dynamic scaling factors

quantumgizmos · Nov 26, 2024 · 9bdb670 · 9bdb670
1 parent 968fc4d
commit 9bdb670
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Showing 3 changed files with 38 additions and 8 deletions.
diff --git a/pyproject.toml b/pyproject.toml
@@ -24,7 +24,7 @@ dependencies = [
     "stim",
     "sinter"
 ]
-version = "2.1.5"
+version = "2.1.6"
 
 [project.urls]
 Documentation = "https://software.roffe.eu/ldpc"

diff --git a/python_test/test_qcodes.py b/python_test/test_qcodes.py
@@ -69,7 +69,7 @@ def test_400_16_6_hgp():
 
     error_rate = 0.01
     run_count = 10000
-    seed = 42
+    seed = 100
     max_iter = 5
     osd_order = 3
     print()
@@ -106,10 +106,20 @@ def test_400_16_6_hgp():
 
     decoder = BpLsdDecoder(hx, error_rate=error_rate, max_iter=max_iter, bp_method="ms", ms_scaling_factor=0.625,
                            schedule="parallel", lsd_order=osd_order, lsd_method="lsd_cs")
-    # decoder.set_do_stats(True)
     ler, min_logical, speed, _ = quantum_mc_sim(hx, lx, error_rate, run_count, seed, decoder,
                                                 f"Min-sum LSD-{osd_order} parallel schedule")
-    # print(json.dumps(decoder.statistics))
+
+    decoder = BpLsdDecoder(hx, error_rate=error_rate, max_iter=max_iter, bp_method="ms", ms_scaling_factor=0,
+                           schedule="parallel", bits_per_step=1, lsd_order=0, lsd_method="osd_e")
+    ler, min_logical, speed, _ = quantum_mc_sim(hx, lx, error_rate, run_count, seed, decoder,
+                                                f"Min-sum LSD-0 parallel schedule, dynamic scaling factor")
+
+
+    decoder = BpLsdDecoder(hx, error_rate=error_rate, max_iter=max_iter, bp_method="ms", ms_scaling_factor=0,
+                           schedule="serial", bits_per_step=1, lsd_order=0, lsd_method="osd_e")
+    ler, min_logical, speed, _ = quantum_mc_sim(hx, lx, error_rate, run_count, seed, decoder,
+                                                f"Min-sum LSD-0 serial schedule, dynamic scaling factor")
+
 
 def test_toric_20():
     hx = scipy.sparse.load_npz("python_test/pcms/hx_toric_20.npz")
@@ -181,5 +191,5 @@ def test_surface_20():
 if __name__ == "__main__":
 
     test_400_16_6_hgp()
-    test_toric_20()
-    test_surface_20()
+    # test_toric_20()
+    # test_surface_20()
diff --git a/src_cpp/bp.hpp b/src_cpp/bp.hpp
@@ -205,6 +205,15 @@ namespace ldpc {
                             }
                         }
                     } else if (this->bp_method == MINIMUM_SUM) {
+
+                        double alpha;
+                        if(this->ms_scaling_factor == 0.0) {
+                            alpha = 1.0 - std::pow(2.0, -1.0*it);
+                        }
+                        else {
+                            alpha = this->ms_scaling_factor;
+                        }
+
                         //check to bit updates
                         for (int i = 0; i < check_count; i++) {
 
@@ -236,8 +245,10 @@ namespace ldpc {
                                 }
 
                                 int message_sign = (sgn % 2 == 0) ? 1.0 : -1.0;
-                                e.check_to_bit_msg *= message_sign * ms_scaling_factor;
+
+                                e.check_to_bit_msg *= message_sign * alpha;
 
+
                                 double abs_bit_to_check_msg = std::abs(e.bit_to_check_msg);
                                 if (abs_bit_to_check_msg < temp) {
                                     temp = abs_bit_to_check_msg;
@@ -431,6 +442,15 @@ namespace ldpc {
                 this->initialise_log_domain_bp();
 
                 for (int it = 1; it <= maximum_iterations; it++) {
+
+                    double alpha;
+                    if(this->ms_scaling_factor == 0.0) {
+                        alpha = 1.0 - std::pow(2.0, -1.0*it);
+                    }
+                    else {
+                        alpha = this->ms_scaling_factor;
+                    }
+
                     if (this->random_schedule_seed > -1) {
                         this->rng_list_shuffle.shuffle(this->serial_schedule_order);
                     } else if (this->schedule == BpSchedule::SERIAL_RELATIVE) {
@@ -483,7 +503,7 @@ namespace ldpc {
                                     }
                                 }
                                 double message_sign = (sgn % 2 == 0) ? 1.0 : -1.0;
-                                e.check_to_bit_msg = ms_scaling_factor * message_sign * temp;
+                                e.check_to_bit_msg = alpha * message_sign * temp;
                                 e.bit_to_check_msg = log_prob_ratios[bit_index];
                                 this->log_prob_ratios[bit_index] += e.check_to_bit_msg;
                             }