Added proper comments to the test.

GPy/core/parameterization/transformations.py

@@ -50,10 +50,12 @@ class Transformation(object):
         import matplotlib.pyplot as plt
         from ...plotting.matplot_dep import base_plots
         x = np.linspace(-8,8)
-        base_plots.meanplot(x, self.f(x),axes=axes*args,**kw)
+        base_plots.meanplot(x, self.f(x), ax=axes, *args, **kw)
         axes = plt.gca()
         axes.set_xlabel(xlabel)
         axes.set_ylabel(ylabel)
+        return axes
+
     def __str__(self):
         raise NotImplementedError
     def __repr__(self):

ib_tests/test_transformation_plot.py

@@ -1,3 +1,14 @@
+"""
+Tests whether or not the tansformation plot works as expected.
+It does not work on the normal build.
+
+Author:
+    Ilias Bilionis
+
+Date:
+    3/8/2015
+"""
+
 import sys
 import os
 # Make sure we load the GP that is here
@@ -5,6 +16,8 @@ sys.path.insert(0, os.path.abspath(os.path.join(os.path.dirname(__file__), '..')
 import GPy
 import matplotlib.pyplot as plt
 
-f = GPy.constraints.Logexp()
-f.plot()
-plt.show(block=True)
+
+if __name__ == '__main__':
+    f = GPy.constraints.Logexp()
+    f.plot()
+    plt.show(block=True)