qpK2R {qpgraph}R Documentation

Partial correlation coefficients

Description

Obtains partial correlation coefficients from a given concentration matrix.

Usage

qpK2R(K)

Arguments

K concentration matrix.

Details

Partial correlation coefficients are obtained from a concentration matrix by scaling it by its diagonal and swapping the sign of the off-diagonal elements.

Value

A matrix with partial correlation coefficients.

Author(s)

R. Castelo and A. Roverato

References

Castelo, R. and Roverato, A. A robust procedure for Gaussian graphical model search from microarray data with p larger than n. J. Mach. Learn. Res., 7:2621-2650, 2006.

See Also

qpI2K

Examples

nVar <- 50 # number of variables
maxCon <- 5  # maximum connectivity per variable

I <- qpRndGraph(n.vtx=nVar, n.bd=maxCon)
K <- qpI2K(I)

R <- qpK2R(K)

# true partial correlation coefficients of the present edges
summary(abs(R[upper.tri(R) & I]))

# true partial correlation coefficients of the missing edges
summary(abs(R[upper.tri(R) & !I]))


[Package qpgraph version 1.0.0 Index]