How to compute a correlation matrix from ternary variables?

Question

[Pas]

Hi all,

I have a matrix of genes whose expression is coded in a ternary system: -1 (down regulated), 0 (no detection) and 1 (up-regulated). The matrix is constituted by ~2000 genes (rows) and 220 samples (columns). Do you have an idea how to correctly create a matrix correlation from these data?

Many thanks,
Pas