From 3aee2fd43e3059a699af2b63c6f2395e5a55e515 Mon Sep 17 00:00:00 2001
From: KatolaZ <katolaz@freaknet.org>
Date: Wed, 27 Sep 2017 15:06:31 +0100
Subject: First commit on github -- NetBunch 1.0

---
 src/cnm/cnm.c | 480 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 480 insertions(+)
 create mode 100644 src/cnm/cnm.c

(limited to 'src/cnm/cnm.c')

diff --git a/src/cnm/cnm.c b/src/cnm/cnm.c
new file mode 100644
index 0000000..d1afb3f
--- /dev/null
+++ b/src/cnm/cnm.c
@@ -0,0 +1,480 @@
+/**
+ *  This program is free software: you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License as
+ *  published by the Free Software Foundation, either version 3 of the
+ *  License, or (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see
+ *  <http://www.gnu.org/licenses/>.
+ *
+ *  (c) Vincenzo Nicosia 2009-2017 -- <v.nicosia@qmul.ac.uk>
+ * 
+ *  This file is part of NetBunch, a package for complex network
+ *  analysis and modelling. For more information please visit:
+ *
+ *             http://www.complex-networks.net/
+ *
+ *  If you use this software, please add a reference to 
+ *
+ *               V. Latora, V. Nicosia, G. Russo             
+ *   "Complex Networks: Principles, Methods and Applications"
+ *              Cambridge University Press (2017) 
+ *                ISBN: 9781107103184
+ *
+ ***********************************************************************
+ *
+ *  This program finds the communities in a graph using the greedy
+ *  modularity optimisation algorithm proposed by Clauset, Newman, and
+ *  Moore.
+ *
+ *  References:
+ * 
+ *  [1] A. Clauset, M. E. J. Newman, and C. Moore. "Finding community
+ *      structure in very large networks". Phys. Rev. E 70 (2004),
+ *      066111.
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <math.h>
+
+#include "utils.h"
+#include "cnm_bst_pq.h"
+#include "dset.h"
+
+
+void usage(char *argv[]){
+
+  printf("********************************************************************\n"
+         "**                                                                **\n"
+         "**                         -*-  cnm  -*-                          **\n"
+         "**                                                                **\n"
+         "**   Find the communities of the input graph 'graph_in' using     **\n"
+         "**   the greedy modularity optimisation algorithm proposed by     **\n"
+         "**   Clauset, Newman, and Moore.                                  **\n"
+         "**                                                                **\n"
+         "**   The input file 'graph_in' is an edge-list.                   **\n"
+         "**   If 'graph_in' is equal to '-' (dash), read the file from     **\n" 
+         "**   the standard input (STDIN).                                  **\n"
+         "**                                                                **\n"
+         "**   The program prints on STDOUT the partition corresponding     **\n"
+         "**   to the largest value of modularity, in the format:           **\n"
+         "**                                                                **\n"
+         "**        node_1 comm_1                                           **\n"
+         "**        node_2 comm_2                                           **\n"
+         "**        node_3 comm_3                                           **\n"
+         "**       .....                                                    **\n"
+         "**                                                                **\n"
+         "**   where 'comm_1' is the community to which 'node_1' belongs.   **\n"
+         "**                                                                **\n"
