Figure Properties - SERC

gmres
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or [], then the maximum number of total iterations is maxit (instead of
restart*maxit).
gmres(A,b,restart,tol,maxit,M) and
gmres(A,b,restart,tol,maxit,M1,M2) use preconditioner M or M = M1*M2 and
effectively solve the system inv(M)*A*x = inv(M)*b for x. If M is [] then gmres
applies no preconditioner. M can be a function that returns M\x.
gmres(A,b,restart,tol,maxit,M1,M2,x0) specifies the first initial guess. If
x0 is [], then gmres uses the default, an all-zero vector.
gmres(afun,b,restart,tol,maxit,m1fun,m2fun,x0,p1,p2,...) passes
parameters to functions afun(x,p1,p2,...), m1fun(x,p1,p2,...), and
m2fun(x,p1,p2,...).
[x,flag] = gmres(A,b,...) also returns a convergence flag:
flag = 0 gmres converged to the desired tolerance tol within maxit
outer iterations.
flag = 1 gmres iterated maxit times but did not converge.
flag = 2 Preconditioner M was ill-conditioned.
flag = 3 gmres stagnated. (Two consecutive iterates were the same.)
Whenever flag is not 0, the solution x returned is that with minimal norm
residual computed over all the iterations. No messages are displayed if the
flag output is specified.
[x,flag,relres] = gmres(A,b,...) also returns the relative residual
norm(b-A*x)/norm(b). If flag is 0, relres