Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

GRESS Version 2.0 user`s manual

Technical Report ·
DOI:https://doi.org/10.2172/10107336· OSTI ID:10107336
GRESS uses a precompiler to interpret FORTRAN statements and determine the mathematical operations embodied in them. As each arithmetic assignment statement in a program is interpreted, information necessary to allow the calculation of derivatives is generated. The result of the precompilation step is a new FORTRAN program that can produce derivatives for any REAL (i.e., single or double precision) variable calculated by the model. Consequently, GRESS enhances FORTRAN programs or subprograms by adding the calculation of derivatives along with the original output. Derivatives from a GRESS enhanced model can be used internally (e.g., iteration acceleration) or externally (e.g., sensitivity studies). By calling GRESS run-time routines, derivatives can be propagated through the code via the chain rule (referred to as the CHAIN option) or accumulated to create an adjoint matrix (referred to as the ADGEN option). A third option, GENSUB, makes it possible to process a subset of a program (i.e., a do loop, subroutine, function, a sequence of subroutines, or a whole program) for calculating derivatives of dependent variables with respect to independent variables.
Research Organization:
Oak Ridge National Lab., TN (United States)
Sponsoring Organization:
USDOE, Washington, DC (United States)
DOE Contract Number:
AC05-84OR21400
OSTI ID:
10107336
Report Number(s):
ORNL/TM--11951; ON: DE92004592
Country of Publication:
United States
Language:
English

Similar Records

GRESS Version 2. 0 user's manual
Technical Report · Thu Oct 31 23:00:00 EST 1991 · OSTI ID:6090743

GRESS (Gradient Enhanced Software System) Version 0. 0 user's manual
Technical Report · Sat Oct 01 00:00:00 EDT 1988 · OSTI ID:6683420

GRESS: gradient-enhanced software system. Version D. User's Guide
Technical Report · Mon Jul 01 00:00:00 EDT 1985 · OSTI ID:6422692