The principal diagonal of a correlation matrix in my experience contains
1s, as it includes the correlations between each variable and itself.
For principal component analysis, that would seem the obvious choice
too.
If there is a reason for something else, perhaps as a consequence of
using some flavour of factor analysis (as your title, but not your
content, implies) then I think you will have to specify what you want in
the principal diagonal.
In short, either the diagonal contains 1s, or there is a reason for your
diagonal to contain something else, and you will have to specify what
that is.
Timura, Catherine A PhD
I am using stata 10 for mac. I want to do a principal component analysis
over a correlation table (and not have the program do an additional
correlation over the data). While the option exists in the menu, it
does
not allow the diagonal to be blank. Please advise on how to allow for
the
diagonal to remain blank, to avoid having it part of the analysis.
We are doing cultural consensus analysis over hand-drawn agreement
tables,
as correlations underestimate agreement between individuals.
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