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Binary Option

It is possible to output an ``unformatted'' or ``binary'' file (dd.bin) with fairly complete information, including header and data sections. This is accomplished by specifying either ALLBIN or ORIBIN in ddscat.par .

Subroutine writebin.f provides an example of how this can be done. The ``header'' section contains dimensioning and other variables which do not change with wavelength, particle geometry, and target orientation. The header section contains data defining the particle shape, wavelengths, particle sizes, and target orientations. If ALLBIN has been specified, the ``data'' section contains, for each orientation, Mueller matrix results for each scattering direction. The data output is limited to actual dimensions of arrays; e.g. nscat,4,4 elements of Mueller matrix are written rather than mxscat,4,4. This is an important consideration when writing postprocessing codes.

A skeletal example of a postprocessing code was written by us and is provided in subdirectory DDA/IDL. If you do plan to use the Interactive Data Language (IDL) for postprocessing, you may consider using the netCDF binary file option which offers substantial advantages over the FORTRAN unformatted write. More information about IDL is available at http://www.rsinc.com/idl. Unfortunately IDL requires a license and hence is not distributed with DDSCAT.



Bruce Draine
Thu Aug 10 09:34:16 EDT 2000