Determines whether a square matrix exhibits compound symmetry (CS), i.e.,
whether all diagonal entries are equal and all off-diagonal entries are
equal.
Arguments
- U
A numeric square matrix.
Value
Logical. TRUE if U has compound symmetry structure,
and FALSE otherwise.
Examples
# Compound symmetry matrix
U1 <- matrix(0.3, nrow = 4, ncol = 4)
diag(U1) <- 1
is.CS(U1)
#> [1] TRUE
# Toeplitz matrix, not CS
U2 <- toeplitz(c(1, 0.5, 0.2, 0.1))
is.CS(U2)
#> [1] FALSE