version1.0

pageranke.py

@@ -0,0 +1,50 @@
+#__author__ = 'admin'
+S=[[0,0.5,0,0],[0.3333,0,0,0.5],[0.3333,0,1,0.5],[0.3333,0.5,0,0]]
+U=[[1,1,1,1],[1,1,1,1],[1,1,1,1],[1,1,1,1]]
+f=[0.25,0.25,0.25,0.25]
+alpha=0.8
+n=len(S)
+
+def multiGeneMatrix(gene,Matrix):
+    mullist=[[0]*len(Matrix) for row in range(len(Matrix))]
+    for i in range(0,len(Matrix)):
+        for j in range(0,len(Matrix)):
+            mullist[i][j] += Matrix[i][j]*gene
+    return mullist
+
+def addMatrix(Matrix1,Matrix2):
+    if len(Matrix1[0])!=len(Matrix2):
+        print("add error...")
+        return
+    addlist=[[0]*len(Matrix1) for row in range(len(Matrix1))]
+    for i in range(0,len(Matrix1)):
+        for j in range(0,len(Matrix2)):
+            addlist[i][j]=Matrix1[i][j]+Matrix2[i][j]
+    return addlist
+
+
+def multiMatrixVector(m,v):
+    rv=list(range(len(v)))
+    for row in range(0,len(m)):
+        temp=0
+        for col in range(0,len(m[1])):
+            temp+=m[row][col]*v[col]
+        rv[row]=temp
+    return rv
+
+f1=multiGeneMatrix(alpha,S)
+f2=multiGeneMatrix((1-alpha)/len(S[0]),U)
+G=addMatrix(f1,f2)
+
+
+count=0
+while(True):
+    count=count +1
+    pr_next=multiMatrixVector(G,f)
+    print ("count: %s " % count)
+    print (str(round(pr_next[0],5)) +"\t" + str(round(pr_next[1],5)) + "\t" + str(round(pr_next[2],5)) + "\t" + str(round(pr_next[3],5)))
+    if round(f[0],5)==round(pr_next[0],5) and round(f[1],5)==round(pr_next[1],5) and round(f[2],5)==round(pr_next[2],5) and round(f[3],5)==round(pr_next[3],5):
+        break
+    f=pr_next
+
+print ("Page Rank complete")