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Mapx: Map Transformations Library

Mapx is a coordinate transformation library developed at NSIDC. The C code was initially developed from equations given by Snyder (1982) and tested against the examples in his Appendix A. Additional projections have been added as needed. The C version of Mapx currently supports 11 common projections, in both spherical and ellipsoid forms when appropriate.

The Java version was ported from the C to simplify using the transforms in Java applets and applications. The Java lags behind the C somewhat and currently supports nine common projections, in both spherical and ellipsoid forms when appropriate.

The Mapx package is licensed under the GNU Lesser General Public License.

A poster describing some uses of the Mapx library.

Overview of mapping and gridding at NSIDC

Download the C library (mapx-x.x.tar.gz) or Java package (mapx-x.x.jar.gz), and/or a collection of grid parameter definition files (nsidc_maps.tar.gz) to use with the software.

Documentation for the Java package

Documentation for the C library

• Points, Pixels, Grids, and Cells : A Mapping and Gridding Primer. This is a tech memo written as part of the Mapx documentation that gives a brief introduction to mapping, gridding, and the associated terminology used in the Mapx library.
• We intend to write unix man pages for the Mapx command-line utilities. Until such a time, users must rely on the usage message produced when you execute one of the utilities with no input parameters.