!C
disp('++++++++++++++++++++++++++++++++++++++++++++++++++++++++')
disp('Eigenvalues and eigenvectors of 2X2 matrices')
disp('++++++++++++++++++++++++++++++++++++++++++++++++++++++++')
disp('points to consider:')
disp(' (1) the orthgonality of the eigenvectors')
disp(' (2) the multiplicity of the eigenvectors')
disp(' (3) complex eigenvalues vs. real eigenvalues')
disp(' (4) the spectral radius vs. the norm')
pause

A=[1 2; 2 3]
eigshow
pause


A=[1 1; 2 2]
eigshow
pause

A=[1 2; -3 4]
eigshow
pause

svdshow
pause

A=[1 1; 0 1]
eigshow
pause
