Results of this program

» power

A =  2    -1     0     0          y =  1
    -1     2    -1     0               0
     0    -1     2    -1               0
     0     0    -1     2               0

Power Method Demonstration
Determine highest (1) or lowest (2) eigenvalue: 1

# 1 Lambda = 2.000000 Error = 50.000000
# 2 Lambda = 2.500000 Error = 20.000000
# 3 Lambda = 2.800000 Error = 10.714286
# 4 Lambda = 3.000000 Error = 6.666667
# 5 Lambda = 3.142857 Error = 4.545455
# 6 Lambda = 3.250000 Error = 3.296703

# 19 Lambda = 3.621001 Error = -0.031430
# 20 Lambda = 3.620179 Error = -0.022703
# 21 Lambda = 3.619585 Error = -0.016407
# 22 Lambda = 3.619156 Error = -0.011861
# 23 Lambda = 3.618846 Error = -0.008577

Highest eigenvalue is 0.381975

» power

Power Method Demonstration
Determine highest (1) or lowest (2) eigenvalue: 2

# 1 Lambda = 0.800000 Error = -25.000000
# 2 Lambda = 2.000000 Error = 60.000000
# 3 Lambda = 2.550000 Error = 21.568627
# 4 Lambda = 2.588235 Error = 1.477273
# 5 Lambda = 2.608333 Error = 0.770532
# 6 Lambda = 2.615161 Error = 0.261088
# 7 Lambda = 2.617215 Error = 0.078456
# 8 Lambda = 2.617804 Error = 0.022519
# 9 Lambda = 2.617970 Error = 0.006337

Lowest eigenvalue is 0.381975

» sort(eig(A))

ans =

    0.3820
    1.3820
    2.6180
    3.6180