FORTRAN subroutine library

The hierarchical code organization is illustrated in Fig. 18.3. This is by code series and then individual codes. ADAS provides extensive Fortran and IDL subroutine libraries which are available for use in a user s own codes and analysis programs. The IDL subroutines support the user s interface to interactive ADAS and graphical presentation of results. Modular basic atomic calculation routines, utilities and access routines to the ADAS data classes are mostly provided in Fortran but generally with IDL versions which use the Fortran through C wrappers. In particular reaEadf .pro and run-adas.pro IDL procedures give access to ADAS data or run ADAS codes at the IDL command line - independent of interactive ADAS. The libraries now include 700 subroutines. 

The BLAS are a collection of 38 FORTRAN callable subroutines that peform many of the basic operations of numerical linear algebra. Contact International Mathematical and Statistical Libraries, (IMSL) for more information. 

The remaining obstacle to producing a working vector processor system is the library of FORTRAN callable subroutines. 

This would certainly have resulted in an operational library in the shortest possible time but at considerable sacrifice in efficiency. All of the VPLIB subroutines were therefore written entirely in Z80A/MVP-9500 assembly language and this produced modules which contained, on average, one third of the assembler instructions produced by F80 for the same operation coded in FORTRAN. In addition to these straightforward savings a considerable amount of hand optimization was possible on the assembler level subroutines. 

The author has presented details of a cost effective vector processor for use with S-100 microcomputers and produced a library of FORTRAN callable subroutines for general purpose floating point computations. Brief details of the construction of a molecular mechanics program using the vector processor have been given. 

The model used to describe the metal deposition process during hydrodemetallisation includes a system of nonlinear parabolic partial differential equations (PDEs) in one space variable (5, 6). These equations were solved numerically with a CONVEX 3840 workstation. Subroutines to solve the set of PDEs are obtained from the NAG Fortran library (1988) (11). 

A set of (n-1) equations such as eq. (15), corresponding to (n-1) lumps of the kinetic scheme, must be solved, together with the deactivation kinetic equation. A program in FORTRAN has been developed for this calculation, which uses the LSODE subroutine from the DSSP library. The composition of the remaining lump is calculated by difference to unity. 

Model calculations comprised the solution of the system of the differential Eqs. (31) and (35) for the case of sorption equilibrium as well as (34) and (35) for the kinetic case (non-equilibrium). Calculations were performed by computer programs in FORTRAN 77 with the aid of the subroutine D03PGF from the NAG-library on the IBM-computer system ES/9600-620 of the research center. The subroutine D03PGF employs Gear s method for the numerical solution of differential equations. 

One solution to this problem is to develop a special user-generated subroutine for the reaction. Aspen Technology has such a subroutine in its library for MTBE (Program Files AspenTech AMSystem 2004.1 Help ADExamples.pdf). It is written in Fortran and is called RAMTBE.f. We will use this subroutine in both the steady-state design in this chapter and in the dynamic control discussed in Chapter 15. 

There is an extensive literature on stiff differential equations (see, for example, Shampine and Gear, 1979 Gear, 1969), and general-purpose subroutines for solving them can be found in the libraries of most computation centers (e.g., the DVOGER subroutine of the IMSL library) or obtained in transportable FORTRAN form from software specialists (Hindmarsh, 1972 Hindmarsh and Byrne, 1977). For combustion modeling, use of standard subroutines for solving stiff sets of differential equations is common practice. 

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