remove now-unused improve_antibandwidth_by_swapping_cheap

diff --git a/cmd/gvmap/country_graph_coloring.c b/cmd/gvmap/country_graph_coloring.c
index e7e6e895bcde404cd62bb361349ca5c5e96ab6f5..a99ff837566c1996f088423a42ff0d111c2afd13 100644 (file)
--- a/cmd/gvmap/country_graph_coloring.c
+++ b/cmd/gvmap/country_graph_coloring.c
@@ -51,173 +51,6 @@ static void get_12_norm(int n, int *ia, int *ja, int *p, real *norm){
   norm[1] /= nz;
 }
 
-static void update_pmin_pmax_aband(int n, int u, int *ia, int *ja, int *p, int *pmin, int *pmax, int *aband_local){
-  int j, aband_u;
-  pmin[u] = n; pmax[u] = -1; aband_u = n;
-  for (j = ia[u]; j < ia[u+1]; j++) {
-    if (ja[j] == u) continue;
-    pmin[u] = MIN(pmin[u], abs(p[u] - p[ja[j]]));
-    pmax[u] = MIN(pmax[u], abs(p[u] - p[ja[j]]));
-    aband_u = MIN(aband_u, abs(p[u] - p[ja[j]]));
-  }
-  aband_local[u] = aband_u;
-}
-
-
-static bool check_swap(int n, int *ia, int *ja,
-                     int u, int p_u, int v, int p_v, int *aband_local, int *p, int *p_inv, int aband, int *pmax, int *pmin, real lambda){
-  /* check if u should swap with v to improve u, without demaging v. Return TRUE if swap is successful. FALSE otherwise. */
-
-  int j, aband_v, aband_v1, aband_u, aband_u1;
-
-  aband_v = aband_local[v];
-  aband_u = aband_local[u];
-  
-  /* if swaping u and v makes v worse & becomes/remains critical, don't do. We first quick check using the max/min neighbor indices.
-     No need to check the other way around since the calling function have ensured that.
-   */
-  if (abs(p_u - pmin[v]) < aband_v && abs(p_u - pmin[v]) <= lambda*aband) return false;
-  if (abs(p_u - pmax[v]) < aband_v && abs(p_u - pmax[v]) <= lambda*aband) return false;
-
-  /* now check in details whether v should swap to u. Do not accept if this makes the antiband width of u worse */
-  aband_u1 = n;
-  for (j = ja[u]; j < ja[u+1]; j++){
-    if (ja[j] == u) continue;
-    if (abs(p_v - p[ja[j]]) < aband_u) {
-      return false;
-    }
-    aband_u1 = MIN(aband_u1, abs(p_v - p[ja[j]]));
-  }
-  
-  /* now check in details whether u should swap to v. Do not accept if this makes antibandwidth of v worse && make/keep v in the critical group */
-  aband_v1 = n;
-  for (j = ja[v]; j < ja[v+1]; j++){
-    if (ja[j] == v) continue;
-    if (abs(p_u - p[ja[j]]) < aband_v && abs(p_u - p[ja[j]]) <= lambda*aband) {
-      return false;
-    }
-    aband_v1 = MIN(aband_v1, abs(p_u - p[ja[j]]));
-  }
-  
-  /* now check if local antiband width has been improved. By that we mean u is improved, or u unchanged, but v improved. */
-  assert(aband_u1 >= aband_u);
-  if (aband_u1 > aband_u || (aband_u1 == aband_u && aband_v1 > aband_v)){
-    p[u] = p_v;
-    p[v] = p[u];
-    p_inv[p[u]] = u;
-    p_inv[p[v]] = v;
-
-    update_pmin_pmax_aband(n, u, ia, ja, p, pmin, pmax, aband_local);
-    update_pmin_pmax_aband(n, v, ia, ja, p, pmin, pmax, aband_local);
-
-    /* this may be expensive, but I see no way to keep pmin/pmax/aband_local consistent other than this update of u/v's neighbors */    
-    for (j = ia[u]; j < ia[u+1]; j++) {
