Isomap-Based Three-Dimensional Operational Modal Analysis

Table 15

PCA and Isomap by LSMS with a real modal damping ratio of 0.05.

Real order	Identified order	LSMS
		PCA (MDS)			Isomap
		MAC	Frequencies	Relative error (%)	MAC	Frequencies	Relative error (%)
1	2	0.6311	1059	0.389	0.6316	1065	0.957
2	1	0.3026	1143	−0.236	0.3019	1143	−0.236
3	3	0.1082	1232	−0.613	0.1088	1229	−0.855
4	4	0.0801	1437	−0.340	0.0788	1441	−0.062
5	6	0.0037	1747	0.402	0.0227	—	—
7	5	0.0219	1868	−0.198	0.0211	1879	0.390