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Mapping Toolbox displays and analyzes geographically based information

Over 60 built-in map projections

The new Mapping Toolbox builds on the numeric and visualization capabilities of MATLAB to provide a comprehensive and open set of tools for analyzing and displaying geographically based information. The toolbox is a collection of MATLAB functions and graphical interfaces for analyzing geographic data, displaying maps, and accessing external geographic data sources. In addition, the toolbox ships with several useful atlas data sets for global and regional displays. Functions are available for displaying 2-D and 3-D data in a variety of map projections, performing matrix and vector map computations, and generating presentation-quality displays.

The toolbox was developed for The MathWorks by Systems Planning and Analysis, Inc., of Alexandria, VA, and has been applied throughout the earth sciences, including oil and gas exploration, aerospace and naval engineering, cartography, and in any other areas where geographical data is analyzed and modeled.

Kenneth S. Casey, of the Universities Space Research Association, uses the Mapping Toolbox to examine ocean dynamics in the North Pacific. Specifically, he uses the toolbox in his work with the TOPEX/Poseidon altimeter, a satellite-based instrument which measures changes in sea surface height. In a recent conversation, Casey said, "The Mapping Toolbox functions make it much easier for me to determine the percentage of global ocean surface area irregularities and save me from having to write my own piece of code to analyze the data."

Mapping Toolbox Highlights

Geographic and scientific data visualization, manipulation, and analysis
60 map projections (forward and inverse)
Project and display vector, matrix, and composite map data
GUIs for building and manipulating maps and data/td
Global and regional atlas data and interfaces to high resolution government data
Geostatistics and navigation functions
Translators for popular geographic data file types such as DCW-DEM, TIGER, ETOPO5, Terrain base, USGS, and more

Multiple display styles

In the Mapping Toolbox, a map is any variable or set of variables representing a geographic region from a single point to an entire planet. The toolbox supports vector, matrix, indexed, and composite map data.

The Mapping Toolbox provides over 60 of the most widely used map projections including cylindrical, pseudocylindrical, conic, polyconic and pseudoconic, and azimuthal and pseudoazimuthal. Forward and inverse projections are provided.

Building on MATLAB's object-oriented graphics foundation, the toolbox extends the MATLAB language to plot latitude-longitude information as easily as any other type of data. To display graphically based 2-D and 3-D data in latitude-longitude coordinates, the toolbox includes specialized functions for viewing:

Contour data (2-D and 3-D)
Line data (2-D and 3-D)
Vector patch polygon(s)
3-D meshes and colored surfaces
Lighting models and light sources
Comet plot (2-D and 3-D)
Quiver plot (2-D and 3-D)
Stem plot (2-D and 3-D)
Labels and legends
Tissot indicatrices and curve markers

AVHRR sea temperature data displayed using a Mollweide
equal-area pseudocylindrical projection.

Here, the file topo.mat that ships with MATLAB is projected using a Miller projection and a colormap developed using the DEM colormap function (demcmap).

Easy-to-use GUIs

Graphical front ends developed in MATLAB—like the viewmaps demo shown below—make it easy to access toolbox functionality, learn the basics of geospatial data analysis and visualization, and complete map-related tasks quickly. Included in the point-and-click GUIs are tools for modifying map display properties, manipulating data, calculating geographic measures, and working with objects in layers.

The viewmaps demonstration allows you to view and experiment with a range of projections.

Geographic data analysis and navigation

Accurate geographic data analysis often requires mathematics based on a spherical non-Cartesian coordinate system. The Mapping Toolbox provides the specialized geostatistical functions that are necessary for accurate geographical computations. Functions for applying geographic calculations to navigation problems are also available. Among the calculations covered are unit conversions, geographic point and line calculations, distance computations (reckoning, great circles, small circles, tracks, and intersections), area computations, and various data reduction operations.

Access to geographical data

Atlas data sets for the world and the United States, as well as astronomical data, are shipped with the toolbox. To make additional public data sets readily accessible, the toolbox provides a number of external data interface functions. Many of these data sets are available on CD-ROM and via the Internet at no charge (see below). Using these public-domain resources, you can gain access to information such as vector data of political entities, infrastructure data, and geographic data (coastlines, rivers, elevations, and land use).

This stemplot superimposed on a map of California shows recent earthquake activity. Dot color corresponds to the intensity on the Richter scale, height shows depth of epi-center. Data: NCEDC, N.CA Seismic Network, USGS, Seismic Station at the Univ. of California, Berkeley.

According to beta users, the Mapping Toolbox User's Guide not only describes the product's full set of features, but also serves as a handbook on the topics of map projection, display, and analysis.

These new mapping tools enable both newcomers and users experienced in map-related work to quickly become proficient in geographical data analysis and display from within MATLAB.

Mapping data is available free of charge from several sources:

U.S. Geological Survey, www.usgs.gov
U.S. Census Bureau, www.census.gov
National Imagery Mapping Agency (formerly the Defense Mapping Agency), www.nima.mil

To learn more, send for a free technical information kit.