Utilisateur:Evahatik/Modélisation des Réseaux (M1, 2018)/Activité E
Graphe slide 25
Etude de la centralité de vecteurs propres de noeuds
Matrice A
a | b | c | d | e | f | g | h | |
---|---|---|---|---|---|---|---|---|
a | 0 | 1 | 1 | 1 | 0 | 0 | 0 | 0 |
b | 0 | 0 | 1 | 0 | 1 | 0 | 0 | 0 |
c | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 |
d | 0 | 0 | 1 | 0 | 0 | 1 | 0 | 0 |
e | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
f | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
g | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
h | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 |
a | b | c | d | e | f | g | h | |
---|---|---|---|---|---|---|---|---|
a | 0 | 1/8 | 1/8 | 1/8 | 0 | 0 | 0 | 0 |
b | 0 | 0 | 1/8 | 0 | 1/8 | 0 | 0 | 0 |
c | 0 | 0 | 0 | 0 | 0 | 0 | 1/8 | 1/8 |
d | 0 | 0 | 1/8 | 0 | 0 | 1/8 | 0 | 0 |
e | 1/8 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
f | 1/8 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
g | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1/8 |
h | 0 | 0 | 0 | 0 | 0 | 0 | 1/8 | 0 |
a | b | c | d | e | f | g | h | |
---|---|---|---|---|---|---|---|---|
a | 0 | 0 | 0 | 0 | 1/8 | 1/8 | 0 | 0 |
b | 1/8 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
c | 1/8 | 1/8 | 0 | 1/8 | 0 | 0 | 0 | 0 |
d | 1/8 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
e | 0 | 1/8 | 0 | 0 | 0 | 0 | 0 | 0 |
f | 0 | 0 | 0 | 1/8 | 0 | 0 | 0 | 0 |
g | 0 | 0 | 1/8 | 0 | 0 | 0 | 0 | 1/8 |
h | 0 | 0 | 1/8 | 0 | 0 | 0 | 1/8 | 0 |
Pa | 1/8 |
---|---|
Pb | 1/8 |
Pc | 1/8 |
Pd | 1/8 |
Pe | 1/8 |
Pf | 1/8 |
Pg | 1/8 |
Ph | 1/8 |
On résout l'équation Mt*P = P
Calcul de Pa : 1/8 Pe + 1/8 Pf = Pa <=> 1/8 . 1/8 + 1/8 . 1/8 = Pa <=> Pa = 1/32
Calcul de Pb :1/8 Pa = Pb <=> Pb = 1/64
Calcul de Pc: 1/8Pa + 1/8Pb + 1/8Pd = Pc <=> Pc = 1/256
Calcul de Pd : Pd = 1/8 Pa <=> Pd = 1/64
Calcul de Pe : Pe = 1/8 Pb <=> Pe = 1/64
Calcul de Pf : Pf = 1/8 Pd <=> Pf = 1/64
Calcul de Pg : Pg = 1/8 Pc + 1/8 Ph <=> Pg = 1/32
Calcul de Ph : Ph = 1/8 Pc + 1/8 Pg <=> Ph = 1/32
On a 3 composantes fortement connexes : (e, b, a, d, f), (c) et (g, h).
Moins il y a de points dans la composantes fortement connexes, plus les valeurs sont petites.
Pour éviter ce problème on pourrait créer des liens de e vers g (ou inversement) et de h vers f (ou inversement).
Graphe Slide 18
Proximité des noeuds :
- Proximité sortante
P1 P1 = 1
P1 P2 = 2
P1 P3 = 1
P1 P4 = 1
c entrante (P1) = 1/(1+2+1+1) = 1/5
P2 P1 = 1
P2 P2 = 0
P2 P3 = 2
P2 P4 = 1
c entrante (P2) = 1/(1+0+2+1) = 1/4
P3 P1 = 1
P3 P2 = 1
P3 P3 = 0
P3 P4 = 2
c entrante (P3) = 1/(1+1+0+2) = 1/4
P4 P1 = 2
P4 P2 = 1
P4 P3 = 3
P4 P4 = 0
c entrante (P4) = 1/(2+1+3+0) = 1/6
- Proximité entrante
P1 P1 = 1
P2 P1 = 1
P3 P1 = 2
P4 P1 = 2
c sortante (P1) = 1/6
P1 P2 = 2
P2 P2 = 0
P3 P2 = 1
P4 P2 = 1
c sortante (P2) = 1/4
P1 P3 = 1
P2 P3 = 2
P3 P3 = 0
P4 P3 = 3
c sortante (P3) = 1/6
P1 P4 = 1
P2 P4 = 1
P3 P4 = 1
P4 P4 = 0
c sortante (P4) = 1/3
Intermédiarité des noeuds
Nombre de liens sortants | c sortants (i) | intermédiarité | |
---|---|---|---|
1 | 3 | 1/5 | 3/5 |
2 | 2 | 1/4 | 1/2 |
3 | 2 | 1/4 | 1/2 |
4 | 1 | 1/6 | 1/6 |
Nombre de liens ENTRANTS | c sortants (i) | intermédiarité | |
---|---|---|---|
1 | 2 | 1/6 | 1/3 |
2 | 2 | 1/4 | 1/2 |
3 | 1 | 1/6 | 1/6 |
4 | 3 | 1/3 | 1 |