**450**wrote:

First, I don't understand what it means by partial correlation matrix. I know correlation matrix, though.

Second, assuming partial correlation matrix is similar to correlation matrix, then how can you refer the connections (edges) between the dots (genes) and how to resolve the directionality?

Third, I am using the R package "parcor". I have read the R manual, some reference papers, but still don't know how to infer a network from the package. Can somebody give a simple tutorial?

Thanks much in advance.