Bilkent University
CS533
Information Retrieval Ssytems


Q8:
Source: M. Franceschet, PageRank: Standing on the Shoulders of Giants. Comm. of the ACM, 54(6):
92-101, 2011.

PageRank values
A: 0.0328
B: 0.3844
C: 0.3429
D: 0.0391
E: 0.0809
F: 0.0391
I: 0.0162
H: 0.0162
L: 0.0162
M: 0.0162
G: 0.0162

MATLAB Program by Muhsin Can Orhan 
May 21, 2013
==================================


alpha = 0.85;

%Indices & Number of outgoing links
% 1 = A & q_A = 0
% 2 = B & q_B = 1
% 3 = C & q_C = 1
% 4 = D & q_D = 2
% 5 = E & q_E = 2 
% 6 = F & q_F = 2 
% 7 = I & q_I = 2
% 8 = H & q_H = 2 
% 9 = L & q_L = 1
%10 = M & q_M = 1
%11 = G & q_G = 2

S = zeros(11,11);

%Node A 
S(1,:) = (1/11) * ones(1,11);

%Node B
S(2,3) = 1; %to C
%Node C
S(3,2) = 1; %to B
% 4 = D
S(4,1) = 1/2;  %to A
S(4,2) = 1/2; %to B

% 5 = E
S(5,2) = 1/3; %to B
S(5,4) = 1/3;  %to D
S(5,6) = 1/3;  %to F

% 6 = F 
S(6,2) = 1/2;  %to B
S(6,5) = 1/2;  %to E

% 7 = I 
S(7,2) = 1/2;  %to B
S(7,5) = 1/2;  %to E

% 8 = H 
S(8,2) = 1/2;  %to B
S(8,5) = 1/2;  %to E

% 9 = L  
S(9,5) = 1;  %to E

%10 = M 
S(10,5) = 1;  %to E

%11 = G
S(11,2) = 1/2;  %to B
S(11,5) = 1/2;  %to E

E = (1/11) * ones(11,11); 

G = alpha * S + (1-alpha) * E;

%Solve pi = pi * G by using Power method

sol = (1/11) * ones(1,11);
sol2 = zeros(1,11);
diff = max(abs(sol - sol2));
  
while diff > 10^(-10)
    sol2 = temp * G;
    diff = max(abs(sol - sol2));
    sol = sol2;
end

fprintf('PageRank values\n');  
fprintf('A: %4.4f\n',sol(1)); 
fprintf('B: %4.4f\n',sol(2)); 
fprintf('C: %4.4f\n',sol(3)); 
fprintf('D: %4.4f\n',sol(4)); 
fprintf('E: %4.4f\n',sol(5)); 
fprintf('F: %4.4f\n',sol(6)); 
fprintf('I: %4.4f\n',sol(7)); 
fprintf('H: %4.4f\n',sol(8)); 
fprintf('L: %4.4f\n',sol(9)); 
fprintf('M: %4.4f\n',sol(10)); 
fprintf('G: %4.4f\n',sol(11));