+         "**   The program prints on STDERR the number of communities and   **\n"
+         "**   the value of modularity obtained at each step, in the        **\n"
+         "**   format:                                                      **\n"
+         "**                                                                **\n"
+         "**        ## nc: NUM_COMM Q_max: Q_MAX                            **\n"
+         "**        nc_1 Q_1                                                **\n"
+         "**        nc_2 Q_2                                                **\n"
+         "**        nc_3 Q_3                                                **\n"
+         "**        ...                                                     **\n"
+         "**                                                                **\n"
+         "**   where 'nc_1', 'nc_2', 'nc_3', etc. is the number of          **\n"
+         "**   communities at the 1st, 2nd, 3rd step etc., and 'Q_1',       **\n"
+         "**   'Q_2', 'Q_3', etc. are the value of the modularity           **\n"
+         "**   function of the corresponding node partition. The first      **\n"
+         "**   output line reports the number of communities NUM_COMM       **\n"
+         "**   and corresponding value of modularity Q_MAX of the best      **\n"
+         "**   partition found.                                             **\n"
+         "**                                                                **\n"
+         "********************************************************************\n"
+         " This is Free Software - You can use and distribute it under \n"
+         " the terms of the GNU General Public License, version 3 or later\n\n"
+         " Please visit http://www.complex-networks.net for more information\n\n"
+         " (c) Vincenzo Nicosia 2009-2017 (v.nicosia@qmul.ac.uk)\n"
+         "********************************************************************\n\n"
+         );
+  printf("Usage: %s <graph_in>\n", argv[0]);
+  exit(1);
+}
+
+
+/* shuffle a vector in-place */
+void shuffle_vector_ptr(unsigned int **v, unsigned int N){
+  
+  int i, pos;
+  void *tmp;
+
+  for(i=N-1; i>=0; i--){
+    pos = rand() % N;
+    if (pos != i){
+      tmp = v[i];
+      v[i] = v[pos];
+      v[pos] = tmp;
+    }
+  }
+}
+
+
+
+
+/* initialise BST-related functions */
+void set_bst_funs(ilfunc_t *f){
+
+  f->alloc = cnm_bst_alloc;
+  f->dealloc = cnm_bst_dealloc;
+  f->compare = cnm_bst_compare;
+  f->print = cnm_bst_print;
+
+}
+
+/* Initialise priority-queue-related functions */
+void set_pq_funs(gen_pqueue_func_t *f){
+  
+  f->compare = cnm_pq_compare;
+  f->alloc_vector = cnm_pq_alloc_vector;
+  f->dealloc_vector = cnm_pq_dealloc_vector;
+  f->alloc_key = cnm_pq_alloc_key;
+  f->copy_key = cnm_pq_copy_key;
+  f->print_elem = cnm_pq_print_elem;
+  f->set_key = cnm_pq_set_key;
+  f->compare_to_key = cnm_pq_compare_to_key;
+}
+
+
+
+void init_bsts(unsigned int *J_slap, unsigned int *r_slap, unsigned int N, 
+               bst_pq_t *b, bst_pq_t *H, gen_stack_t *node_cache){
+  
+  unsigned int i, j, n, m, deg_i, deg_j;
+  //struct_key_t dQ;
+  double dQ;
+  //struct_neigh_t ith, jth;
+  unsigned int K;
+  node_t *node_ptr;
+
+  ilfunc_t bst_funs;
+  gen_pqueue_func_t pq_funs;
+  unsigned int *nodes;
+
+  set_bst_funs(&bst_funs);
+  set_pq_funs(&pq_funs);
+
+  K = r_slap[N]/2;
+  *H = bst_pq_create(&bst_funs, &pq_funs, MAX_QUEUE, N, node_cache);
+  nodes = malloc(N * sizeof(unsigned int));
+  for (i=0; i<N; i++){
+    nodes[i] = i;
+  }
+  shuffle_vector(nodes, N);
+
+  for(n=0; n<N; n++){
+    i = nodes[n];
+    //ith.neigh = i;
+    deg_i = r_slap[i+1] -  r_slap[i];
+    if (deg_i == 0){
+      b[i] = NULL;
+      continue;
+    }
+    /* create the BST_PQ for the current node i */
