9. The non-transitory machine-readable storage medium of claim 8 wherein calculating the rank value for the document based on the one or more coefficients comprises: (a) for each row of a core data structure: reading a row of the core data structure into a local memory, inflating the row, converting the row into a row of a damped matrix, and multiplying the row of the damped matrix by a current vector to get a value of a next vector; (b) comparing the next vector to the current vector, wherein if a difference between the next vector and the current vector is greater than an error value, setting the next vector as the current vector and repeating step (a), and wherein if the difference is less than the error value, determining rank values from the next vector.
11. The non-transitory machine-readable storage medium of claim 9 wherein the damped matrix is positive.