-      update_pmin_pmax_aband(n, ja[j], ia, ja, p, pmin, pmax, aband_local);
-    }
-
-    for (j = ia[u]; j < ia[u+1]; j++) {
-      update_pmin_pmax_aband(n, ja[j], ia, ja, p, pmin, pmax, aband_local);
-    }
-    return true;
-  }
-  
-
-  return false;
-}
-
-static void improve_antibandwidth_by_swapping_cheap(SparseMatrix A, int *p){
-  /*on entry:
-    A: the graph, must be symmetric matrix
-    p: a permutation array of length n
-    lambda: threshold for deciding critical vertices.*/
-  real lambda = 1.2;
-  int n = A->m;
-  int *p_inv;
-  int i, j;
-  int *pmax, *pmin;/* max and min index of neighbors */
-  int *ia = A->ia, *ja = A->ja;
-  int aband = n;/* global antibandwidth*/
-  int *aband_local;/* antibandwidth for each node */
-  PriorityQueue pq = NULL;
-  bool progress = true, swapped;
-  int u, v, gain, aband_u, p_u, p_v;
-  
-  pq = PriorityQueue_new(n, n);
-  p_inv = MALLOC(sizeof(int)*n);
-  pmax = MALLOC(sizeof(int)*n);
-  pmin = MALLOC(sizeof(int)*n);
-  aband_local = MALLOC(sizeof(int)*n);
-
-  while (progress) {
-    progress = false;
-    for (i = 0; i < n; i++){
-      pmax[i] = -1; pmin[i] = n+1;
-      assert(p[i] >= 0 && p[i] < n);
-      p_inv[p[i]] = i;
-      aband_local[i] = n;
-      for (j = ia[i]; j < ia[i+1]; j++){
-       if (ja[j] == i) continue;
-       pmax[i] = MAX(pmax[i], p[ja[j]]);
-       pmin[i] = MIN(pmin[i], p[ja[j]]);
-       aband_local[i] = MIN(aband_local[i], abs(p[i] - p[ja[j]]));
-      }
-      aband = MIN(aband, aband_local[i]);
-    }
-    fprintf(stderr," antibandwidth = %d", aband);
-    
-    /* find critical vertices */
-    for (i = 0; i < n; i++){
-      if (aband_local[i] <= lambda*aband){
-       PriorityQueue_push(pq, i, n - aband_local[i]);
-      }
-    }
-    
-    /* check critcal nodes u to see if any swaps with v are possible */
-    while (PriorityQueue_pop(pq, &u, &gain)){
-      aband_u = n - gain;
-      p_u = p[u];
-      assert(aband_u <= lambda*aband);
-      assert(aband_u == aband_local[u]);
-      swapped = false;
-      for (p_v = 0; p_v <= pmin[u] - aband_u; p_v++){
-       v = p_inv[p_v];
-       if (check_swap(n, ia, ja, u, p_u, v, p_v, aband_local, p, p_inv, aband, pmax, pmin, lambda)){
-         swapped = true; progress = true;
-         break;
-       }
-      }
-      if (swapped) continue;
-      
-      for (p_v = pmax[u] + aband_u; p_v < n; p_v++){
-       v = p_inv[p_v];
-       if (check_swap(n, ia, ja, u, p_u, v, p_v, aband_local, p, p_inv, aband, pmax, pmin, lambda)){
-         swapped = true; progress = true;
-         break;
-       }
-      }
-      if (swapped) continue;
-      
-      for (p_v = pmin[u] + aband_u; p_v <= pmax[u] - aband_u; p_v++) {
-       v = p_inv[p_v];
-       if (check_swap(n, ia, ja, u, p_u, v, p_v, aband_local, p, p_inv, aband, pmax, pmin, lambda)){
-         progress = true;
-         break;
-       }
-      }
-      
-      
-    }
-  }
-  
-
-  FREE(p_inv);
-  FREE(pmax);
-  FREE(pmin);
-  FREE(aband_local);
-  PriorityQueue_delete(pq);
-
-}
-
 void improve_antibandwidth_by_swapping(SparseMatrix A, int *p){
   bool improved = true;
   int cnt = 1, n = A->m, i, j, *ia = A->ia, *ja = A->ja;