| duplication {rggm} | R Documentation |
duplication(n)
n |
a positive integer |
A n*(n+1)/2 matrix with real values.
Masashi Miyamura
Jan R. Magnus and Heinz Neudecker, (1999) Matrix Differential Calculus with Applications in Statistics and Econometrics, Second Edition, John Wiley & Sons
vech, duplication.inverse, elimination
m <- matrix(c(1, 2, 3,
2, 5, 6,
3, 6, 9),
3, 3)
duplication(3) %*% vech(m) # identical to as.vector(m)