DOC recommend pydot-ng

doc/cifarSC2011/advanced_theano.txt

@@ -464,7 +464,7 @@ The graph after optimization:
 
 Picture Printing of Graphs
 ~~~~~~~~~~~~~~~~~~~~~~~~~~
-``pydotprint`` requires graphviz and pydot.
+``pydotprint`` requires graphviz and either pydot or pydot-ng.
 
 The graph before optimization:
 

doc/crei2013/advanced_theano.txt

@@ -202,7 +202,7 @@ The graph after optimization:
 Picture Printing of Graphs
 ~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-``pydotprint`` requires graphviz and pydot.
+``pydotprint`` requires graphviz and either pydot or pydot-ng.
 
 The graph before optimization:
 

doc/install.txt

@@ -59,7 +59,8 @@ The following libraries and software are optional:
     `Git <http://git-scm.com>`_
         To download bleeding-edge versions of Theano.
 
-    `pydot-ng <https://github.com/pydot/pydot-ng>`_ or `pydot <https://code.google.com/p/pydot/>`_
+    `graphiz <http://www.graphviz.org/>`__ and either
+    ``pydot-ng <https://github.com/pydot/pydot-ng>`_ or `pydot <https://code.google.com/p/pydot/>`_
         To be able to make picture of Theano computation graph.
 	pydot-ng is a pydot compatible replacement that support newer Python.
 

doc/library/d3viz/index.txt

@@ -17,12 +17,8 @@ Requirements
 ------------
 
 ``d3viz`` requires the `pydot <https://pypi.python.org/pypi/pydot>`__
-package. If you're using Python 2.x install pydot with pip::
-
-    pip install pydot
-
-In Python 3.x install `pydot-ng <https://pypi.python.org/pypi/pydot-ng>`__
-fork instead::
+package. `pydot-ng <https://github.com/pydot/pydot-ng>`__ fork is better
+maintained, and it works both in Python 2.x and 3.x. Install it with pip::
 
     pip install pydot-ng
 

theano/d3viz/formatting.py

@@ -52,8 +52,9 @@ class PyDotFormatter(object):
     def __init__(self, compact=True):
         """Construct PyDotFormatter object."""
         if not pydot_imported:
-            raise ImportError('Failed to import pydot. You must install pydot'
-                              ' and graphviz for `PyDotFormatter` to work.')
+            raise ImportError('Failed to import pydot. You must install '
+                              'graphviz and either pydot or pydot-ng for '
+                              '`PyDotFormatter` to work.')
 
         self.compact = compact
         self.node_colors = {'input': 'limegreen',

theano/printing.py

@@ -747,8 +747,9 @@ def pydotprint(fct, outfile=None,
         outputs = fct.outputs
         topo = fct.toposort()
     if not pydot_imported:
-        raise RuntimeError("Failed to import pydot. You must install pydot"
-                           " and graphviz for `pydotprint` to work.",
+        raise RuntimeError("Failed to import pydot. You must install graphviz"
+                           " and either pydot or pydot-ng for "
+                           "`pydotprint` to work.",
                            pydot_imported_msg)
 
     g = pd.Dot()