function [A,xinitial] = genmatrix1(n) % GENMATRIX1 : Create sample data for Homework 1 % % [A,xinitial] = genmatrix1(n) % % This returns an n-by-n matrix whose largest eigenvalue % is known, for testing CS240A problem 1. It also returns % a randomly chosen n-vector to start the power iteration. % % John R. Gilbert 13 Jan 2006 A = ones(n,n) / sqrt(n); A = A + diag(2*sqrt(n)*ones(1,n)); A = A - diag(sqrt(n)*ones(1,n-1),-1); A = A - diag(sqrt(n)*ones(1,n-1),1); A(1,n) = A(1,n) - sqrt(n); A(n,1) = A(n,1) - sqrt(n); xinitial = randn(n,1);