[DataFrame] readthedocs page for Pandas on Ray (#1714)

doc/source/index.rst

@@ -80,6 +80,12 @@ Ray comes with libraries that accelerate deep learning and reinforcement learnin
    rllib.rst
    rllib-dev.rst
 
+.. toctree::
+   :maxdepth: 1
+   :caption: Pandas on Ray
+
+   pandas_on_ray.rst
+
 .. toctree::
    :maxdepth: 1
    :caption: Examples

doc/source/pandas_on_ray.rst

@@ -0,0 +1,71 @@
+Pandas on Ray
+=============
+
+Pandas on Ray is an early stage DataFrame library that wraps Pandas and
+transparently distributes the data and computation. The user does not need to
+know how many cores their system has, nor do they need to specify how to
+distribute the data. In fact, users can continue using their previous Pandas
+notebooks while experiencing a considerable speedup from Pandas on Ray, even
+on a single machine. Only a modification of the import statement is needed, as
+we demonstrate below. Once you’ve changed your import statement, you’re ready
+to use Pandas on Ray just like you would Pandas.
+
+.. code-block:: python
+
+  # import pandas as pd
+  import ray.dataframe as pd
+
+Currently, we have part of the Pandas API implemented and are working toward
+full functional parity with Pandas.
+
+Using Pandas on Ray on a Single Node
+------------------------------------
+
+In order to use the most up-to-date version of Pandas on Ray, please follow
+the instructions on the `installation page`_
+
+Once you import the library, you should see something similar to the following
+output:
+
+.. code-block:: text
+
+  >>> import ray.dataframe as pd
+
+  Waiting for redis server at 127.0.0.1:14618 to respond...
+  Waiting for redis server at 127.0.0.1:31410 to respond...
+  Starting local scheduler with the following resources: {'CPU': 4, 'GPU': 0}.
+
+  ======================================================================
+  View the web UI at http://localhost:8889/notebooks/ray_ui36796.ipynb?token=ac25867d62c4ae87941bc5a0ecd5f517dbf80bd8e9b04218
+  ======================================================================
+
+If you do not see output similar to the above, please make sure that you have
+built Ray using the instructions on the `installation page`_
+
+One you have executed  ``import ray.dataframe as pd``, you're ready to begin
+running your Pandas pipeline as you were before. Please note, the API is not
+yet complete. For some methods, you may see the following:
+
+.. code-block:: text
+
+  NotImplementedError: To contribute to Pandas on Ray, please visit github.com/ray-project/ray.
+
+If you would like to request a particular method be implemented, feel free to
+`open an issue`_. Before you open an issue please make sure that someone else
+has not already requested that functionality.
+
+Using Pandas on Ray on a Cluster
+--------------------------------
+
+Currently, we do not yet support running Pandas on Ray on a cluster. Coming
+Soon!
+
+Examples
+--------
+You can find an example on our recent `blog post`_ or on the
+`Jupyter Notebook`_ that we used to create the blog post.
+
+.. _`installation page`: http://ray.readthedocs.io/en/latest/installation.html
+.. _`open an issue`: http://github.com/ray-project/ray/issues
+.. _`blog post`: http://rise.cs.berkeley.edu/blog/pandas-on-ray
+.. _`Jupyter Notebook`: http://gist.github.com/devin-petersohn/f424d9fb5579a96507c709a36d487f24#file-pandas_on_ray_blog_post_0-ipynb