+    b[i] = bst_pq_create(&bst_funs, &pq_funs, MAX_QUEUE, deg_i, node_cache);
+    /* Let's shuffle the ids of the neighbours of i, to have a somehow
+     balanced BST on average  */
+    shuffle_vector(J_slap + r_slap[i], deg_i);
+    /* Now we insert all the neighbours of i into b[i] */
+    for(m = r_slap[i]; m<r_slap[i+1]; m++){
+      j = J_slap[m];
+      if(i == j)
+        continue;
+      deg_j = r_slap[j + 1] - r_slap[j];
+      dQ = 2.0 * (1.0 / (2.0*K) - 1.0 * (deg_i * deg_j)/ (4.0 * K * K));
+      bst_pq_insert(b[i], j, dQ);
+    }
+    /* then we get the maximum value of modularity in the neighbourhood of i */
+    node_ptr = bst_pq_peek(b[i]);
+    if (node_ptr){
+      dQ = cnm_get_Q(node_ptr);
+      /* and insert it into H */
+      bst_pq_insert(*H, i, dQ);
+    }
+  }
+  free(nodes);
+}
+
+
+dset_t*  cnm(unsigned int *J_slap, unsigned int *r_slap, unsigned int N,
+         bst_pq_t *b, bst_pq_t H){
+  
+  double *a;
+  double Q;
+  double dQ_ik, dQ_jk, corr;
+  double dQ;
+  //struct_neigh_t ith, jth, kth;
+  int i, j, k;
+  node_t *best, *merge, *tmp;
+  unsigned int K;
+  node_t **neighs; /* pointers to the neighbours of a node */
+  int num_neighs;
+  double Q_max;
+  int l, m, N_max;
+  double Q_step;
+  char found_max;
+
+  dset_t *comms;
+  
+  Q = 0;
+  K = r_slap[N]/2;
+  
+  
+  a = malloc(N * sizeof(double));
+  neighs = malloc(N * sizeof(node_t*));
+  
+  comms = malloc(N * sizeof(dset_t));
+  
+  for (l=0; l<N; l++){
+    a[l] = 1.0 * (r_slap[l+1] - r_slap[l]) / (2.0 * K);
+    Q -= a[l] * a[l];
+    comms[l] = NULL;
+    dset_makeset_id(comms + l, l);
+  }
+
+  Q_max = Q;
+  N_max = N;
+  found_max = 0;
+
+  for(l=0; l<N; l++){
+    fprintf(stderr, "%d %g\n", N-l, Q);
+    /* Get the maximum from H and remove the element */
+    best = bst_pq_peek(H);
+    if (!best)
+      break;
+    j = cnm_get_id(best);
+    
+    //Q_step = cnm_get_Q(best);
+    merge = bst_pq_peek(b[j]);
+    if (!merge){
+      /* the node j does not have any neighbour, indeed... discard it
+         and continue */
+      bst_pq_delete(H, j);
+       continue;
+    }
+
+    i = cnm_get_id(merge);
+    /* So, we will merge community i into community j */
+    if (i == j){
+      /* This should never happen */
+      fprintf(stderr, "Error!!!! i and j are the same node!!!!\n");
+      exit(1);
+    }
+
+    Q_step = cnm_get_Q(best);
+    if (Q_step < 0){
+      found_max = 1;
+    }
+    Q += Q_step;
+
+
+    /* Let's go to the neighbours of i */
+    memcpy(neighs, b[i]->v, (b[i]->last + 1) * sizeof(node_t *));
+    num_neighs = b[i]->last + 1;
+    shuffle_vector_ptr((void*)neighs, num_neighs);
+
+    for(m=0; m<num_neighs; m++){
+      /* let's call this neighbour k */
+      k = cnm_get_id(neighs[m]);
+
+      if (k == j)
+        continue;
+      /* let's check whether k is also a neighbour of j already */
+      tmp = bst_pq_lookup_active(b[j], k);
+      if (tmp){ /* this is a closed triangle k-i-j */
+        dQ_ik = cnm_get_Q(neighs[m]); /* this is i-k*/
+        dQ_jk = cnm_get_Q(tmp); /* this is j-k */
+
+        dQ = dQ_ik + dQ_jk;
+        
+        /* now we update Q_jk and Q_kj */
+        if (bst_pq_change_key(b[j], k, dQ)){
+          fprintf(stderr, "error changing key %d into %d-th tree!!! (%s: %d)\n", 
+                  k, j, __FILE__, __LINE__);
+          exit(1);
+        }
+        if (bst_pq_change_key(b[k], j, dQ)){
+          fprintf(stderr, "error changing key %d into %d-th tree!!! (%s: %d)\n", 
+                  j, k, __FILE__, __LINE__);
+          exit(1);
+        }
+        bst_pq_delete(b[k], i);
+      }
+      else{ /* this is a chain k-i-j */
+        dQ_ik = cnm_get_Q(neighs[m]);
+        corr = -2.0 * a[j] * a[k];
+        dQ = dQ_ik + corr;
