Replaced a missing "not".

[dead/census-tools.git] / doc / project_overview / index.xhtml

diff --git a/doc/project_overview/index.xhtml b/doc/project_overview/index.xhtml
index 3201609ff353831172b13b440e926a270903e302..d1544b603165acd09b99a1566422204e3c565af7 100644 (file)
--- a/doc/project_overview/index.xhtml
+++ b/doc/project_overview/index.xhtml
@@ -30,7 +30,7 @@
     One of the foremost goals that must be achieved is to model the
     average population density throughout the United States. Using
     this data, we would like to be able to calculate the risk
-    associated with an <em>event</em> taking place somewhere in the
+    associated with an <q>event</q> taking place somewhere in the
     United States. This will, in general, be an accident or other
     unexpected event that causes some damage to the surrounding
     population and environment.
@@ -75,6 +75,22 @@
   </p>
 
   <ol>
+    <li>
+      Most of the application code is written in <a
+      href="http://www.python.org/">Python</a>, and so the Python
+      runtime is required to run it.
+
+      <ol>
+       <li>
+         We utilize a third-party library called <a
+         href="http://pypi.python.org/pypi/Shapely">Shapely</a> for
+         Python/GEOS integration. GEOS is required by PostGIS (see
+         below), so it is not listed as a separate requirement, even
+         though Shapely does depend on it.
+       </li>
+      </ol>
+    </li>
+
     <li>
       The build system utilizes <a
       href="http://www.gnu.org/software/make/">GNU Make</a>. The
@@ -162,7 +178,7 @@
     </li>
 
     <li>
-      A redundant field, called <em>blkidfp00</em>, which contains the
+      A redundant field, called <q>blkidfp00</q>, which contains the
       concatenation of block/state/county/tract. This is our unique
       identifier.
     </li>
@@ -180,7 +196,7 @@
     We need to correlate the TIGER/Line geometric information with the
     demographic information contained in the Summary File 1 geographic
     header records. To do this, we need to rely on the unique
-    <em>blkidfp00</em> identifier.
+    <q>blkidfp00</q> identifier.
   </p>
 
   <p>
@@ -198,8 +214,8 @@
   <p>
     <em>
       Note: the <a href="../../makefile">makefile</a> provides a task
-      for creation/import of the databases, but its use is strictly
-      required.
+      for creation/import of the databases, but its use is not
+      strictly required.
     </em>
   </p>
 
@@ -208,16 +224,16 @@
 
   <p>
     A Postgres/PostGIS database is required to store our Census
-    data. The database name is unimportant (default: <em>census</em>),
+    data. The database name is unimportant (default: <q>census</q>),
     but several of the scripts refer to the table names. For
-    simplicity, we will call the database <em>census</em> from now on.
+    simplicity, we will call the database <q>census</q> from now on.
   </p>
 
   <p>
     Once the database has been created, we need to import two PostGIS
     tables so that we can support the GIS functionality. These two
-    files are <em>lwpostgis.sql</em> and
-    <em>spatial_ref_sys.sql</em>. See the <a
+    files are <q>lwpostgis.sql</q> and
+    <q>spatial_ref_sys.sql</q>. See the <a
     href="../../makefile">makefile</a> for an example of their import.
   </p>
 
@@ -254,12 +270,12 @@
   <p>
     Since the shapefiles are in a standard format, we can use
     pre-existing tools to import the data in to our SQL
-    database. PostGIS provides a binary, <em>shp2pgsql</em>, that will
+    database. PostGIS provides a binary, <q>shp2pgsql</q>, that will
     parse and convert the shapefiles to SQL.
   </p>
 
   <p>
-    There is one caveat here: the <em>shp2pgsql</em> program requires
+    There is one caveat here: the <q>shp2pgsql</q> program requires
     an SRID as an argument; this SRID is assigned to each record it
     imports. We have designated an SRID of 4269, which denotes
     <q>NAD83</q>, or the North American Datum (1983). There may be
@@ -326,7 +342,7 @@
   
   <h3>Switch from GiST to GIN Indexes</h3>
   <p>
-    When the TIGER data is imported via <em>shp2pgsql</em>, a <a
+    When the TIGER data is imported via <q>shp2pgsql</q>, a <a
     href="http://www.postgresql.org/docs/8.4/static/textsearch-indexes.html">GiST</a>
     index is added to the geometry column by means of the
     <strong>-I</strong> flag. This improves the performance of the