Geography Reference
In-Depth Information
ogr2ogr
With ogr2ogr , you can convert a vector layer from one format to
another, optionally translating the coordinate system along the
way. This can be especially handy when you get some new piece
of data and want to get it into your favorite format or coordinate
system.
ogrtindex
Unless you're a MapServer user, you likely won't use ogrtindex . It
creates a tile index from a group of files (for example, vectors) that
can be used with MapServer.
Here's a tip that you'll find useful: both the gdalinfo and the ogrinfo
commands accept a --formats switch. 17 This is a quick way to find out
which formats are supported for a given installation of GDAL/OGR.
This is important because both GDAL and OGR can be compiled and
distributed with support for a number of optional features. If in doubt,
using --formats is a quick way to see whether the magic you are about
to attempt is supported.
For a more comprehensive look at both the GDAL and OGR utilities,
see Section 11.2 , Using GDAL and OGR, on page 186 .
Generic Mapping Tools
GMT is written in C
This next set of command-line tools can create some really impressive
output. In fact, that's its whole aim—to create quality output that can
be printed or included in other documents. The Generic Mapping Tools
(GMT) has been around a long time. This is a testament to both its util-
ity and acceptance by the user community. GMT was originally devel-
oped in 1988 by Paul Wessel and Walter H. F. Smith and is currently
hosted at the University of Hawaii.
GMT allows you to create cartographic-quality maps from the command
line. This sounds simple, but in fact it has quite sophisticated features
including base map creation, plotting x-y values, lines, and polygons,
coordinate transformations, gridding, contouring, and 3D illuminated
surfaces.
Now I know you are probably thinking that GMT doesn't exactly fit your
idea of a desktop GIS application. In fact, it can be a valuable addition
17. In fact, almost all of the GDAL and OGR utilities accept the --formats switch.
 
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