Using the results of Problem 21.10, develop function ssorpregmres(A,b,x0,m,tol, maxiter) that uses as a preconditioner for discusses the nonsymmetric matrix with dimension that arises from a...

Using the results of Problem 21.10, develop function

ssorpregmres(A,b,x0,m,tol, maxiter) that uses

as a preconditioner for

discusses the nonsymmetric matrix
with dimension

that arises from a reservoir engineering problem. Let

₀



and tol

⁻⁶

Solve the system


using the functions gmresb, mpregmres, and ssorpregmres.

The positive definite matrix

presented in Problem 21.25 required experimenting with a drop tolerance when preconditioning using the incomplete Cholesky decomposition. Using


^T

₀

solve

using ssorpregmres with tol

⁻⁶

and maxiter