OpenAD/F : a modular, open-source tool for automatic differentiation of Fortran codes.

Journal Article · Tue Jan 01 04:00:00 EST 2008 · ACM Trans. Math. Software

DOI:https://doi.org/10.1145/1377596.1377598· OSTI ID:935914

Utke, J; Naumann, U; Fagan, M; Tallent, N; Strout, M; Heimbach, P; Hill, C; Wunsch, C; MIT,

The OpenAD/F tool allows the evaluation of derivatives of functions defined by a Fortran program. The derivative evaluation is performed by a Fortran code resulting from the analysis and transformation of the original program that defines the function of interest. OpenAD/F has been designed with a particular emphasis on modularity, flexibility, and the use of open source components. While the code transformation follows the basic principles of automatic differentiation, the tool implements new algorithmic approaches at various levels, for example, for basic block preaccumulation and call graph reversal. Unlike most other automatic differentiation tools, OpenAD/F uses components provided by the OpenAD framework, which supports a comparatively easy extension of the code transformations in a language-independent fashion. It uses code analysis results implemented in the OpenAnalysis component. The interface to the language-independent transformation engine is an XML-based format, specified through an XML schema. The implemented transformation algorithms allow efficient derivative computations utilizing locally optimized cross-country sequences of vertex, edge, and face elimination steps. Specifically, for the generation of adjoint codes, OpenAD/F supports various code reversal schemes with hierarchical checkpointing at the subroutine level. As an example from geophysical fluid dynamics a nonlinear time-dependent scalable, yet simple, barotropic ocean model is considered. OpenAD/F's reverse mode is applied to compute sensitivities of some of the model's transport properties with respect to gridded fields such as bottom topography as independent (control) variables.

• Research Organization: Argonne National Laboratory (ANL)
• Sponsoring Organization: SC; NSF; NASA
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 935914
• Report Number(s): ANL/MCS/JA-57906
• Journal Information: ACM Trans. Math. Software, Journal Name: ACM Trans. Math. Software Journal Issue: 4 ; 2008 Vol. 34
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

54 ENVIRONMENTAL SCIENCES
97 MATHEMATICS AND COMPUTING
ALGORITHMS
COMPUTER CALCULATIONS
FORTRAN
GENERAL CIRCULATION MODELS
O CODES
OCEANIC CIRCULATION