Update installation instruction for Mac.

doc/install.txt

@@ -525,44 +525,33 @@ everything is working properly.
 MacOS
 -----
 
-There are various ways to install Theano dependencies on a Mac.
-Here we describe the process in detail with EPD, Anaconda or with MacPorts, but if you did
-it differently and it worked, please let us know the details on the
-`theano-users`_ mailing-list, so that we can add alternate instructions
-here.
+There are various ways to install Theano dependencies on a Mac. Here
+we describe the process in detail with Canopy, Anaconda or Homebrew, but
+if you did it differently and it worked, please let us know the
+details on the `theano-users`_ mailing-list, so that we can add
+alternate instructions here.
 
 
-In academia: Enthought Python Distribution (EPD)
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+In academia: Enthought Canopy
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 If you are working in academia, the easiest way to install most of the
 dependencies is to install
-`Enthought Python Distribution (EPD) <http://enthought.com/products/epd.php>`_.
-If you are affiliated with a university (as student or employee), you can
-download the installer for free.
-
-EPD installation includes in particular Python (and the development headers),
-NumPy, SciPy, nose, sphinx, easy_install, pydot (but *not* `Graphviz`_, which is
-necessary for it to work) and the MKL implementation of blas. The Mac OS and
-Linux version do not include g++.
-
-pip is not included in EPD. After the installation of EPD,
-you can simply install it with::
-
-    .. code-block:: bash
+`Canopy <http://enthought.com/products/canopy/>`_.
+If you are affiliated with a university (as student or employee), you
+can download the installer for free.
 
-        $ sudo easy_install pip
+The Canopy installation includes in particular Python (and the
+development headers), NumPy, SciPy, nose, sphinx, pip, pydot
+(but *not* `Graphviz`_, which is necessary for it to work) and the MKL
+implementation of blas.
 
-Then in a terminal execute this command to install the latest Theano release:
+To install the latest Theano release execute this in a terminal:
 
     .. code-block:: bash
 
         $ sudo pip install Theano
 
-If you want the bleeding edge version, `download
-and install git <http://git-scm.com/downloads>`_. Then in a
-terminal excute this command:
-
 .. code-block:: bash
 
     $ sudo pip install --upgrade --no-deps git+git://github.com/Theano/Theano.git
@@ -570,18 +559,19 @@ terminal excute this command:
 See the section `install_bleeding_edge`_ for more
 information on the bleeding edge version.
 
-Then you must install g++. You can do this by installing XCode. See the first bullet in the :ref:`macports` section.
+Then you must install the compiler. See :ref:`compiler_osx` below.
 
 .. note::
 
-   If you use the trunk or version 0.6 or later of Theano, we try to
-   automatically link with the EPD blas version.  Due to Mac OS
-   peculiarities, we need a user intervention to do it.  We detect
-   if the user did the modification and if not, we tell him how to do
-   it.
+   If you use version 0.6 or later of Theano, we try to automatically
+   link with the Canopy blas version.  Due to Mac OS peculiarities,
+   this requires user intervention.  We detect if the manipulation was
+   done or not and give an error message explaining what to do in case
+   it hasn't been done.
+
 
-Anaconda 1.5
-~~~~~~~~~~~~
+Anaconda
+~~~~~~~~
 
 An easy way to install most of the dependencies is to install
 `Anaconda <http://continuum.io/downloads.html>`_. There is a free
@@ -590,9 +580,9 @@ Optimizations`` product (free for academic, ~30$ otherwise) Theano
 will also be optimized as we will reuse the faster BLAS version
 automatically.
 
-Anaconda installation includes in particular Python (and the development headers),
-NumPy, SciPy, nose, sphinx, pip, and a acceptable BLAS version. The Mac OS and
-Linux version do not include g++.
+The Anaconda installation includes in particular Python (and the
+development headers), NumPy, SciPy, nose, sphinx, pip, and a
+acceptable BLAS version.
 
 After installing Anaconda, in a terminal execute this command to
 install the latest Theano release:
@@ -607,9 +597,7 @@ To install the missing Theano optional dependency (pydot):
 
         $ conda install pydot
 
-If you want the bleeding edge version, `download
-and install git <http://git-scm.com/downloads>`_. Then in a
-terminal execute this command:
+If you want the bleeding edge version instead execute this command:
 
 .. code-block:: bash
 
@@ -618,17 +606,53 @@ terminal execute this command:
 See the section `install_bleeding_edge`_ for more
 information on the bleeding edge version.
 
-Then you must install g++. You can do this by installing XCode. See the first bullet in the :ref:`macports` section.
+Then you must install the compiler. See :ref:`compiler_osx` below.
 
 .. note::
 
-   If you use the trunk or a version after 0.6rc3 of Theano, we try to
-   automatically link with the python library.  Due to Mac OS
-   peculiarities, we need a user intervention to do it.  We detect
-   if the user did the modification and if not, we tell him how to do
-   it.
+   If you use version 0.6 or later of Theano, we try to automatically
+   link with the python library.  Due to Mac OS peculiarities, this
+   requires user intervention.  We detect if the user did the
+   modification and if not, we tell him how to do it.
+
+.. _compiler_osx:
+
+Installing the compiler
+~~~~~~~~~~~~~~~~~~~~~~~
+
+Theano officially supports only clang on OS X.  This can be installed
+by getting XCode from the App Store and running it once to install the
+command-line tools.
+
+If you still want to use g++ you can do so by setting its full path in
+the theano config flag `gxx`.  Note that any bug reports on Mac using
+g++ will be ignored unless it can be reproduced with clang.
+
+
+Homebrew
+~~~~~~~~
+
+Install python with homebrew:
+
+.. code-block:: bash
+
+    $ brew install python # or python3 if you prefer
+
+This will install pip.  Then use pip to install numpy, scipy:
+
+.. code-block:: bash
+
+    $ pip install numpy scipy
+
+If you want to use openblas instead of Accelerate, you have to install
+numpy and scipy with hombrew:
+
+.. code-block:: bash
+
+    $ brew tap homebrew/python
+    $ brew install numpy --with-openblas
+    $ brew install scipy --with-openblas
 
-.. _macports:
 
 MacPorts
 ~~~~~~~~
@@ -723,14 +747,6 @@ Theano dependencies is easy, but be aware that it will take a long time
 
         $ python -c "import theano; theano.test()"
 
-Homebrew
-~~~~~~~~
-
-There are some `instructions
-<https://github.com/samueljohn/homebrew-python>`__ by Samuel John on how to install
-Theano dependencies with Homebrew instead of MacPort.
-
-
 .. _gpu_macos:
 
 Using the GPU