int main(int argc, char** argv)
{
struct timeval start, end;
int i,j,k;
double totaltime;
// Check input arguments
if (argc < 5)
{
printf("Error in arguments! Three arguments required: graph filename, N, threshold and d\n");
return 0;
}
// get arguments
char filename[256];
strcpy(filename, argv[1]);
N = atoi(argv[2]);
threshold = atof(argv[3]);
d = atof(argv[4]);
num_threads = atoi(argv[5]);
// Check input arguments
if ((num_threads < 1) || (num_threads > maxThreads))
{
printf("Threads number must be >= 1 and <= %d!\n", maxThreads);
exit(1);
}
Threads_Allocation();
Nodes_Allocation();
// OR read probabilities from files
Read_from_txt_file(filename);
//Read_P_from_txt_file();
//Read_E_from_txt_file();
Random_P_E();
printf("\n");
printf("Parallel version of Pagerank\n");
gettimeofday(&start, NULL);
Pagerank();
gettimeofday(&end, NULL);
/*for (i = 0; i < N; i++)
{
printf("P_t1[%d] = %f\n",i, Nodes[i].p_t1);
}
printf("\n");*/
// Print no of iterations
printf("Total iterations: %d\n", iterations);
totaltime = (((end.tv_usec - start.tv_usec) / 1.0e6+ end.tv_sec - start.tv_sec) * 1000) / 1000;
printf("\nTotaltime = %f seconds\n", totaltime);
printf("End of program!\n");
return (EXIT_SUCCESS);
}
int main(int argc, char** argv)
{
// Check input arguments
if (argc < 5)
{
printf("Error in arguments! Three arguments required: graph filename, N, threshold and d\n");
return 0;
}
// get arguments
char filename[256];
strcpy(filename, argv[1]);
N = atoi(argv[2]);
threshold = atof(argv[3]);
d = atof(argv[4]);
int i, j, k;
double totaltime;
// a constant value contributed of all nodes with connectivity = 0
// it's going to be addes to all node's new probability
double sum = 0;
// Allocate memory for N nodes
Nodes = (Node*) malloc(N * sizeof(Node));
for (i = 0; i < N; i++)
{
Nodes[i].con_size = 0;
Nodes[i].To_id = (int*) malloc(sizeof(int));
}
Read_from_txt_file(filename);
// set random probabilities
Random_P_E();
// OR read probabilities from files
//Read_P_from_txt_file();
//Read_E_from_txt_file();
gettimeofday(&start, NULL);
/********** Start of algorithm **********/
// Iterations counter
int iterations = 0;
int index;
// Or any value > threshold
double max_error = 1;
printf("\nSerial version of Pagerank\n");
// Continue if we don't have convergence yet
while (max_error > threshold)
{
sum = 0;
// Initialize P(t) and P(t + 1) values
for (i = 0; i < N; i++)
{
// Update the "old" P table with the new one
Nodes[i].p_t0 = Nodes[i].p_t1;
Nodes[i].p_t1 = 0;
}
// Find P for each webpage
for (i = 0; i < N; i++)
{
if (Nodes[i].con_size != 0)
{
// Compute the total probability, contributed by node's neighbors
for (j = 0; j < Nodes[i].con_size; j++)
{
index = Nodes[i].To_id[j];
Nodes[index].p_t1 = Nodes[index].p_t1 + (double) Nodes[i].p_t0 / Nodes[i].con_size;
}
}
else
{
// Contribute to all
sum = sum + (double)Nodes[i].p_t0 / N;
}
}
max_error = -1;
// Compute the new probabilities and find maximum error
for (i = 0;i < N; i++)
{
Nodes[i].p_t1 = d * (Nodes[i].p_t1 + sum) + (1 - d) * Nodes[i].e;
if (fabs(Nodes[i].p_t1 - Nodes[i].p_t0) > max_error)
{
max_error = fabs(Nodes[i].p_t1 - Nodes[i].p_t0);
}
}
printf("Max Error in iteration %d = %f\n", iterations+1, max_error);
iterations++;
}
gettimeofday(&end, NULL);
printf("\n");
// Print final probabilitities
/*for (i = 0; i < N; i++)
{
printf("P_t1[%d] = %f\n",i,Nodes[i].p_t1);
}
printf("\n");*/
// Print no of iterations
printf("Total iterations: %d\n", iterations);
totaltime = (((end.tv_usec - start.tv_usec) / 1.0e6 + end.tv_sec - start.tv_sec) * 1000) / 1000;
printf("\nTotaltime = %f seconds\n", totaltime);
printf("End of program!\n");
return (EXIT_SUCCESS);
}
