Revert all of that work, fix the comprehension error that lead to it

Instead of putting the "if you work harder you can get better performance" note before the code, make the code the first thing you see and only note that you could do it another way in the performance testing section. Also switches to code-blocks throughout. Adds note that the openblas thread limit note seems to be outdated, the section above notes that we should be linked to multithreaded blas already, and testing seems to suggest we are.

Revert all of that work, fix the comprehension error that lead to it
eb33aa5a · Mike C. Fletcher · 0bc6906d · eb33aa5a
--- a/doc/install_ubuntu.txt
+++ b/doc/install_ubuntu.txt
 .. _install_ubuntu:
-Easy Installation of an optimized Theano on Ubuntu
+Easy Installation of an Optimized Theano on Current Ubuntu
-==================================================
+==========================================================
-These instructions were written for Ubuntu 11.04, 11.10, 12.04, 12.10, 13.04,
+For Ubuntu 11.10 through 14.04:
-13.10 and 14.04.
+.. code-block: bash
+    sudo apt-get install python-numpy python-scipy python-dev python-pip python-nose g++ libopenblas-dev git
+    sudo pip install Theano
+For Ubuntu 11.04:
+.. code-block: bash
+    sudo apt-get install python-numpy python-scipy python-dev python-pip python-nose g++ git libatlas3gf-base libatlas-dev
+    sudo pip install Theano
 .. note::
-    It is possible to have a faster installation of Theano than the one these
+    If you have error that contain "gfortran" in it, like this one:
-    instructions will provide, but this will make the installation more
-    complicated and/or may require that you buy software. This is a simple set
+        ImportError: ('/home/Nick/.theano/compiledir_Linux-2.6.35-31-generic-x86_64-with-Ubuntu-10.10-maverick--2.6.6/tmpIhWJaI/0c99c52c82f7ddc775109a06ca04b360.so: undefined symbol: _gfortran_st_write_done'
-    of installation instructions that will leave you with a relatively
-    well-optimized version that uses only free software. With more work or by
+    The problem is probably that NumPy is linked with a different blas
-    investing money (i.e. buying a license to a proprietary BLAS
+    then then one currently available (probably ATLAS). There is 2
-    implementation), it is possible to gain further performance.
+    possible fixes:
+    1) Uninstall ATLAS and install OpenBLAS.
+    2) Use the Theano flag "blas.ldflags=-lblas -lgfortran"
+    1) is better as OpenBLAS is faster then ATLAS and NumPy is
+    probably already linked with it. So you won't need any other
+    change in Theano files or Theano configuration.
 .. note::
@@ -46,79 +64,32 @@ These instructions were written for Ubuntu 11.04, 11.10, 12.04, 12.10, 13.04,
   probably supports Python 3.2, but we do not test on it.
-Installation steps
+Bleeding Edge Installs
-~~~~~~~~~~~~~~~~~~
+----------------------
-Ubuntu 14.04:
-The following will set up Theano from source packages in a `Virtual Environment`_
-on an Ubuntu 14.04 machine. Setting up Theano in a Virtual Environment allows 
-you to have different working environments for different projects. If you would
-prefer not to use a Virtual Environment, you will need to use `--user` flags 
-to `pip` to install into user-writable directories.
-.. _`Virtual Environment`: https://virtualenv.pypa.io/en/latest/
-.. code-block: bash
-    sudo apt-get install python-numpy python-scipy python-dev python-pip \
-    python-nose g++ libopenblas-dev git libblas-dev liblapack-dev fortran-compiler
-    # Configure openblas as our BLAS of record...
-    update-alternatives --list libblas.so.3 | grep openblas
-    sudo update-alternatives --set libblas.so.3 $(update-alternatives --list libblas.so.3 | grep openblas)
-    # Setup and then activate the working virtualenv
-    virtualenv -p python2.7 theano-env
-    source theano-env/bin/activate
-    # Theano setup.py won't pull in Numpy, so 
-    # scipy dependency installation will fail
-    pip install numpy
-    # Installation of current release:
-    pip install Theano
-    python -c "import theano; theano.test()"
-If you would like, instead, to install the bleeding edge Theano (from github), replace
+If you would like, instead, to install the bleeding edge Theano (from github) 
-the `pip install Theano` command with:
+such that you can edit and contribute to Theano, replace the `pip install Theano` 
+command with:
 .. code-block: bash
-    # Bleeding edge installation (Theano from git):
    git clone git://github.com/Theano/Theano.git
    cd Theano 
-    python setup.py develop 
+    python setup.py develop --user
    cd ..
