How can I use a covariance matrix with Onyx?

Covariance matrices can be defined in text files using a set of keywords and your data. Use the keyword “COVARIANCE” to start a tab-separated block containing your covariance matrix. It is sufficient to enter the lower diagonal of the matrix because it is symmetric. Use the keyword “OBSERVED VARIABLES” to start a block containing the tab-separated names of your variables. Use a keyword “SAMPLE SIZE” to start a block containing the numeric sample size.

Here is an example:

COVARIANCE
10
5 21
8 3 40
9 9 17 20
OBSERVED VARIABLES
age education cognition brain
SAMPLE SIZE
100

 

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