MATLAB Function Reference Volume 1: A - E - Bad Request

cgs
2-238
progress of cgs by plotting the relative residuals at each iteration starting from
the initial estimate (iterate number 0) with
semilogy(0:iter2,resvec2/norm(b),'-o')
xlabel('iteration number')
ylabel('relative residual')
relative residual
10 0
10 −2
10 −4
10 −6
10 −8
10 −10
10 −12
10 −14
10
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
−16
iteration number
See Also bicg, bicgstab, gmres, lsqr, luinc, minres, pcg, qmr, symmlq
@ (function handle), \ (backslash)
References [1] Barrett, R., M. Berry, T. F. Chan, et al., Templates for the Solution of Linear
Systems: Building Blocks for Iterative Methods, SIAM, Philadelphia, 1994.
[2] Sonneveld, Peter, “CGS: A fast Lanczos-type solver for nonsymmetric linear
systems”, SIAM J. Sci. Stat. Comput., January 1989, Vol. 10, No. 1, pp. 36-52.