Merge pull request #191 from tcjansen/download_data-doc

Reworded the bit about downloading data for pre-defined quantities

docs/index.rst

@@ -68,29 +68,27 @@ You can install **synphot** using one of the following ways:
     cd synphot_refactor
     python setup.py install
 
-To use the pre-defined standard star, extinction laws, and bandpasses, it is
-recommended that you copy
-`synphot.cfg <https://github.com/spacetelescope/synphot_refactor/blob/master/synphot/synphot.cfg>`_
-to your ``$HOME/.astropy/config/`` directory.
-In doing so, you can avoid connecting directly to STScI HTTP service,
-which is slower and might not be available all the time.
-
-If necessary (i.e., if you are not an internal STScI user), replace
-``/grp/hst/cdbs`` with your local directory name
-(e.g., ``/my/local/dir/cdbs``), where you plan to store the data files.
-Then, follow the instructions below to "install" the data files.
+To use the pre-defined standard star, extinction laws, and bandpasses, it is 
+recommended for non-internal STScI users to download the necessary data files to
+a local directory so you can avoid connecting directly to STScI HTTP service,
+which is slower and might not be available all the time. To download the files
+via HTTP, create a local directory where you plan to store the data files
+(e.g., ``/my/local/dir/cdbs``) and run the following:
+
+    >>> from synphot.utils import download_data
+    >>> file_list = download_data('/my/local/dir/cdbs')
+
+Then copy `synphot.cfg <https://github.com/spacetelescope/synphot_refactor/blob/master/synphot/synphot.cfg>`_
+to your ``$HOME/.astropy/config/`` directory, and replace every instance of
+``/grp/hst/cdbs`` with ``/my/local/dir/cdbs`` so that ``synphot`` knows where to 
+look for these files.
 
 .. note::
 
     **synphot** data files are a minimal subset of those required by
     **stsynphot**. If you plan to use the latter anyway, please also read the
     instructions in its documentation.
 
-To install local data files via HTTP into, say, ``/my/local/dir/cdbs``::
-
-    >>> from synphot.utils import download_data
-    >>> file_list = download_data('/my/local/dir/cdbs')
-
 If you have your own version of the data files that you wish to use, you can
 modify ``synphot.cfg`` to point to your own copies without having to download
 using the function above. However, before you do so, make sure that your own