by Mary C. Hill
This report is available as a pdf below
This report documents PCG2 : a numerical code to be used with the U.S. Geological Survey modular three-dimensional, finite-difference, ground-water flow model . PCG2 uses the preconditioned conjugate-gradient method to solve the equations produced by the model for hydraulic head. Linear or nonlinear flow conditions may be simulated.
PCG2 includes two preconditioning options : modified incomplete Cholesky preconditioning, which is efficient on scalar computers; and polynomial preconditioning, which requires less computer storage and, with modifications that depend on the computer used, is most efficient on vector computers . Convergence of the solver is determined using both head-change and residual criteria. Nonlinear problems are solved using Picard iterations.
This documentation provides a description of the preconditioned conjugate gradient method and the two preconditioners, detailed instructions for linking PCG2 to the modular model, sample data inputs, a brief description of PCG2, and a FORTRAN listing.
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U.S. Department of the Interior, U.S. Geological Survey
Maintainer: Publications Team Last update: 15:55:40 Wed 29 Jan 2003 Privacy Statement || Disclaimer || Accessibility URL: http://pubs.water.usgs.gov/wrir_90-4048 |
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