Significant digits in calculations.

From: mcintosh;at;ccwf.cc.utexas.edu (aubrey mcintosh)
Subject: Significant digits in calculations.
Date: Thu, 12 Dec 91 10:44:01 -0600

As a chemist, I have always wanted my programs to recognize and manage
 significant digits.
 At this time, I have code that records significant digits on input, manages them
 correctly on add/subtract/multiply/divide, and correctly formats output.
 FORTRAN style input, e.g. 1.234567E+021 is accepted.  On output, the exponent
 is changed to a SI suffix, e.g. (E-003, m), (E-006, u), (E-009, n), (E+006, M).
 These
 are recognized on input as well.
 A  matrix algebra package is provided on top of these libraries.  It is quite
 interesting
 to perform matrix calculations, especially eigenvector calculations, using
 significant
 digits.
 The library and matrix multiply source is available, and is described briefly in
 an upcoming article in Computers and Mathematics with Applications.
 I have been using this code now for over a year with minimal changes.  I would
 now like some volunteers to "exercise" this code.  System requirements
 are
    1) A SPARC station.
    2) A Mac II (68020 or higher)
 or  3) A vax running Ultrix and an X terminal.
 ftp access is recommended.  Some setup is required.
 --Aubrey McIntosh