591058.fig.006
Figure 6: The relative error for the frequency 𝜔 ( 𝛼 = 1 , 𝜃 = 0 . 9 9 9 9 3 9 , = 2 . 3 ). Dash-dotted line with symbols: relative error between 2nd-order HAM approximation and numerical results; solid line with symbols: relative error between 5th-order HAM approximation and numerical results.