User Guide

122
Appendix B
Toeplitz. This covariance
structure has homogenous
variances and heterogenous
correlations between elements.
The correlation between adjacent
elements is homogenous across
pairs of adjacent elements. The
correlation between elements
separated by a third is again
homogenous, and so on.
Toeplitz: Heterogenous. This
covariance structure has
heterogenous variances and
heterogenous correlations
between elements. The
correlation between adjacent
elements is homogenous across
pairs of adjacent elements. The
correlation between elements
separated by a third is again
homogenous, and so on.
Unstructured. This is a
completely general covariance
matrix.
Unstructured: Correlation Metric.
This covariance structure has
heterogenous variances and
heterogenous correlations.
Variance Components. This structure assigns a scaled identity (ID) structure to each of the
specified random effects.
s
r
r
r
rrr
rr r
rrr
2
123
112
21 1
321
1
1
1
1
L
N
M
M
M
M
O
Q
P
P
P
P
s ssr ssr ssr
ssr s ssr ssr
ssr ss r s ssr
ssr ssr ssr s
1
2
211 312 413
211 2
2
321 422
312 321 3
2
431
413 422 431 4
2
L
N
M
M
M
M
O
Q
P
P
P
P
ssss
ssss
ss ss
sss s
1
2
21 31 41
21 2
2
32 42
31 32 3
2
43
41 42 43 4
2
L
N
M
M
M
M
O
Q
P
P
P
P
s ssr ssr ssr
ssr s ssr ssr
ssr ss r s ssr
ssr ssr ssr s
1
2
2121 3131 4141
2121 2
2
3 2 32 4 2 42
3131 3232 3
2
4343
4 1 41 4 2 42 4 3 43 4
2
L
N
M
M
M
M
O
Q
P
P
P
P