Isomap-Based Three-Dimensional Operational Modal Analysis

Table 16

PCA and Isomap by LSMS with a real modal damping ratio of 0.1.

Real order	Identified order	LSMS
		PCA (MDS)			Isomap
		MAC	Frequencies	Relative error (%)	MAC	Frequencies	Relative error (%)
1	2	0.7248	1073	1.716	0.7256	1080	2.379
2	1	0.4890	1140	−0.498	0.4887	1137	−0.759
3	3	0.3430	1199	−3.275	0.3379	1178	−4.969
4	4	0.2435	1414	−1.935	0.2434	1391	−3.530
5	6	0.6293	1747	0.402	0.0002	—	—
7	5	0.2520	1854	−0.946	0.2710	1800	−3.831