+
+        /* we add Q_{jk} which did not exist before */
+        bst_pq_insert(b[j], k, dQ);
+        /* we add Q_{kj} which did not exist before */
+        bst_pq_insert(b[k], j, dQ);
+        bst_pq_delete(b[k], i);
+      }
+      
+      /* now we update the maximum value associated to k in H */
+      tmp = bst_pq_peek(b[k]);
+      if (tmp){
+        dQ = cnm_get_Q(tmp);
+        bst_pq_change_key(H, k, dQ);
+      }
+    }
+
+    /* We delete the value associated to i in j */
+    bst_pq_delete(b[j], i);
+    
+    
+    /* Let's start with the neighbours of j */
+    memcpy(neighs, b[j]->v, (b[j]->last + 1) * sizeof(node_t *));
+    num_neighs = b[j]->last + 1;
+    shuffle_vector_ptr((void*)neighs, num_neighs);
+    
+    for(m=0; m<num_neighs; m++){
+      k = cnm_get_id(neighs[m]);
+      if (k == i)
+        continue;
+      /* let's check whether k is also a neighbour of i */
+      tmp = bst_pq_lookup_active(b[i], k);
+      if(! tmp){ /* this is a chain i-j-k */
+        dQ_jk = cnm_get_Q(neighs[m]);
+        corr = -2.0 * a[i] * a[k];
+        dQ = dQ_jk + corr;
+       
+        /* update Q_jk and Q_kj */
+        if (bst_pq_change_key(b[j], k, dQ)){
+          fprintf(stderr, "error changing key %d into %d-th tree!!! (%s: %d)\n", 
+                  k, j, __FILE__, __LINE__);
+          exit(1);
+
+        }
+        if (bst_pq_change_key(b[k], j, dQ)){
+          fprintf(stderr, "error changing key %d into %d-th tree!!! (%s: %d)\n", 
+                  j, k, __FILE__, __LINE__);
+          exit(1);
+        }
+      }
+
+      /* now we update the value associated to k in H */
+      tmp = bst_pq_peek(b[k]);
+      if (tmp){
+        dQ = cnm_get_Q(tmp);
+        bst_pq_change_key(H, k, dQ);
+      }
+    }
+    
+    /*  We can now free the BST_PQ associated to node i, since it will
+       not be used ever again...*/
+    bst_pq_destroy(b[i], 0);
+    b[i] = NULL;
+
+    /* We can now remove the value associated to i in H */
+    bst_pq_delete(H, i);
+    
+    /* OK, now we should update the value associated to j in H */
+    tmp = bst_pq_peek(b[j]);
+    if (tmp){
+      dQ = cnm_get_Q(tmp);
+      bst_pq_change_key(H, j, dQ);
+    }
+    a[j]+= a[i];
+    a[i] = 0;
+    if (! found_max)
+      dset_union_opt(comms[j], comms[i]);
+    
+    if (Q>Q_max){
+      Q_max = Q;
+      N_max = N-l-1;
+    }
+  }
+  fprintf(stdout, "### nc: %d Q_max: %g\n", N_max, Q_max);
+  free(a);
+  free(neighs);
+
+  return comms;
+}
+
+
+void dump_communities(dset_t *comms, unsigned int N){
+  
+  int i;
+
+  for(i=0; i<N; i++){
+    fprintf(stdout, "%d %d\n", i, dset_find_id_opt(comms[i]));
+  }
+}
+
+
+int main(int argc, char *argv[]){
+
+  unsigned int *J_slap = NULL, *r_slap = NULL;
+  unsigned int N, K;
+  bst_pq_t *b = NULL;
+  bst_pq_t H = NULL;
+  dset_t *comms;
+  int i;
+  
+  gen_stack_t *node_cache = NULL;
+  
+  FILE *filein;
+  
+  if(argc < 2){
+    usage(argv);
+    exit(1);
+  }
+
+  srand(time(NULL));
+  
+  if (!strcmp(argv[1], "-")){
+    /* take the input from STDIN */
+    filein = stdin;
+  }
+  else {
+    filein = openfile_or_exit(argv[1], "r", 2);
+  }
+  
+  
+  read_slap(filein, &K, &N, &J_slap, &r_slap);
+
+  b = malloc(N * sizeof(bst_pq_t));
+  
+  node_cache = malloc(sizeof(gen_stack_t));
+  gen_stack_create(node_cache);
+
+  
+  init_bsts(J_slap, r_slap, N, b, &H, node_cache);
+
+
+  comms = cnm(J_slap, r_slap, N, b, H);
+  dump_communities(comms, N);
+
+  free(J_slap);
+  free(r_slap);
+  for(i=0; i<N; i++){
+    if(b[i]){
+      bst_pq_destroy(b[i], 0);
+    }
+    if (comms[i])
+      free(comms[i]);
+  }
+  free(b);
+  bst_pq_destroy(H, 1);
+  free(comms);
+  fclose(filein);
+  return 0;
+}
+
+
+
-- 
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