fix unchanged diff issue

Xtra-Computing · Jun 21, 2018 · 574318b · 574318b
1 parent 1fb7ad2
commit 574318b
Showing 1 changed file with 18 additions and 2 deletions.
diff --git a/src/thundersvm/solver/csmosolver.cpp b/src/thundersvm/solver/csmosolver.cpp
@@ -52,6 +52,9 @@ CSMOSolver::solve(const KernelMatrix &k_mat, const SyncArray<int> &y, SyncArray<
     //avoid infinite loop of repeated local diff
     int same_local_diff_cnt = 0;
     float_type previous_local_diff = INFINITY;
+    int swap_local_diff_cnt = 0;
+    float_type last_local_diff = INFINITY;
+    float_type second_last_local_diff = INFINITY;
 
     for (int iter = 0;; ++iter) {
         //select working set
@@ -79,20 +82,33 @@ CSMOSolver::solve(const KernelMatrix &k_mat, const SyncArray<int> &y, SyncArray<
         update_f(f_val, alpha_diff, k_mat_rows, k_mat.n_instances());
         float_type *diff_data = diff.host_data();
         local_iter += diff_data[1];
+
+        //track unchanged diff
         if (fabs(diff_data[0] - previous_local_diff) < eps * 0.001) {
             same_local_diff_cnt++;
         } else {
             same_local_diff_cnt = 0;
             previous_local_diff = diff_data[0];
         }
 
-        if (iter % 100 == 0)
+        //track unchanged swapping diff
+        if(fabs(diff_data[0] - second_last_local_diff) < eps * 0.001){
+            swap_local_diff_cnt++;
+        } else {
+            swap_local_diff_cnt = 0;
+        }
+        second_last_local_diff = last_local_diff;
+        last_local_diff = diff_data[0];
+
+        //if (iter % 100 == 0)
             LOG(INFO) << "global iter = " << iter << ", total local iter = " << local_iter << ", diff = "
                       << diff_data[0];
         //todo find some other ways to deal unchanged diff
         //training terminates in three conditions: 1. diff stays unchanged; 2. diff is closed to 0; 3. training reaches the limit of iterations.
+        //repeatedly swapping between two diffs
         if ((same_local_diff_cnt >= 10 && fabs(diff_data[0] - 2.0) > eps) || diff_data[0] < eps ||
-            (out_max_iter != -1) && (iter == out_max_iter)) {
+            (out_max_iter != -1) && (iter == out_max_iter) ||
+            (swap_local_diff_cnt >= 10 && fabs(diff_data[0] - 2.0) > eps)) {
             rho = calculate_rho(f_val, y, alpha, Cp, Cn);
             LOG(INFO) << "global iter = " << iter << ", total local iter = " << local_iter << ", diff = "
                       << diff_data[0];