MaRC Files

• Data generated by the MU, MU0, PHASE, LATITUDE and LONGITUDE virtual images are now automatically offset and scaled by the largest power of 10 suitable for maximizing the number of significant digits retained when storing their floating point values in integer typed maps. For example, MU image data, which has a range of [-1, 1], will be scaled and offset to a range of [0, 200] for a map with BYTE (unsigned 8 bit integer) data, [-10000, 10000] for a SHORT (signed 16 bit integer) data type map, and [-1e+09, 1e+09] for LONG (signed 32 bit integer) typed maps.

The virtual image data is only automatically scaled and/or offset for integer typed maps. They are not scaled or offset when creating maps with a floating point data type (DATA_TYPE of FLOAT or DOUBLE).

The necessary scale and offset needed to obtain the true values of these virtual images in integer typed maps is now automatically written to the map FITS header as well.

NOTE: The hardcoded scale value of 10000 for the MU, MU0 and PHASE virtual images that existed in previous versions of MaRC has been removed for all map data types. Due to the automatic scaling that now occurs, the results will be the same for SHORT map types, but not the other types. As described above, a better scaling factor and offset will be chosen.

• Corrected problem where flat-field correction would fail.

• Improved accuracy of vector magnitude calculations by leveraging an implementation that avoids floating point underflow and overflow, as well as having extremely low floating point error.

• Improved accuracy of quadratic equation root calculations by using an implementation that avoids loss of significant digits (i.e. catastrophic cancellation). This impacts the sky removal feature and the Orthographic map projection.

• LONG map types are now correctly written to the map FITS file on 64 bit platforms where the fundamental C language 'long' integer type is 8 bytes wide.

• Improved memory management.

• Better C++ exception safety.
• Reduced run-time memory requirements.

• Slighty improved performance due to less deep copies of large arrays.

• Fixed inversion of source photo images from left to right and top to bottom.

• Support for maps containing 64 bit signed integer data has been added. Set DATA_TYPE in your MaRC input file to LONGLONG to use this feature.

• Fixed problem where negative data was not plotted in maps with a floating point data type.

• Initial support for Doxygen based MaRC source code documentation generation is now available. Assuming Doxygen is installed, run `make doxygen-doc' from the top-level MaRC source directory to generate MaRC library and program source code documentation. Generated documentation will reside in the doc/doxygen directory.