make.symmetric {dclone}R Documentation

Make a square matrix symmetric by averaging.

Description

Matrix symmetry might depend on numerical precision issues. There is a bug in JAGS related to this issue for multivariate normal nodes. This simple function can fix the issue.

Usage

make.symmetric(x)

Arguments

x A square matrix.

Details

The function takes the average of (x[i, j] + x[j, i]) / 2 for each off diagonal cells.

Value

A symmetric square matrix.

Note

The function works for any matrix, even for those not intended to be symmetric.

Author(s)

P\'eter S\'olymos, solymos@ualberta.ca

Examples

x <- as.matrix(as.dist(matrix(1:25, 5, 5)))
diag(x) <- 100
x[lower.tri(x)] <- x[lower.tri(x)] - 0.1
x[upper.tri(x)] <- x[upper.tri(x)] + 0.1
x
make.symmetric(x)

[Package dclone version 1.0-0 Index]