If P = projection onto the one dimensional space
spanned by 1, the vector consisting of n 1's, then
using the usual formula for projections we have
P = 11'/1'1 = J/n
and writing I+cJ in terms of P we have:
I+cJ = (I-P) + (cn+1)P
which is an eigen expansion showing that
I+cJ has one eigenvalue of
"Stefano Sofia" <[EMAIL PROTECTED]> writes:
> Dear R users,
> even if this question is not related to an issue about R, probably some of
> you will be able to help me.
>
> I have a square matrix of dimension k by k with alpha on the diagonal and
> beta everywhee else.
> This symmetric matrix is
Dear R users,
even if this question is not related to an issue about R, probably some of you
will be able to help me.
I have a square matrix of dimension k by k with alpha on the diagonal and beta
everywhee else.
This symmetric matrix is called symmetric compound matrix and has the form
a( I + c
