Conventions

In this book, you will find a number of styles of text that distinguish between different kinds of information. Here are some examples of these styles, and an explanation of their meaning.

Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, and user input are shown as follows: "We will import the firenews.csv file that stores a series of web news collected from various RSS feeds".

A block of code is set as follows:

SELECT ROUND(SUM(chp02.proportional_sum(ST_Transform(a.geom,3734), b.geom, b.pop))) AS population FROM
     nc_walkzone AS a, census_viewpolygon as b
     WHERE ST_Intersects(ST_Transform(a.geom, 3734), b.geom)
     GROUP BY a.id;

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

SELECT ROUND(SUM(chp02.proportional_sum(ST_Transform(a.geom,3734), b.geom, b.pop))) AS population FROM
     nc_walkzone AS a, census_viewpolygon as b
     WHERE ST_Intersects(ST_Transform(a.geom, 3734), b.geom)
     GROUP BY a.id;

Any command-line input or output is written as follows:

> raster2pgsql -s 4322 -t 100x100 -F -I -C -Y C:\postgis_cookbook\data\chap5\PRISM\us_tmin_2012.*.asc chap5.prism | psql -d postgis_cookbook

New terms and important words are shown in bold. Words that you see on the screen, in menus or dialog boxes for example, appear in the text like this: "clicking the Next button moves you to the next screen".