From 0471ee7493576e45e926a8a8a73234d9aec2cf92 Mon Sep 17 00:00:00 2001
From: Krishna Praneet Gudipaty <kgudipaty@umass.edu>
Date: Sun, 7 Apr 2024 16:53:40 -0400
Subject: [PATCH] Fix: fixed iterations for bp decoder and added additional
 tests

---
 src/decoders/belief_propagation.jl |  2 +-
 test/test_bp_decoder.jl            | 31 ++++++++++++++++++++++++++++++
 2 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/src/decoders/belief_propagation.jl b/src/decoders/belief_propagation.jl
index 741a95e..ef4e190 100644
--- a/src/decoders/belief_propagation.jl
+++ b/src/decoders/belief_propagation.jl
@@ -118,7 +118,7 @@ function decode!(decoder::BeliefPropagationDecoder, syndrome::AbstractVector) #
   end
 
   converged = false
-  for iter::Int in decoder.max_iters
+  for iter::Int in 1:decoder.max_iters
     for i in 1:decoder.s
       temp::Float64 = (-1) ^ syndrome[i]
       for k::Int in nzrange(decoder.sparse_HT, i)
diff --git a/test/test_bp_decoder.jl b/test/test_bp_decoder.jl
index d4040b9..8673945 100644
--- a/test/test_bp_decoder.jl
+++ b/test/test_bp_decoder.jl
@@ -55,9 +55,40 @@ using LDPCDecoders
     return ler
   end
 
+  function test_ldpcdecoder()
+    H = LDPCDecoders.parity_check_matrix(1000,10,9);
+    decoder = LDPCDecoders.BeliefPropagationDecoder(H, 0.01, 100);
+    count = 0
+    for _ in 1:1000
+        error = rand(1000) .< 0.01;
+        syndrome = (H * error) .% 2;
+        guess, success = LDPCDecoders.decode!(decoder, syndrome);
+        count += error == guess
+    end
+    return 1-count/1000
+  end
+
+  function test_ldpcdecoder_old()
+    H = LDPCDecoders.parity_check_matrix(1000,10,9);
+    decoder = LDPCDecoders.BeliefPropagationDecoder(H, 0.01, 100);
+    count = 0
+    for _ in 1:1000
+        error = rand(1000) .< 0.01;
+        syndrome = (H * error) .% 2;
+        LDPCDecoders.reset!(decoder)
+        LDPCDecoders.syndrome_decode!(decoder, decoder.scratch, syndrome)
+        count += error == decoder.scratch.err
+    end
+    return 1-count/1000
+  end
+
+
   @test test_bp_decoder()
 
   # There is a low possibility of these tests failing
   @test test_bp_decoder_batch() < 0.005
   @test test_deprecated_syndrome_decoder() < 0.005
+
+  @test test_ldpcdecoder() < 0.001
+  @test test_ldpcdecoder_old() < 0.001
 end