5. Extrapolation procedures

According to Theorem 1, r _c is a rational function with a numerator of degree p – 1 with vector coefficients and a scalar denominator of degree p – 1. Moreover, r _c tends to the PageRank vector $\overline{r}$ when c tends to 1.

We'll therefore calculate r _c for various values of c smaller than the desired one (we've already mentioned that the extra cost is low thanks to properties 7 and 8), interpolate these vectors by a rational fraction of the same type but with smaller degrees, and then extrapolate this rational fraction...