regrid_solvers subroutine, public subroutine, public regrid_solvers::solve_linear_system (A, R, X, N, answers_2018) solve_linear_system A A R R X X N N answers_2018 answers_2018 Solve the linear system AX = R by Gaussian elimination. This routine uses Gauss's algorithm to transform the system's original matrix into an upper triangular matrix. Back substitution yields the answer. The matrix A must be square, with the first index varing down the column. n The size of the system a The matrix being inverted [nondim] r system right-hand side [A] x solution vector [A] answers_2018 If true or absent use older, less efficient expressions. mom_error_handler::mom_error regrid_edge_values::edge_slopes_implicit_h3 regrid_edge_values::edge_values_explicit_h4 regrid_edge_values::edge_values_implicit_h4 subroutine, public subroutine, public regrid_solvers::linear_solver (N, A, R, X) linear_solver N N A A R R X X Solve the linear system AX = R by Gaussian elimination. This routine uses Gauss's algorithm to transform the system's original matrix into an upper triangular matrix. Back substitution then yields the answer. The matrix A must be square, with the first index varing along the row. n The size of the system a The matrix being inverted [nondim] r system right-hand side [A] x solution vector [A] mom_error_handler::mom_error subroutine, public subroutine, public regrid_solvers::solve_tridiagonal_system (Al, Ad, Au, R, X, N, answers_2018) solve_tridiagonal_system Al Al Ad Ad Au Au R R X X N N answers_2018 answers_2018 Solve the tridiagonal system AX = R. This routine uses Thomas's algorithm to solve the tridiagonal system AX = R. (A is made up of lower, middle and upper diagonals) n The size of the system ad Matrix center diagonal al Matrix lower diagonal au Matrix upper diagonal r system right-hand side x solution vector answers_2018 If true use older, less acccurate expressions. regrid_edge_values::edge_slopes_implicit_h3 regrid_edge_values::edge_slopes_implicit_h5 regrid_edge_values::edge_values_implicit_h4 regrid_edge_values::edge_values_implicit_h6 subroutine, public subroutine, public regrid_solvers::solve_diag_dominant_tridiag (Al, Ac, Au, R, X, N) solve_diag_dominant_tridiag Al Al Ac Ac Au Au R R X X N N Solve the tridiagonal system AX = R. This routine uses a variant of Thomas's algorithm to solve the tridiagonal system AX = R, in a form that is guaranteed to avoid dividing by a zero pivot. The matrix A is made up of lower (Al) and upper diagonals (Au) and a central diagonal Ad = Ac+Al+Au, where Al, Au, and Ac are all positive (or negative) definite. However when Ac is smaller than roundoff compared with (Al+Au), the answers are prone to inaccuracy. n The size of the system ac Matrix center diagonal offset from Al + Au al Matrix lower diagonal au Matrix upper diagonal r system right-hand side x solution vector Solvers of linear systems. Date of creation: 2008.06.12 L. White.This module contains solvers of linear systems. These routines have now been updated for greater efficiency, especially in special cases.