This tarfile represents Los Alamos preprint LA-UR-92-2541, whose title page
includes material given [in (Rev)TeX form] below. It was submitted Computers in
Physics around August 15, 1992. The paper (13 pages) can be printed either from
the FrontFort.ps file (if launched into Preview, it doesn't look so great but
it prints out OK) or from the FrontFort.dvi file (through TeXview). The figures
(7 pages) were generated by Diagram! but are included here as a .ps file that
can also be viewed and printed with Preview.

    Richard R. Silbar
    silbar@whistler.lanl.gov
    silbar@lampf.bitnet

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\begin{title}

An Interactive NeXTstep Interface to a Fortran Code 
for Solving Coupled Differential Equations 

\end{title}

\author{Richard R. Silbar}

\begin{instit}

Theoretical Division, Los Alamos National Laboratory
University of California, Los Alamos, New Mexico 87545

\end{instit}

\begin{abstract}

This paper describes a user-friendly frontend to a Fortran program that
integrates coupled nonlinear ordinary differential equations. The user
interface is built using the NeXTstep Interface Builder, together with a
public-domain graphical palette for displaying intermediate and final results.
The main problem is how to communicate between the Objective-C environment of
NeXTstep and the Fortran code. This is resolved by breaking up the Fortran into
separate subroutines, corresponding to the various control buttons in the
interface. These subroutines are then compiled in such a way that they can be
called as ordinary C functions.

\end{abstract}