, what does “D = diag(W.1)” means?on page #2, just below equation (6)
PFA screenshot and here is the link of the paper -
original paper
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$\begingroup$ X-posted: math.stackexchange.com/q/3289370/339790 $\endgroup$ – Rodrigo de Azevedo Jul 11 '19 at 10:30
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2$\begingroup$ It already has answers there, please don't cross-post. That way, you don't waste people's time. $\endgroup$ – nicoguaro♦ Jul 11 '19 at 14:00
I believe that $\mathbf W\cdot \mathbf 1$ denotes a matrix-vector product of a matrix $\mathbf W$ with a vector of ones $\mathbf 1$ of the corresponding size (number of columns).
The result of this operation is a vector (of the size of number of rows of $\mathbf W$), so, it makes total sense to apply a diagonal function on it to arrive to a matrix form.
Disclaimer: my assumption is based solely on reading the formula at question, and not looking at the rest of the paper at all.