psd2edm {edmcr} | R Documentation |
psd2edm
Transform a positive semi-definite matrix to a Euclidean Distance Matrix
psd2edm(S, V = NULL)
S |
A symmetric, positive semi-definite matrix |
V |
A projection matrix satisfying V'1 = 0 and VV' = I |
The psd2edm function performs the inverse operation of the edm2psd function,
taking a matrix in S_{n-1}^{+}
and transforming it to a matrix in D_{n}^{-}
.
psd2edm(S_{n-1}^{+}) = D_{n}^{-}
Therefore, psd2edm on S_{n-1}^{+}
is the inverse operator of edm2psd on D_{n}^{-}
.
For a symmetric positive semi-definite matrix S, psd2edm(S) will be in D_{n}^{-}
.
D A Euclidean Distance Matrix.
XY <- cbind(runif(100,0,1),runif(100,0,1))
S <- edm2psd(as.matrix(dist(XY)))
D <- psd2edm(S)