Pagerank

[danzhechen]

Hi there,

I am going through the PageRank paper right now. And here a thing that I do not understand. In this equation 5.1, how can we reach the last equation. It seems that the article does not include a direct formula to translate P to P bar, we need to make every row non-zero, but what is a in this case?

Thank you for your help in advance.

[mikeizbicki]

You're right that the paper doesn't do a good job with defining $\bar P$. It's first defined in words in Section 3.1 (and that's the definition I used in class/have in my quiz key notes), but then it is re-defined in an un-numbered formula in the very last sentence of Section 4. The formula is $\bar P = P + \mathbf a \mathbf v^T$, and they define the meaning of $\mathbf a$ in the preceding sentence. I remember also being frustrated by the lack of a straightforward "definition location" when I first read the paper many years ago.