50 lines
922 B
Plaintext
50 lines
922 B
Plaintext
|
|
type rank(node, int, float).
|
|
type calcRank(node, int, sum float).
|
|
% type persistent numPages(node, int).
|
|
type persistent numPages(node, sum int).
|
|
type numLinks(node, sum int).
|
|
type path(node, node).
|
|
|
|
const damping = 0.85.
|
|
const num_iterations = 100.
|
|
% extern float to_float(int).
|
|
% extern float float_abs(float).
|
|
|
|
rank(A, 0, 1.0 / to_float(T)) :- numPages(A,T).
|
|
rank(A, I, V) :-
|
|
numLinks(B,L),
|
|
numPages(A, Ps),
|
|
calcRank(A, I, T),
|
|
% Before = I - 1,
|
|
% rank(A, Before, VOld),
|
|
V = damping + (1.0 - damping) * T,
|
|
I =< num_iterations.
|
|
|
|
% //float_abs((damping + (1.0 - damping) * T) - VOld) > 0.001.
|
|
|
|
calcRank(A, I + 1, 0.0) :-
|
|
rank(A, I, _).
|
|
calcRank(A, I + 1, O / to_float(C)) :-
|
|
edge(B, A),
|
|
rank(B, I, O),
|
|
numLinks(B, C).
|
|
|
|
numLinks(A, 1) :-
|
|
edge(A,B).
|
|
|
|
numPages(A, 1) :- path(A,_).
|
|
|
|
path(A, B) :-
|
|
edge(A,B).
|
|
path(A, B) :-
|
|
edge(B,A).
|
|
path(A, B) :-
|
|
edge(A,C),
|
|
path(C,B).
|
|
path(A, B) :-
|
|
edge(C,A),
|
|
path(C,B).
|
|
|
|
|