code based on
 
R.W. Schaefer
Calculation of the light scattered by randomly oriented
ensembles of spheroids of size comparable to the wavelenght,
Thesis, State Univ. of New York, Albany, 1980. 



Dear Thomas,

As promised, I would look whether some code was still
present at the VU. And I did find the code. I have not looked
at it in years. Apart from the code itself there are some
tools to change single to double precision. I can not
remember whether that worked, or that we tried to change
some things and gave it up.

As I have no time to work on it, it seems best to simply
attach the files that are present in the directory and
mail them to you. Perhaps they can be of use to you.
Near the beginning of each program there are instructions
for its use. Futher documentation is, as far as I can remember
in the Appendix of Schaefer's thesis.

If you have further questions, please let me know.

Kind regards
Johan de Haan
Fri Apr 20 10:13:49 2001

"Johan de Haan" 
<haandej@knmi.nl>
<johan@nat.vu.nl>

Dear Thomas,

I am afraid R.W Schaefer's scattering code is lost.
It was written for a CDC mainframe computer and when
the mainframe computer at our university changed to an
IBM machine it failed to work. Problems occurred because
the IBM machine could represent numbers between 10-78
and 10+78, whereas the CDC machine could represent
values between 10-300 and 10+300.
Professional programmers that supported the transfer to the
IBM mainframe have worked on the code for about a
week, but they failed to get it working properly.
Some of the algorithms for the special functions
would have to be rewritten and there were stability
problems with solving the systems of equations.

A few years later a back-up copy was lost.

Note: Schaefer hinself worked in Holland for several
weeks and tried to get his code running on the mainframe
computer in Leiden (not a CDC machine). After three
weeks he could get access to a CDC machine outside Leiden,
and used that machine to do his calculations. This shows
that his code was not very portable.

When I am back at the Free University, in a few
days, I might look whether there is something left,
but I don not think so. If I find something I will
let you know.

Kind regards,
Johan de Haan
Wednesday, April 18, 2001 4:40 PM
