int getTopSimUsers(gk_csr_t *adjMat, int user, gk_fkv_t *topUsers, int nsim) { //to store the restart distributon of vertices float *pr; int i, j, count; int iter = 0; gk_fkv_t *pRanks; pr = (float*) malloc(sizeof(float)*adjMat->nrows); //initialize the restart distribution for user pr[user] = 1.0; iter = gk_rw_PageRank(adjMat, 0.5, 0.000001, 100, pr); fprintf(stderr, "Iter: %d\n", iter); count = 0; //count the non-zero values in pr and sort them for (i = 0; i < adjMat->nrows; i++) { if (pr[i] > 0 && i != user) { count++; } } //printf("Found %d similar users.\n", count); pRanks = gk_fkvmalloc(count, "store page ranks"); for (i = 0, j = 0; i < adjMat->nrows; i++) { if (pr[i] > 0 && i != user) { pRanks[j].key = pr[i]; pRanks[j].val = i; j++; } } nsim = gk_min(nsim, count); gk_dfkvkselect(count, nsim, pRanks); gk_fkvsortd(nsim, pRanks); gk_fkvcopy(nsim, pRanks, topUsers); free(pr); free(pRanks); return nsim; }
int main(int argc, char *argv[]) { ssize_t i, j, niter; params_t *params; gk_csr_t *mat; FILE *fpout; /* get command-line options */ params = parse_cmdline(argc, argv); /* read the data */ mat = gk_csr_Read(params->infile, GK_CSR_FMT_METIS, 1, 1); /* display some basic stats */ print_init_info(params, mat); if (params->ntvs != -1) { /* compute the pr for different randomly generated restart-distribution vectors */ float **prs; prs = gk_fAllocMatrix(params->ntvs, mat->nrows, 0.0, "main: prs"); /* generate the random restart vectors */ for (j=0; j<params->ntvs; j++) { for (i=0; i<mat->nrows; i++) prs[j][i] = RandomInRange(931); gk_fscale(mat->nrows, 1.0/gk_fsum(mat->nrows, prs[j], 1), prs[j], 1); niter = gk_rw_PageRank(mat, params->lamda, params->eps, params->niter, prs[j]); printf("tvs#: %zd; niters: %zd\n", j, niter); } /* output the computed pr scores */ fpout = gk_fopen(params->outfile, "w", "main: outfile"); for (i=0; i<mat->nrows; i++) { for (j=0; j<params->ntvs; j++) fprintf(fpout, "%.4e ", prs[j][i]); fprintf(fpout, "\n"); } gk_fclose(fpout); gk_fFreeMatrix(&prs, params->ntvs, mat->nrows); } else if (params->ppr != -1) { /* compute the personalized pr from the specified vertex */ float *pr; pr = gk_fsmalloc(mat->nrows, 0.0, "main: pr"); pr[params->ppr-1] = 1.0; niter = gk_rw_PageRank(mat, params->lamda, params->eps, params->niter, pr); printf("ppr: %d; niters: %zd\n", params->ppr, niter); /* output the computed pr scores */ fpout = gk_fopen(params->outfile, "w", "main: outfile"); for (i=0; i<mat->nrows; i++) fprintf(fpout, "%.4e\n", pr[i]); gk_fclose(fpout); gk_free((void **)&pr, LTERM); } else { /* compute the standard pr */ int jmax; float diff, maxdiff; float *pr; pr = gk_fsmalloc(mat->nrows, 1.0/mat->nrows, "main: pr"); niter = gk_rw_PageRank(mat, params->lamda, params->eps, params->niter, pr); printf("pr; niters: %zd\n", niter); /* output the computed pr scores */ fpout = gk_fopen(params->outfile, "w", "main: outfile"); for (i=0; i<mat->nrows; i++) { for (jmax=i, maxdiff=0.0, j=mat->rowptr[i]; j<mat->rowptr[i+1]; j++) { if ((diff = fabs(pr[i]-pr[mat->rowind[j]])) > maxdiff) { maxdiff = diff; jmax = mat->rowind[j]; } } fprintf(fpout, "%.4e %10zd %.4e %10d\n", pr[i], mat->rowptr[i+1]-mat->rowptr[i], maxdiff, jmax+1); } gk_fclose(fpout); gk_free((void **)&pr, LTERM); } gk_csr_Free(&mat); /* display some final stats */ print_final_info(params); }