Table 1.

Both the ad hoc and discrete spectral approaches were used to fit simulated, noise-free stress-relaxation data generated using M=3 Maxwell branches. R² and mean squared error (MSE) for each fitting were calculated. The results for M=1, 2, 3, and 4 correspond to Fig. 2 (ad hoc approach) while the results for M=1000 correspond to Fig. 3 (discrete spectral approach). The approaches required comparable CPU time (f=25000 data points, 1000 iterations).

M	1	2	3	4	1000
R2	0.9957	0.9999	0.9999	0.9999	0.9999
MSE	0.6 × 10−2	3.7 × 10−3	1.6 × 10−9	2.1 × 10−9	1.8 × 10−9
CPU time (s)	7.0	6.1	3.7	5.6	6.4