From it compute a lel eigenvector of p the entry ai

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: e next step?   Recall that row i of the transi*on prob. Matrix P tells us where we go next from state i.   So from x, our next state is distributed as xP   E.g., (000…1…000) means we re in state i. 1 i n More generally, the vector x = (x1, … xn) means the walk is in state i with probability xi. n ∑x i   The one aler that is xP2, then xP3, etc.   (Where) Does the converge? = 1. i =1 Introduc)on to Informa)on Retrieval Sec. 21.2.2 Introduc)on to Informa)on Retrieval How do we compute this vector? Pagerank summary   Let a = (a1, … an) denote the row vector of steady ­ state probabili*es.   If our current posi*on is described by a, then the next step is distributed as aP.   But a is the steady state, so a=aP.   Solving this matrix equa*on gives us a. Sec. 21.2.2   Preprocessing:   So a is the (lel) eigenvector for P.   (Corresponds to the principal eig...
View Full Document

{[ snackBarMessage ]}

Ask a homework question - tutors are online