A=[[-2 1 0; 0 -2 1; 0 0 -2], zeros(3,2); zeros(2,3) [-5 1; 0 -5]];
expm(A)

logm(ans)

norm(ans-A)

B=[expm(A(1:3,1:3)), zeros(3,2); zeros(2,3), expm(A(4:5,4:5))]

expm3(A)

eig(A)'

funm(A,'sin')

E=sinm1(A)