an issue with Python 3 or with specifying axes on a facetted plot?</p>
  
  <pre><code>UserWarning: tight_layout : falling back to Agg renderer
  </code></pre>
  
  <p>warnings.warn("tight_layout : falling back to Agg renderer")</p>
  
  <pre><code>test_plot.set_xticks(np.arange(1,4,1))
  AttributeError: 'FacetGrid' object has no attribute 'set_xticks'
  </code></pre>