-Ubuntu 11.10/12.04/12.10/13.04/13.10:
+VirtualEnv
- 1) ``sudo apt-get install python-numpy python-scipy python-dev python-pip python-nose g++ libopenblas-dev git``
+----------
- 2) ``sudo pip install Theano``
- If the packages ``libatlas3gf-base`` or ``libatlas-dev`` are already installed, there will be problems as they conflict with ``libopenblas-dev``.
- If you see NumPy errors, the simplest is to remove ``libopenblas-dev`` and its dependency ``libopenblas-base`` like this: ``sudo apt-get remove libopenblas-base``.
- The ideal would be that you remove ``libatlas3gf-base`` and ``libatlas-dev``,
- but you will need to reinstall python-numpy, python-scipy and all other packages that used it.
- OpenBLAS is faster then ATLAS most of the time and it allows to control the number of threads used during the execution.
-Ubuntu 11.04:
- 1) ``sudo apt-get install python-numpy python-scipy python-dev python-pip python-nose g++ git libatlas3gf-base libatlas-dev``
- 2) ``sudo pip install Theano``
-.. note::
-    If you have error that contain "gfortran" in it, like this one:
-        ImportError: ('/home/Nick/.theano/compiledir_Linux-2.6.35-31-generic-x86_64-with-Ubuntu-10.10-maverick--2.6.6/tmpIhWJaI/0c99c52c82f7ddc775109a06ca04b360.so: undefined symbol: _gfortran_st_write_done'
-    The problem is probably that NumPy is linked with a different blas
+If you would like to install Theano in a VirtualEnv, you will want to pass the 
-    then then one currently available (probably ATLAS). There is 2
+`--system-site-packages` flag when creating the VirtualEnv so that it will pick up 
-    possible fixes:
+the system-provided `Numpy` and `SciPy`.
-    1) Uninstall ATLAS and install OpenBLAS.
+.. code-block: bash
-    2) Use the Theano flag "blas.ldflags=-lblas -lgfortran"
-    1) is better as OpenBLAS is faster then ATLAS and NumPy is
+    virtualenv --system-site-packages -p python2.7 theano-env
-    probably already linked with it. So you won't need any other
+    source theano-env/bin/activate
-    change in Theano files or Theano configuration.
+    pip install Theano
 Test the newly installed packages
@@ -161,6 +132,15 @@ Theano should link to a parallel version of Blas and use all cores
 when possible. By default it should use all cores. Set the environment
 variable "OMP_NUM_THREADS=N" to specify to use N threads.
+.. note::
+    It is possible to have a faster installation of Theano than the one these
+    instructions provide, but this will make the installation more
+    complicated and/or may require that you buy software. This is a simple set
+    of installation instructions that will leave you with a relatively
+    well-optimized version that uses only free software. With more work or by
+    investing money (i.e. buying a license to a proprietary BLAS
+    implementation), it is possible to gain further performance.
 Updating Theano
 ~~~~~~~~~~~~~~~
@@ -184,13 +164,22 @@ system package, you can run this:
 Bleeding edge
 ~~~~~~~~~~~~~
-Do like in the section "Updating Theano", but use
+Change to the Theano directory and run:
-``git+git://github.com/Theano/Theano.git`` instead of ``theano``.
+.. code-block: bash
+    git pull
+    python setup.py develop --user
 Manual Openblas instruction
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+.. comment::
+    I believe this is outdated, my machine seems to be using 8 threads 
+    happily with the binary openblas...
 The openblas included in Ubuntu is limited to 2 threads. If you want
 to use more cores at the same time, you will need to compile it
 yourself. Here is some code that will help you.