PRECONDITIONED CONJUGATE-GRADIENT 2 (PCG2), a computer program for solving ground-water flow equations
Water-Resources Investigations Report
90-4048
By: Mary C. Hill
Links
- More information: Publisher Index Page (html)
- Download citation as: RIS | Dublin Core
Abstract
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 reconditioning 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.
| Publication type | Report |
|---|---|
| Publication Subtype | USGS Numbered Series |
| Title | PRECONDITIONED CONJUGATE-GRADIENT 2 (PCG2), a computer program for solving ground-water flow equations |
| Series title | Water-Resources Investigations Report |
| Series number | 90-4048 |
| DOI | 10.3133/wri904048 |
| Edition | - |
| Year Published | 1990 |
| Language | ENGLISH |
| Publisher | U.S. Geological Survey ; Books and Open-File Reports Section, |
| Description | iii, 43 p. :ill. ;28 cm. |
| Google Analytic Metrics | Metrics page |